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Selected Physics Topics at the Electron-Ion-Collider. Antje Bruell, JLab ECT workshop, July 2008. nuclear effects in deep inelastic scattering from fixed target experiments prospects for EIC TMDs and GPDs at EIC Summary. x and A dependence of the EMC effect.
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Selected Physics Topics at the Electron-Ion-Collider Antje Bruell, JLab ECT workshop, July 2008 • nuclear effects in deep inelastic scattering from fixed target experiments • prospects for EIC • TMDs and GPDs at EIC • Summary
NMC experimental set-up cancellation of acceptance and luminosity
Gluon Saturation at EIC ? Gluon distribution G(x,Q2) • What can we measure at EIC ? • Extract from scaling violation in F2: dF2/dlnQ2 • FL ~ as G(x,Q2) • Other Methods: • 2+1 jet rates (needs jet algorithm and modeling of hadronization for inelastic hadron final states) • inelastic vector meson production (e.g. J/) • diffractive vector meson production - very sensitive to G(x,Q2)
The Gluon Contribution to the Nucleon Spin Antje Bruell, Jlab EIC meeting, MIT, April 7 2007 • Introduction • G from scaling violations of g1(x,Q2) • The Bjorken Sum Rule • G from charm production
The Gluon Contribution to the Nucleon Spin Antje Bruell, Jlab EIC meeting, MIT, April 7 2007 • Introduction • G from scaling violations of g1(x,Q2) • The Bjorken Sum Rule • G from charm production
The Gluon Contribution to the Nucleon Spin Antje Bruell, Jlab EIC meeting, MIT, April 7 2007 • Introduction • G from scaling violations of g1(x,Q2) • The Bjorken Sum Rule • G from charm production
The Gluon Contribution to the Nucleon Spin Antje Bruell, Jlab EIC meeting, MIT, April 7 2007 • Introduction • G from scaling violations of g1(x,Q2) • The Bjorken Sum Rule • G from charm production
The Gluon Contribution to the Nucleon Spin Antje Bruell, Jlab EIC meeting, MIT, April 7 2007 • Introduction • G from scaling violations of g1(x,Q2) • The Bjorken Sum Rule • G from charm production
The Gluon Contribution to the Nucleon Spin Antje Bruell, Jlab EIC meeting, MIT, April 7 2007 • Introduction • G from scaling violations of g1(x,Q2) • The Bjorken Sum Rule • G from charm production
5 GeV 50 GeV/c (e P) • Q2=4 GeV2 • 2= 0.2 • P’ tagging required • Exclusivity • Resolution • () ≈ 0.3GeV2 without tagging • Transverse Imaging
Exclusive charged pion production Assume: 100 days, Luminosity=10E34 Detect the neutron Ep=50 GeV Ee=5 GeV Missing mass reconstruction 10<Q2<15 10<Q2<15 15<Q2<20 15<Q2<20 35<Q2<40 35<Q2<40 Γ dσ/dt (ub/GeV2) Γ dσ/dt (ub/GeV2) 0.02<x<0.05 0.05<x<0.1 0.01<x<0.02 0.05<x<0.1 -t (GeV2) -t (GeV2) • Neutron acceptance limits the t-coverage • The missing mass method gives full t-coverage for x<0.2 Assume dp/p=1% (pπ<5 GeV)
Transversity and friends Unpol. DF Helicity Transversity q(x) Dq(x) dq(x) Sivers function Boer-Mulders function EIC workshop, May 21th R.Seidl: Transversity measurements at EIC 20
First successful attempt at a global analysis for the transverse SIDIS and the BELLE Collins data HERMES AUTp data COMPASS AUT d data Belle e+ e- Collins data Kretzer FF First extraction of transversity (up to a sign) Anselmino et al: hep-ex 0701006 R.Seidl: Transversity measurements at EIC 21 EIC workshop, May 21th
What can be expected at EIC? • Larger x range measured b y existing experiments COMPASS ends at ~ 0.01, go lower by almost one order of magnitude, but asymmetries become small • Have some overlap at intermediate x to test evolution of Collins function and higher twist but at higher Q2 EIC workshop, May 21th R.Seidl: Transversity measurements at EIC 22
The Gluon Contribution to the Nucleon Spin Antje Bruell, Jlab EIC meeting, MIT, April 7 2007 • Introduction • G from scaling violations of g1(x,Q2) • The Bjorken Sum Rule • G from charm production
Sivers effect: Kaon electroproduction EIC CLAS12 • The low x of EIC makes it ideal place to study the Sivers asymmetry in Kaon production (in particular K-). • Combination with CLAS12 data will provide almost complete coverage in x
Correlation between Transverse Spin and Momentum of Quarks in Unpolarized Target All Projected Data Perturbatively Calculable at Large pT Vanish like 1/pT (Yuan) ELIC
Summary • eA data from fixed target experiments insufficient to constrain nuclear gluon distribution • large kinematic range of EIC will provide precision data on e.g. Q2 dependence of F2A/F2D and x dependence of FLA/FLD and will thus allow to investigate the low x phyiscs of saturation in the nucleus • high luminosity and large kinematic coverage will allow to do gluon and quark “tomography” via exclusive processes (measurement of fully differential cross sections for diffractive and non-diffractive channels) • single spin asymmetries will determine transverse spin effects and get access to orbital momenta