1 / 8

GPD E from Transverse SSA

Ds 2s. ep ep g. s + - s - s + + s -. A =. =. x = x B /(2-x B ). k = t/4M 2. GPD E from Transverse SSA. Unpolarized beam, transverse target:. Ds UT ~ sin f {k(F 2 H – F 1 E ) + …. . }d f. Requires: Good knowledge of H …. Background: p 0.

ataret
Download Presentation

GPD E from Transverse SSA

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Ds 2s ep epg s+ - s- s+ + s- A = = x = xB/(2-xB) k = t/4M2 GPD E from Transverse SSA Unpolarized beam, transverse target: DsUT~ sinf{k(F2H – F1E) + …..}df Requires: Good knowledge of H ….. Background: p0 Global analysis of polarized and unpolarized data needed for precision measurements

  2. Ds 2s ep epg s+ - s- s+ + s- -t F1 F2 H H E A = = 0.1 0.81 1.34 1.90 0.65 0.76 0.3 0.56 0.82 1.24 0.44 0.46 0.5 0.42 0.54 0.88 0.32 0.31 0.7 0.33 0.38 0.66 0.24 0.21 x = xB/(2-xB) k = t/4M2 GPD E from beam SSA Polarized beam, unpolarized target: x=0.3,t=-0.3 ~ ~ DsLU~ sinf{F1H+ x(F1+F2)H+kF2E}df 2-5% Kinematically suppressed, requires: Precision measurement of H,H~ large t, small x ……. Background: p0

  3. Q2=5 GeV2 GPD E form Exclusiver0transverse target 2D (Im(AB*))/p T AUT = - |A|2(1-x2) - |B|2(x2+t/4m2) - Re(AB*)2x2 A ~ 2Hu + Hd r0 B ~ 2Eu + Ed A~ Hu - Hd B ~ Eu - Ed r+ Eu, Edneeded for angular momentum sum rule. r0 K. Goeke, M.V. Polyakov, M. Vanderhaeghen, 2001 B

  4. OAM sensitive observables in exclusive production? H. Avakian, QCD’N 2006,June 14, 2006 • DVCS • DVMP • Link between GPDs and TMDs?

  5. 1 1 1 [ ] ò = - J G = x + x J q xdx H q( x , , 0 ) E q( x , , 0 ) 2 2 - 1 X. Ji, Phy.Rev.Lett.78,610(1997) Quark Angular Momentum Sum Rule GPDs Hu, Hd, Eu, Edprovide access to total quark contribution to proton angular momentum. ½ = ½ (Du+Dd+Ds) + Lq + Jg Proton’s spin J q Large x contributions important.

  6. L = 1x1035 T = 2000 hrs DQ2 = 1 GeV2 Dx = 0.05 CLAS12- DVCS/BH Beam Asymmetry e p epg E = 11 GeV DsLU~sinfIm{F1H+..}df Sensitive to GPDH Selected Kinematics

  7. CLAS12-DVCS/BH Target Asymmetry e p epg Transversely polarized target Sample kinematics E = 11 GeV Q2=2.2 GeV2, xB = 0.25, -t = 0.5GeV2 DsUT~ sinfIm{k1(F2H– F1E) +…}df AUTx Target polarization in scattering plane AUTy Target polarization perpendicular to scattering plane • Asymmetry highly sensitive to the u-quark contributions to the proton spin.

  8. CLAS12-DVCS/BH Target Asymmetry L = 2x1035 cm-2s-1 T = 1000 hrs DQ2 = 1GeV2 Dx = 0.05 e p epg E = 11 GeV Longitudinally polarized target ~ Ds~sinfIm{F1H+x(F1+F2)H...}df CLAS preliminary AUL E=5.75 GeV <Q2> = 2.0GeV2 <x> = 0.2 <-t> = 0.25GeV2

More Related