Observation of Long-Range Elliptic Azimuthal Anisotropies in √s=13 and 2.76 TeV pp Collisions with the ATLAS Detector

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Observation of Long-Range Elliptic Azimuthal Anisotropies in √s=13 and 2.76 TeV pp Collisions with the ATLAS Detector. / The ATLAS collaboration.

In: Physical Review Letters, Vol. 116, No. 17, 172301, 27.04.2016.

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

BibTeX

@article{7e6540af7029441a82a8c756f512e0e5,

title = "Observation of Long-Range Elliptic Azimuthal Anisotropies in √s=13 and 2.76 TeV pp Collisions with the ATLAS Detector",

abstract = "ATLAS has measured two-particle correlations as a function of the relative azimuthal angle, Δφ, and pseudorapidity, Δη, in s=13 and 2.76 TeV pp collisions at the LHC using charged particles measured in the pseudorapidity interval |η|<2.5. The correlation functions evaluated in different intervals of measured charged-particle multiplicity show a multiplicity-dependent enhancement at Δφ∼0 that extends over a wide range of Δη, which has been referred to as the {"}ridge.{"} Per-trigger-particle yields, Y(Δφ), are measured over 2<|Δη|<5. For both collision energies, the Y(Δφ) distribution in all multiplicity intervals is found to be consistent with a linear combination of the per-trigger-particle yields measured in collisions with less than 20 reconstructed tracks, and a constant combinatoric contribution modulated by cos(2Δφ). The fitted Fourier coefficient, v2,2, exhibits factorization, suggesting that the ridge results from per-event cos(2φ) modulation of the single-particle distribution with Fourier coefficients v2. The v2 values are presented as a function of multiplicity and transverse momentum. They are found to be approximately constant as a function of multiplicity and to have a pT dependence similar to that measured in p+Pb and Pb+Pb collisions. The v2 values in the 13 and 2.76 TeV data are consistent within uncertainties. These results suggest that the ridge in pp collisions arises from the same or similar underlying physics as observed in p+Pb collisions, and that the dynamics responsible for the ridge has no strong s dependence.",

author = "{The ATLAS collaboration} and G. Aad and B. Abbott and J. Abdallah and O. Abdinov and R. Aben and M. Abolins and Abouzeid, {O. S.} and H. Abramowicz and H. Abreu and R. Abreu and Y. Abulaiti and Acharya, {B. S.} and L. Adamczyk and Adams, {D. L.} and J. Adelman and S. Adomeit and T. Adye and Affolder, {A. A.} and T. Agatonovic-Jovin and J. Agricola and Aguilar-Saavedra, {J. A.} and Ahlen, {S. P.} and F. Ahmadov and G. Aielli and H. Akerstedt and {\AA}kesson, {T. P.A.} and Akimov, {A. V.} and Alberghi, {G. L.} and J. Albert and S. Albrand and {Alconada Verzini}, {M. J.} and M. Aleksa and Aleksandrov, {I. N.} and C. Alexa and G. Alexander and T. Alexopoulos and Anisenkov, {A. V.} and Baldin, {E. M.} and Bobrovnikov, {V. S.} and Buzykaev, {A. R.} and Kazanin, {V. F.} and Kharlamov, {A. G.} and Korol, {A. A.} and Maslennikov, {A. L.} and Maximov, {D. A.} and Peleganchuk, {S. V.} and Rezanova, {O. L.} and Soukharev, {A. M.} and Talyshev, {A. A.} and Tikhonov, {Yu A.}",

note = "Publisher Copyright: {\textcopyright} 2016 CERN.",

year = "2016",

month = apr,

day = "27",

doi = "10.1103/PhysRevLett.116.172301",

language = "English",

volume = "116",

journal = "Physical Review Letters",

issn = "0031-9007",

publisher = "American Physical Society",

number = "17",

}

RIS

TY - JOUR

T1 - Observation of Long-Range Elliptic Azimuthal Anisotropies in √s=13 and 2.76 TeV pp Collisions with the ATLAS Detector

AU - The ATLAS collaboration

AU - Aad, G.

AU - Abbott, B.

AU - Abdallah, J.

AU - Abdinov, O.

AU - Aben, R.

AU - Abolins, M.

AU - Abouzeid, O. S.

AU - Abramowicz, H.

AU - Abreu, H.

AU - Abreu, R.

AU - Abulaiti, Y.

AU - Acharya, B. S.

AU - Adamczyk, L.

AU - Adams, D. L.

AU - Adelman, J.

AU - Adomeit, S.

AU - Adye, T.

AU - Affolder, A. A.

AU - Agatonovic-Jovin, T.

AU - Agricola, J.

AU - Aguilar-Saavedra, J. A.

AU - Ahlen, S. P.

AU - Ahmadov, F.

AU - Aielli, G.

AU - Akerstedt, H.

AU - Åkesson, T. P.A.

AU - Akimov, A. V.

AU - Alberghi, G. L.

AU - Albert, J.

AU - Albrand, S.

AU - Alconada Verzini, M. J.

AU - Aleksa, M.

AU - Aleksandrov, I. N.

AU - Alexa, C.

AU - Alexander, G.

AU - Alexopoulos, T.

AU - Anisenkov, A. V.

AU - Baldin, E. M.

AU - Bobrovnikov, V. S.

AU - Buzykaev, A. R.

AU - Kazanin, V. F.

AU - Kharlamov, A. G.

AU - Korol, A. A.

AU - Maslennikov, A. L.

AU - Maximov, D. A.

AU - Peleganchuk, S. V.

AU - Rezanova, O. L.

AU - Soukharev, A. M.

AU - Talyshev, A. A.

AU - Tikhonov, Yu A.

PY - 2016/4/27

Y1 - 2016/4/27

N2 - ATLAS has measured two-particle correlations as a function of the relative azimuthal angle, Δφ, and pseudorapidity, Δη, in s=13 and 2.76 TeV pp collisions at the LHC using charged particles measured in the pseudorapidity interval |η|<2.5. The correlation functions evaluated in different intervals of measured charged-particle multiplicity show a multiplicity-dependent enhancement at Δφ∼0 that extends over a wide range of Δη, which has been referred to as the "ridge." Per-trigger-particle yields, Y(Δφ), are measured over 2<|Δη|<5. For both collision energies, the Y(Δφ) distribution in all multiplicity intervals is found to be consistent with a linear combination of the per-trigger-particle yields measured in collisions with less than 20 reconstructed tracks, and a constant combinatoric contribution modulated by cos(2Δφ). The fitted Fourier coefficient, v2,2, exhibits factorization, suggesting that the ridge results from per-event cos(2φ) modulation of the single-particle distribution with Fourier coefficients v2. The v2 values are presented as a function of multiplicity and transverse momentum. They are found to be approximately constant as a function of multiplicity and to have a pT dependence similar to that measured in p+Pb and Pb+Pb collisions. The v2 values in the 13 and 2.76 TeV data are consistent within uncertainties. These results suggest that the ridge in pp collisions arises from the same or similar underlying physics as observed in p+Pb collisions, and that the dynamics responsible for the ridge has no strong s dependence.

AB - ATLAS has measured two-particle correlations as a function of the relative azimuthal angle, Δφ, and pseudorapidity, Δη, in s=13 and 2.76 TeV pp collisions at the LHC using charged particles measured in the pseudorapidity interval |η|<2.5. The correlation functions evaluated in different intervals of measured charged-particle multiplicity show a multiplicity-dependent enhancement at Δφ∼0 that extends over a wide range of Δη, which has been referred to as the "ridge." Per-trigger-particle yields, Y(Δφ), are measured over 2<|Δη|<5. For both collision energies, the Y(Δφ) distribution in all multiplicity intervals is found to be consistent with a linear combination of the per-trigger-particle yields measured in collisions with less than 20 reconstructed tracks, and a constant combinatoric contribution modulated by cos(2Δφ). The fitted Fourier coefficient, v2,2, exhibits factorization, suggesting that the ridge results from per-event cos(2φ) modulation of the single-particle distribution with Fourier coefficients v2. The v2 values are presented as a function of multiplicity and transverse momentum. They are found to be approximately constant as a function of multiplicity and to have a pT dependence similar to that measured in p+Pb and Pb+Pb collisions. The v2 values in the 13 and 2.76 TeV data are consistent within uncertainties. These results suggest that the ridge in pp collisions arises from the same or similar underlying physics as observed in p+Pb collisions, and that the dynamics responsible for the ridge has no strong s dependence.

UR - http://www.scopus.com/inward/record.url?scp=84971330904&partnerID=8YFLogxK

U2 - 10.1103/PhysRevLett.116.172301

DO - 10.1103/PhysRevLett.116.172301

M3 - Article

AN - SCOPUS:84971330904

VL - 116

JO - Physical Review Letters

JF - Physical Review Letters

SN - 0031-9007

IS - 17

M1 - 172301

ER -

ID: 34661231