newport beach, ca 25 october 2012

Overview of Medium Energy Physics (Cold QCD): Presentation to the Hadron Physics Town Meeting

(Presentation to the 2007 NSAC Long Range Plan Implementation Subcommittee)

Roy J. Holt

Newport Beach, CA 25 October 2012

Argonne National Laboratory

Key questions in hadron physicsWhat is confinement and how is it connected with dynamical chiral symmetry breaking, the origin of more than 98% of visible mass in the Universe?What are the dynamics underlying elastic and transition form factors and structure functions of hadrons? How does valence quark structure affect the sea?Where is the missing spin in the nucleon? Are there significant contributions from gluons or valence quark orbital angular momentum?Can we reveal a novel landscape of nucleon substructure through measurements of new multidimensional distribution functions?Do gluonic excitations have a role in the spectroscopy of light mesons and baryons?

How do nuclei emerge from QCD?What is the relation between short-range N-N correlations and the partonic structure of nuclei?

Argonne National Laboratory*


Elastic electron scattering from a nucleonArgonne National Laboratory*Cross section for scattering from a point-like objectj=J=Nucleon vertex:Dirac Pauli1990 Nobel Prize1961 Nobel PrizeDeep inelastic scattering


Tremendous advances in electron scatteringArgonne National Laboratory*Unprecedented capabilities: High Intensity High Duty Factor High Polarization- M. Poelker (2012 Lawrence Award) Large acceptance detectors State-of-the-art polarimetry, polarized targetsFocal plane polarimeter Jefferson LabPolarized 3He target


Argonne National Laboratory*The proton form factor: Re-wrote the textbooksPolarization measurements ) Revolutionized our knowledgeNP2010

Two-photon experiments: OLYMPUS (DESY), JLab, Novosibirsk


Flavor separation of proton form factors

Very different behavior for u & d quarks Evidence for diquark correlations axial diquark -> soft f.f.

Thanks to Craig Roberts*Cates, de Jager, Riordan, Wojtsekhowski, PRL 106 (2011) 252003Q4 F1qNSAC milestone HP4 (2010) completedQ4F2q/k

Thanks to Craig Roberts

Only JLab 12 GeV can access these form factors to ~10 GeV2

Argonne National Laboratory*Locations of the zeroes depend on the relative probability of finding scalar & axial diquarks in proton

Requires SBS

Six 12-GeV experimentsPlot credit: JLab whitepaper


Proton Radius PuzzleArgonne National Laboratory*rp0.8768(69)fm (ep atom)rp0.8772(46)fm (ep scattering)rp=0.84184(67)fm (p atom)Future sub 1% measurements: (1) ep elastic scattering at JLab (2) p elastic scattering at PSI - 16 U.S. institutions!(~$2 M, no contingency)PSAS 2012 Symposium

ECT* Workshop - Nov. 2012

7 sX. Zhan et al, PLB 705 (2011) 59Thanks to R. Gilman, H. Gao


Hadron polarizabilities Compton scatteringHigh Intensity Gamma Source (HIgS)Proton, neutron polarized H target Polarized 3He target(9 U.S. institutions)MAMI (3 U.S. institutions)Polarized hydrogen target + Crystal BallComplete proton in 2014, begin neutron

Argonne National Laboratory*Thanks to H. Gao, H. Griesshammer, D. Phillips, W. Briscoe, R. Miskimen, B. Norum D. Shukla, A. Nogga, D. Phillips, PRL (2007)HIgS projectionLattice calculationsChiral perturbation theoryInterplay of pion cloud and shorter distance effects

Pion polarizabilityCOMPASS II (CERN)(UIUC)Faraday effect


Argonne National Laboratory*Partonic structure of the nucleonThree longitudinal structure functions:EIC whitepaper


The Neutron Structure FunctionProton structure function:

Neutron structure function (isospin symmetry):

Ratio:

Focus on high x:

Three 12-GeV experimentsProton : PVDIS and SoLID (K. Paschke)Deuteron: radial TPC and CLAS123H/3He: 3H target and existing spectrometers

Argonne National Laboratory*DSENSAC milestone HP14 (2018)Thanks to C. Keppel, K. Kumar, G. Petratos


Spin Structure of the neutron valence regionCourtesy of Z.-E. Meziani, K. Griffioen, S. Kuhn, G. PetratosNSAC milestone HP14 (2018)Polarized electron scattering from a polarized nucleonThanks to N. Makins, Z.-E. MezianiThree 12-GeV experiments(benefits from SoLID)

Tensor charge from transversity measurements at JLabArgonne National Laboratory*Thanks to A. Prokudin and Z.-E. MezianiTensor Charge

Collins fragmentation function from KEK-B/Belle - M. Grosse-Perdekamp (UIUC)dd benefits from SoLIDTwo 12-GeV experimentsDistribution of transversely polarized quarks inside a transversely polarized proton


Drell-Yan is the best way to measure anti-quark distributionsArgonne National Laboratory*What is the A dependence of antiquarks?No model predicts dbar/ubar

HERMES Surprise!Strange quark distribution Future: COMPASS-II at CERN (2015), JLab with12 GeV (RICH)A. Airapetian et al, PLB 666 (2008) 446Deep inelastic scattering with flavor tagging

Serious discrepancy with decades of neutrino data

Thanks to H. Jackson, J.-C. Peng Intrinsic sea?

Strange sea and LHCArgonne National Laboratory*rs = ( s + sbar)/dbarSea appears to be flavor symmetric at low x, consistent with HERMESATLAS Collaboration,ArXiV:1203.4051 [hep-ex]Parton distribution uncertainties at high x feed into benchmark LHC processesThanks to T. LeCompte


Worldwide quest: spin structure of the nucleonFrom DIS measurementsDS 0.3DG = 1.01.2

quark polarization Dq(x)first 5-flavor separation from HERMES: Dq 0RHIC-spin: future charge- current measurements

gluon polarizationG(x)RHIC-spin, HERMES, COMPASS

orbital angular momentum L GPDs and TMDsFar future: EICSpin budget of the proton30%70%What is the origin of the proton spin?Jets, pions, ALL

Measurement of the gluon polarization DG at RHICD. de Florian et al,Prog. in Part. Nucl. Phys.67 (2012) 251Dominates at high pTDominates at low pTdxDg(x,Q2=10GeV2) = 0.13 (error?)0.050.2RHIC whitepaperSee E. Aschenauers talk for impact of 2013-14 experiments.

W production expected from RHIC runs 12+13Argonne National Laboratory*B. Jacak, N. Xu, RHIC PAC 2012NSAC milestone HP8 (2013)Provides an important check of SIDIS method

No fragmentation function

Q2=MW2 (no high twist effects)http://www.bnl.gov/npp/pac0612.aspThanks to E. AschenaurSee E. Aschenauers talk for impact on


Is there a flavor asymmetry in the sea quark helicity distributions?Sea quark polarization at high xJLab 12 GeV (Hall B)Kaon detection - RICH

Argonne National Laboratory*Plot credit: K. Hafidi


Multidimensional parton distribution functionsArgonne National Laboratory*JLab whitepaperGeneralized parton distribution functionsTransverse momentum distribution functionseg., Sivers distributioneighteen 12-GeV experiments! Separate talk: M. Guidal


Transverse Momentum Distributions: The Sivers effectNSAC Milestone HP13 (2015) Test unique QCD predictions for relations between single-transverse spin phenomena in p-p scattering and those observed in deep-inelastic scattering.COMPASS-II, RHIC-spin, polarized FNAL

HERMESThanks to H. Jackson, M. Burkhardt

Polarized Drell-Yan and W production (2014+)Argonne National Laboratory*COMPASS-II (2014, if upgraded)1 U. S. institution~ $0.9M NSF (large area trackers)FNAL Polarized SeaQuest (>2017)8 U.S. institutions, 4 off-shore institutions~$10.5M including 50% contingency

PHENIXThanks to E. Aschenauer, W. Lorenzon, M. Liu, M. Grosse-PerdekamppolarizedDelivered 500 pb-1Forward upgrades -> transverse spin asymmetriesSTAR


Generalized parton distributions and DVCSVector: H (x,,t)Tensor: E (x,,t)Hq(x,0,0) = q(x) Forward limit (t 0, x0) Sum rulesA. Radyushkin,PRD 56 (1996) 5524

C. Munoz Comacho et al,PRL 97 (2006) 262002 ;F. X. Girod et al, PRL 100 (2008)162002.

Extraction of quark total angular momentum NSAC milestones HP11 (2012), HP9 (2014)DVCS is the golden channel:g* + N -> g + NLattice + experiment provides a much greater constraint on GPDs than from either alone. - J. Negele

Major program for JLab 12 GeV, COMPASS-II, EICPlot credit: JLab whitepaper

DVCS measurements and imagingArgonne National Laboratory*Thanks to Z.-E. Meziani, JLab whitepaper


A new form of matter: Matter formed from the force field (gluons): meson spin

intrinsic parity

charge conjugationConventional mesons:K. Juge et al, nucl-th:030711 separate talk: J. DudekThanks to C. Meyer, C. D. Roberts

Search for exotic hybrid mesons at the 12-GeV JLabArgonne National Laboratory*Hybrids are predicted by modern QCD treatments: DSE, latticeNSAC milestone HP15 (2018)Complementary work: GSI (PANDA) : antiproton-proton annihilation in charmonium region (2017-) (Northwestern U.)

BES-III: electron-positron annihilation in charmonium region also decays to light quark bound states(Indiana U.)Plot credit: NP2010 Two 12-GeV JLab experimentsThanks to K. Seth, M. Shepherd, J. Dudek


Baryon resonances JLab Physics Analysis CenterArgonne National Laboratory*Kamano, Nakamura, Lee et al., 2012NSAC milestones HP3 (2009) completed, HP7 (2012)Future: J-PARC, Mainz 6 U. S. institutionsThanks to K. Hicks, W. Briscoe, M. Pennington, T.-S. H. LeePrevious (p,2p) data in the N* mass range are all from 1970s bubble chambers!New Lattice calculations: arXiv:1201.2349 N* resonances and exotic baryons.

Coupled channels dynamics are essential!


A look at quarks in the nucleus: the EMC effectEMC effect discovered 1982 (H. Montgomery et al.), remains a mystery todayScattering from quarks in a nucleus is not just a superposition of scattering from quarks in nucleonsDependence on nuclear density, short range correlations, flavor, spin, isospin?

Argonne National Laboratory*SLAC E-139, 1984, J. Gomez et al.J. Seeley et al, PRL 103 (2009)


EMC effect and short range N-N interaction*EMC effect is correlated with short range N-N interaction L. Weinstein et al, PRL 106, 052301 (2011) , J. Arrington et al, arXiv:1206.6343

Flavor, isospin and spin dependence of EMC effect? JLab@12, Drell-Yan, MINERvA

Plot credit: JLab whitepaperN. Fomin et al, PRL 108, 092502 (2012)

SRC Scaling factors xB 1.5Four JLab 12 GeV experiments

MINERnA Main Injector ExpeRiment -A*MINERvA is studying A dependence of neutrino interactions in unprecedented detail, with He, C, Scintillator (CH), H2O, Fe, Pb targets.Uses high intensity NuMI Beamline at FNAL with MINOS near detector as muon spectrometer

Nuclear physics goalsHigh precision measurement of the axial form factor to high Q2 and search for A dependence of form factorStudies of quark-hadron duality in neutrino interactions, complementing JlabStudying partonic nuclear effects with neutrino interactionsPrecision cross section measurements and studies of final states ScheduleLow E and anti- (average E ~4 GeV) 11/09-4/12~1.7 Million CC interactions and 250 K anti- CC interactions on scintillator, ~300 K CC interactions on Fe and PbMedium E (avg E ~8 GeV) spring 2013 to about 2019MEP ParticipationHampton, Rutgers PMT detector construction and testing, scintillator plane construction. He target funded by MEP

Slide credit: R. Ransome

Hadronization and quark propagation in nuclear matterProduction lengthParton energy lossFormation lengthColor transparencyHadron multiplicitypT broadening

CEBAF @ 12 GeV + CLAS12: ideal facility to study light quark hadronization: What governs the transition of quarks and gluons into pions and nucleons? NSAC 2007W. Brooks, K. Hafidi, K. Joo et al.

The EIC (>2020)Argonne National Laboratory*Source: EIC whitepaperGluon saturationGluon and sea quark polarizationGluon imagingQuark propagationSea quark imaging


2020 and beyond: Electron Ion Collider

We recommend the allocation of resources to develop accelerator and detector technology necessary to lay the foundation for a polarized Electron-Ion Collider. NSAC LRP 2007Brookhaven National LabJefferson LabUnique: high-luminosity with polarized electrons, nuclear and polarized ion beams

Non-JLab, non-RHIC cold-QCD experimentsArgonne National Laboratory**ExpectedThanks to C. Howell

ProgramContactStatusLab# U.S. MEPInstitutionsEducation # U.S. MEP postdocs, grad. students, undergradsn polarizability, GDH, few-bodyH. GaoOngoingHIgS92, 5, 3Drell-YanD. Geesaman, P. ReimerOngoingFNAL87, 7, 4COMPASS-IIM. Grosse-PerdekampOngoingCERN11, 2, 4N polarizabilityR. MiskimenOngoingMainz32, 3, 1Baryon resonancesW. BriscoeOngoingMainz61, 3, 6MINERvAR. RansomeOngoingFNAL22, 2, 2N polarizability, GDH, few-body, Bethe-HeitlerB. NorumOngoingHigS42, 1, 2OLYMPUSR. MilnerOngoingDESY43, 6, 6HERMESH. JacksonOngoingDESY31, 4, 1BES-IIIM. ShepherdOngoingBES11 ,2, 0Threshold pion photoproductionA. BernsteinOngoingMainz31, 0, 0Radiative pion productionB. NorumNewMainz20.2, 0, 0Polarized Drell-YanW. LorenzonNewFNAL80.5, 0.5, 3N polarizabilityR. MiskimenNewHIgS40, 0, 1Proton radiusR. GilmanNewPSI161, 0, 0Baryon resonancesK. HicksNewJ-PARC62, 5, 0*Charmed mesonsK. SethNewGSI11, 2, 0


Concluding statement

Understanding hadrons will be one of nuclear physics greatest contributions to science

New 21st century tools have positioned us well for the next decade: JLab 12 GeV, RHIC - Major U.S. facilities lead the worldFNAL MI, CERN COMPASS-II, HIgS, Mainz, J-PARC, FAIR provide targeted experiments that complement the central programFar future: EIC

We are camped on one of the most interesting frontiers in science

Argonne National Laboratory*


Many thanks toArgonne National Laboratory*M. AhmedE. AschenauerJ. ArringtonT. BarnesD. BeckW. BriscoeM. BurkhardtG. CatesA. DesphandeC. DjalaliE. DownieR. EntC. GagliardiH. GaoD. GeesamanR. GilmanH. GriesshammerM. Grosse-PerdekampK. HafidiK. HicksC. HowellB. Jacak

Helpful documents:

NP2010 Report

NSAC 2007 Long Range Plan

Whitepaper drafts:JLab 12 GeVThe Case for Continuing RHIC OperationsElectron Ion Collider

JLab12, RHIC, COMPASS-II proposals

STAR and PHENIX decadal plans

NSAC Performance Measures 2008

J.-C. PengM. PenningtonD. PhillipsG. PetratosJ. QiuR. RansomeP. ReimerC. RobertsJ. RubinK. SethM. ShepherdM. StratmannB. SurrowS. VigdorW. VogelsangH. WellerR. WiringaB. WojtsekhowskiN. XuH. JacksonK. JooB. KeisterC. KeppelW. KorschK. KumarT.-S. H. LeeM. LiuW. LorenzonT. LeCompteN. MakinsC. MeyerZ.-E. MezianiR. McKeownR. MilnerR. MiskimenH. MontgomeryJ. NagleB. NorumK. OrginosK. Paschke


Go to "View | Header and Footer" to add your organization, sponsor, meeting name here; then, click "Apply to All"*Go to "View | Header and Footer" to add your organization, sponsor, meeting name here; then, click "Apply to All"Go to "View | Header and Footer" to add your organization, sponsor, meeting name here; then, click "Apply to All"*Go to "View | Header and Footer" to add your organization, sponsor, meeting name here; then, click "Apply to All"Go to "View | Header and Footer" to add your organization, sponsor, meeting name here; then, click "Apply to All"*Go to "View | Header and Footer" to add your organization, sponsor, meeting name here; then, click "Apply to All"**Go to "View | Header and Footer" to add your organization, sponsor, meeting name here; then, click "Apply to All"*Test*Go to "View | Header and Footer" to add your organization, sponsor, meeting name here; then, click "Apply to All"Took data through the end of April 2012. Assume medium energy run is for 6 years (NOvA plans to take 3 years of neutrinos and 3 years of anti-neutrinos, what they really end up wanting to take may change, of course. Go to "View | Header and Footer" to add your organization, sponsor, meeting name here; then, click "Apply to All"Go to "View | Header and Footer" to add your organization, sponsor, meeting name here; then, click "Apply to All"*Go to "View | Header and Footer" to add your organization, sponsor, meeting name here; then, click "Apply to All"

newport beach, ca 25 october 2012

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