An Electron Ion Collider at HIAF Xurong Chen for the EIC@HIAF study group The Institute of Modern Physics, CAS, Lanzhou, China The 5th Workshop on Hadron Physics in China and Opportunities in USA Huangshan, July 3, 2013

Outline Introduction to IMP EIC@HIAF Physics and Simulations Conclusions

The Institute of Modern Physics (IMP) The institute of Modern Physics(IMP) was founded in 1957. It is affiliated with Chinese Academy of Science (CAS) The national Laboratory for the heavy Ion Research Facility in Lanzhou was established at the IMP in 1991. IMP mainly focuses on basic research in heavy ion physics and its related interdisciplinary science There are about 800 scientists and engineers, including two academicians of CAS and 60 full professors IMP is one of the well-known research centers of low-and intermediate energy heavy ion physics in the world.

IMP @ Lanzhou

Main EIC plans in the world EIC@HIAF LHC  LHeC RHIC  eRHIC CEBAF  MEIC/EIC HERA FAIR  ENC

The Layout of HIAF Complex 2.4GeV ER eLinac-Ring 2.4 GeV (e) 3.0×1013 ICR-43 12.0 GeV (p) 4.1×1012 Key Characteristics: High energy & High intensity & Pulse Cooled intense primary beam & RIBs Beam compression Super long period slow extraction Multi-operation modes CBR-13/12 3.9ms/turn, 173turns, 680 ms (A=400,ε=2.3, f=1.5) ABR-20/18 3.0 GeV (p) 2.8×1012 SLinac 0.34 GeV/u (238U34+) 2.7×1011 17 MeV/u (U34+) 50 MeV/u (p) 40 pmA 5 Hz, 430 μs 1 pmA 1 Hz, 680 μs 6.2ms/turn, 70turns, 430 ms (A=400,ε=5.7, f=1.5) For more details, see Jiancheng Yang’s talk 6 6

Lepton-Nucleon Facilities EIC@HIAF: e(2.4 GeV) +p(12 GeV), both polarized, L = 4 x 1032cm2/s HIAF

e(2.4 GeV) +p(12 GeV), both polarized, L = 4 x 1032cm2/s EIC@HIAF Kinematic Coverage Comparison with JLab 12 GeV e(2.4 GeV) +p(12 GeV), both polarized, L = 4 x 1032cm2/s EIC@HIAF Phase-1: ~2019: 2.4 x12 GeV Both e and p polarized Luminosity: 4 x 1032cm2/s EIC@HIAF Phase-2: ~2030 10 x 100 GeV EIC@HIAF: study sea quarks (x > 0.01) deep exclusive scattering at Q2 > 5-10 higher Q2 in valance region

Unified view of nucleon structure EIC – 3D imaging of nucleon structure: TMDs – confined motion in a nucleon (semi-inclusive DIS) GPDs – Spatial imaging of quarks and gluons (exclusive DIS)

The Unique Advantages of EIC@HIAF The main theme for JLab 12 GeV is the study of the valance quark structure (and confinement) The main theme for full EIC (eRHIC, ELIC, LHeC…) is to understand the gluons The energy reach of the EIC@HIAF is higher than JLab 12GeV but lower than the full EIC being considered in US (at about the lower end) EIC@HIAF phase-1 (3GeV e x 12 GeV p): x is in region[0.01,0.1]. It’s the best region for sea quark study

Spin-Flavor Study at EIC@HIAF Unique opportunity for Δs JLab12 GeV energy not high enough to have clean Ds measurements But, EIC@HIAF, combination of energy and luminosity： By semi-inclusive DIS, in particular, for Kaons , will help to identify strange quark helicity

TMD Study at EIC@HIAF Unique opportunity for TMD in “sea quark” region reach x ~ 0.01 (JLab12 mainly valence quark region, reach x ~ 0.1) Semi-inclusive DIS, for charged hadrons, to measure TMD sea quark distributions Charm-pair production to measure TMD gluon distributions Significant increase in Q2 range for valence region energy reach Q2 ~40 GeV2 at x ~ 0.4 (JLab12, Q2 < 10)

GPD Study at EIC@HIAF Significant increase in range for DVCS Extend the kinematics covered by JLab Unique opportunity for Deeply virtual meson production (DVMP) (pion/Kaon) flavor decomposition needs DVMP energy reach Q2 > 5-10 GeV2 JLab12 energy not high enough to have clean light meson deep exclusive process which is the case for EIC@HIAF design

Hadron Physics at EIC@HIAF Many aspects of hadron’s partonic structure can be naturally addressed by EIC, but, not other machines: e+ e-, pp, pA, AA There are a lot to be done in the meson (including exotic meson) and X-Y-Z particles, where EIC might have an important role to play

Golden Measurements at EIC@HIAF To measure strange quark polarization in kaon Semi-inclusive DIS production TMD Sivers function in Semi-inclusive DIS, Q2 evolution, etc. DVCS/DVMP, to measure quark orbital angular momentum Quark propagation in medium to compare with heavy ion collisions

EIC@HIAF meeting The 2nd International workshop on QCD and Hadron Physics, March 30-April 3, 2013, Lanzhou QCD and hadron physics EIC Physics EIC@HIAF

EIC@HIAF meeting The four experiments were re-affirmed as good candidates for golden measurements Some of the unique advantages of the EIC@HIAF (comparing to fixed target experiments) for SIDIS study were emphasized (Ahbay and Elka), especially the clean separation of the current fragmentation from the target fragmentation (Delta_s, TMDs and hadronization clean measurements) Adjustability of beam energy is needed for flavor separation of GPD study (which is the case for EIC@HIAF design) We decided to do simulation and whitepaper at once, and should be done before July 2013

Two More Golden Measurements Craig Roberts: Pointed out the importance of higher Q2 EIC@HIAF will provide (comparing to JLab12), which are essential for clean measurement in the valence quark region Suggests: (5) the pion and kaon structure function measurment, which can be a benchmark experiment to test non-perturbative QCD calculations Eli: (6): EMC-SRC measurement: which will be a high impact experiment if EIC@HIAF can make precision measurement

Simulation Progress Xiaodong Jiang's group (Los Alamos) is doing the sea-quark polarization simulation and it has been done The TMD simulation is done by Haiyan's group (Duke). The plot is being finalized. The GPD group (Saclay/ODU/JLab) is doing the GPD (DVMP with pi/K) simulation, they are trying to produce results Paul Reimer (Argonne) is doing the pion structure function simulation. Craig has produced first draft of a write-up

The TMD simulation: Projections for SIDIS Asymmetry π+ By Haiyan’s group EIC@HIAF may reach the same precision with SoLID

Sea Quark Sivers Function we can clearly see that the EIC will be a powerful facility enabling access to TMDs with unprecedented precision, and particularly in the currently unexplored sea quark region This precision is not only crucial for the fundamental QCD test of the sign change between the Sivers asymmetries in the DIS and Drell-Yan processes, but also important to investigate the QCD dynamics in the hard processes in SIDIS Exploration of the sea quark Sivers function will provide, for the first time, the unique information on the spin-orbital correlation in the small-x region

Simulated errors for pi structure function measurement By Paul E. Reimer Simulated errors for DIS events using a 3 GeV electron beam on a 12 GeV proton beam with a luminosity of 5 x 1032 cm−2 s−1 and 106 s of running. A precise result could be obtained on the domain x <= 0.9

Our Future Plan Physics Simulations (will be done very soon) Detector simulations Whitepaper writing Jianwei Qiu, Feng Yuan, etc., are working hard on it The first draft will come up very soon Chinese version is needed It really needs international community efforts on simulations and whitepaper writing !

Job Opportunities Welcome! Now we have several immediate openings for postdoctoral researchers/guest Professors to work on EIC related physics (such as QCD, nucleon structure, small x physics, hadron physics, etc.) For further information you may refer to the following links: http://inspirehep.net/record/1189703 http://inspirehep.net/record/1206133 http://inspirehep.net/record/1210538 If one needs further information please contact us: zhpm@impcas.ac.cn (theory) xchen@impcas.ac.cn (experiment)  Welcome!

Summary EIC@HIAF opens up a new window to study/understand nucleon structure, especially the sea quark Anthony Thomas: This proposal at IMP is extremely exciting and to have this working in 6 years would be wonderful. It is a machine ideally suited to a number of important problems. Craig Roberts: Providing the understanding of hadrons, verifying QCD, perhaps, or replacing it, will be one of Nuclear Physics’ greatest contributions to science. It is in a position to make concrete predictions (Predictions for GPDs and TMDs will follow).Such predictions represent consequences of statements about confinement and DCSB (Dynamical Chiral Symmetry Breaking ) If China-EIC is in a position to test those predictions, then we can get to the heart of the most interesting problem in fundamental physics today