Nonequilibrium production of photons via pi(0)->2 gamma in disoriented chiral condensates

被引:31
作者
Boyanovsky, D
deVega, HJ
Holman, R
Kumar, SP
机构
[1] UNIV PARIS 06, LPTHE, F-75252 PARIS 05, FRANCE
[2] CARNEGIE MELLON UNIV, DEPT PHYS, PITTSBURGH, PA 15213 USA
关键词
D O I
10.1103/PhysRevD.56.3929
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We study the production of photons via the nonequilibrium relaxation of a disoriented chiral condensate with the chiral order parameter having a large initial amplitude along the pi(0) direction. Assuming the validity of the low-energy coupling of the neutral pion to photons via the U-A(1) anomalous vertex, we find that for large initial amplitudes along the pi(0) direction photon production is enhanced by parametric amplification. These processes are nonperturbative with a large contribution during the nonequilibrium stages of the evolution and result in a distinct distribution of the produced photons and a polarization asymmetry. For initial amplitudes of the pi(0) component of the order parameter between 200 and 400 MeV, corresponding to energy densities between 1 and 12 GeV/fm(3), we find a peak in the photon distribution at energies between approximate to 300 and 600 MeV. We also find polarization asymmetries typically between 5% and 10%. We discuss the potential experimental impact of these results as well as the problems associated with its detection.
引用
收藏
页码:3929 / 3942
页数:14
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共 61 条
[1]   Coherent amplification of classical pion fields during the cooling of droplets of quark plasma [J].
Abada, A ;
Birse, MC .
PHYSICAL REVIEW D, 1997, 55 (11) :6887-6899
[2]  
[Anonymous], UNPUB
[3]  
ANSELM A, 1991, PHYS LETT B, V226, P482
[4]   CLASSICAL STATES OF THE CHIRAL FIELD AND NUCLEAR COLLISIONS AT VERY HIGH-ENERGY [J].
ANSELM, AA .
PHYSICS LETTERS B, 1989, 217 (1-2) :169-172
[5]   Anomalous processes in effective chiral theories at high temperatures [J].
Baier, R ;
Dirks, M ;
Kober, O .
PHYSICAL REVIEW D, 1996, 54 (03) :2222-2227
[6]  
BAKSHI PM, 1963, J MATH PHYS, V4, P12, DOI 10.1063/1.1703879
[7]   OUT OF EQUILIBRIUM PHASE-TRANSITIONS AND A TOY MODEL FOR DISORIENTED CHIRAL CONDENSATES [J].
BEDAQUE, PF ;
DAS, A .
MODERN PHYSICS LETTERS A, 1993, 8 (33) :3151-3163
[8]   A FULL-ACCEPTANCE DETECTOR FOR SSC PHYSICS AT LOW AND INTERMEDIATE MASS SCALES - AN EXPRESSION OF INTEREST TO THE SSC [J].
BJORKEN, JD .
INTERNATIONAL JOURNAL OF MODERN PHYSICS A, 1992, 7 (18) :4189-4257
[9]   HIGHLY RELATIVISTIC NUCLEUS-NUCLEUS COLLISIONS - THE CENTRAL RAPIDITY REGION [J].
BJORKEN, JD .
PHYSICAL REVIEW D, 1983, 27 (01) :140-151
[10]  
BJORKEN JD, 1992, ACTA PHYS POL B, V23, P561