Measurement with the ATLAS detector of multi-particleazimuthal correlations in p plus Pb collisions at root s(NN)=5.02 TeV
2013 (English)In: Physics Letters B, ISSN 0370-2693, Vol. 725, no 1-3, 60-78 p.Article in journal (Refereed) Published
In order to study further the long-range correlations ("ridge") observed recently in p + Pb collisions at root s(NN) = 5.02 TeV, the second-order azimuthal anisotropy parameter ofcharged particles, v(2), has been measured with the cumulant method using the ATLASdetector at the LHC. In a data sample corresponding to an integrated luminosity ofapproximately 1 mu b(-1), the parameter v(2) has been obtained using two- and four-particlecumulants over the pseudorapidity range vertical bar eta vertical bar < 2.5. The results are presented as a function of transverse momentum and the event activity, defined in terms of thetransverse energy summed over 3.1 < eta < 4.9 in the direction of the Pb beam. They show features characteristic of collective anisotropic flow, similar to that observed in Pb + Pb collisions. A comparison is made to results obtained using two-particle correlation methods, and to predictions from hydrodynamic models of p + Pb collisions. Despite the small transverse spatial extent of the p + Pb collision system, the large magnitude of v(2) and its similarity to hydrodynamic predictions provide additional evidence for the importance of final-state effects in p + Pb reactions.
Place, publisher, year, edition, pages
2013. Vol. 725, no 1-3, 60-78 p.
IdentifiersURN: urn:nbn:se:uu:diva-207089DOI: 10.1016/j.physletb.2013.06.057OAI: oai:DiVA.org:uu-207089DiVA: diva2:646540
ATLAS Collaboration, for complete list of authors see http://dx.doi.org/10.1016/j.physletb.2013.06.0572013-09-092013-09-092014-06-23Bibliographically approved