高能氘核光致蜕变中的极化测量

Polarization measurements in high-energy deuteron photodisintegration.

作者信息

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 D, Strauch S, Suleiman R, Todor L, Ulmer P E, Urciuoli G M, Wojtsekhowski B, Xiong F, Xu W

机构信息

Université Blaise Pascal/IN2P, Aubière, France.

出版信息

Phys Rev Lett. 2001 Apr 2;86(14):2975-9. doi: 10.1103/PhysRevLett.86.2975.

DOI:10.1103/PhysRevLett.86.2975

PMID:11290086

Abstract

We present measurements of the recoil proton polarization for the d(gamma-->,p-->)n reaction at straight theta(c.m.) = 90 degrees 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 p(y) 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(gamma,p)n cross sections is not a result of perturbative QCD. These data should provide important tests of new nonperturbative calculations in the intermediate energy regime.

摘要

我们给出了在质心系中θ = 90°直线条件下，对于光子能量高达2.4 GeV的d（γ，p）n反应的反冲质子极化测量结果。这些是该反应中关于圆偏振光子极化转移的首批数据。与介子 - 重子模型预期相反，诱导极化p（y）在1 GeV以上消失，在该模型中，共振会导致大极化。然而，极化转移Cx在1 GeV以上并不消失，这与强子螺旋度守恒不一致。因此，我们表明在d（γ，p）n截面中观察到的标度行为不是微扰量子色动力学的结果。这些数据应为中能区新的非微扰计算提供重要检验。