Hadronic Physics with Lepton and Hadron Beams

Sep 5, 2017, 8:00 AM → Sep 8, 2017, 6:00 PM US/Eastern

F113 (CEBAF Center)

Alessandro Pilloni (Jefferson Lab), Jozef Dudek (JLab), Wally Melnitchouk (JLab)

With the commencement of operations at the 12 GeV Upgraded Continuous Electron Beam Accelerator Facility at Jefferson Lab, and construction under way of the new Facility for Antiproton and Ion Research (FAIR) in Germany, a new era is opening up of high-precision experimental studies of hadron structure and spectroscopy. This meeting will bring together theoretical and experimental physicists from the lepton and hadron scattering communities to discuss synergies between the programs at these new facilities.

Poster poster.pdf

Tue, September 5

1 Welcome

Speaker: Stuart Henderson (Argonne National Lab/Jefferson Lab)

Spectroscopy

Convener: Robert Edwards (Jefferson Lab)

2 GlueX results and overview over pentaquark searches

Speaker: Justin Stevens (College of William and Mary)

Slides hadronGlueXStevens.pdf

3 JPAC program for hadron spectroscopy

Speaker: Dr Alessandro Pilloni (Jefferson Lab)

Slides jpac.pdf

4 Meson spectroscopy at CLAS and CLAS12

Speaker: Dr Lei Guo (Florida International University)

Slides Meson_L_Guo.pdf

10:30 AM Coffee break

5 Overview of Baryon Spectroscopy (experiment)

Speaker: Prof. Volker Crede (Florida State University)

Slides Crede_JLab.pdf

6 Overview of Baryon Spectroscopy (theory)

Speaker: Michael Doring (GW)

Slides 5_-_Doring.pdf

7 Finite-Energy Sum Rules in Pseudoscalar-meson Photoproduction off the Nucleon

Pseudoscalar-meson photoproduction on the nucleon is of current interest for hadron reaction studies. At low energies it provides information about the nucleon spectrum, while at high energies it reveals details of the residual hadron interactions due to cross-channel particle (Reggeon) exchanges. These two regimes are analytically connected, a feature that can be used to relate properties of resonances in the direct channel to Reggeons in the cross channels. In practice this can be accomplished through dispersion relations and finite-energy sum rules (FESR) [1]. At high energies ($E_{lab} > 4$ GeV), only the unpolarized differential cross section of eta photoproduction had been measured before, providing little constraints on theoretical models. The novel data from the GlueX experiment at Jefferson Lab provide us with invaluable new information. Even though photons couple to both isospin $I=0,1$ states, there are some notable differences between high energy photoproduction of the $\eta$ ($I=0$) and the $\pi^0$ ($I=1$). In contrast to the $\eta$, the $\pi^0$ differential cross section has a dip in the momentum transfer range, $-t\sim 0.5-0.6$ GeV${}^2$. The dip in $\pi^0$ photoproduction is expected to be associated with zeros in the residues of the dominant $\rho/\omega$ Regge exchanges [2,3]. It is an open question, what mechanisms are responsible for filling in the dip in eta photoproduction. It is often assumed that large unnatural contributions come into play. Finite-energy sum rules can provide clues here by relating the $t$-dependence of Regge amplitudes to that of the low-energy amplitude, usually described in terms of a finite number of partial waves. Early attempts could not resolve this issue due to the low quality of the data and the large uncertainties in the parametrization of the partial waves. Nowadays, however, there are several models that have been developed for the resonance region of $\eta$ photoproduction allowing for a more precise FESR analysis. The largest uncertainty in $\eta$ photoproduction stems from the unnatural parity Regge exchanges. These contributions can be isolated through photon beam asymmetry measurement. Such measurements are now possible with the GlueX experiment. The experiment uses linearly polarized photons with energy $E_{lab}\sim 9$ GeV and it has simultaneously measured $\eta$ and $\pi^0$ production. Those data will reduce the systematic uncertainties and provide a better constraint on Regge amplitudes. We have analyzed $\gamma N \to \eta N$ within a FESR framework [4]. Using these sum rules, one is able to obtain the t-dependence of the high-energy Regge residues using low-energy models. We found that a residue nonsense-wrong signature zero (NWSZ) seems to be lacking in the $t$-channel helicity flip amplitude of the $\rho$ residue. Including this in our model results in a mechanism where the dip in $\eta$ photoproduction is filled up with natural contributions, rather than genuinely assumed unnatural b exchange [5]. The predictions from this approach were then tested against the first GlueX results [6], confirming the above explanation: photon beam asymmetry close to $\Sigma=+1$ within the range $-t\approx 0.5-0.6$ GeV${}^2$ indicate that the absence of a dip in eta photoproduction should indeed be attributed to natural exchanges. [1] V. Mathieu, I. V. Danilkin, C. Fernández-Ramirez, M. R. Pennington, D. Schott, A. P. Szczepaniak, and G. Fox, Phys. Rev. D92, 074004 (2015). [2] V. Mathieu, G. Fox, and A. P. Szczepaniak, Phys. Rev. D92, 074013 (2015). [3] V. Mathieu et al., In preparation. [4] J. Nys, V. Mathieu, C. Fernández-Ramirez, A. N. Hiller Blin, A. Jackura, M. Mikhasenko, A. Pilloni, A. P. Szczepaniak, G. Fox, and J. Ryckebusch (JPAC), (2016), Phys.Rev. D95 (2017) no.3, 034014 [5] F. D. Gault and A. D. Martin, Nucl. Phys. B32, 429 (1971). [6] H. Al Ghoul et al. (GlueX) Phys. Rev. C95 (2017) no.4, 042201

Speaker: Jannes Nys (Ghent University)

Slides JLAB_hadronic_JannesNys.pdf

12:20 PM Lunch

Structure

Convener: Larry cardman (Jefferson Lab)

8 Results on DCVS

Speaker: Raphaël Dupré (IPN Orsay)

Slides GPD-JLab.pdf

9 Status of TMD extraction

Speaker: Andrea Signori (Jefferson Lab)

Slides hadwork_JLab_Signori.pdf

10 PVDIS and Effective electron-quark couplings

Speaker: Dr Xiaochao Zheng (University of Virginia)

Slides pvdis_Hadron2017_JLab.pdf

3:30 PM Coffee break

11 Two-photon exchange experiment: present and future

Speaker: Dr Douglas Hasell (M.I.T.)

Slides Hasell.pdf

12 Proton radius

Speaker: Haiyan Gao (Duke University)

Slides PRad-HGao-LeptonHadron2017.pdf

13 Hadron structure at COMPASS

Speaker: Prof. Krzysztof Kurek (National Centre for Nuclear Research)

Slides kurek_hadron_jlab_2017.pdf

5:30 PM Reception

Wed, September 6

Structure

Convener: Dr Wally Melnitchouk (Jefferson Lab)

14 Accessing the proton's tensor structure in inclusive DIS

Speaker: Alberto Accardi (Hampton U. and Jefferson Lab)

Slides Accardi_-_Jet_correlators.pdf

15 Global QCD analysis / simultaneous PDF/FF fits

Speaker: Jacob Ethier (College of William and Mary/Jefferson Lab)

Slides Ethier_Hadron17.pdf

16 The SeaQuest experiment

Speaker: Dr Markus Diefenthaler (Jefferson Lab)

Slides Diefenthaler_-_Hadronic_Physics_with_Lepton_and_Hadron_Beams.pdf

10:30 AM Coffee break + Group photo

17 Nucleon spin / JLab program

Speaker: Prof. Karl Slifer (University of New Hampshire)

Slides 4_-_Slifer.pdf

18 3He as a laboratory to study neutron structure from elastic form factors to transverse momentum parton distributions

Speaker: Emanuele Pace (Tor Vergata U.)

Slides PE2017.pdf

19 Hadron Mass Effects for Kaon Production on deuteron

The spin-independent cross section for semi-inclusive lepton-nucleon scattering are derived in the framework of collinear factorization, including the effects of the target and produced hadron masses at small momentum transfer squared $Q^2$. At leading order, the cross section factorizes into products of parton distributions and fragmentation functions evaluated in terms of new, mass-dependent scaling variables. This talk focuses on Kaon production at HERMES and COMPASS kinematics. In particular, hadron mass corrections for integrated kaon multiplicities measured by the two collaborations are shown to sizeably reduce the apparent large discrepancy between the results for both experiments.

Speaker: Mr Juan Guerrero (Hampton University/Jefferson Lab)

Slides 6_-_Guerrero.pdf

12:20 PM Lunch

Spectroscopy

Convener: Jozef Dudek (JLab)

20 Overview of qPDF

Speaker: Dr Jianwei Qiu (Jefferson Lab)

Slides 1_-_Qiu.pdf

21 Electrocouplings at JLab6 and prospects for JLab12

Speaker: Viktor Mokeev (JLab)

Slides Hadron_mokeev090617_final.pdf

22 Hyperon spectroscopy

Speaker: Dr Karin Schoenning (Uppsala Universitet)

Slides schoenning_hyperon_JLAB_2017_v4.pdf

3:30 PM Coffee break

23 Hadron Spectroscopy at COMPASS

Speaker: Mr Stefan Wallner (TUM)

Slides swallner_170906_Spectroscopy-COMPASS.pdf

24 Nucleon resonances in the timelike region at HADES

Speaker: Beatrice Ramstein (Institut de Physique Nucleaire)

Slides Jlabworkshop_Ramstein.pptx

25 ISR measurements at BaBar

Speaker: Dr Konrad Griessinger (Institute for Nuclear Physics - Mainz University)

Slides BaBar.pdf

Thu, September 7

Spectroscopy

Convener: Dr Alessandro Pilloni (Jefferson Lab)

26 Overview of XYZ theory

Speaker: Prof. Eric Swanson (Univ Pittsburgh)

Slides Exotica-theory-short.pdf

27 Production of charmonia and the PANDA program

Speaker: Mr Thomas Mehen (Duke University)

Slides JLAB_9_7__17.key JLAB_9_7__17.pdf

28 Heavy spectroscopy on the lattice

Speaker: Dr Daniel Mohler (Helmholtz-Institut Mainz)

Slides Mohler_JLab_2017.pdf

10:30 AM Coffee break

29 Modification of the static potential in the presence of a hadron

Speaker: Prof. Francesco Knechtli (University of Wuppertal)

Slides hadrons17_knechtli.pdf

30 Hadron Spectroscopy at BESIII

Speaker: Dr Beijiang Liu (Institute of High Energy Physcis, CAS)

Slides BJLiu_Jlabworkshop.pdf

31 Nuclear medium effects

Speaker: Gastao Krein (IFT)

Slides gkrein_hadron-lepton.pdf

12:30 PM Lunch

Structure

Convener: Gastao Krein

32 Transition form factors at BESIII

Speaker: Dr Christoph Redmer (Johannes Gutenberg-University Mainz)

Slides CFR170907.pdf

33 Experimental aspects of short range correlations

Speaker: Or Hen (MIT)

34 Theory of short range correlations

Speaker: Prof. Ruiz Arriola Enrique (Universidad de Granada)

Slides Hadronic-Physics-2017-Ruiz-Arriola.pdf

3:30 PM Coffee break

35 Lattice progress for the muon g-2

Speaker: Prof. Harvey Meyer (Mainz University)

Slides meyerhJLAB2017.pdf

36 Dispersive approaches to hadronic light-by-light scattering and the muon g-2

Speaker: Danilkin Igor (Mainz U.)

Slides Danilkin_Jlab.pdf

6:00 PM Social dinner

P.F. Chang

Fri, September 8

Structure

Convener: Dr David Richards (Jefferson Lab)

37 Light spectroscopy on the Lattice

Speaker: Raul Briceno (Jefferson Lab)

Slides Briceno.pdf

38 PDFs and moments in lattice QCD

Speaker: Prof. Huey-Wen Lin (Michigan State University)

Slides hwlin-JLab-HP17.v1.pdf

39 Quasi-PDFs and exploration of pseudo-PDFs

Speaker: Anatoly Radyushkin (ODU/JLab)

Slides Radyushkin_0908.pdf

40 Form factors on the lattice

Speaker: Bipasha Chakraborty (Postdoctoral researcher)

Slides Chakraborty_JLAB_Sept2017.pdf

11:00 AM Coffee break

41 QWeak seminar

Speaker: Mark Pitt (Virginia Tech)

12:30 PM Lunch

Future facilities

Convener: David Gaskell (Jefferson Lab)

42 Prospects for Belle II

Speaker: Dr Anselm Vossen (Indiana University)

Slides JlabHadronicPhysicsAtBelle2_4.pdf

43 Prospects at JPARC

Speaker: Prof. Shunzo Kumano (KEK/J-PARC)

Slides sk-j-parc-jlab-2017-09.pdf

3:00 PM Coffee break

44 Prospects for MESA

Speaker: Dr Sabato Stefano Caiazza (JGU Mainz)

Slides 2017-09-08_-_The_MESA_projects-Cleaned.pptx 2017-09-08_-_The_MESA_projects.pdf

45 Prospects for EIC

Speaker: Rikutaro Yoshida (Jefferson Lab)

Slides Hadrons_EIC_talk.pptx

46 Conclusing remarks