Marco Maggiora
(INFN Torino)
27/06/2017, 18:30
Poster
The Beijing Electron Spectrometer III (BESIII) is a multi-purpose detector collecting data provided by the
collisions in the Beijing Electron Positron Collider II (BEPCII), hosted at the Institute of High Energy Physics of
Beijing. BESIII has already collected the world's largest sample of $J/\psi$ and $\psi(2s)$. Due to the unprecedented
luminosity of the BEPCII, the most inner part of the...
Mr
Oleksii Gryniuk
(JGU Mainz)
27/06/2017, 18:30
Poster
We provide an updated analysis of the forward J/$\psi$-p scattering amplitude, relating its imaginary part to $\gamma p \to J/\psi p$ and $\gamma p \to c\bar{c}$ cross sections data, and calculating its real part through a once-subtracted dispersion relation.
From a global fit to both differential and total cross section data, we extract a value for the spin-averaged J/$\psi$-p s-wave...
Mr
Martin Ripka
(JGU KPH)
27/06/2017, 18:30
Poster
Using the data sets taken at center-of-mass energies above 4 GeV by the BESIII detector at the BEPCII storage ring, we search for the reaction $e^+e^-\to\gamma_{\mathrm{ISR}} X(3872)\to\gamma_{\mathrm{ISR}}\pi^+\pi^-J/\psi$ via the Initial State Radiation technique. The production of a resonance with quantum numbers $J^{PC}=1^{++}$ such as the $X(3872)$ via single photon $e^+e^-$ annihilation...
Mr
Mirco Christmann
(KPH), Dr
Patrick Achenbach
(Mainz University)
27/06/2017, 18:30
Poster
At the Institute for Nuclear Physics in Mainz the new electron accelerator MESA will go into operation within the next years. In the extracted beam operation (155 MeV, 150 uA) the P2 experiment will measure the weak mixing angle in electron-proton scattering with a very high precision. For the desired accuracy 10,000 hours of operation time are needed and therefore the high-power beam dump of...
Dr
Dmitry Zhuridov
(University of Silesia)
27/06/2017, 18:30
Poster
The composite models, which address the existing problems of the Standard Model, generally include the excited leptons. I introduce new scenarios for possible generation of the baryon asymmetry of the universe using these new particles. The scenarios do not contradict to the small neutrino masses and the proton stability, and can be tested at the LHC.
Dr
Yuping Guo
(KPH, JGU Mainz)
27/06/2017, 18:30
Poster
Using a data set of 2.93 fb$^{−1}$ taken at a center-of-mass energy of 3.773 GeV with the BESIII detector at the BEPCII collider, a search for an extra U(1) gauge boson, also denoted as a dark photon, has been performed. We examine the initial state radiation reactions $e^{+}e^{-}\to e^{+}e^{−}\gamma_{ISR}$ and $e^{+}e^{-}\to\mu^{+}\mu^{−}\gamma_{ISR}$ for this search, where the dark photon...
Ms
Judith Plenter
(Helmholtz-Institut für Strahlen- und Kernphysik, Bonn-Cologne Graduate School of Physics and Astronomy)
27/06/2017, 18:30
Poster
It has been shown that the decay amplitude $\eta'\rightarrow \pi^+\pi^-\gamma$ has an important impact on the dispersion-theoretical analysis of the singly-virtual $\eta'$ transition form factor [1]. Consequently, we expect that the *doubly*-virtual transition form factor can be understood in more detail, starting from an analysis of the decay $\eta'\rightarrow2(\pi^+\pi^-)$. It was found that...
Nikoilay Kivel
(HIM)
27/06/2017, 18:30
Poster
Due to multiple possible polarizations hard exclusive production of tensor mesons by virtual photons or in heavy meson decays offers interesting possibilities to study the helicity structure of the underlying short-distance process. Motivated by the first measurement of the transition form factor $\gamma^*\gamma \to f_2(1270)$ at large momentum transfers by the BELLE collaboration we present...
Mr
Pepe Guelker
(KPH - JGU Mainz)
27/06/2017, 18:30
Poster
**MAGIX** is a planned experiment that will be implemented at the upcoming accelerator MESA in Mainz. Due to its location in the energy-recovering lane of the accelerator beam-currents up to **1 mA** with a maximum energy of **105 MeV** will be provided for precision experiments. MAGIX itself consists of a jet-target and two magnet-spectrometers. Inside the spectrometers **GEM**-based...
Stephan Marcus Aulenbacher
(JGU Mainz)
27/06/2017, 18:30
Poster
MAGIX is a planned experiment that will be implemented at the upcoming accelerator MESA in Mainz. Due to its location in the energy-recovering lane of the accelerator beam currents up to 1 mA with a maximum energy of 105 MeV will be provided for precision experiments.
MAGIX itself consists of a Jet Target and two magnet-spectrometers. The Jet-Target consists of a Laval-Nozzle and a catcher...
Long Bai
(Bonn University)
27/06/2017, 18:30
Poster
The neutral pion transition form factor plays prominent roles both in the hadronic light-by-light scattering corrections to the muon anomaly and in the electromagnetic rare decays of the pion. The singly-virtual transition form factor has been investigated in dispersion relations [1], where the form factor in time-like region was predicted based on the $e^+e^-\to 3 \pi$ cross section data...
Dr
Patrik Adlarson
(Johannes Gutenberg Universität-Mainz), Dr
Vahe Sokhoyan
(Johannes Gutenberg Universität-Mainz)
27/06/2017, 18:30
Poster
One of today’s most pressing question in nuclear physics is the
understanding of the so-called "proton radius puzzle". The puzzle
originates from a striking discrepancy between the electric charge
radius of the proton, extracted from the muonic hydrogen Lamb shift,
compared to measurements based on electron-proton scattering
experiments and atomic transition measurements in...
Dr
Antoine Gerardin
(Institute for Nuclear Physics, University of Mainz)
27/06/2017, 18:30
Poster
We report on the lattice QCD calculation of the π0→γ∗γ∗ form factor with photon virtualities in the range Q2∈[0−1.5]~GeV2. Different lattice spacings and pion masses are used to extrapolate our result to the physical point. First, we check that our results, once extrapolated to the chiral and continuum limit, are compatible with the chiral anomaly. Then, the shape of the form factor is...
Mr
Sabato Stefano Caiazza
(KPH Institut, JGU Universitaet Mainz)
27/06/2017, 18:30
Poster
Running in parallel to the existing MAMI electron accelerator, the new workhorse of the Institute of Nuclear Physics of the University of Mainz is an energy recovering electron recirculator capable of delivering 1 mA polarized currents at 105 MeV to a fix target experiment in its path. The Magix experiment is currently being developed to exploit that power to perform high-precision...
Mrs
Tatyana Kharlamova
(BINP)
27/06/2017, 18:30
Poster
We report a new precise measurement J/$\psi$ meson leptonic width performed with the KEDR detector at the VEPP-4M $e^+e^-$ collider. Cross sections for the processes $e^+e^-\to hadrons$ and $e^+e^- \to e^+e^-$ were measured at J/$\psi$ resonance energy range and $\Gamma_{ee}*B_{hadrons}$(J/$\psi$) value was obtained with accuracy about 2%. Leptonic and total widths were calculated, using the...
Mr
Andrey Sukharev
(BINP)
27/06/2017, 18:30
Poster
Based on the nine data sets taken with the KEDR detector since 2004 in charmonia region, we report $\Gamma_{ee} \times \mathcal{B}_{\mu\mu} = 19.4 \pm 0.3 \pm 0.4$ eV for $\psi(2s)$ meson. The total luminosity accounted for is more than 6.5 pb$^{-1}$, corresponding to about $4 \times 10^6 \psi(2s)$.
There were several scans of the resonance allowing us to know the collider energy spread and...
Xingyu Zhou
(IHEP Beijing)
27/06/2017, 18:30
Poster
We measure the cross sections of $e^+e^- \to e^+e^-$ and $e^+e^- \to \mu^+\mu^-$ processes using the data set collected with the BESIII detector at fifteen energy points around the $J/\psi$ resonance. By fitting the theoretical cross section curves of the two processes as functions of energy to the measured cross section data simultaneously, the combinations of $J/\psi$ decay widths...
Mr
Malwin Niehus
(Helmholtz Institut für Strahlen- und Kernphysik, Universität Bonn and Bonn-Cologne Graduate School of Physics and Astronomy)
27/06/2017, 18:30
Poster
Usually the simulation of scattering processes in lattice QCD is carried out at unphysical high values of the quark masses [1]. Hence, a method to extrapolate data obtained in lattice calculations to physical masses is needed to allow for comparison between theory and experiment. To obtain a sound extrapolation, dispersion relations and chiral perturbation theory (ChPT) can be invoked. While a...
Prof.
Gennady Fedotovich
(Budker institute of nuclear physics)
27/06/2017, 18:30
Poster
After the upgrade of the positron injection facility the electron-positron collider VEPP-2000 started to operate at the end of last year and delivers an excellent luminosity, which is higher than the previous in 2-3 times. The detector CMD-3 has gained a new statistic, which corresponds to integrated luminosity of about 30 pb$^{-1}$. Many processes in the energy region from 1 to 2 GeV go...
Dr
Zhiqing Liu
(postdoc)
27/06/2017, 18:30
Poster
With the high luminosity accelerator -- BEPCII and the BESIII detector located in Beijing, China, for the first time, we are able to search for a non-vector charmoinum -- the $\chi_{c1}$ state in $e^+e^-$ direct production. In order to investigate the full interference line shape of $\chi_{c1}$ with continuum background, we propose to take data with $e^+e^-$ central-of-mass energy 2 MeV below,...
Dr
Olga Shekhovtsova
(Institute of Nuclear Physics)
27/06/2017, 18:30
Poster
We analyze the contribution from intermediate spin–0 and spin–2 resonances to the $\tau\rightarrow 3\pi \nu_\tau$ decay by means of a chiral invariant Lagrangian incorporating these mesons. In particular, we study the corresponding axial-vector form-factors. The
advantage of this procedure with respect to previous analyses is that it incorporates chiral (and isospin) invariance and, hence,...
Mr
Alexander Botov
(Budker Institute of Nuclear Physics)
27/06/2017, 18:30
Poster
The reaction $e^+e^- \to \pi^+\pi^-\pi^0\eta$ has been studied in the experiment
with the SND detector at the VEPP-2000 $e^+e^-$ collider. The reaction proceeds
via the four intermediate states:
$\omega\eta$, $\phi\eta$, $a_0\rho$ and structureless $\pi^+\pi^-\pi^0\eta$
state, which may be, for example, $\rho(1450)\pi$ with $\rho(1450) \to \rho(770)\eta$.
The total $e^+e^- \to...
Patrycja Kisza
(University of Silesia)
27/06/2017, 18:30
Poster
The integrated luminosity in the BELLE II experiment (20-50 ab$^{-1}$) will allow to access information never available before. It was found, within the model implemented
in the newly updated Monte Carlo generator EKHARA, that at BELLE II it will be possible to study in detail $\chi_{ci} − \gamma^∗ − \gamma$ form factors through measurements of the reaction $e^+e^- \to e^+e^-\chi_{ci} (\to...
Dr
Brice Garillon
(JGU Mainz)
27/06/2017, 18:30
Poster
The BESIII experiment based at the BEPCII $e^{+}e^{-}$ collider (Beijing, China) is investigating physics in the charm-$\tau$ region.
Processes in which the particles emission peaks towards small polar angles,
such as Initial State Radiations (ISR) from $e^{+}e^{-}$ annhiliations, are currently detected with limited efficiency.
In order to improve their detections, we propose two small...
Mrs
Silke Grieser
(WWU Münster)
27/06/2017, 18:30
Poster
The experiments at the future electron accelerator MESA (Mainz Energy-recovering Superconducting Accelerator) at the University of Mainz focus on the validity of the Standard Model of particle physics. Thereby, the main interest is the search for dark photons as candidates for dark matter, and precision measurements of fundamental constants, such as the proton radius or the electroweak mixing...
Prof.
Michael Kohl
(Hampton University)
27/06/2017, 18:30
Poster
The proton is not an elementary particle but has a substructure governed by the interaction of quarks and gluons. The size of the proton is manifest in the spatial distributions of the electric charge and magnetization, which determine the response to electromagnetic interaction. Recently, contradictory measurements of the proton charge radius between muonic hydrogen and electronic probes have...
Prof.
Michael Kohl
(Hampton University)
27/06/2017, 18:30
Poster
Hard two-photon exchange has been favored theoretically to explain the previously observed discrepancy in measurements of the elastic proton electric-to-magnetic form factor ratio with polarized and unpolarized methods. Several experiments have been carried out to investigate the effects of two-photon exchange. The OLYMPUS experiment at DESY has been one of three dedicated experiments to use...
Mr
Daniel Molnar
(JGU Mainz)
27/06/2017, 18:30
Poster
In this work, we aim to provide a physical description of the recent BESIII data on the exotic meson decay, $ Y(4260) \to J/ \psi \; \pi^{+} \pi^{-}$. In the $\psi \pi$ invariant mass distribution, one can observe two peaks, which correspond to the exotic meson $Z_c(3900)$ and its kinematic reflection. Its shape can be parameterized as a S-wave Breit-Wigner and a background, which comes from...
Szymon Tracz
(University of Silesia)
27/06/2017, 18:30
Poster
Phenomenological model, which describe very well the coupling of the $\pi^0, \eta, \eta^{'}$ mesons to two photons is presented. The model of the form factors is consistent with the data in the space-like region, as well with the data in the time-like region with exception of the $\pi^0$ BaBar data and $\eta$ CMD2 data. The obtained form factors are implemented in Monte Carlo event generator...
