Scattering Amplitudes and Resonance Properties from Lattice QCD

Europe/Berlin
02.430 (Mainz Institute for Theoretical Physics, Johannes Gutenberg University)

02.430

Mainz Institute for Theoretical Physics, Johannes Gutenberg University

Staudingerweg 9 / 2nd floor, 55128 Mainz
Description

[from D. R. Bolton, R. A. Briceño, D. J. Wilson, Phys. Lett. B757 (2016) 50-56, arXiv:1507.07928]

Figure 1: Postdiction of the ππ → ππ scattering phase in the ρ channel, made by fitting LQCD data at heavier pion masses using unitarized chiral perturbation theory (ChPT), and then extrapolating to the physical pion mass.
 

In recent years, Lattice QCD (LQCD) calculations of stable-hadron properties have become considerably more precise, and as a result, LQCD inputs are having an increasing impact on Standard-Model phenomenology. Considering this progress, it is natural to also examine the prospects for using lattice QCD to calculate the properties of unstable hadrons, i.e. QCD resonances that decay via the strong force. The extraction of resonance properties is much more challenging, but also in this sector enormous progress has been made in the development of both theoretical methods and numerical techniques. A major focus here is the approach, pioneered by Lüscher, of relating finite-volume energies to infinite-volume scattering observables. [See, for example, Figure 1.]

The long-term goal is to use LQCD to study various exotic resonances, including the recently-discovered X, Y and Z states as well as excited nucleon states, including the Roper resonance, which decays predominantly to Nπ and Nππ.

[J. Bulava, B. Hörz, B. Fahy, K. J. Juge, C. Morningstar, C. H. Wong, PoS LATTICE2015 069, arXiv:1511.02351]

Figure 2: The time-like pion form factor, as determined in a LQCD calculation with mπ ∼ 240 MeV. The curve corresponds to a Gounaris-Sakurai parameterization with the ρ-resonance mass and the ρππ coupling determined from the lattice data.

Beyond extracting QCD resonance properties, one can also use the relation between finite- and infinite-volume matrix elements to study electroweak transitions. Applying these methods will allow one to extract resonance form factors and to perform precision tests of the Standard Model. For instance, processes such as B → K* (di-lepton) → Kπ (di-lepton) are particularly important for LHCb phenomenology. Another example is the time-like pion form factor, which can be related to the low-energy electron-positron annihilation cross section and represents a crucial input quantity for the determination of the hadronic-vacuum-polarization contribution to the anomalous magnetic moment of the muon, (g − 2)μ. Formalism for extracting this quantity from LQCD is understood and numerical calculations are underway [See Figure 2].

The aim of this workshop is to bring together experts in developing the formalism and lattice practitioners, in order to review the status of ongoing calculations and discuss future prospects. The workshop will emphasize the future role of LQCD in precision resonance physics, especially in the context of forthcoming experiments.

Executive Summary (PDF)
Participants (PDF)
    • 10:00 10:45
      A new paradigm for heavy-light meson spectroscopy 45m
      Speaker: Prof. Christoph Hanhart (IAS/IKP Forschungszentrum Jülich)
      Slides
    • 10:45 11:15
      Coffee 30m
    • 11:15 12:00
      Experimental motivation for studying multi-particle processes on the lattice 45m
      Speaker: A. Pilloni
      Slides
    • 14:00 14:45
      Masses and decay constants of the Ds0 and Ds1 close to the physical point 45m
      Speaker: S. Collins
      Slides
    • 14:45 15:15
      Coffee 30m
    • 15:15 16:00
      On the properties of radial and orbital excited heavy-light mesons 45m
      Speaker: B. Blossier
      Slides
    • 09:30 10:15
      Computing tetraquark resonances with two static quarks and two dynamical quarks: I - Lattice QCD computation of potentials 45m
      Speaker: M. Wagner
      Slides
    • 10:15 11:00
      Computing tetraquark resonances with two static quarks and two dynamical quarks: II - Born-Oppenheimer approximation and emergent wave method 45m
      Speaker: P. Bicudo
      Slides
    • 11:00 11:30
      coffee 30m
    • 11:30 12:15
      Recent results from HAL QCD potential method 45m
      Speaker: S. Aoki
      Slides
    • 14:00 14:45
      The isovector pion-pion scattering amplitude and timelike pion form factor: finite volume and cutoff effects 45m
      Speaker: J. Bulava
      Slides
    • 14:45 15:15
      coffee 30m
    • 09:30 10:15
      Scalar resonances in coupled-channel scattering from lattice QCD 45m
      Speaker: D. Wilson
      Slides
    • 10:15 11:00
      Dynamically-coupled partial-waves in ρπ scattering and meson-meson operators 45m
      Speaker: C. Thomas
      Slides
    • 11:00 11:30
      coffee 30m
    • 11:30 12:15
      H dibaryon using hexaquark and two-baryon interpolators 45m
      Speaker: A. Hanlon
      Slides
    • 14:00 15:00
      Optional discussion or talks 1h
    • 09:30 10:15
      Finite density particle condensation and scattering data 45m
      Speaker: C. Gattringer
      Slides
    • 10:15 11:00
      Scattering and resonances in composite Higgs models 45m
      Speaker: T. Janowski
      Slides
    • 11:00 11:30
      coffee 30m
    • 11:30 12:15
      Locality and multi-level sampling of hadronic correlators 45m
      Speaker: M. Ce
      Slides
    • 14:00 14:45
      Charmonium spectroscopy from CLS ensembles 45m
      Speaker: M. Padmanath
      Slides
    • 14:45 15:15
      coffee 30m
    • 15:15 16:15
      General discussion 1h
    • 09:30 10:15
      Progress on the relativistic three-particle quantization condition 45m
      Speaker: S. Sharpe
      Slides
    • 10:15 11:00
      From two to three-body scattering in the finite volume: The role of unitarity 45m
      Speaker: M. Doring
      Slides
    • 11:00 11:30
      coffee 30m
    • 11:30 12:15
      Three-particle dynamics and resonances in a finite volume 45m
      Speaker: H.W. Hammer
      Slides
    • 14:00 14:45
      Energy level shifts in the three-particle system 45m
      Speaker: A. Rusetsky
      Slides
    • 14:45 15:45
      Discussion session on three particle formalism 1h
    • 16:00 16:45
      Workshop summary (optional) 45m
Your browser is out of date!

Update your browser to view this website correctly. Update my browser now

×