EPJ Web of Conferences
Volume 71, 20142nd International Conference on New Frontiers in Physics
|Number of page(s)||8|
|Published online||29 April 2014|
Overview of the nucleon spin studies at COMPASS
LIP, Av. Elias Garcia 14 - 1° 1000-149 Lisboa
a e-mail: firstname.lastname@example.org
Published online: 29 April 2014
The COMPASS experiment  at CERN is one of the leading experiments studying the spin structure of the nucleon. These studies are being carried on since 2002, by measuring hadrons produced in deep inelastic scattering (DIS) of 160 GeV/c polarised muons off different polarised targets (NH3 for polarised protons and 6LiD for polarised deuterons). One of the main goals is to determine how the total longitudinal spin projection of the nucleon, 1/2, is distributed among its constituents, quarks and gluons. We review here the recent results on the quark and gluon helicities obtained by COMPASS, using a longitudinally polarised target. However, the understanding of the nucleon (spin) structure based only on the parton helicities is not in any way complete. It basically provides us with a one-dimensional picture in a longitudinal momentum space. Therefore, COMPASS also studies the transverse momentum dependent parton distributions (TMDs) with a transversely polarised target. Concerning the TMDs, the latest results on the Collins and Sivers asymmetries will be shown. The former is sensitive to the transverse spin structure of the nucleon, while the latter reﬂects the correlations between the quarks transverse momentum and the nucleon spin.
© Owned by the authors, published by EDP Sciences
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 2.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.