Eur. Phys. J. C 18, 639-644
DOI: 10.1007/s100520100564
Transversity distribution and polarized fragmentation function from semi-inclusive pion electroproduction
V.A. Korotkov1, 2, W.-D. Nowak2 and K.A. Oganessyan2, 3, 41 IHEP, 142284 Protvino, Russia
2 DESY Zeuthen, 15738 Zeuthen, Germany
3 INFN, Laboratori Nazionali di Frascati, 00044 Frascati, Italy
4 Yerevan Physics Institute, 375036 Yerevan, Armenia
(Received: 18 June 2000 / Revised version: 20 November 2000 / Published online: 5 February 2001 -© Springer-Verlag 2001)
Abstract
A method is discussed to determine the hitherto unknown u-quark
transversity distribution
from a planned HERMES
measurement of a single target-spin asymmetry in semi-inclusive pion
electroproduction off a transversely polarized target.
Assuming u-quark dominance, the measurement yields the shapes of the
transversity distribution
and of the ratio
, of polarized and unpolarized
u-quark fragmentation functions. The unknown relative
normalization can be obtained by identifying the transversity
distribution with the well-known helicity distribution at large x
and small Q2.
The systematic uncertainty of the method is dominated
by the assumption of u-quark dominance.
© Società Italiana di Fisica, Springer-Verlag 2001