# 56. International Winter Meeting on Nuclear Physics

Europe/Berlin
Bormio, Italy

#### Bormio, Italy

, ,
Description
Long-standing conference bringing together researchers and students from various fields of subatomic physics. The conference location is Bormio, a beautiful mountain resort in the Italian Alps.
• Monday, 22 January
• 09:00 13:15
Monday Morning
• 09:10
Precision Physics at the LHC 45m
Measurements at the LHC have already reached a remarkable precision. This opens up new opportunities for New Physics searches. However, the accuracy of experimental data must be matched by the theoretical one. In this talk, I will discuss recent progress in precision QCD predictions.
Speaker: Prof. Giulia Zanderighi (CERN)
• 09:55
Studying the dense matter equation of state via electromagnetic observations of neutron stars. 45m
Densities in neutron star cores can reach up to ten times the density of a normal atomic nucleus, and the stabilising effect of gravitational confinement permits long-timescale weak interactions. This generates matter that is neutron-rich, and opens up the possibility of stable states of strange matter, something that can only exist in neutron stars. Our uncertainty about the nature of matter under these conditions is encoded in the Equation of State (EOS), which can be linked to macroscopic observables like mass, radius, tidal deformation or moment of inertia. I will review efforts to measure the EOS using electromagnetic observations of neutron stars. This is a major goal of current telescopes like NICER, as well as future facilities like the Square Kilometer Array and the proposed large area X-ray telescopes eXTP and Strobe-X.
Speaker: Dr Anna Watts (University of Amsterdam)
• 10:40
Coffee Break 25m
• 11:05
Precision atomic physics measurements in Penning traps and tests of fundamental symmetries 45m
The presentation will concentrate on recent applications with exciting results of Penning traps in atomic and nuclear physics with cooled and stored exotic ions. These are high-accuracy atomic mass measurements of short-lived radionuclides, *g*-factor determinations of the bound-electron in highly-charged, hydrogen-like ions and *g*-factor as well as mass measurements of the proton and antiproton. The experiments are dedicated to nuclear-, neutrino- and astrophysics studies in the case of mass measurements on radionuclides, and to the determination of fundamental constants and a CPT symmetry test with measurements on the proton and antiproton.
Speaker: Prof. Klaus Blaum (Max-Planck-Institut für Kernphysik)
• 11:50
Correlations, Fluctuations and the QCD phase diagram 35m
I will discuss the status of the present effort exploring the QCD phase diagram. Emphasis will be given on the measurement and interpretation of correlations and fluctuation and its implication for the possible existence of high density phase in QCD.
Speaker: Volker Koch (LBNL)
• 17:00 23:00
Monday Afternoon
• 17:00
Inclusive J/ψ and ψ(2S) production in p-Pb collisions with ALICE at the LHC 3m
The ALICE Collaboration has studied inclusive J/$\psi$ and $\psi$(2S) production in p-Pb collisions at $\sqrt{s_{\rm NN}}$ = 5.02 and 8.16 TeV. The measurements were performed at forward (2.03 $<$ $y_{\rm cms}$ $<$ 3.53), mid ($-$1.37 $<$ $y_{\rm cms}<$ 0.43) and backward ($-$4.46 $<$ $y_{\rm cms}$ $<$ $-$2.96) centre of mass rapidities. In this presentation, the nuclear modification factor of J/$\psi$ and $\psi$(2S), measured as a function of rapidity, transverse momentum and event centrality, will be discussed. Theoretical models based on nuclear shadowing and/or coherent energy loss are in reasonable agreement with the J/$\psi$ results at the two energies but cannot describe the $\psi$(2S) behaviour. Other final-state mechanisms must be invoked in order to explain the $\psi$(2S) suppression in p-Pb collisions.
Speaker: Dr Biswarup Paul (Universita e INFN Torino (IT))
• 17:03
Studies of the nucleosynthesis $^{12}C\left(\alpha,\gamma\right)\!~^{16}O$ in inverse kinematic for the MAGIX experiment on MESA 3m
MAGIX is a versatile fixed-target experiment and will be built on the new accelerator MESA (Mainz Energy-Recovering Superconducting Accelerator) in Mainz. The accelerator will deliver polarized electron beams with currents up to $1\,\mathrm{mA}$ and energy up to $105\,\mathrm{MeV}$. Using its internal gas-target, MAGIX will reach a luminosity of $O\left(10^{35}\,\mathrm{cm}^{-2}\mathrm{s}^{-1}\right)$. This allows to study processes with very low cross section at small momentum transfer in a rich physical program. The poster presents the planned measurements of the inverse kinematic of the nucleosynthesis process $^{12}C\left(\alpha,\gamma\right)\!~^{16}O$ to determine its S-factor. In the experiment we will scatter electrons on oxygen atoms and we will detect the scattered electrons in coincidence with the produced α-particles. With this measurement we will determine the cross section as a function of the outgoing center of mass energy of the carbon-α-system, to calculate the S-factor. We will hereby present the results of the first simulations which can be used to understand the parameter range that MAGIX will be able to explore.
Speaker: Mr Stefan Lunkenheimer (KPH)
• 17:06
Investigating the EMC Effect in Highly-Virtual Nucleons at Jefferson Lab 3m
The EMC effect, the phenomenon by which quark distributions are modified in bound nucleons, has defied explanation since its discovery over 30 years ago. Recently, there have been indications, experimentally and theoretically, that the EMC effect may be linked to high-momentum nucleons. Rather than the EMC effect being caused by a modest modification in all nucleons, it is possible that highly virtual nucleons are modified substantially. BAND (Backward Angle Neutron Detector) is an experiment in 2018 at Jefferson Lab Hall B to search for medium-modification in high-momentum nucleons. By using a method of spectator-tagging, one can tag on the virtuality of the struck proton to study modification in deep inelastic scattering. In my talk, I will present the EMC effect, discuss its possible connection to high momentum nucleons, and describe how BAND will select on these nucleons (spectator-tagging) to extract medium-modification effects. Finally, I will present recent results from a Geant4 simulation, the results of measurements at our detector development test stand at MIT to select detector component models, and the status of construction of the BAND array.
Speaker: Efrain Segarra (Massachusetts Institute of Technology)
• 17:09
An ATCA-based Readout System for the Belle II Pixel Detector 3m
The future Belle II experiment will reach a total luminosity of $8\cdot 10^{35} cm^{−2} s^{−1}$. With such high luminosities, the innermost detector, the Pixeldetector (PXD), will produce raw data rates of up to 20 GB/s. In order to reduce these rates, a high bandwidth data aquisition and data reduction system for the PXD is required. The so-called ONline SElection Node (ONSEN)-system will consist of 32 ATCA based Com- pute Nodes (CN) with Xilinx Virtex-5 FPGA’s. These will perform a Region Of Interest (ROI) selection based upon online track extrapolation from the outer detectors. A reduction factor >10 is planned. We present recent tests of a reduced ONSEN setup, with data taken during a testbeam campaign at DESY as well as a high bandwith lab-test with the full setup.
Speaker: Mr Klemens Lautenbach (JLU Giessen)
• 17:12
Characteristics of charmonium production in Pb$-$Pb collisions at $\sqrt{s_{\rm NN}}$ = 5.02 TeV measured with ALICE. 3m
J/$\psi$ measurements in Pb$-$Pb collisions at $\sqrt{s_{\rm NN}}$ = 2.76 TeV clearly show a smaller suppression than the one expected from color screening, when compared to binary-scaled pp collisions. The increased yield in Pb$-$Pb collisions can be explained by models that contain a (re)generation component, based on the (re)combination of c$\overline{\rm{c}}$-quarks. Hence, one of the main experimental challenges is to impose strong enough constraints on the production models to shed further light on the behaviour of J/$\psi$ in a hot and dense medium.\\ With unprecedented collision energies during Run 2 of the Large Hadron Collider (LHC) and the unique capabilities of the ALICE detector to study J/$\psi$, new insights on the charmonium production in high-energy Pb$-$Pb collisions can be obtained. The latest results on J/$\psi$ elliptic flow and the inclusive nuclear modification factor as a function of centrality, rapidity and transverse momentum measured in Pb$-$Pb collisions at $\sqrt{s_{\rm NN}}$ = 5.02 TeV with ALICE will be presented.
Speaker: Pascal Dillenseger (for the ALICE Collaboration)
• 17:15
Coherent pi^0 photoproduction on spin-zero nuclei 3m
The method of coherent $\pi^0$ photoproduction ( $\gamma$+ A${}_\text{g.s.}$ $\rightarrow$ $\pi^0$+ A${}_\text{g.s.}$, where A${}_\text{g.s.}$ is a nucleus in its ground state) provides an efficient tool to study nucleon distribution and the neutron skin of various nuclei. We investigate the case of nuclei with zero spin and isospin from the theoretical point of view in the framework of a distorted wave impulse approximation in the momentum space. For the pion-nucleus final-state interaction we employ a phenomenological pion- nucleus optical potential which involves analysis of pion-pion elastic scattering as a solution of the Lippmann-Schwinger integral equation. As a first application, we show results for the ${}^{12}$C nucleus, for which the harmonic oscillator shell model is used to develop a second-order optical potential.
Speaker: Mr Viacheslav Tsaran (JGU Mainz)
• 17:18
Correlation Analysis Tool using the Schrödinger equation (CATS) 3m
Femtoscopy is a method used to investigate particle correlations by using the experimentally accessible two-particle momentum correlation function C(k). This function can be mathematically obtained by integrating the product of the source function and the two-particle wave function. The main goals of femtoscopy are to investigate the properties of the emission source and the interaction potential between particles. Currently there is a lot of focus on investigating hyperon-nucleon interactions, e.g. by using experimental data collected by ALICE at LHC and by HADES at GSI. In order to interpret the results one should be capable of obtaining the theoretical C(k) for a given source and an interaction potential. Presently there are tools capable of performing those tasks, however most of them are not tuned to work with very small sources (1-1.5 fm) or are not flexible enough to be incorporated without significant modifications into any external analysis framework. This motivated the development of a C++ software tool called “Correlation Analysis Tools using the Schrödinger equation” (CATS) which relies entirely on numerical methods to evaluate the correlation function. The tool is designed to handle any short-range potential with or without the inclusion of the Coulomb interaction and/or quantum statistics. The interaction is modeled by solving the Schrödinger equation fully numerically and thus obtaining an accurate solution that is independent of the source size. Furthermore CATS is capable of working with either an analytical or a data-driven source. This enables the use of transport models for the investigation of the emission source. The methods used by CATS and the first results obtained using this tool will be presented in this talk. There will be a detailed discussion of those results and how they relate to experimental data and other theoretical calculations of the correlation function, e.g. the Lednický model.
Speaker: Mr Dimitar Mihaylov (TU Munich)
• 17:21
Lattice QCD studies of pseudo-PDFs 3m
Ioffe-time distributions, which are functions of the Ioffe-time $\nu$, are the Fourier transforms of parton distribution functions with respect to the momentum fraction variable $x$. These distributions can be obtained from appropriate equal time, quark bilinear hadronic matrix elements which can be calculated from first principles via lattice QCD methods. Here, we present the first numerical results of the Ioffe-time distributions of the nucleon.
Speaker: Dr Savvas Zafeiropoulos (Universitaet Heidelberg)
• 17:24
Diffusion of conserved charges in relativistic heavy ion collisions 3m
We calculate all diffusion constants of the conserved baryon, electric and strangeness charge in hot relativistic multi-component systems using kinetic theory. Applying the algorithm for massive pions, kaons, nucleons, lambda- and sigma-baryons, with resonance cross sections when possible, we present for the first time realistic values for the hadronic diffusion coefficient matrix. These values can readily be used in dissipative hydrodynamic calculations for baryon rich systems and serve as benchmark for other theoretical approaches. In order to put the hadronic results in context, we compute the diffusion matrix for the quark-gluon plasma (QGP). To this end we use massless quarks and gluons, fixing the shear viscosity to the lower bound of $1/4\pi$. For all but the baryon-electric cross diffusion coefficient, we find that the QGP result matches the hadronic result around the phase transition temperature. All results fulfill the Onsager theorem and the qualitative similarity to the relaxation time approximation. We find that the baryon diffusion current depends strongly on baryon chemical potential, and, we see a comparable strength of the baryon-strange cross diffusion to baryon diffusion. Electric current is equally strongly affected from baryon, electric and strangeness gradients, whereas strangeness currents depend mostly on strange and baryon gradients. These results imply, that calculations involving only the diagonal diffusion effects are incomplete.
Speaker: Mr Moritz Greif (Goethe University Frankfurt)
• 17:27
Lifetime measurements using a fast timing array of LaBr3 detectors 3m
Characteristic decay properties of radionuclides are essential in the study of nuclear spectroscopy. Lifetime measurements and transition moments for excited nuclear levels form part of this extensive study that seeks to unveil properties of nuclear structure. Scintillation detectors prove to be formidable in gamma ray detection and lifetime measurements. With advent of LaBr3 detectors it is now possible to have both excellent timing properties, (around 300ps) and energy resolution (approximately 3.0% at 1332keV ). Recently a fast timing array has been commissioned at iThemba LABS, Cape Town consisting of eight 2” by 2” LaBr3(Ce) detectors. Several experiments been performed with short-lived radioactive sources showing impressive lifetime measurements. Furthermore, the detectors were used for in-beam measurements at iThemba LABS in order measure the nuclear lifetimes of 42Ca, 44Sc and 62,63Ni. Results will be presented of the measurements undertaken for radioactive sources.
Speaker: Mr Lumkile Msebi (University of Johannesburg)
• 17:30
Cross section measurements of the elastic electron - deuteron scattering 3m
The electromagnetic form factors of light nuclei provide a sensitive test of our understanding of nuclei. The deuteron in particular, as the only bound two-nucleon system, is a fundamental system that has received extensive attention in the past, by both theory and experiment. Because the deuteron has spin one, three form factors are needed to fully describe the electromagnetic structure of the deuteron. Especially the deuteron charge radius is a favourite observable to compare experiment and calculation. In 2014, an extensive measurement campaign has been performed at MAMI (Mainz Microtron) to determine the deuteron charge radius using elastic electron scattering - with the aim to halve the error compared to previous such experiments. The experiment took place at the 3-spectrometer facility of the A1-collaboration. Cross section measurements of the elastic electron-deuteron scattering have been performed for 180 different kinematic settings in the low momentum transfer region. From these, the charge form factor can precisely be determined. Fitting the form factor with a sum of gaussians fit function, the radius can then be determined from the slope at zero momentum transfer. The determined radius could then be used as a counterweight to the value obtained from advanced atomic Lamb shift measurements, thus providing additional insight to the proton radius puzzle.
Speaker: Yvonne Stöttinger (Universität Mainz)
• 17:33
Decays of Vector Glueball in a Chiral Approach 3m
We calculate two- and three-body decays of the (lightest) vector glueball into (pseudo)scalar, (axial-)vector, as well as pseudovector and excited vector mesons in the framework of an effective model of QCD. While absolute values of widths cannot be predicted because the corresponding coupling constants are unknown, some interesting branching ratios can be evaluated by setting the mass of the yet hypothetical vector glueball to $3.8$ GeV as predicted by quenched Lattice QCD. We find that the decay mode $\omega\pi\pi$ should be one of the largest (both through the decay chain $\mathcal{O}\rightarrow b_{1}\pi\rightarrow$ $\omega\pi\pi$ and through the direct coupling $\mathcal{O}\rightarrow\omega\pi\pi$)$.$ Similarly, the (direct and indirect) decay into $\pi KK^{\ast}(892)$ is sizable. Moreover, the decays into $\rho\pi$ and $K^{\ast}(892)K$ are, although subleading, possible and could play a role in explaining the $\rho\pi$ puzzle of the charmonium state $\psi(2S)$ thank to a (small) mixing with the vector glueball. The vector glueball can be directly formed at the ongoing BESIII experiment as well as at the future PANDA experiment at the FAIR facility. [PRD 95, 11.4004 (2017)][1] [1]: https://journals.aps.org/prd/abstract/10.1103/PhysRevD.95.114004
Speaker: Ms Julia Sammet (Goethe University Frankfurt)
• 17:36
The Crystal Zero Degree Detector at BESIII 3m
The BESIII experiment at the BEPCII electron positron collider at IHEP (Beijing) is collecting data in the charm-$\tau$ mass region. In electron positron collisions one of the initial leptons may emit a real photon before the annihilation (initial state radiation, ISR). As a result, the remaining system is boosted and has an effective center-of-mass energy lower than the nominal one ($2m_e\leq\sqrt{s'}<\sqrt{s}$). While the accelerator is tuned to a fixed $\sqrt{s}$, the analysis of ISR events provides simultanious access to processes at different $\sqrt{s'}$ making it a great tool for measurements of e.g. timelike hadron formfactors or the $R$-value. However, the photons from ISR are strongly peaked towards small polar angles and are currently detected with limited efficiency. In order to increase the detection efficiency of these photons, we are developing small-size calorimeters to be placed in the very forward and backward regions. Each detector will consist of two arrays of LYSO crystals separated by a small gap. The scintillation light will be collected by silicon photomultipliers (SiPMs). The expected event rate in the MHz range requires flash ADCs recording the preamplified SiPM outputs. The digitized waveforms will be analyzed in realtime on FPGA-based hardware performing sub-event building, buffering, and event correlation with the BESIII trigger. A single crystal equipped with four SiPMs was instrumented as a prototype detector. Tests with an electron beam at the MAMI facility in Mainz were performed successfully.
Speaker: Mr Leonard Koch (JLU Giessen)
• 17:39
The A1 - Jet-Target-Project 3m
In the Year 2017 a new target has been installed @A1 in Mainz. This target is a Cluster-Jet-Target, which means that a hydrogen jet streams through the vacuum chamber, perpendicular to Mamis electron beam. By cooling down to gas temperatures of 40 K, the gas jet gets high densities in the core, due to the formation of clusters. The Jet-Target enables high precision measurements due to its windowless design. This poster shows the details of the entire construction and the first performed measurements regarding the density profile of the jet and the cooling behavior of the system.
Speaker: Stephan Aulenbacher (JGU Mainz)
• 17:42
The latest developments in preparations of the LHC community for the computing challenges of the High Luminosity LHC 3m
After the LHC community successfully completed Run 1, the capacity of the Worldwide LHC Computing Grid (WLCG) became the limiting factor in the processing of ever growing volumes of data produced from LHC collisions. During the last five years the LHC community launched a number of activities to increase computing performance and optimize usage of available resources. These activities are particularly important in preparation for Run 3 (2021-2023) and Run 4 (2026-2029), the era of the High Luminosity LHC, because mainstream technology evolution might fall short by up to a factor 10 with respect to WLCG needs. The endeavours must constantly adapt to the new technologies; they concentrate on redesigning the computing models of the LHC experiments, improving the efficiency of the data processing chains, adaptation of software to fast and/or cheap CPU architectures, and increased use of diverse resources like private and public clouds or high performance computing (HPC) facilities. WLCG was built during a time when there was no experience with or example of such an infrastructure from industry or elsewhere. This situation changed during Run 1 when the global internet and computing industry began to provide on-demand services and developed tools and solutions which are of interest also to WLCG. The latest strategies to increase the WLCG performance are therefore also concerned with utilization of tools provided from outside the LHC community: use of commercial cloud services for LHC data simulation and processing; formation and exploitation of data lakes; use of popular data mining and analytics pipelines. The HEP Software Foundation was formed to try and orchestrate the processes of software transformation toward higher efficiency and adaptation to new computing technologies. The need for essential changes and external expertise was recognized: for example, the use of Python-based notebooks for high-level interactive analysis, or the integration of Machine Learning in reconstruction. There are opportunities for more commonality across experiments and there is an increasing collaboration with other big-data projects like the Square Kilometer Array (SKA). Important steps forward are also expected from the continued collaboration with IT industry through CERN openlab. In this contribution we will present the latest innovative strategies of the LHC community to get prepared for the computing challenges of the next ten years and especially for the demands of the High Luminosity LHC.
Speaker: Dr Dagmar Adamova (Nuclear Physics Institute AS CR)
• 17:45
Complex Langevin simulations of a finite density matrix model for QCD 3m
We study the Stephanov model, which is a Random Matrix Theory model for QCD at finite baryon density, using the Complex Langevin algorithm. Naive implementation of the algorithm shows convergence towards the phase quenched or quenched theory rather than to the intended theory with dynamical quarks. A detailed analysis of this issue various potential resolutions of the failure of this algorithm are discussed.
Speaker: Dr Savvas Zafeiropoulos (Universitaet Heidelberg)
• 17:51
Production of neutron-rich nuclei approaching r-process by 238U photofission at ELI-NP 3m
The investigation of very neutron-rich nuclei are of significant importance for nuclear physics and nuclear astrophysics. However, so far, only few neutron-rich nuclei near the stability have been measured, while most neutron-rich nuclei have not been experimentally studied due to their small production cross sections and short half-lives. Very brilliant and intense gamma beams planned at ELI-NP provide new opportunities to investigate very neutron-rich fragments, especially those close to the r-process path, produced by photofission of 238U targets at the center of a gas cell. An empirical parameterization has been developed to accurately calculate the production cross sections (rates) of neutron-rich fragments produced by 238U photofission. By doing GEANT4 simulations, the design of the gas cell has been optimized to stop and extract photofission fragments. The extraction time and efficiency of photofission fragments have been optimized by SIMION simulations. According to these simulations, a fast extraction time and a high extract efficiency can be achieved for fragments produced in the 238U targets, which allows one to measure the very neutron-rich fragments with short half-lives.
Speaker: Dr Bo Mei (Extreme Light Infrastructure - Nuclear Physics (ELI-NP))
• Tuesday, 23 January
• 09:00 13:25
Tuesday Morning
• 09:00
Black holes, neutron stars and the birth of gravitational wave astronomy 45m
Gravitational waves, ripples in the fabric of space-time produced by catastrophic astrophysical events, are arguably the most elusive prediction of Einstein’s theory of General Relativity, so feeble that Einstein himself thought their detection would be impossible. One hundred years later, the Laser Interferometer Gravitational-wave Observatory (LIGO) and its sister project Virgo have observed multiple gravitational wave signals from the collision of pairs of black holes, a groundbreaking discovery that opened a new observational window on the Universe. An equally momentous discovery took place on August 17, 2017, with the first detection of gravitational waves from the collision of two neutron stars in coincidence with a gamma ray burst and followed by the identification of an optical transient and the multi-wavelenght observation of a kilonova by the worldwide astronomy community. We are now in a new era of multi-messenger astrophysics, where gravitational waves are a new important probe in the universe. This talk will present the current status of the LIGO and Virgo detectors, our most recent results, the implications for gravitational wave astronomy and the outlook for future generations of gravitational wave detectors.
• 09:45
Neutrinos and Nuclei 45m
Many important large-scale experiments are now operating to uncover fundamental properties of neutrinos including the mass hierarchy, mixing angles, CP violation and the Majorana nature of the neutrino. These very different experiments probe different regimes of energy and momenta, but all should be described by a realistic picture of nuclear interactions and currents. I will describe recent developments in our understanding of beta decay at very low momentum transfer, quasi-elastic neutrino scattering at much higher energy and momentum transfer. Finally I will describe how the effects discovered in beta decay and accelerator neutrinos may impact double beta decay matrix elements and astrophysical neutrinos.
Speaker: Dr Joseph Carlson (LANL)
• 10:30
Coffee Break 30m
• 11:45
Hidden and open charm exotic hadrons 30m
Exotic heavy hadrons are a hot topic since the discovery of a narrow tetraquark, X(3872) and the hidden-charm pentaquark Pc(4450), recently observed by the LHCb collaboration. In this talk I will present a few examples of hidden and also open charm hadrons that might be interpreted as molecular states. Reactions where these hadrons could be observed will also be discussed.
Speaker: Prof. Angels Ramos (University of Barcelona)
• 12:15
Status and Prospect of Belle II at SuperKEKB 25m
Construction of the new SuperKEKB B-Factory is now complete. The new collider, presently under commissioning at the KEK laboratory in Japan, is scheduled to deliver the first $e^+e^-$ collisions in the first half of 2018, to open a new era in the arena of physics at the high intensity frontier. We will present some highlights of the physics program, with emphasis on the first collision measurements. We will then present some first preliminary results of SuperKEKB's single beam commissioning and beam background studies. We will describe the performance improvements obtained with the upgrade of the Belle II detector, and present the status of the final phases of the detector commissioning and operation.
Speaker: Dr Riccardo de Sangro (INFN - LNF)
• 17:00 19:30
Tuesday Afternoon
• 17:00
PUMA: Radioactive nuclei and Antiprotons 25m
Antiprotons as probe for nuclear studies with short-lived isotopes remain unexploited despite past pioneer works at CERN/LEAR and Brookhaven. Antiprotons may represent a unique probe sensitive to the ratio of neutron and proton densities at annihilation site, i.e. in the tail of the nuclear density. Realising antiproton capture from short-lived nuclei is the objective of a new project named PUMA (antiProton Unstable Matter Annihilation) which will be introduced.
Speaker: Dr Alexandre Obertelli (TU Darmstadt)
• 17:25
Axion-like particles at the LHC and future colliders 20m
Axion-like particles at the LHC and future colliders
Speaker: Prof. Matthias Neubert (Johannes Gutenberg University Mainz)
• 17:45
Recent results from the ATLAS heavy ion program 20m
The heavy-ion program in the ATLAS experiment at the LHC originated as an extensive program to probe and characterize the hot, dense matter created in relativistic lead-lead collisions. In recent years, the program has also broadened to a detailed study of collective behavior in smaller systems. In particular, the techniques used to study larger systems are also applied to proton-proton and proton-lead collisions over a wide range of particle multiplicities, to try and understand the early-time dynamics which lead to similar flow-like features in all of the systems. Another recent development is a program studying ultra-peripheral collisions, which provide gamma-gamma and photonuclear processes over a wide range of CM energy, to probe the nuclear wavefunction. This talk presents a subset of the the most recent results from the ATLAS experiment based on Run 1 and Run 2 data, including measurements of collectivity over a wide range of collision systems, potential nPDF modifications — using electroweak bosons, inclusive jets, and quarkonia — and photonuclear dijet production.
Speaker: Laura Havener (Columbia University)
• 18:05
The micro-RWELL technology: status and perspectives 20m
The micro-Resistive-WELL (μ-RWELL) has been conceived as a compact, simple and robust Micro-Pattern Gaseous Detector (MPGD) for large area HEP applications requiring the operation in harsh environment. The detector amplification stage is realized with a polyimide structure micro-patterned with a blind-hole matrix, embedded through a thin Diamond Like Carbon (DLC) resistive layer in the readout PCB. The DLC surface resistivity, typically in the range 10÷200 MOhm/square, affects the detector performance. The introduction of the resistive layer, mitigating the transition from streamer to spark, gives the possibility to achieve large gains (> 10$^4$). Different detector layouts have been studied: the most simple one based on a single-resistive layer with edge grounding has been designed for low-rate applications (up to 30-40 kHz/cm$^2$); while more sophisticated schemes are under study for high-rate purposes (up to 2-3 MHz/cm$^2$). The single-resistive layer scheme has been extensively tested and validated and it is substantially ready for applications in HEP (CMS, LHCb, SHiP), as well as for non-HEP applications (ERM network for EURDEP). In this review of the R&D activity, after an introduction on the principle of operation of the detector we will give an overview of the performance mainly measured with single-resistive layer detectors: gain, space and time resolution, rate capability, aging studies. In particular concerning the space performance of the detector we will discuss the preliminary results of a recent analysis based on the micro-TPC mode, that combined with the classical charge-centroid method will lead to a uniform space resolution in the range 100÷150 µm, for non-orthogonal tracks and/or in presence of an high magnetic field (up to 1 T). An overview of the different architectures under study for the high rate version of the detector will be eventually presented.
Speaker: Dr Gianfranco Morello (Laboratori Nazionali di Frascati dell'INFN)
• 18:25
Probing resonance matter with HADES 20m
In heavy-ion collisions at few GeV per nucleon, QCD matter with densities several times larger than the normal nuclear matter density and temperatures of about 80 MeV is created. At such extreme conditions the fundamental properties of the hadrons are expected to be modified. Properties of produced QCD matter can be extracted directly from its emissivity in the electromagnetic sector or from the production of rare (multi-) strange particles and them collective flow paterns. In addition the collective motion of final state hadrons reveals important information about both, the properties of the hot and dense medium created in a heavy-ion collision and the collision dynamics. The High Acceptance DiElecton Spectrometer (HADES), installed at the heavy-ion synchrotron SIS18 at the GSI Helmholtzzentrum für Schwerionenforschung (Darmstadt), is currently the only experiment studying properties of strongly interacting matter in the few A GeV energy regime. HADES is a fixed-target experiment with large angular acceptance and high rate capabilities. It used to study dielectron and hadron production in heavy-ion collisions, as well as in proton- and pion-induced reactions in the energy range of 1 − 4 GeV. In this contribution the main emphasis will be put on most recent results on strangeness and dielectron production in Au+Au collisions at sqrt(sNN) = 2.42 GeV. The high statistics data allows to study multi-differential distributions. Experimental spectra will be confronted with results obtained by former experiments as well as with available model calculations. The investigation of the the kinetic freeze-out conditions by applying simultaneous blast wave fits to the transverse mass spectra of hadrons will be presented as well. The future experimental program at SIS18 during FAIR Phase-0 will finally be presented.
Speaker: Dr Malgorzata Gumberidze (TU Darmstadt/GSI)
• 18:45
Importance of initial and final state effects for azimuthal correlations in p+Pb collisions 20m
The question behind our work is the origin of the observed large momentum anisotropies in high energy pA collisions. It has been shown that initial state momentum correlations are sizeable in such small systems, and evidently, final state interactions of some form are also present and important. Because of the large gradients present in the spatial gluon distribution and the small number of particles present, these final state interactions are unlikely to be properly described by hydrodynamics, despite many attempts in this direction. We establish a novel, unique methodology, combining a state-of-the-art initial state model (Yang-Mills dynamics of pre-equilibrium gluon fields, “IP-GLASMA”) with an explicit and exact non-equilibrium solution of the Boltzmann equation (parton cascade “BAMPS”) which is far more general than hydrodynamic calculations. In this study we focus on high and low multiplicity p+Pb collisions at top LHC energies. The average parton number per rapidity in pA collisions is on the order of 5-30, which is very little compared to rather well-understood heavy-ion collision systems where parton numbers reach a few thousand, and hydrodynamics can be successful. So far, our framework is the first and only one giving quantitative insights of both the initial state correlations and final state interactions in azimuthal correlation observables. The results show the interplay of classical Yang-Mills dynamics and the potential onset of thermalization quantitatively in high and low multiplicity pA systems. It is the dynamics on the border of initial state dominated to final state dominated - but not yet fully developed hydrodynamic - behavior. More precise, we find that signatures of both the initial state correlations and final state interactions are seen in azimuthal correlation observables, such as $v_2\{2P C\} (p_T)$, their strength depending on the event multiplicity and transverse momentum. Initial state correlations dominate $v_2\{2P C\} (p_T)$ in low multiplicity events for transverse momenta p T > 2 GeV. While final state interactions are dominant in high multiplicity events, initial state correlations affect $v_2\{2P C\} (p_T)$ for $p_T > 2~\mathrm{GeV}$ as well as the pT integrated $v_2\{2P C\} (p_T)$. Preprint [arxiv:1708.02076][1] [1]: https://arxiv.org/abs/1708.02076
Speaker: Mr Moritz Greif (Goethe University Frankfurt)
• 19:05
Photon Production in a Hadronic Transport Approach 20m
Photons play an important role in the investigation and understanding of the QGP. Unlike hadrons, which are likely to interact with the medium before detection, photons only interact electromagnetically, their mean free path is much larger than the size of the system. They are direct probes of the observed medium and offer unique insights into the fireball and the hadronic phase. Additionally, measurements at RHIC and LHC show unexpectedly large momentum anisotropies for photons presumably produced in the hadronic phase of heavy ion collisions. Further investigation of photons in a strongly-interacting medium is hence necessary to solve the direct photon flow puzzle. To improve the theoretical understanding of photons in heavy ion reactions, scattering processes involving photons have been implemented into a hadronic transport approach (SMASH), which simulates hot and dense strongly-interacting nuclear matter. Comparisons of the obtained thermal rates in infinite matter calculations to theoretical predictions and to the ones used in hydrodynamic calculations will be shown. The plan for the future is to apply this hadronic transport approach within a hybrid approach to RHIC/LHC energies.
Speaker: Anna Schäfer (Frankfurt Institute for Advanced Studies)
• Wednesday, 24 January
• 09:00 12:40
Wednesday Morning
• 09:00
Studies of deconfined matter at the LHC with ALICE 45m
Deconfined matter is produced in the laboratory at highest energy densities in heavy-ion collisions at the LHC. A selection of recent results from ALICE will be presented, spanning observables from the soft sector (bulk particle production and correlations) to hard probes (charmed hadrons and jets).
• 09:45
Physics with ultracold neutrons 45m
Ultracold neutrons (UCNs) can be confined and manipulated in traps and are an excellent probe to study fundamental symmetries and interactions. Storage lifetimes of several hundred seconds enable high-precision experiments with impact on astrophysics and cosmology, complementary to high-energy physics. Although longstanding, the search for a non-vanishing electric dipole moment of the neutron is currently a hot topic pursued by many research groups around the world. A non-zero result would provide evidence of CP violation beyond the CKM mechanism of the standard model of particle physics and help understanding the asymmetry of baryonic matter and antimatter in the universe. The neutron lifetime is a second key observable investigated with ultracold neutrons. It determines the primordial abundances of the light chemical elements after the big bang and is still astonishingly poorly known. A third example of current studies covered in this talk is a search for deviations from Newton’s gravity law at distances in the micrometre range, using spectroscopy of quantum states of the neutron confined by a horizontal mirror and gravity. A major step forward in experimental accuracies is expected from the availability of advanced UCN sources, such as currently being developed at the ILL in Grenoble and based on superfluid helium as a converter medium.
Speaker: Prof. Zimmer Oliver
• 10:30
Coffee Break 30m
• 11:00
Nuclear Physics with Strangeness 40m
Nuclear Physics with Strangeness
Speaker: Prof. HIROKAZU TAMURA (Department of Physics, Tohoku University)
• 11:40
Testing the conjecture of partial chiral symmetry restoration - meson-nucleus potentials and the search for meson-nucleus bound states 30m
Chiral model calculations, assuming a partial restoration of chiral symmetry in a nuclear medium, predict modifications of meson properties within nuclei. An overview will be given on current experiments studying in-medium properties of mesons and the meson-nucleus interaction to extract meson-nucleus potentials. The real part of the meson nucleus potential describes whether the interaction is attractive or repulsive while the imaginary part is a measure for the meson absorption in nuclei. The real part of the potential can be determined by comparing measured meson momentum distributions or excitation functions with collision model or transport model calculations. The imaginary part is extracted from transparency ratio measurements. Results on K+, K0, K-, η, η’, ω, and ϕ mesons turn out to be largely consistent with chiral model predictions. In view of the potential parameters, the criteria and chances for observing meson-nucleus bound states will be discussed. The most promising candidates appear to be the K-,η and η’ meson.
Speaker: Prof. Volker Metag (II. Physikalisches Insititut)
• 12:10
The Pierre Auger Observatory 30m
The Pierre Auger Observatory, located on a vast, high plain in western Argentina, is the world's largest cosmic ray observatory. The objectives of the Observatory are to probe the origin and characteristics of cosmic rays with energies above $10^{17}$ eV and to study the interactions of these most energetic particles observed in nature. The Observatory design features an array of 1660 water-Cherenkov particle-detector stations spread over 3000 km$^2$, overlooked by 27 air-fluorescence telescopes. The Observatory has been in successful operation since its completion in 2008 and has recorded data from an exposure exceeding 80,000 km$^2$ sr yr. We will give a short historical overview of efforts in this field of research, discuss the measurement of the energy spectrum of cosmic rays, studies of the cosmic-ray mass composition, the discovery of a large-scale anisotropy in the arrival direction of cosmic rays, report on tests of hadronic interactions beyond LHC energies, multi-messenger analyses with neutral primaries and the progress and performance of the upgrade of the Observatory aimed to clarify the origin of the observed flux suppression at the ultrahigh energies.
Speaker: Dr Darko Veberic (Karlsruhe Institute of Technology)
• 17:00 19:40
Wednesday Afternoon
• 17:00
I understand the topic has been suggested by the conference organizers. Please let me know if you'd like a full abstract. Best wishes, Rudolf Oldeman
Speaker: Dr Rudolf Oldeman (INFN sezione di Cagliari and Università di Cagliari)
• 17:25
Study of rare B decays at BABAR 20m
Flavour-changing neutral currents, such as $B \to K^{(*)} \ell^+\ell^-$ or $B \to X_s \gamma$, are forbidden at tree level in the Standard Model. At lowest order, they occur at 1-loop level, making them sensitive to quantum corrections from particles beyond the Standard Model (SM). Via these virtual contributions, one can probe mass scales which are currently inaccessible in direct production. In this talk, we present the most recent results from BABAR, using 471 million $B\bar{B}$ pairs, on the decays $B \to K^* \ell^+\ell^-$. The quantities $A_{FB}$ and $F_L$, which are sensitive to the presence of particles beyond the SM in the loops, are determined using an angular analysis. We also report on a search for the decay $B \to K \tau^+ \tau^-$.
Speaker: Prof. Wolfgang Gradl (Universität Mainz)
• 17:45
Particle spectra from the NA61/SHINE experiment 20m
NA61/SHINE is a large acceptance hadron spectrometer at CERN SPS. Its main goals are to search for the critical point of the strongly interacting matter, to study the onset of deconfinement, and to study high transverse momentum phenomena in a fixed target environment. The physics program of the experiment contains data taking in p+p, p+A, and A+A collisions at various energies. In this contribution the latest results on particle spectra from NA61/SHINE will be presented for different interactions.
Speaker: Krisztina Marton (Wigner RCP of HAS, Budapest, Hungary)
• 18:05
The MVD detector project 20m
monolotic detector sensors for CBM
Speaker: Prof. Joachim Stroth (Uni. Frankfurt)
• 18:25
Low-mass dielectrons in pp, p–Pb and Pb–Pb collisions measured with ALICE at the LHC 20m
In ultra-relativistic heavy-ion collisions at the LHC, hadronic matter is believed to form a new state of matter comprising deconfined quarks and gluons — the quark- gluon plasma (QGP). Electron-positron pairs are produced during all stages of such collisions and carry information unperturbed by final-state effects, thus providing us with a unique experimental tool to study the whole space-time evolution of the system. Dielectron invariant-mass distribution is very rich in physics sources, among them the thermal black-body radiation is of particular interest as it carries information about the temperature of the hot and dense system created in the collision. The dielectron continuum is also sensitive to medium modifications of the spectral function of short-lived vector mesons that are linked to the potential restoration of chiral symmetry at high temperatures. Correlated dielectron pairs from semi-leptonic charm and beauty decays provide complementary information about the heavy-quark energy loss. In this talk we present an extensive summary of the ALICE results in pp, p–Pb and Pb–Pb collisions, including the latest analysis of Run-2 pp collisions at 13 TeV collected with a trigger on high charged-particle multiplicities. The measurements of dielectron production in minimum bias pp collisions serve as an important vacuum reference to quantify any observed modifications in heavy-ion collisions, and the studies in p–Pb collisions are used to investigate cold nuclear matter effects. Furthermore, the progress on the multivariate analysis techniques being developed in ALICE will be reported.
Speaker: Ivan Vorobyev (Technische Universität München)
• 18:45
Nuclear reactions in laser Plasma 20m
Plasma state is characterized by a complexity that vastly exceeds that exhibited in the solid, liquid, and gaseous states, Correspondingly, the physical properties of nuclear matter (structure, life times, reaction mechanisms etc.) could be drastically changed inside the plasma. These studies represent one of the most far ranging, difficult and challenging research areas today, implications could cover different fields of interest for physics. In the astrophysics context one of the most crucial aspects concerns the role of electron screening. Direct and indirect measurements of the relevant cross sections have been performed over the years. The electron screening effect is significantly affected by the target conditions and composition, it is of particular importance for the measurement of cross-sections at extremely low energetic domains including plasma effects, i.e. in an environment that under some circumstances and assumptions can be considered as “stellar-like” (for example, for the study of the role played by free/bounded electrons on the Coulombian screening can be done in dense and warm plasmas). Electron screening prevents a direct measurement of the bare nucleus cross section at the energies of astrophysical interest. In the last decade, the bare cross section has been successfully measured in certain cases by using several indirect methods . In order to study the electronic screening problem in a wide variety of cases and configurations with different purposes, we are proposing the construction of a general experimental setup, where it will be possible In particular to study the screening effects on low energy fusion reactions and on weakly bound nuclear states (Hoyle, Efimov etc.). To perform this kids of experiments, we aim to take advantage from the excellent and unique performance of the ELI-NP facility and realize an experimental setup where two laser beams generate two colliding plasmas. In particular the main laser pulse impinging on B, C or Li thin foil generates a primary plasma which impacts on a second plasma slab produced through the interaction of a secondary laser pulse on a He or D2 gas jet target . In particular the main laser pulse imping on B, C or Li thin foil generates a primary plasma which impacts on a second plasma slab produced through the interaction of a secondary laser pulse on a He or D2 gas jet target . The the detectors configuration combine the high granularity SiC charged particles detectors (in vacuum) and a new generation of neutrons time-of-flight detectors (in air). Among this detectors very interesting is the development of Silicon carbide (SiC) is one of the compound semiconductor which has been considered as a potential alternative to Silicon for the realization of charge particles detectors and dosimeters in high energy physics. The chemical and physical material properties are promising for high temperature and high radiation operation conditions. SiC diodes are predicted to be radiation harder than Si due to the high displacement threshold and potentially used as radiation detectors in high radiation condition.
Speaker: Dr sebastiana puglia (LNS-INFN)
• 19:05
Hadronic structure and precision tests of Standard Model 20m
Measuring the parameters of the Standard Model (SM) at low energies with high precision allows one to discover physics beyond the SM (BSM) if a deviation from the SM prediction is observed experimentally, or constrain the BSM contributions if no such deviation is seen. The precision of modern experiments makes them sensitive to heavy New Physics at scales of several tens of TeV, making them complementary to direct searches at colliders. To interpret such experiments in terms of New Physics, the SM radiative corrections, including those depending on the hadronic structure, have to be taken into account. In the context of the parity-violating electron scattering program at Mainz and Jefferson Lab, and $\beta$-decay of free and bound neutrons, I review the current status of the theory of electroweak box corrections that involve an exchange of a heavy $W^\pm$ or $Z$-boson and a photon.
Speaker: Dr Mikhail Gorshteyn (JGU)
• Thursday, 25 January
• 09:00 13:00
Thursday Morning
• 09:00
Higgs and New Physics at ATLAS and CMS 45m
Higgs and New Physics at ATLAS and CMS
Speaker: Prof. Fairouz Malek (LPSC-Grenoble)
• 09:45
Recent results from BES III 45m
Recent results from BES III
Speaker: Prof. Xiaoyan Shen (IHEP, CAS)
• 10:30
Coffee Break 30m
• 11:00
Applications for Harvested Isotopes 30m
Accelerator facilities inevitably amass a small collection of activated components like beamstops and collimators. Depending on the chemical composition of the component and the properties of the accelerated particles, transmuted inventories will potentially include valuable radioisotopes for applied and basic science research. For example, at PSI’s proton accelerator, a copper beamdump accumulated 60Fe, 53Mn, and 44Ti over many years, and researchers involved in the ERAWAST campaign successfully retrieved those nuclides for astrophysics-related research. At the upcoming Facility for Rare Isotope Beams (FRIB) in the US, a new circulating-water beamstop will allow almost real-time collection of fragmented heavy ions, meaning that isotopes with shorter half-lives can be withdrawn, or “harvested”, from the beamstop. This will allow a multitude of applied research projects ranging from medical imaging and therapy to hyperfine studies in metallo-enzymes. The development of FRIB continues a trend in nuclear physics research: as the basic science progresses, the generated nuclear data, techniques, and by-products are fruitfully applied to solving problems outside of the field.
Speaker: Prof. Gregory W. Severin (Michigan State University)
• 11:30
Search for the tetra neutron 30m
Search for the tetra neutron
Speaker: Prof. Thomas Aumann (TU Darmstadt)
• 12:00
Status of the proton radius puzzle 30m
Laser spectroscopy of muonic hydrogen [1,2] yielded a proton rms charge radius which is 4% (or ~6 sigmas) smaller than the CODATA value [3]. Also the deuteron charge radius from muonic deuterium [4] is 6 sigmas smaller than the CODATA value, but consistent with the smaller proton inside the deuteron. These smaller charge radii, when combined with precision measurements of the 1S-2S transitions in regular (electronic) hydrogen [5] and deuterium [6], yield a 6 sigmas smaller value of the Rydberg constant [7], compared to the CODATA value. In this talk I will report about a new measurement of the Rydberg constant from the 2S-4P transition in regular hydrogen performed in Garching [8], which supports the smaller, "muonic" value. I will also discuss the measurements in muonic hydrogen, deuterium, and helium, and the consequences for the "proton radius puzzle". [1] Pohl et al. (CREMA Coll.), Nature 466, 213 (2010) [2] Antognini et al. (CREMA Coll.), Science 339, 417 (2013) [3] Mohr et al. (CODATA 2014), Rev. Mod. Phys. 88, 035009 (2016) [4] Pohl et al. (CREMA Coll.), Science 353, 669 (2016) [5] Parthey et al., PRL 107, 203001 (2011) [6] Parthey et al., PRL 104, 233001 (2010) [7] Pohl et al., Metrologia 54, L1 (2017) [8] Beyer et al., Science 358, 79 (2017)
Speaker: Prof. Randolf Pohl (Johannes Gutenberg University Mainz)
• 17:00 20:05
Thursday Afternoon
• 17:00
Flavour results at LHCb 25m
Flavour results at LHCb
Speaker: Dr Patrizia de Simone (LNF-INFN)
• 17:25
The FOOT experiment: status and first experimental results 20m
Hadrontherapy is a powerful radiotherapy technique characterized by a dose deposition highly localized in the tumor target and by a minimal dose released to the surrounding healthy tissues. However, on the path inside the patient, nuclear interactions of the beam with the tissues produce fragments with high Relative Biological Efficiency (RBE). An accurate measurement of fragments production is needed to improve the RBE models and, ultimately, the clinical treatment plans. The FOOT (FragmentatiOn Of Target) experiment aims at identifying the fragments produced in the human body during hadrontherapy and at measuring their cross sections. A dedicated experimental apparatus is being designed to fully characterize the fragments produced by therapeutical beams on hydrogenated targets. The apparatus is composed of a start counter that provides the trigger information and the start of the time-of-flight (TOF) measurement when crossed by a primary particle. A beam monitoring drift chamber reconstructs the direction and impinging point of the ion beam on the target. A series of silicon pixel detectors track the fragments after the target. Then, a dedicated magnetic spectrometer separates the fragments and a silicon strip detector measures the momentum and allows matching the tracks with the hits occurring in the last two elements in the detection chain dedicated to the particles identification: a ΔE-TOF detector, which measures the energy released in a thin plastic scintillator and the stop of the TOF, and a calorimeter, which measures the kinetic energy of the fragments. In addition, an emulsion spectrometer can be inserted after the target (replacing the magnetic silicon tracker subsystems) to characterize the production of low Z fragments. The final goal of the FOOT experiment is to measure the differential cross section with 5% uncertainty for ions beams impinging on different targets (e.g., C, C$_2$H$_2$) to be obtained after inverse kinematics reconstruction. The required resolutions to achieve these experimental goals have been estimated by means of a Monte Carlo simulation of the apparatus. In particular, a time resolution σ of approximately 100 ps and a energy resolution of a few % should be accomplished by the final ΔE-TOF detector to comply with the general experimental requirements, the momentum of the fragments should be known with a 5% resolution, and the kinetic energy should be determined by the calorimeter with a 2% resolution. A large effort has been dedicated to optimize the design of the experiment by means of simulations and first prototypes, which are being developed and characterized with test beams. In this work, the experimental design and the requirements of the FOOT experiment will be discussed, and the first results on the experimental studies that were performed will be presented. In particular, for the ΔE-TOF detector a first prototype was developed and characterized in terms of energy and time resolution, by irradiating it with proton beams of different energies. An energy resolution of 8% and a time resolution of 140 ps were obtained with a 70 MeV proton beam. Even though the performances tended to deviate from the experiment requirements for higher beam energies, they are expected to improve for heavier ions, due to the increase in the released energy. The results of this first prototype are currently being used to improve the design of the ΔE-TOF detector (i.e, bar readout, coupling and wrapping). The limitations and the ongoing improvements will be shown and discussed.
Speaker: Dr Matteo Morrocchi (INFN - Sezione di Pisa)
• 17:45
"Searches of dark sector particles with positron annihilations" 20m
Speaker: Dr Paolo Valente (INFN Roma)
• 18:05
Comparision of hydrodynamical and transport theoretical calculation for p+A and A+A collisions. 20m
One of the big uncertainties in extracting the transport coefficients by comparing the experimental data from A+A or p+A collisions to the results from relativistic dissipative fluid dynamics is the applicability of fluid dynamics in describing the evolution of such small systems. We investigate the applicability of fluid dynamics by comparing fluid-dynamical calculations to the solutions of the Boltzmann equation. We study several different systems by varying the system size and the underlying microscopic cross section. In particular, we analyze the space-time evolution of the energy density, number density, and velocity fields. Furthermore, we investigate different freeze-out conditions and the applicability of fluid dynamics, with dissipative corrections to the particle distribution function at freeze-out, in describing the final particle spectra and flow coefficients in p+p, p+A and A+A collisions.
Speaker: Prof. Carsten Greiner (Goethe University Frankfurt)
• 18:25
First Fully Exclusive Measurement of SRC Pairs at JINR 20m
Approximately 20% of nucleons in a nucleus are localized in short-range correlated (SRC) pairs, with relative momentum that exceeds the nuclear fermi momentum. Both inclusive and exclusive electron scattering experiments have confirmed that this pairing is a universal phenomenon, and that high-momentum nucleons always have a correlated partner. However, little is known about the state of the residual nucleus after hard knock-out reactions Nuclear beams at the Joint Institute for Nuclear Research offer unique opportunities to perform the fully exclusive measurements of Short-Range Correlations (SRC) via hard nucleon knock-out in inverse kinematics. Our recent run in December 2017 used a 4 GeV/c/u 12C beam on a H target to knockout a proton from an SRC pair in the carbon nucleus, and detect in coincidence the target-scattered proton along with the residual A-2 system. For the first time, we can begin to understand the state of the nucleus when a SRC pair is formed. In my talk, I will present briefly past efforts to study SRC pairs, the aspects of inverse kinematics to how we study SRC pairs, the theoretical motivation for fully exclusive SRC measurements, and the physical setup with preliminary analysis from our recent run.
Speaker: Efrain Segarra (Massachusetts Institute of Technology)
• 18:45
Neutrino-Nucleus Interactions and Long-Baseline Experiments 20m
The extraction of neutrino mixing parameters and the CP-violating phase requires knowledge of the neutrino energy. This energy must be reconstructed from the final state of a neutrino-nucleus reaction since all long-baseline experiments use nuclear targets. This reconstruction requires detailed knowledge of the neutrino reactions with bound nucleons and of the final state interactions of hadrons with the nuclear environment. Quantum-kinetic transport theory has been used to build the event generator GiBUU hat has been applied to and tested for many different reactions, from heavy-ion collisions to neutrino-nucleus reactions. In this talk I will confront results of GiBUU with results from neutrino experiments. Some examples are also discussed that show the effects of nuclear interactions on observables in long-baseline experiments.
Speaker: Prof. Ulrich Mosel (Universitaet Giessen)
• 19:05
Effective Field Theory Analysis of CRESST-II data 20m
CRESST is a direct detection dark matter experiment located in Italy at the Laboratori Nazionali del Gran Sasso. The target used consists of scintillating CaWO4 crystals operated at low mK temperatures. Phonon and light signals are used for particle discrimination. For the ongoing data taking of CRESST-III, starting in 2016, an unprecedented energy threshold of below 100 eV was achieved. Results from CRESST-II and CRESST-III set the most constraining limits in the field for spin-independent interaction and low dark matter masses in the sub-GeV/c$^2$ and the low GeV/c$^2$ mass region. In order to account for more exotic dark matter models, possible momentum dependences of the interaction, and differences between target materials, data from CRESST-II has been reanalyzed using a more general effective field theory (EFT) approach instead of the standard differentiation between spin-independent and spin-dependent interaction.
Speaker: Vincent Schipperges (Universität Tübingen)
• Friday, 26 January
• 09:00 13:10
Friday Morning
• 09:00
Nuclear Physics and the Origin of Heavy Elements 45m
The theoretical quest to explain the synthesis of heavy elements has not yet been fully solved. These nuclei are considered to be produced mainly in neutron-capture processes and, to a lesser extent, in charge-particle reactions. Advances in this field have been possible through comprehensive astrophysical studies, which combine hydrodynamic simulations and reaction network calculations. The later are sensitive to both the astrophysical conditions and the properties of the nuclei involved. In this presentation, I will discuss the most relevant aspects in nuclear-physics affecting the nucleosynthesis of heavy elements. Special emphasis will be given to charge-particle reactions in neutrino-driven winds, and their possible connection to the synthesis of the so-called light r-elements (Sr, Y, and Zr).
Speaker: Prof. Jorge Pereira (NSCL)
• 09:45
Transport Theory for Energetic Nuclear Reactions 45m
Transport theory is a common tool in drawing conclusions from energetic nuclear reactions. Successes and struggles of the theory will be discussed. Currently, a new precision of the theory is demanded as efforts are under way to learn about symmetry energy at supranormal densities and to extrapolate from laboratory measurements to neutron star properties. The project of transport code comparisons will be, in particular, discussed, aiming at enhanced precision of the inferences from data. In the project, the researchers from around the world test their codes in simplified situations, against each other and against benchmark results that can be calculated by other methods. Sensitivity to physical inputs of interest to the experiments is being assessed and uncertainties tied to technical details are quantified.
Speaker: Prof. Pawel Danielewicz (Michigan State University)
• 10:30
Coffee Break 30m
• 11:00
Baryon-Baryon Interactions from Lattice QCD 30m
Baryon-Baryon Interactions from Lattice QCD
Speaker: Dr Tetsuo Hatsuda (RIKEN)
• 11:30
Heavy Ion results from LHCb 25m
A summary of recent results by LHCb on heavy-ion physics is given.
Speaker: Dr Michael Winn (Université Paris-Saclay)
• 11:55
Standard model and heavy-ion physics at ATLAS and CMS 45m
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Speaker: Mr Yi Chen (CERN)
• 17:00 19:40
Friday Afternoon
• 17:00
Towards finite density QCD with an effective lattice theory 20m
Finite density QCD is not directly accessible to Monte Carlo simulations because of the so-called sign problem. I summarize recent efforts to construct an effective lattice theory based on strong coupling and hopping expansions, which is valid either for heavy quarks close to the continuum or for chiral quarks on very coarse lattices. These effective theories permit determinations of the phase diagram in the parameter regimes where they are valid. Besides providing qualitative insights, the results also bound those for physical QCD. In particular, using these approaches it is possible to address the nuclear liquid gas transition directly from QCD.
Speaker: Prof. Owe Philipsen (Goethe-University Frankfurt)
• 17:20
Recent developments in the area of SoftQCD and Diffractive Physics at the ATLAS Experiment 20m
The ATLAS Collaboration released several new measurements in the area of SoftQCD and diffractive physics, ranging from the exclusive production of dimuons, over the total pp cross section measurement to studies of correlated hadron production. An overview of these most recent developments will be given in this talk: The total inelastic proton-proton cross section and the diffractive part of the inelastic cross section has been measured at 8 and 13 TeV in special data sets taken with low beam currents and using forward scintillators. More precise measurements of the total pp cross section and the elastic and inelastic contributions have been extracted from measurements of the differential elastic cross section using the optical theorem. In the absence of forward proton tagging, exclusive processes can be distinguished in the central part of the ATLAS detector exploiting the large rapidity gap in the central region and the absence of charged particles reconstructed in the inner tracking detector. This strategy has been exploited to study the exclusive production of dilepton pairs in the data taken at centre-of-mass energies of 7 TeV and the exclusive production of W pairs in the 8TeV data. We present recent results on exclusive dimuon production at 13 TeV. Last but not leasts, new studies of correlated hadron production have been conducted, as they are an important source of information about the early stages of hadron formation, not yet understood from first principles. Although experimental high energy physics employs several semi–classical models of hadronization which describe the formation of jets with remarkable accuracy, correlation phenomena are more elusive.
Speaker: Dr Robert Astalos (Comenius University Bratislava)
• 17:40
Light and strange baryon spectrum from functional methods 20m
In this talk I report on recent results on the spectrum and properties of three-quark states as obtained in the framework of Dyson-Schwinger and Bethe-Salpeter equations. I will discuss the spectrum of light baryons with focus on the comparison with quark model expectations, the impact of dynamical mass generation and explain the importance of relativistic components in the wave functions of baryons.
Speaker: Prof. Christian Fischer (JLU Giessen)
• 18:00
Antimatter in Space 20m
Measuring antimatter in space excellently probes various astrophysical processes. The abundancies and energy spectra of antiparticles reveal a lot about the creation and propagation of cosmic-ray particles in the universe. Abnormalities in their spectra can reveal exotic sources or inaccuracies in our understanding of the involved processes. I will review the measurement of antiprotons in cosmic rays and the status of the search for antideuterons and antihelium on stratospheric research balloons, satellites, and the International Space Station. I will describe future experiments that mainly focus on low kinetic energies---claiming promising discovery potentials for exotic production processes---and the influence of the near-Earth environment on these experiments.
Speaker: Mr Thomas Poeschl (Technical University of Munich)
• 18:20
Underground Nuclear Astrophysics: Present and future of the LUNA experiment 20m
The evolution of all the celestial bodies is regulated by gravitation and thermonuclear reaction rates,while the Big Bang nucleosynthesis depends on the competition between the expanding universe and the cross section of several nuclear processes. The LUNA Collaboration has shown that, by exploiting the ultra low background achieable deep underground, it is possible to study the relevant nuclear processes down to the nucleosynthesis energy inside stars and during the first minutes of Universe. In this talk the main results obtained by LUNA and their implications in astrophysics, particle physics and cosmology are reported. The scientific program of LUNA with the forthcoming 3.5 MV accelerator is also discussed.
Speaker: Dr Carlo Gustavino (INFN-Roma1)
• 18:40
Measurements of open heavy-flavour production in proton-proton, proton-lead and lead-lead collisions with ALICE at the LHC 20m
The production of heavy quarks (charm and beauty) in collider experiments occurs primarily due to hard scattering processes in the initial stages of a collision, and not through thermal processes at later stages. This property makes them an excellent probe to study the evolution of the strongly interacting medium produced in central Pb--Pb collisions at the LHC. Proton--proton collisions serve as a crucial baseline, allowing the modification of particle spectra in nuclear collisions to be studied. Furthermore, comparisons between proton--lead and lead--lead collisions allow initial-state nuclear effects to be disentangled from final-state effects in the medium, which is necessary to properly interpret the Pb--Pb results. In addition, the production of heavy-flavour particles can be measured as a function of the multiplicity of charged particles produced in the collision in order to more closely examine particle production mechanisms and determine the influence of multi-parton interactions on heavy-flavour production. Thanks to its excellent tracking and particle identification capabilities, the ALICE detector at the CERN LHC is well suited to the study of open heavy-flavour particles via the reconstruction of the decays of D mesons and $\Lambda_\mathrm{c}$ baryons to hadronic final states at mid-rapidity, and the semileptonic decays of charm and beauty hadrons (including the $\Xi_\mathrm{c}$ baryon) to electrons at mid-rapidity, and to muons at forward/backward rapidity. This talk will present a review of the main ALICE results on open heavy-flavour production in pp, p--Pb and Pb--Pb collisions in Run 1 and Run 2 of the LHC, with an outlook towards future prospects in this field.
Speaker: Dr Jeremy Wilkinson (Università e INFN Bologna)
• 19:00
Photonuclear astrophysics at ELI-NP 20m
Photonuclear reactions at threshold energies are of great interest in nuclear astrophysics. At the Extreme Light Infrastructure - Nuclear Physics (ELI-NP[1]) we are currently developing a new silicon-strip detector array (ELISSA, ELI Silicon Strip Array) to be used with the Gamma Beam System (GBS) that is being installed and will be operational in 2019. The ELI-NP GBS will provide beams in the range between 200 keV and 19.5 MeV with a bandwidth better than 0.5$\%$, spectral density of about 10$^{4}$ photons/(eV·s) and linear polarization higher than 95$\%$. ELISSA is an almost 4$\pi$ array made by 35 Micron X3 position sensitive silicon detectors in a barrel configuration and 8 Micrion QQQ3 double-sided silicon detectors as end-caps, which grant very good energy (better than 1$\%$) and position (1-2mm) resolutions. Such combined performances will allow the measurement of controversial reaction cross-sections, such as $^{12}$C($\alpha$,$\gamma$)$^{16}$O through the inverse $^{16}$O photo-disintegration, $^{24}$Mg($\alpha$,$\gamma$)$^{20}$Ne and many other photodissociation processes relevant to stellar evolution and nucleosynthesis[1]. The physics cases of interest for ELISSA with emphasis of the considered day-one experiments and the results of the tests that were performed so far are discussed. Also, the Monte Carlo tool based on GEANT4[2] and ROOT[3] that is being developed for the study of photonuclear reactions at ELI-NP will be introduced. Finally the results from the simulations performed in order to evaluate the reaction rates, the effects of the straggling of the exit particles due to the thickness of the target and of the resolution of the silicon detectors in photonuclear experiments will be shown. [1] D. Filipescu et al., Eur. Phys. J., A51, 185 (2015).\newline [2] GEANT4: A Simulation toolkit - GEANT4 Collaboration (Agostinelli, S. et al.), Nucl.Instrum.Meth. A506 (2003) 250-303 SLAC-PUB-9350, FERMILAB-PUB-03-339. [3] ROOT - An Object Oriented Data Analysis Framework - Rene Brun and Fons Rademakers, Proceedings AIHENP'96 Workshop, Lausanne, Sep. 1996, Nucl. Inst. \& Meth. in Phys. Res. A 389 (1997) 81-86. See also http://root.cern.ch/.