Hard photodisintegration of a proton pair

• Published in: Physics letters. B 2010-02, Vol.684 (2-3), p.106-109
• Main Authors: Pomerantz, I., Bubis, N., Allada, K., Beck, A., Beck, S., Berman, B.L., Boeglin, W., Camsonne, A., Canan, M., Chirapatpimol, K., Cisbani, E., Cusanno, F., de Jager, C.W., Dutta, C., Garibaldi, F., Geagla, O., Gilman, R., Glister, J., Higinbotham, D.W., Jiang, X., Katramatou, A.T., Khrosinkova, E., Lee, B.W., LeRose, J.J., Lindgren, R., McCullough, E., Meekins, D., Michaels, R., Moffit, B., Petratos, G.G., Piasetzky, E., Qian, X., Qiang, Y., Rodriguez, I., Ron, G., Saha, A., Sarty, A.J., Sawatzky, B., Schulte, E., Shneor, R., Sparveris, N., Subedi, R., Strauch, S., Sulkosky, V., Wang, Y., Wojtsekhowski, B., Yan, X., Yao, H., Zhan, X., Zheng, X.
• Format: Article
• Language: English
• Subjects: ATOMIC AND MOLECULAR PHYSICS; CROSS SECTIONS; DEUTERONS; ENERGY; Exact sciences and technology; NEUTRONS; Nuclear physics; NUCLEAR PHYSICS AND RADIATION PHYSICS; PHOTONS; PHOTONUCLEAR REACTIONS; Physics; PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; PROTONS; SCALING; The physics of elementary particles and fields; YIELDS
• ISSN: 0370-2693; 1873-2445
• DOI: 10.1016/j.physletb.2009.12.050

We present a study of high energy photodisintegration of proton-pairs through the γ+He3→p+p+n channel. Photon energies, Eγ, from 0.8 to 4.7 GeV were used in kinematics corresponding to a proton pair with high relative momentum and a neutron nearly at rest. The s−11 scaling of the cross section, as predicted by the constituent counting rule for two nucleon photodisintegration, was observed for the first time. The onset of the scaling is at a higher energy and the cross section is significantly lower than for deuteron (pn pair) photodisintegration. For Eγ below the scaling region, the scaled cross section was found to present a strong energy-dependent structure not observed in deuteron photodisintegration.