Post on 26-Jan-2016
description
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A QCD evolution equation and
EIC@HIAF
ZHU WEI ECNU
2013.7. WeiHai
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• Parton distributions in proton and nuclei is an important knowledge for EIC
EIC@HIAF vs BEPC
QCD evolution equation is a necessary tool for understanding parton distributions
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Kinematic domainEIC@HIAF
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QCD evolution equations
• DGLAP x>10^{-3}, Q^2>1-4 GeV^2
• GLRMQ x<10^{-2}?
• BFKL x<10^{-4}?
• BK x<10^{-4}?
• JIMWLK x<10^{-4}, Q^2>1 GeV^2
• ZRS x>10^{-4}, Q^2>0.06 GeV^2
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Gribov, Levin and Ryskin , Mueller and Qiu
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W.Zhu, D.L.Xue, K.M. Chai, Z.X. Xu, Phys. Lett. B317 (1993) 200
W.Zhu, K.M.Chai, B.He, Nucl. Phys. B427 (1994) 525
W.Zhu, K.M.Chai, B.He, Nucl. Phys. B449 (1995) 183
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Zhu-Shen-Ruan
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Complete version of equation
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W. Zhu, Nucl. Phys. B551, 245 (1999).W. Zhu and J.H.Ruan, Nucl. Phys. B559, 378 (1999). W. Zhu, Z.Q. Shen and J.H. Ruan, Nuclear Physics B 692 (2004) 417.
L.V. Gribov, E.M. Levin and M.G. Ryskin, Phys. Rep. 100, 1 (1983).
A.H. Mueller and J. Qiu, Nucl. Phys. B268, 427 (1986)
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1. First realize three valence quark input
• G. Parisi and R. Petronzio, Phys. Lett. 62B, 331 (1976)
• V.A. Novikov, M.A. Shifman, A.I. Vainshtein, V.I. Zakharov:JETP Len. 24 (1976) 341
• M. Gluck, E. Reya: Nucl. Phys. B130, 76 (1977)
Unsuccessful
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Input distributions
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Why equation can work at Q^2<<1 GeV^2?
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A bridge connecting withChiral quark model
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2. Minimum free parameters
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Typical database of PDF
• Proton GRV 23 parameters+DGLAP
• CTEQ 36parameters+DGLAP
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Proton 4 free parameters
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3. EMC effectAdd 2 free parameters
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4. Nuclear PDF
• HKM 16 free parameters
• EPS 24 free parameters
• Our 2 free parameters
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5. Quark saturation
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Quark saturation has similar properties as JIMWLK saturation
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JIMWLK saturation (gluon)
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6. Nuclear shadowing saturation
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Next step in EIC@HIAF
• PDF database for proton
• nPDF database for nuclei
• Spin-dependent PDF
• PDF for pion and kaon
• SRC
• Antishadowing
• TMD…….