Multiplicity and transverse-momentum dependence of two- and four-particle correlations in pPb and PbPb collisions
S. Chatrchyan
,
M. Besançon
(1)
,
F. Couderc
(1)
,
M. Dejardin
(1)
,
D. Denegri
(1)
,
B. Fabbro
(1)
,
J.L. Faure
(1)
,
F. Ferri
(1)
,
S. Ganjour
(1)
,
A. Givernaud
(1)
,
P. Gras
(1)
,
G. Hamel de Monchenault
(1)
,
P. Jarry
(1)
,
E. Locci
(1)
,
J. Malcles
(1)
,
L. Millischer
(1)
,
A. Nayak
(1)
,
J. Rander
(1)
,
A. Rosowsky
(1)
,
M. Titov
(1)
,
S. Baffioni
(2)
,
F. Beaudette
(2)
,
L. Benhabib
(2)
,
M. Bluj
(2)
,
Pierre Busson
(2)
,
C. Charlot
(2)
,
N. Daci
(2)
,
T. Dahms
(2)
,
M. Dalchenko
(2)
,
L. Dobrzynski
(2)
,
A. Florent
(2)
,
R. Granier de Cassagnac
(2)
,
M. Haguenauer
(2)
,
P. Mine
(2)
,
C. Mironov
(2)
,
I.N. Naranjo
(2)
,
M. Nguyen
(2)
,
C. Ochando
(2)
,
P. Paganini
(2)
,
D. Sabes
(2)
,
R. Salerno
(2)
,
Y. Sirois
(2)
,
C. Veelken
(2)
,
A. Zabi
(2)
,
J.-L. Agram
(3)
,
J. Andrea
(3)
,
D. Bloch
(3)
,
D. Bodin
(3)
,
J.-M. Brom
(3)
,
E.C. Chabert
(3)
,
C. Collard
(3)
,
E. Conte
(3)
,
F. Drouhin
(3)
,
J.-C. Fontaine
(3)
,
D. Gele
(3)
,
U. Goerlach
(3)
,
C. Goetzmann
(3)
,
P. Juillot
(3)
,
A.-C. Le Bihan
(3)
,
P. van Hove
(3)
,
S. Gadrat
(4)
,
S. Beauceron
(5)
,
N. Beaupere
(5)
,
G. Boudoul
(5)
,
S. Brochet
(5)
,
J. Chasserat
(5)
,
R. Chierici
(5)
,
D. Contardo
(5)
,
P. Depasse
(5)
,
H. El Mamouni
(5)
,
J. Fay
(5)
,
S. Gascon
(5)
,
M. Gouzevitch
(5)
,
B. Ille
(5)
,
T. Kurca
(5)
,
M. Lethuillier
(5)
,
L. Mirabito
(5)
,
S. Perries
(5)
,
L. Sgandurra
(5)
,
V. Sordini
(5)
,
Y. Tschudi
(5)
,
M. Vander Donckt
(5)
,
P. Verdier
(5)
,
S. Viret
(5)
S. Chatrchyan
- Function : Author
Pierre Busson
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R. Granier de Cassagnac
- Function : Author
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C. Mironov
- Function : Author
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P. Paganini
- Function : Author
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J.-L. Agram
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C. Collard
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E. Conte
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P. van Hove
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M. Gouzevitch
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M. Lethuillier
- Function : Author
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- IdHAL : morgan-lethuillier
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V. Sordini
- Function : Author
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P. Verdier
- Function : Author
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S. Viret
- Function : Author
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Abstract
Measurements of two- and four-particle angular correlations for charged particles emitted in pPb collisions are presented over a wide range in pseudorapidity and full azimuth. The data, corresponding to an integrated luminosity of approximately 31 inverse nanobarns, were collected during the 2013 LHC pPb run at a nucleon-nucleon center-of-mass energy of 5.02 TeV by the CMS experiment. The results are compared to 2.76 TeV semi-peripheral PbPb collision data, collected during the 2011 PbPb run, covering a similar range of particle multiplicities. The observed correlations are characterized by the near-side (abs(Delta(phi)~0) associated pair yields and the azimuthal anisotropy Fourier harmonics (v[n]). The second-order (v[2]) and third-order (v[3]) anisotropy harmonics are extracted using the two-particle azimuthal correlation technique. A four-particle correlation method is also applied to obtain the value of v[2] and further explore the multi-particle nature of the correlations. Both associated pair yields and anisotropy harmonics are studied as a function of particle multiplicity and transverse momentum. The associated pair yields, the four-particle v[2], and the v[3] become apparent at about the same multiplicity. A remarkable similarity in the v[3] signal as a function of multiplicity is observed between the pPb and PbPb systems. Predictions based on the color glass condensate and hydrodynamic models are compared to the experimental results.