Hadronic Physics
Report from the Town Meeting October 25
Sebastian Kuhn, Old Dominion University
Agenda
Town Meeting “Hadronic Physics”
* 7:00 Medium Energy Physics Overview - Roy Holt
* 7:40 The future of hadron physics - Craig Roberts
* 8:00 Nucleon structure with Jefferson Lab at 12 GeV - Latifa Elouadhriri
* 8:20 QCD and nuclei - Larry Weinstein
* 8:40 The RHIC spin program - Elke Aschenauer
* 9:00 Hadronic physics at other facilities - Jen-Chieh Peng
* 9:20 Open Mic - opportunity to present a few slides
o Mark Pitt
o Seamus Riordan
* 9:40 Discussion and Closeout
* 10:00 Adjourn
http://www.odu.edu/~skuhn/HadronTownMeet
Central Questions in
Hadronic Physics
What is the Nature of Confinement?
Spectroscopy and form factors of hadrons
The role of gluonic excitations
Hadronization
What is the Internal Structure of the Nucleon? (1D → 3D)
How are spin and momentum distributed among partons?
Correlations and 3D structure
Orbital angular momentum of quarks
How do Nuclear Properties Emerge from Quarks and Gluons?
Are nucleons modified inside the nucleus?
Hadrons
C.D. Roberts, Prog. Part. Nucl. Phys. 61 (2008) 50
M. Bhagwat & P.C. Tandy, AIP Conf.Proc. 842 (2006) 225-227
*Dynamical Chiral Symmetry Breaking
Hadrons
Meson Spectroscopy -> Anomalies
Search for exotic hadrons, e.g. hybrid mesons
Precision experimental study of valence region, and
theoretical computation of distribution functions and
distribution amplitudes
Accurate elastic and transition form factor data drive
paradigmatic shifts in our pictures of hadrons and
their structure; e.g.,
role of orbital angular momentum and nonpointlike diquark
correlations
scale at which p-QCD effects become evident
strangeness content
meson-cloud effects
Valence Glue
NSAC milestone HP15 (2018)
Excited Glue
Exotics and hybrids are truly
novel states
They’re not matter as we know it
In possessing valence glue, such
states confound the distinction
between matter fields and force
carriers
But they’re only exotic in a
quantum mechanics based on
constituent-quark degrees-offreedom
Plot credit: NP2010
They’re natural in quantum field
theory, far from the nonrelativistic (potential model)
limit
No symmetry forbids them, QCD
interaction promotes them, so
they very probably exist!
Longitudinal
Structure
NSAC milestone HP14 (2018)
JLab@12 GeV has unique capability to
define the valence region
SU(6)
Helicity
conservation
1
Scalar diquark
in units of h
1
ò Dg(x,Q2) dx
xmin
0.8
2
Q = 10 GeV
2
forward h
0.6
RHIC
500 GeV
+BONuS 12 GeV Projected
0.4
DSSV++
DIS
RHIC
200 GeV
0.2
0
10
-3
10 E.C.
-2
-1
Aschenauer
10
x
min
Transverse Quark
Motion
PhT
SIDIS
NSAC Milestone HP13 (2015) “Test unique QCD
predictions for relations between singletransverse spin phenomena in p-p scattering
and those observed in deep-inelastic
scattering.”
JLab @12 GeV, COMPASS-II, RHIC-spin,
polarized FNAL, FAIR/PANDA…
Drell-Yan
Nucleon Tomography
Quark angular momentum (Ji’s sum rule)
ò1( H(x,x,t=0) + E(x,x,t=0) ) x dx = Jquark
-1
=1/2 DS + D Lz
X. Ji, Phy.Rev.Lett.78,610(1997)
Nucleons in Nuclei
L. Weinstein et al, PRL 106, 052301 (2011) , J. Arrington et al, arXiv:1206.6343
J. Seeley et al, PRL 103 (2009)
SRC Scaling factors xB ≥ 1.5
Flavor, isospin and spin
dependence of EMC effect?
JLab@12, Drell-Yan,
MINERvA
11 JLab 12 GeV
experiments, incl.
nuclear structure,
nucleon modifications
and Color Transparency
N. Fomin et al, PRL 108, 092502 (2012)
CT, Hadronization and All That
R( z, , pT2 , Q 2 ) 


h
DIS
h
DIS
( A)
( D)
 What governs the transition
of quarks and gluons into pions
and nucleons? NSAC 2007
Production length
Parton energy loss
Formation length
Color transparency
Hadron multiplicity
pT broadening
CEBAF @ 12 GeV + CLAS12: ideal
facility to study light quark
hadronization:
12 GeV Anticipated Data: 1035 cm-2s-1
W. Brooks, K. Hafidi, K. Joo et al.
Jefferson Lab at 12 GeV
Upgrade is designed to build on existing
facility: vast majority of accelerator and
experimental equipment have continued use
Upgrade arc magnets
and supplies
Add 5
cryomodules
20 cryomodules
CHL
upgrade
Add arc
The completion of the
12 GeV Upgrade of CEBAF
was ranked the highest
priority in the 2007 NSAC
Long Range Plan.
Enhanced capabilities
in existing Halls
New Hall
Maintain capability to
deliver lower pass beam
energies: 2.2, 4.4, 6.6….
20 cryomodules
Add 5
cryomodules
Scope of the project includes:
• Doubling the accelerator beam energy
• New experimental Hall and beamline
• Upgrades to existing Experimental Halls
Jefferson Lab at 12 GeV
Hall D – exploring origin of confinement by
studying hybrid mesons and rare decays
Hall B – understanding nucleon structure via PDFs,
TMDs and generalized parton distributions
Hall C – precision determination of valence quark
properties in nucleons and nuclei
Hall A – form factors, GPDs, nucleon structure
Future new experiments (e.g., SoLID and MOLLER)
12 GeV – Upgrade Status
Hall D – equipment installation in progress
Hall D Interior
Two high-gradient 12 GeV cryomodules installed
and delivering high quality beam; third moved to tunnel
CHL-2 equipment (compressors, coldboxes) in place
Third C-100 Cryomodule
transferred to tunnel
Hall B Pre-Shower
Calorimeter
Central Helium Liquefier-2
installation
CLAS12 R2
final DC
Superconducting magnets under construction
All major detector systems under construction
All 48 Hall D BCAL modules on site (U. Regina)
Region 2 DC CLAS12 completed (Old Dominion U.)
Performance Index: schedule 95% ; cost 96%
Hall C Dipole
Prototype Coil
Other Physics Topics @ JLab 12 GeV
Testing the Standard Model
Parity Violating DIS: SoLID
(and a rich program in hadronic Physics)
Parity Violating Möller
Scattering
Direct Search for “Dark Photons”
APEX, Dark light, HPS
RHIC Spin Program
STAR Preliminary Run 2012
AL
p+p ® W± ® e± + n
e
s=510 GeV
25 < ET < 50 GeV
15
0.5
W
-
2
Q = 10 GeV
2
DSSV++
Dc2
0
-0.5
DSSV: arXiv:0904.3821
DSSV+: DSSV+COMPASS
DSSV++: DSSV+ & RHIC 2009
10
Rel lumi
syst
Dc = 2% in DSSV analysis
2
W+
5
DSSV
DSSV08 RHICBOS
DSSV08 CHE NLO
-1
DSSV+
DSSV08 L0 with D c =1 pdf error
2
0
3.4% beam pol scale uncertainty not shown
Remaining syst <10% of stat errors
-1
0
RHIC W±-data will constrain
-
s = 510 GeV
0 < q < 3 GeV/c
s = 510 GeV
0 < q < 3 GeV/c
0.15
T
0.35
T
Projection, Ldt=500 pb -1
0.04
0.1
s = 510 GeV
0 < q < 1 GeV/c
4 < mg * < 8 GeV/c
arXiv: 0903.3629
2
0.2
-0.02
0.8
2
Q = 10 GeV
forward h
0
-0.04
RHIC
500 GeV
DIS
RHIC
200 GeV
DSSV++
0.2
-0.06
-0.05
0.1
2
0.4
0.15
Projection, Ldt=500 pb -1
-0.08
0.05
-0.1
PHENIX
arXiv: 0912.1319
0
-0.1
0
-2
xmin
0
0.05
0.2
2
ò Dg(x,Q2) dx
arXiv: 0903.3629
0.25
0.1
Dg(x,Q ) dx
1
0.6
T
0.02
STAR
ò
1
Expected asymmetries in Drell-Yan
Projection, Ldt=500 pb -1
STAR
0.3
AN
AN
AN
0.4
Expected asymmetries for W + -bosons
0 0.2
0.05
and
Transverse Asymmetries
Expected asymmetries for W -bosons
-0.1
1
2
lepton h
in units of h
-2
-1
0
1
2
y
W
-0.15
-2
-1
0
1
2
y
-4
-2
0
2
4
y
W
g*
10
-3
10
-2
10
-1
xmin
Other Facilities
Fermilab: Drell-Yan (pol. and unpol.), Neutrinos (Minera),
Project X?
HigS (TUNL), Mainz, Bonn: Spectroscopy, ChPT Tests, form
factors, polarizabilities few-body nuclei
COMPASS II (CERN): 1-3D SFs, Drell-Yan, GPDs , Primakoff
GSI / FAIR (Panda, PAX,…): Hadron Spectroscopy, Drell-Yan
J-PARC (strangeness), BES, PSI, …
…and ongoing analyses of existing data (JLAB, HERMES,
RHIC,…)
Theory
NSAC milestones HP3 (2009) completed, HP7 (2012)
Baryon spectrum from EBAC & Bonn-Ga (PDG12)
Lattice-QCD
Significant progress in the last five
years
This must continue
Bound-state problem in
continuum quantum field theory
Significant progress, too
Must also continue
Completed and planned experiments will
deliver the pieces of the puzzle that is
QCD.
Theory must be developed to explain how
they fit together
Kamano, Nakamura, Lee et al., 2012
Hadron physics must deploy a diverse array of
probes and tools in order to define and solve
the problems of confinement and its
relationship with Dynamical Chiral Symmetry
Breaking
Summary and Outlook
Hadronic Physics is poised for an exciting time, major
breakthroughs
There is only one high-energy, high-intensity electron
scattering lab left worldwide: Jefferson Lab @ 12 GeV
Large investment, extensive program (>7 years)
Nearing completion, large contributions from users
>50 approved proposals with 600 authors and 125
spokespersons
RHIC spin program will provide complementary data
Many other labs can make important
contributions
Long-term goal for the community: EIC
> 7 years!