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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Measurements of long-range azimuthal anisotropies and associated Fourier coefficients for pp collisions at √s = 5.02 and 13 TeV and p + Pb collisions at √sNN = 5.02 TeV with the ATLAS detector
AU - Barton, Adam Edward
AU - Beattie, Michael
AU - Bertram, Iain Alexander
AU - Borissov, Guennadi
AU - Bouhova-Thacker, Evelina Vassileva
AU - Dearnaley, William
AU - Fox, Harald
AU - Grimm, Kathryn Ann Tschann
AU - Henderson, Robert Charles William
AU - Hughes, Gareth
AU - Jones, Roger William Lewis
AU - Kartvelishvili, Vakhtang
AU - Long, Robin Eamonn
AU - Love, Peter Allan
AU - Muenstermann, Daniel Matthias Alfred
AU - Parker, Adam Jackson
AU - Skinner, Malcolm
AU - Smizanska, Maria
AU - Walder, James William
AU - Wharton, Andy
AU - The ATLAS collaboration
PY - 2017/8/22
Y1 - 2017/8/22
N2 - ATLAS measurements of two-particle correlations are presented for √s =5.02 and 13 TeV pp collisions and for √sNN =5.02 TeV p+Pb collisions at the LHC. The correlation functions are measured as a function of relative azimuthal angle Δϕ, and pseudorapidity separation Δη, using charged particles detected within the pseudorapidity interval |η|<2.5. Azimuthal modulation in the long-range component of the correlation function, with |Δη|>2, is studied using a template fitting procedure to remove a “back-to-back” contribution to the correlation function that primarily arises from hard-scattering processes. In addition to the elliptic, cos(2Δϕ), modulation observed in a previous measurement, the pp correlation functions exhibit significant cos(3Δϕ) and cos(4Δϕ) modulation. The Fourier coefficients vn,n associated with the cos(nΔϕ) modulation of the correlation functions for n=2–4 are measured as a function of charged-particle multiplicity and charged-particle transverse momentum. The Fourier coefficients are observed to be compatible with cos(nϕ) modulation of per-event single-particle azimuthal angle distributions. The single-particle Fourier coefficients vn are measured as a function of charged-particle multiplicity, and charged-particle transverse momentum for n=2–4. The integrated luminosities used in this analysis are, 64 nb−1 for the √s =13 TeV pp data, 170 nb−1 for the √s =5.02 TeV pp data, and 28 nb−1 for the √sNN =5.02 TeV p+Pb data.
AB - ATLAS measurements of two-particle correlations are presented for √s =5.02 and 13 TeV pp collisions and for √sNN =5.02 TeV p+Pb collisions at the LHC. The correlation functions are measured as a function of relative azimuthal angle Δϕ, and pseudorapidity separation Δη, using charged particles detected within the pseudorapidity interval |η|<2.5. Azimuthal modulation in the long-range component of the correlation function, with |Δη|>2, is studied using a template fitting procedure to remove a “back-to-back” contribution to the correlation function that primarily arises from hard-scattering processes. In addition to the elliptic, cos(2Δϕ), modulation observed in a previous measurement, the pp correlation functions exhibit significant cos(3Δϕ) and cos(4Δϕ) modulation. The Fourier coefficients vn,n associated with the cos(nΔϕ) modulation of the correlation functions for n=2–4 are measured as a function of charged-particle multiplicity and charged-particle transverse momentum. The Fourier coefficients are observed to be compatible with cos(nϕ) modulation of per-event single-particle azimuthal angle distributions. The single-particle Fourier coefficients vn are measured as a function of charged-particle multiplicity, and charged-particle transverse momentum for n=2–4. The integrated luminosities used in this analysis are, 64 nb−1 for the √s =13 TeV pp data, 170 nb−1 for the √s =5.02 TeV pp data, and 28 nb−1 for the √sNN =5.02 TeV p+Pb data.
U2 - 10.1103/PhysRevC.96.024908
DO - 10.1103/PhysRevC.96.024908
M3 - Journal article
VL - 96
JO - Physical Review C
JF - Physical Review C
SN - 0556-2813
IS - 2
M1 - 024908
ER -