Up and down quark contributions to spin content of Λ from fragmentation

被引:13
作者
Yang, JJ
机构
[1] Univ Tecn Federico Santa Maria, Dept Fis, Valparaiso, Chile
[2] Nanjing Normal Univ, Dept Phys, Nanjing 210097, Peoples R China
基金
中国国家自然科学基金;
关键词
D O I
10.1016/S0370-2693(01)00698-0
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We check the u and d quark contributions to the spin content of the Lambda by means of the q --> Lambda fragmentation and find that the u and d quarks of the Lambda are likely positively polarized. The parton distributions in the Lambda are given by a successful statistical model which can reproduce and correlate a vast body of polarized and unpolarized structure function and parton distribution data of the nucleon. With the Gribov-Lipatov relation between the quark distributions and fragmentation functions, the longitudinal spin transfer for the Lambda production in the polarized charged lepton deep inelastic scattering (DIS) process and the Lambda -polarization in the neutrino (antineutrino) DIS process are predicted. The available experimental data suggests that the u and d quark contributions to the spin of the Lambda are positive. In addition, our results provide a collateral evidence for the SU(3) symmetry breaking in hyperon semileptonic decays of the octet baryons, which is very important for a deeper understanding of the proton 'spin crisis'. (C) 2001 Published by Elsevier Science B.V.
引用
收藏
页码:57 / 64
页数:8
相关论文
共 27 条
[1]   Statistical model for the nucleon structure functions [J].
Bhalerao, RS .
PHYSICS LETTERS B, 1996, 380 (1-2) :1-6
[2]  
Bhalerao RS, 1996, PHYS LETT B, V387, P881
[3]   UNIFIED DESCRIPTION OF INCLUSIVE AND EXCLUSIVE REACTIONS AT ALL MOMENTUM-TRANSFERS [J].
BLANKENBECLER, R ;
BRODSKY, SJ .
PHYSICAL REVIEW D, 1974, 10 (09) :2973-2992
[4]   QCD CONSTRAINTS ON THE SHAPE OF POLARIZED QUARK AND GLUON DISTRIBUTIONS [J].
BRODSKY, SJ ;
BURKARDT, M ;
SCHMIDT, I .
NUCLEAR PHYSICS B, 1995, 441 (1-2) :197-214
[5]  
Brodsky SJ., 1979, PROG MATH PHYS, V4, P255
[6]   A positive test for Fermi-Dirac distributions of quark-partons [J].
Buccella, F ;
Pisanti, O ;
Rosa, L ;
Dorsner, I ;
Santorelli, P .
MODERN PHYSICS LETTERS A, 1998, 13 (06) :441-451
[7]   POLARIZED Q-]LAMBDA FRAGMENTATION FUNCTIONS FROM E+E--]LAMBDA+X [J].
BURKARDT, M ;
JAFFE, RL .
PHYSICAL REVIEW LETTERS, 1993, 70 (17) :2537-2540
[8]   QCD analysis of unpolarized and polarized Λ-baryon production in leading and next-to-leading order [J].
de Florian, D ;
Stratmann, M ;
Vogelsang, W .
PHYSICAL REVIEW D, 1998, 57 (09) :5811-5824
[9]   Interaction-driven equilibrium and statistical laws in small systems: The cerium atom [J].
Flambaum, VV ;
Gribakina, AA ;
Gribakin, GF ;
Ponomarev, IV .
PHYSICAL REVIEW E, 1998, 57 (05) :4933-4942
[10]  
Flores-Mendieta R, 1998, PHYS REV D, V58, DOI 10.1103/PhysRevD.58.094028