Polarization measurements in high-energy deuteron photodisintegration

• Main Authors: Wijesooriya, K, Afanasev, A, Amarian, M, Aniol, K, Becher, S, Benslama, K, Bimbot, L, Bosted, P, Brash, E, Calarco, J, Chai, Z, Chang, C C, Chang, T, Chen, J P, Choi, S, Chudakov, E, Churchwell, S, Crovelli, D, Dieterich, S, Dumalski, S, Dutta, D, Epstein, M, Fissum, K, Fox, B, Frullani, S, Gao, H, Gao, J, Garibaldi, F, Gayou, O, Gilman, R, Glamazdin, S, Glashausser, C, Gomez, J, Gorbenko, V, Hansen, O, Holt, R J, Hovdebo, J, Huber, G M, De Jager, C W, Jiang, X, Jones, C, Jones, M K, Kelly, J, Kinney, E, Kooijman, E, Kumbartzki, G, Kuss, M, LeRose, J, Liang, M, Lindgren, R, Liyanage, N, Malov, S, Margaziotis, D J, Markowitz, P, McCormick, K, Meekins, D, Meziani, Z E, Michaels, R, Mitchell, J, Morand, L, Perdrisat, C F, Pomatsalyuk, R, Punjabi, V, Ransome, R D, Roche, R, Rvachev, M, Saha, A, Sarty, A, Schulte, E C, Simon, Daniel, Strauch, S, Suleiman, R, Todor, L, Ulmer, P E, Urciuoli, G M, Wojtsekhowski, B, Xiong, F, Xu, W
• Format: Others
• Language: English
• Published: University of Illinois, Urbana-Champaign, USA 2001
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-94197

We present measurements of the recoil proton polarization for the d(γ⃗,p⃗)n reaction at θc.m. = 90° for photon energies up to 2.4 GeV. These are the first data in this reaction for polarization transfer with circularly polarized photons. The induced polarization py vanishes above 1 GeV, contrary to meson-baryon model expectations, in which resonances lead to large polarizations. However, the polarization transfer Cx does not vanish above 1 GeV, inconsistent with hadron helicity conservation. Thus, we show that the scaling behavior observed in the d(γ,p)ncross sections is not a result of perturbative QCD. These data should provide important tests of new nonperturbative calculations in the intermediate energy regime.