Issue |
EPJ Web of Conferences
Volume 95, 2015
3rd International Conference on New Frontiers in Physics
|
|
---|---|---|
Article Number | 04047 | |
Number of page(s) | 9 | |
Section | Parallel | |
DOI | https://doi.org/10.1051/epjconf/20159504047 | |
Published online | 29 May 2015 |
https://doi.org/10.1051/epjconf/20159504047
Scaling of charged particle production and centrality determination in p-Pb collisions at √sNN = 5.02 TeV at ALICE
INFN, Via P. Giuria 1, 10125 Torino, ITALY
Published online: 29 May 2015
Proton-nucleus collisions are studied in order to disentangle initial state effects, already present in cold nuclear matter, from final state effects, that are associated to the hot and strongly interacting medium created in A-A collisions. However, after the 2013 p-Pb data taking at LHC, the importance of p-A collisions on their own has been acknowledged. Several measurements clearly showed that p-A collisions cannot simply be explained by an incoherent superposition of proton-nucleon collisions, but indicate the presence of coherent and collective effects, with a strong dependence on the collision geometry. These measurements pointed out the need for a detailed characterization of the collision geometry.
Typically, parameters such as the number of binary collisions Ncoll or the number of participating nucleons Npart are used to characterize the centrality. In nucleus-nucleus interactions the centrality is usually estimated by measuring the charged particle multiplicity. However, in contrast to A-A, in p-A collisions the large fluctuations in a much reduced multiplicity environment generate a dynamical bias in centrality classes based on particle multiplicity measurement.
The centrality determination is critically addressed and a different approach to extract the average Ncoll values, needed to compare p-A to pp data, is presented. The centrality dependence of primary charged-particle production and of transverse momentum distributions in p-A collisions at √sNN = 5.02 TeV measured by ALICE are presented.
© Owned by the authors, published by EDP Sciences, 2015
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, 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.