The role of spin in fragmentation production J/ψ(1S) and γ(1S)

作     者：Sepahvand, Reza Dadfar, Sareh 

作者机构：Lorestan Univ Fac Sci Dept Phys Khorramabad *** Iran 

出 版 物：《NUCLEAR PHYSICS A》 (Nucl. Phys. A)

年 卷 期：2010年第848卷第1-2期

页      面：218-229页

核心收录：

学科分类：07[理学] 070203[理学-原子与分子物理] 0702[理学-物理学] 

主　　题：Fragmentation functions Spin Heavy quarkonium 

摘      要：In this work we calculate the process independent fragmentation functions for a heavy quark Q to fragment into vector Q (Q) over bar(S-3(1)) and pseudoscalar Q (Q) over bar(S-1(0)) heavy quarkonium to leading order perturbative QCD We investigate the role of the spin orientation of the initial and final heavy quarks on the fragmentation functions In the special case we calculate fragmentation functions by using average over spin of initial state heavy quark and sum over spin of final states The universal fragmentation probabilities for the c - J/psi(1S) and b - r(1s) are about 10(-4) and 10(-5) respectively Moreover the spin dependent observables such as V/(V + P) and V I P ratios are estimated (C) 2010 Elsevier B V All rights reserved