3rd Proton Mass Workshop; Origin and Perspective

Jan 14, 2021, 8:00 AM → Jan 16, 2021, 4:00 PM America/New_York

Virtual (Argonne National Laboratory)

Ian CLOËT (Argonne National Laboratory), Xiangdong JI (University of Maryland), Zein-Eddine MEZIANI (Argonne National Laboratory), Jianwei QIU (Jefferson Lab)

The next major facility construction in the US is the Electron-Ion Collider planned at Brookhaven National Laboratory. A science assessment by the National Academy of Sciences (https://www.nap.edu/catalog/25171/an-assessment-of-us-based-electron-ion-collider-science) found three central questions that the facility should address, and among these is "How does the mass of the nucleon arise?"

This question goes to the essence of QCD and embodies many of its mysteries and emergent phenomena, such as color confinement. Its understanding is fundamental to the future of nuclear physics, and we think that addressing this question within QCD will expose deep connections and significantly impact the broader fields of cosmology, particle physics, condensed matter, and biology.

In the spirit of the questions posed by Hilbert in the 1900 Mathematics Congress and the Millennium Prize Problems in Mathematical Physics, we would like to identify key theoretical questions to further inform and guide the science program of the Electron-Ion Collider. Our hope is that by posing the right questions this workshop can have a lasting impact on our understanding of the visible universe.

More broadly, this workshop will address and hone key questions related to the proton mass. It is organized around four interelated areas which include the broader fields of physics, the fundamentals of QCD, lattice calculations, hadron models, and last but not least to  experiments and specific observables.

A sample of questions includes:

1. Broader questions
   1. The nucleon mass is the most crucial gravitational charge in the universe below the scale of galaxies. How does the strong interaction scale or mass affect the visible universe?
   2. Can the nucleon's transverse momentum parton distributions reveal the temperature at which the nucleon is formed?
   3. What determines the QCD scale?
   4. What does QCD dynamics predict about the proton mass if the scale is just a parameter?
   5. How would the physical world (condensed matter, chemistry, and biology) change if Λ_QCD is increased or decreased by a factor of 2?
   6. What is the interplay between the Higgs and QCD mass generation mechanisms?
2. Fundamentals of QCD
   1. What is the role of the trace anomaly in QCD? Does it reflect both color confinement and dimensional transmutation?
   2. What is the role of chiral symmetry breaking (CSB) in determining the nucleon mass? What is the interplay between the CSB and color confinement?
   3. Why are the nucleon resonances (with change of spin and isospin) separated by a large mass gap? 
   4. Can a relativistic Virial theorem tell us something deeper about the origin of mass?
3. Lattice QCD calculations questions
   1. Can one calculate the anomaly contribution on the lattice?
   2. Can the lattice calculate the mass distribution in the nucleon?
   3. Why is the color magnetic field depleted inside the proton?
   4. How does the kinetic energy of quarks balance the color confinement energy of the gluon?
   5. Should a glue ball mass be lighter or heavier than the proton mass or 2 pions mass? If so why?
4. Hadron models questions
   1. What is the relation between the trace anomaly and the MIT bag constant?
   2. Can AdS/CFT models tell us something deep about the proton mass?
   3. Can 2D models, or simple 4D models (sigma model, NJL model, etc.) tell us something about the mass?
   4. What is the interplay of the Higgs mechanism and QCD mass generation for the mass of hadrons (meson, baryons, XYZ, etc.) with heavy flavors?

1st Proton Mass Workshop

2nd Proton Mass Workshop

Thursday, January 14

Thursday Morning

Convener: Dr Ian CLOËT (Argonne National Laboratory)

1 Welcome

Speaker: Ian CLOËT (Argonne National Laboratory)

welcome.pdf

2 Questions about nucleon mass

Speaker: Prof. Xiangdong JI (University of Maryland)

massquestions.pdf

3 Two-dimensional models for QCD

Speaker: Prof. Igor KLEBANOV (Princeton University)

Argonne.pdf

10:50 AM Coffee break/Discussion

4 Quark masses

Speaker: Dr Andreas KRONFELD (Fermilab)

ask4proton.pdf

5 J/Psi photoproduction near threshold and the proton mass distribution

Speaker: Prof. Dmitri KHARZEEV (Stony Brook & BNL)

Proton_mass_Kharzeev_v3.pdf

11:55 AM Discussion and short contributions

12:35 PM Lunch Break

Thursday Afternoon

Convener: Prof. Xiangdong JI (University of Maryland)

Contributions NJLandscalingProtonMass.pdf

6 Mechanical properties of particles

Speaker: Prof. Maxim POLYAKOV (Bochum University)

MVPolyakov_3rd_mass_workshop_pdf.pdf

7 Topological origin of the hadronic mass

Speaker: Prof. Ismail ZAHED (Stony Brook University)

Argonne-Zahed-21.pdf

2:50 PM Coffee break/Discussion

8 Decomposition of proton mass and rest energy

Speaker: Prof. Keh-Fei LIU (University of Kentucky)

Decomposition_Mass_RestEnergy_Argonne.pdf

9 The proton mass from first principles: lattice QCD at the physical point

Speaker: Prof. Martha CONSTANTINOU (Temple University)

Proton_Mass_2021_Constantinou.pdf

10 Model studies of energy-momentum tensor and mechanical properties

Speaker: Prof. Peter SCHWEITZER (University of Connecticut)

Talk-2021-01-mass-workshop-3.pdf

4:20 PM Discussion and short contributions

Friday, January 15

Friday Morning

Convener: Dr Jianwei QIU (Jefferson Laboratory)

11 Protons in Perspective

Speaker: Prof. Mikhail SHIFMAN (University of Minesota)

2021_PROTON.pdf

12 Insights into hadron structure from superconformal light-front holographic QCD

Speaker: Prof. Guy DE TERAMOND (University of Costa Rica)

GdT.Proton Mass Workshop.pdf

10:50 AM Coffee break/Discussion

13 The physical meaning of the various mass decompositions

Speaker: Prof. Cédric LORCÉ (Ecole Polytechnique)

Lorcé.pdf

14 Energy-Momentum Tensor form factors for QED, a one-loop example

Speaker: Mr Simone RODINI (University of Pavia)

rodini.pdf

15 Mass sum rules for the proton

Speaker: Prof. Andreas METZ (Temple University)

ANL_proton_mass_Metz.pdf

12:20 PM Discussion and short contributions

1:00 PM Lunch break

Friday Afternoon

Convener: Dr Andreas KRONFELD (Fermilab)

Contributions eta meson_proton_mass2.pdf PM_3rd_AC.pdf

16 Towards the proton mass decomposition from lattice QCD

Speaker: Prof. Constantia ALEXANDROU (University of Cyprus)

CA-ProtonMass.pdf

17 A view on the proton mass: Sigma terms, the trace anomaly and all that

Speaker: Prof. Ulf-G. MEISSNER (University of Bonn/FZ Jülich)

Ulf-G-Meißner-proton3pp4.pdf

3:05 PM Coffee break/Discussion

18 Quantum anomalous energy effects on the nucleon mass

Speaker: Dr Yizhuang LIU (Regensberg)

proton mass.pptx

19 From Nucleon to Nuclear Structure and Neutron Stars

Speaker: Prof. Anthony THOMAS (University of Adelaide)

AWThomas_ANL_Workshop_Jan_2021.pdf

20 Energy-momentum tensor in static-quark systems on the lattice

Speaker: Prof. Masakiyo KITAZAWA (University of Osaka)

kitazawa.pdf

4:35 PM Discussion and short contributions

Saturday, January 16

Saturday Morning

Convener: Prof. Dmitri KHARZEEV (Stony Brook & Brookhaven National Laboratory)

Contributions

• Additional slides.pdf
• LPentchev_Jpsi_GlueX.pdf
• remark-e-x.pdf

21 Quarkonium photoproduction

Speaker: Prof. Marc VANDERHAGHEN (University of Mainz)

MVdH_quarkonium_production_argonne2021.pdf

22 Quarkonium photo and lepto-production and the mass problem

Speaker: Dr Yoshitaka HATTA (Brookhaven National Laboratory)

Hatta.pdf

10:50 AM Coffee break/Discussion

23 Pion and kaon structure and the origin of mass

Speaker: Dr Rolf ENT (Jefferson Lab)

PIK_STRUCTURE_MASS_011621.pptx

24 Meson-induced quarkonium production

Speaker: Prof. Jen-Chieh PENG (University of Illinois at Urbana-Champaign)

PMASS_Peng.pdf

25 Quarkonium production at threshold from JLab to EIC

Speaker: Dr Zein-Eddine MEZIANI (Argonne National Laboratory)

3rd-pm-workshop-meziani.pdf

12:20 PM Discussion/short contributions

26 Closeout

Closeout_ANLjan2021.pdf