Principal-component analysis of two-particle azimuthal correlations in PbPb and pPb collisions at CMS

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Principal-component analysis of two-particle azimuthal correlations in PbPb and pPb collisions at CMS. / The CMS collaboration.

In: Physical Review C, Vol. 96, No. 6, 064902, 05.12.2017.

Research output: Contribution to journal › Article › peer-review

BibTeX

@article{62053f3fbc224620a934fc6ec1065547,

title = "Principal-component analysis of two-particle azimuthal correlations in PbPb and pPb collisions at CMS",

abstract = "For the first time a principle-component analysis is used to separate out different orthogonal modes of the two-particle correlation matrix from heavy ion collisions. The analysis uses data from sNN=2.76TeV PbPb and sNN=5.02TeV pPb collisions collected by the CMS experiment at the CERN Large Hadron Collider. Two-particle azimuthal correlations have been extensively used to study hydrodynamic flow in heavy ion collisions. Recently it was shown that the expected factorization of two-particle results into a product of the constituent single-particle anisotropies is broken. The new information provided by these modes may shed light on the breakdown of flow factorization in heavy ion collisions. The first two modes ({"}leading{"} and {"}subleading{"}) of two-particle correlations are presented for elliptical and triangular anisotropies in PbPb and pPb collisions as a function of pT over a wide range of event activity. The leading mode is found to be essentially equivalent to the anisotropy harmonic previously extracted from two-particle correlation methods. The subleading mode represents a new experimental observable and is shown to account for a large fraction of the factorization breaking recently observed at high transverse momentum. The principle-component analysis technique was also applied to multiplicity fluctuations. These also show a subleading mode. The connection of these new results to previous studies of factorization is discussed.",

keywords = "QUARK-GLUON PLASMA, PERSPECTIVE, SPECTRA",

author = "{The CMS collaboration} and Sirunyan, {A. M.} and A. Tumasyan and W. Adam and F. Ambrogi and E. Asilar and T. Bergauer and J. Brandstetter and E. Brondolin and M. Dragicevic and J. Er{\"o} and M. Flechl and M. Friedl and R. Fr{\"u}hwirth and Ghete, {V. M.} and J. Grossmann and J. Hrubec and M. Jeitler and A. K{\"o}nig and N. Krammer and I. Kr{\"a}tschmer and D. Liko and T. Madlener and I. Mikulec and E. Pree and D. Rabady and N. Rad and H. Rohringer and J. Schieck and R. Sch{\"o}fbeck and M. Spanring and D. Spitzbart and J. Strauss and W. Waltenberger and J. Wittmann and Wulz, {C. E.} and M. Zarucki and V. Chekhovsky and V. Mossolov and {Suarez Gonzalez}, J. and {De Wolf}, {E. A.} and X. Janssen and J. Lauwers and {Van De Klundert}, M. and {Van Haevermaet}, H. and {Van Mechelen}, P. and {Van Remortel}, N. and {Van Spilbeeck}, A. and V. Blinov and Y. Skovpen and D. Shtol",

note = "Publisher Copyright: {\textcopyright}2017 CERN, for the CMS Collaboration. Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.",

year = "2017",

month = dec,

day = "5",

doi = "10.1103/PhysRevC.96.064902",

language = "English",

volume = "96",

journal = "Physical Review C",

issn = "2469-9985",

publisher = "American Physical Society",

number = "6",

}

RIS

TY - JOUR

T1 - Principal-component analysis of two-particle azimuthal correlations in PbPb and pPb collisions at CMS

AU - The CMS collaboration

AU - Sirunyan, A. M.

AU - Tumasyan, A.

AU - Adam, W.

AU - Ambrogi, F.

AU - Asilar, E.

AU - Bergauer, T.

AU - Brandstetter, J.

AU - Brondolin, E.

AU - Dragicevic, M.

AU - Erö, J.

AU - Flechl, M.

AU - Friedl, M.

AU - Frühwirth, R.

AU - Ghete, V. M.

AU - Grossmann, J.

AU - Hrubec, J.

AU - Jeitler, M.

AU - König, A.

AU - Krammer, N.

AU - Krätschmer, I.

AU - Liko, D.

AU - Madlener, T.

AU - Mikulec, I.

AU - Pree, E.

AU - Rabady, D.

AU - Rad, N.

AU - Rohringer, H.

AU - Schieck, J.

AU - Schöfbeck, R.

AU - Spanring, M.

AU - Spitzbart, D.

AU - Strauss, J.

AU - Waltenberger, W.

AU - Wittmann, J.

AU - Wulz, C. E.

AU - Zarucki, M.

AU - Chekhovsky, V.

AU - Mossolov, V.

AU - Suarez Gonzalez, J.

AU - De Wolf, E. A.

AU - Janssen, X.

AU - Lauwers, J.

AU - Van De Klundert, M.

AU - Van Haevermaet, H.

AU - Van Mechelen, P.

AU - Van Remortel, N.

AU - Van Spilbeeck, A.

AU - Blinov, V.

AU - Skovpen, Y.

AU - Shtol, D.

N1 - Publisher Copyright: ©2017 CERN, for the CMS Collaboration. Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

PY - 2017/12/5

Y1 - 2017/12/5

N2 - For the first time a principle-component analysis is used to separate out different orthogonal modes of the two-particle correlation matrix from heavy ion collisions. The analysis uses data from sNN=2.76TeV PbPb and sNN=5.02TeV pPb collisions collected by the CMS experiment at the CERN Large Hadron Collider. Two-particle azimuthal correlations have been extensively used to study hydrodynamic flow in heavy ion collisions. Recently it was shown that the expected factorization of two-particle results into a product of the constituent single-particle anisotropies is broken. The new information provided by these modes may shed light on the breakdown of flow factorization in heavy ion collisions. The first two modes ("leading" and "subleading") of two-particle correlations are presented for elliptical and triangular anisotropies in PbPb and pPb collisions as a function of pT over a wide range of event activity. The leading mode is found to be essentially equivalent to the anisotropy harmonic previously extracted from two-particle correlation methods. The subleading mode represents a new experimental observable and is shown to account for a large fraction of the factorization breaking recently observed at high transverse momentum. The principle-component analysis technique was also applied to multiplicity fluctuations. These also show a subleading mode. The connection of these new results to previous studies of factorization is discussed.

AB - For the first time a principle-component analysis is used to separate out different orthogonal modes of the two-particle correlation matrix from heavy ion collisions. The analysis uses data from sNN=2.76TeV PbPb and sNN=5.02TeV pPb collisions collected by the CMS experiment at the CERN Large Hadron Collider. Two-particle azimuthal correlations have been extensively used to study hydrodynamic flow in heavy ion collisions. Recently it was shown that the expected factorization of two-particle results into a product of the constituent single-particle anisotropies is broken. The new information provided by these modes may shed light on the breakdown of flow factorization in heavy ion collisions. The first two modes ("leading" and "subleading") of two-particle correlations are presented for elliptical and triangular anisotropies in PbPb and pPb collisions as a function of pT over a wide range of event activity. The leading mode is found to be essentially equivalent to the anisotropy harmonic previously extracted from two-particle correlation methods. The subleading mode represents a new experimental observable and is shown to account for a large fraction of the factorization breaking recently observed at high transverse momentum. The principle-component analysis technique was also applied to multiplicity fluctuations. These also show a subleading mode. The connection of these new results to previous studies of factorization is discussed.

KW - QUARK-GLUON PLASMA

KW - PERSPECTIVE

KW - SPECTRA

UR - http://www.scopus.com/inward/record.url?scp=85038612821&partnerID=8YFLogxK

U2 - 10.1103/PhysRevC.96.064902

DO - 10.1103/PhysRevC.96.064902

M3 - Article

AN - SCOPUS:85038612821

VL - 96

JO - Physical Review C

JF - Physical Review C

SN - 2469-9985

IS - 6

M1 - 064902

ER -

ID: 9865774