Transversity distributions from difference asymmetries in semi-inclusive DIS.

Apr 9, 2019, 4:32 PM
Rettorato - Aula Principi d'Acaja

Rettorato - Aula Principi d'Acaja

via Verdi, 8 Turin
Parallel Session Talk WG6: Spin and 3D structure WG6: Spin and 3D structure


Franco Bradamante


In recent years information on the transversity distribution $h_1$ has been obtained
combining the Collins asymmetry results from semi-inclusive deep inelastic scattering
(SIDIS) data on transversely polarized nucleon targets and the information on the
fragmentation function of a transversely polarized quark from the asymmetries measured
in $e^+e^-$ annihilation into hadrons. An alternative method was proposed long time ago,
which does not require the $e^+e^-$ data, but allows one to get ratios of the $u$ and
$d$ quark transversity distributions from the SIDIS data alone. The method utilizes
the ratio of the difference of the Collins asymmetries of positively and negatively
charged hadrons produced on transversely polarized proton and deuteron targets.
We have applied this method to the COMPASS proton and deuteron data, and extracted
the ratio $h_1^d/h_1^u$. Our results are very close to those obtained in a previous
point--by--point extraction based both on SIDIS and $e^+e^-$ data. Thus the new
method strengthens the validity of the determination and of the procedures presented
in earlier works on the subject.

Primary authors

Franco Bradamante Vincenzo Barone (University of Piemonte Orientale) Andrea Bressan Albi Kerbizi (Universita e INFN Trieste (IT)) Anna Martin (Trieste University and INFN (IT)) Andrea Moretti (Universita e INFN Trieste (IT)) Jan Matousek (Universita e INFN Trieste (IT)) Giulio Sbrizzai (Universita e INFN, Trieste (IT))

Presentation materials