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ASI-2008 « SYMMETRY and SPIN ». PRAHA -2008. Oleg V. Selyugin. Spin-flip amplitude in the impact parameter represantation. BLTPh,JINR. Introduction Structure of hadron elastic scattering amplitude Non-linear equations and saturation
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ASI-2008 « SYMMETRY and SPIN » PRAHA -2008 Oleg V. Selyugin Spin-flip amplitude in the impact parameter represantation BLTPh,JINR
Introduction • Structure of hadron elastic scattering amplitude • Non-linear equations and saturation • Basic properties of the unitarization schemes • b-dependence of the phases • Analysing power in different unitarization schemes • Summary
Total cross-section • Understand the asymptotic behavior of stot • new (precise) data to constraint the fit: stotvs (ln s)g • 1% error ~1mb
Pomerons stot(s)~ Regge theory Landshoff 1984 – soft P a = 0.08 Simple pole – (s/s0)a Double pole – Ln(s/s0) Triple pole – Ln2(s/s0) +C 1976 BFKL (LO) - P -a2 = 0.4 a2 = 0.45 1988 HERA data (Landshoff ) – hard P 2005 – Kovner – 7 P -ai = 0. ..0.4. .0.8
Regge limit for fixed t The crossing matrix factorized in the limit the Regge-pole contributions to the helicity amplitudes in the s-chanel when exchanged Regge poles have natural parity
Normalization and forms of unitarization Low energies
Inelastic cross sections eikonal U-matrix
Asymptotic features of unitarization schemes Low energies High energies
Effect of antishadowing S. Troshin (hep-ph/0701241 v4 June 4 « Black Disk Limit is a direct consequence of the exponential unitarization with an extra assumption on the pure imaginary nature of the phase shift » Renormalized eikonal
RHIC beams +internal targets º fixed target mode Ö s ~ 14 GeV
K-matrix U-matrix
Summary • Unitarization effects is very important for the description spin correlation parameters at RHIC • Non-linear equations correspond to the different forms of the unitarization schemes. They can have the same asymptotic regime. • An interpolating form of unitarization can reproduce both the eikonal • and the K-matrix (extended U-matrix} unitarization
Summary • The true form of the unitarization, which is still to be determined, • can help to determine the form of the non-linear equation, • which describes the non-perturbative processes at high energies.
The experiments on proton elastic scattering occupy • an important place in the research program at the LHC. It is very likely that BDL regime will be reached at LHC energies. It will be reflected in the behavior of B(t) and r(t).
The Elastic Process: Kinematics scattered proton (polarized) proton beam RHIC beams + internal targets º fixed target mode Ö s ~ 14 GeV polarized proton target or Carbon target recoil proton or Carbon essentially 1 free parameter: momentum transfer t = (p3 – p1)2 = (p4 – p2)2 <0 + center of mass energy s = (p1 + p2)2 = (p3 – p4)2 + azimuthal angle j if polarized ! Þ elastic pp kinematics fully constrained by recoil proton only ! Alessandro Bravar
Some AN measurements in the CNI region pC Analyzing Power E950@BNL p = 21.7 GeV/c PRL89(02)052302 pp Analyzing Power E704@FNAL p = 200 GeV/c PRD48(93)3026 no hadronic spin-flip with hadonic spin-flip AN(%) no hadronic spin-flip r5pCµ Fshad / Im F0had Re r5 = 0.088 ± 0.058 Im r5 = -0.161 ± 0.226 highly anti-correlated -t Alessandro Bravar
Spin correlation parameter - AN ANbeam (t ) = ANtarget (t ) for elastic scattering only! Pbeam = Ptarget . eB / eT
Soft and hard Pomeron Donnachie-Landshoff model; Schuler-Sjostrand model
Such form of U-matrix does not have the BDL regime Predictions at LHC (14 TEV)