Cross-section values for Compton scattering on the proton were measured at 25 kinematic settings over the range s=5-11 and -t=2-7 GeV2 with a statistical accuracy of a few percent. The scaling power for the s dependence of the cross section at fixed center-of-mass angle was found to be 8.0+/-0.2, strongly inconsistent with the prediction of perturbative QCD. The observed cross-section values are in fair agreement with the calculations using the handbag mechanism, in which the external photons couple to a single quark.

Danagoulian, A

Mamyan, VH

Roedelbronn, M

Aniol, KA

Annand, JRM

Bertin, PY

Bimbot, L

Bosted, P

Calarco, JR

Camsonne, A

Chang, CC

Chang, T-H

Chen, J-P

Choi, Seonho

Chudakov, E

Degtyarenko, P

de Jager, CW

Deur, A

Dutta, D

Egiyan, K

Gao, H

Garibaldi, F

Gayou, O

Gilman, R

Glamazdin, A

Glashausser, C

Gomez, J

Hamilton, DJ

Hansen, J-O

Hayes, D

Higinbotham, DW

Hinton, W

Horn, T

Howell, C

Hunyady, T

Hyde, CE

Jiang, X

Jones, MK

Khandaker, M

Ketikyan, A

Kubarovsky, V

Kramer, K

Kumbartzki, G

Laveissière, G

Lerose, J

Lindgren, RA

Margaziotis, DJ

Markowitz, P

McCormick, K

Meekins, DG

Meziani, Z-E

Michaels, R

Moussiegt, P

Nanda, S

Nathan, AM

Nikolenko, DM

Nelyubin, V

Norum, BE

Paschke, K

Pentchev, L

Perdrisat, CF

Piasetzky, E

Pomatsalyuk, R

Punjabi, VA

Rachek, I

Radyushkin, A

Reitz, B

Roche, R

Ron, G

Sabatié, F

Saha, A

Savvinov, N

Shahinyan, A

Shestakov, Y

Sirca, S

Slifer, Karl

Solvignon, P

Stoler, P

Tajima, S

Sulkosky, V

Todor, L

Vlahovic, B

Weinstein, LB

Wang, K

Wojtsekhowski, B

Voskanyan, H

Xiang, H

Zheng, X

Zhu, L

Jefferson Lab Hall A Collaboration

published 

April 13, 2007

General Physics

Physical Review Letters  Journal