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Probing novel long-range correlation phenomena in pPb collisions with identified particles at CMS

Observation of a long-range near-side two-particle correlation (known as the Ridge) in high-multiplicity pp and pPb collisions opened up new opportunities of exploring novel QCD dynamics in small collision systems. To further investigate the origin of this phenomenon, studies of two-particle correl...

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Detalles Bibliográficos
Autor principal: Chen, Zhenyu
Lenguaje:eng
Publicado: 2014
Materias:
Acceso en línea:https://dx.doi.org/10.1088/1742-6596/612/1/012016
http://cds.cern.ch/record/1972010
Descripción
Sumario:Observation of a long-range near-side two-particle correlation (known as the Ridge) in high-multiplicity pp and pPb collisions opened up new opportunities of exploring novel QCD dynamics in small collision systems. To further investigate the origin of this phenomenon, studies of two-particle correlations with identified $K^0_s$ and Lambda trigger particles in 5.02 TeV pPb collisions are presented, and compared to PbPb collisions over a similar multiplicity range. The $K^0_s$ and Lambdas are cleanly reconstructed via their secondary decay vertices over a wide pseudorapidity and transverse momentum range. The second-order ($v_2$) and third-order ($v_3$) anisotropy harmonics of $K^0_s$ and Lambda are extracted from long-range correlations as a function of particle multiplicity and $p_T$. The wide $p_T$ coverage and rich sample of high multiplicity pPb events allow (1) a precise examination of the mass ordering effect of $v_n$ at low $p_T$ as predicted by hydrodynamics for a collectively expanding medium; (2) exploration of possible constituent quark number scaling of $v_2$ and $v_3$ between mesons and baryons as was observed in high-energy nucleus-nucleus collisions.