Evidence for Collectivity in pp Collisions at the LHC
Physics Letters B 2017
CERN international group of authors, Viesturs Veckalns

Measurements of two- and multi-particle angular correlations in pp collisions at s=5,7, and 13TeV are presented as a function of charged-particle multiplicity. The data, corresponding to integrated luminosities of 1.0pb −1 (5 TeV), 6.2pb −1 (7 TeV), and 0.7pb −1 (13 TeV), were collected using the CMS detector at the LHC. The second-order (v 2 ) and third-order (v 3 ) azimuthal anisotropy harmonics of unidentified charged particles, as well as v 2 of K S 0 and Λ/Λ‾ particles, are extracted from long-range two-particle correlations as functions of particle multiplicity and transverse momentum. For high-multiplicity pp events, a mass ordering is observed for the v 2 values of charged hadrons (mostly pions), K S 0 , and Λ/Λ‾, with lighter particle species exhibiting a stronger azimuthal anisotropy signal below p T ≈2GeV/c. For 13 TeV data, the v 2 signals are also extracted from four- and six-particle correlations for the first time in pp collisions, with comparable magnitude to those from two-particle correlations. These observations are similar to those seen in pPb and PbPb collisions, and support the interpretation of a collective origin for the observed long-range correlations in high-multiplicity pp collisions.


Atslēgas vārdi
CMS, Correlation, Heavy ion, Physics, pp, Ridge
DOI
10.1016/j.physletb.2016.12.009
Hipersaite
https://www.sciencedirect.com/science/article/pii/S037026931630747X?via%3Dihub

international group of authors, C., Veckalns, V. Evidence for Collectivity in pp Collisions at the LHC. Physics Letters B, 2017, Vol.765, 193.-220.lpp. ISSN 0370-2693. Pieejams: doi:10.1016/j.physletb.2016.12.009

Publikācijas valoda
English (en)
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