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Nonperturbative-transverse-momentum effects and evolution in dihadron and direct photon-hadron angular correlations in p+p collisions at s =510 GeV

Adare, A ; Aidala, C. ; Ajitanand, N. N. ; Akiba, Y. ; Akimoto, R. ; Alexander, J J ; Alfred, M. ; Andrieux, V. ; Aoki, K. and Apadula, N , et al. (2017) In Physical Review D - Particles, Fields, Gravitation and Cosmology 95(7).
Abstract

Dihadron and isolated direct photon-hadron angular correlations are measured in p+p collisions at s=510 GeV. Correlations of charged hadrons of 0.7<pT<10 GeV/c with π0 mesons of 4<pT<15 GeV/c or isolated direct photons of 7<pT<15 GeV/c are used to study nonperturbative effects generated by initial-state partonic transverse momentum and final-state transverse momentum from fragmentation. The nonperturbative behavior is characterized by measuring the out-of-plane transverse momentum component pout perpendicular to the axis of the trigger particle, which is the high-pT direct photon or π0. Nonperturbative evolution effects are extracted from Gaussian fits to the away-side inclusive-charged-hadron yields for different... (More)

Dihadron and isolated direct photon-hadron angular correlations are measured in p+p collisions at s=510 GeV. Correlations of charged hadrons of 0.7<pT<10 GeV/c with π0 mesons of 4<pT<15 GeV/c or isolated direct photons of 7<pT<15 GeV/c are used to study nonperturbative effects generated by initial-state partonic transverse momentum and final-state transverse momentum from fragmentation. The nonperturbative behavior is characterized by measuring the out-of-plane transverse momentum component pout perpendicular to the axis of the trigger particle, which is the high-pT direct photon or π0. Nonperturbative evolution effects are extracted from Gaussian fits to the away-side inclusive-charged-hadron yields for different trigger-particle transverse momenta (pTtrig). The Gaussian widths and root mean square of pout are reported as a function of the interaction hard scale pTtrig to investigate possible transverse-momentum-dependent evolution differences between the π0-h± and direct photon-h± correlations and factorization breaking effects. The widths are found to decrease with pTtrig, which indicates that the Collins-Soper-Sterman soft factor is not driving the evolution with the hard scale in nearly back-to-back dihadron and direct photon-hadron production in p+p collisions. This behavior is in contrast to Drell-Yan and semi-inclusive deep-inelastic scattering measurements.

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organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physical Review D - Particles, Fields, Gravitation and Cosmology
volume
95
issue
7
article number
072002
publisher
American Physical Society
external identifiers
  • wos:000399390700001
  • scopus:85019564142
ISSN
2470-0010
DOI
10.1103/PhysRevD.95.072002
language
English
LU publication?
yes
id
18319945-325a-4931-8f45-e6265362f3d9
date added to LUP
2017-06-14 09:46:31
date last changed
2023-04-07 17:29:04
@article{18319945-325a-4931-8f45-e6265362f3d9,
  abstract     = {{<p>Dihadron and isolated direct photon-hadron angular correlations are measured in p+p collisions at s=510 GeV. Correlations of charged hadrons of 0.7&lt;pT&lt;10 GeV/c with π0 mesons of 4&lt;pT&lt;15 GeV/c or isolated direct photons of 7&lt;pT&lt;15 GeV/c are used to study nonperturbative effects generated by initial-state partonic transverse momentum and final-state transverse momentum from fragmentation. The nonperturbative behavior is characterized by measuring the out-of-plane transverse momentum component pout perpendicular to the axis of the trigger particle, which is the high-pT direct photon or π0. Nonperturbative evolution effects are extracted from Gaussian fits to the away-side inclusive-charged-hadron yields for different trigger-particle transverse momenta (pTtrig). The Gaussian widths and root mean square of pout are reported as a function of the interaction hard scale pTtrig to investigate possible transverse-momentum-dependent evolution differences between the π0-h± and direct photon-h± correlations and factorization breaking effects. The widths are found to decrease with pTtrig, which indicates that the Collins-Soper-Sterman soft factor is not driving the evolution with the hard scale in nearly back-to-back dihadron and direct photon-hadron production in p+p collisions. This behavior is in contrast to Drell-Yan and semi-inclusive deep-inelastic scattering measurements.</p>}},
  author       = {{Adare, A and Aidala, C. and Ajitanand, N. N. and Akiba, Y. and Akimoto, R. and Alexander, J J and Alfred, M. and Andrieux, V. and Aoki, K. and Apadula, N and Aramaki, Y and Asano, H. and Atomssa, E. T. and Awes, T. C. and Ayuso, Carmen and Azmoun, B. and Babintsev, V. and Bai, M and Bai, X. and Bandara, N. S. and Bannier, B and Barish, K N and Bathe, S and Baublis, V. and Baumann, C. and Baumgart, S. and Bazilevsky, A and Beaumier, M. and Beckman, S. and Belmont, R and Berdnikov, A and Berdnikov, Y. and Black, D and Blau, D. S. and Boer, M. and Bok, J S and Boyle, K and Brooks, M L and Bryslawskyj, J. and Buesching, H and Bumazhnov, V. and Butler, Christopher C. and Butsyk, S. and Campbell, S. and Canoa Roman, V. and Cervantes, R. and Christiansen, P. and Oskarsson, A. and Silvermyr, D. and Stenlund, E.}},
  issn         = {{2470-0010}},
  language     = {{eng}},
  month        = {{04}},
  number       = {{7}},
  publisher    = {{American Physical Society}},
  series       = {{Physical Review D - Particles, Fields, Gravitation and Cosmology}},
  title        = {{Nonperturbative-transverse-momentum effects and evolution in dihadron and direct photon-hadron angular correlations in p+p collisions at s =510 GeV}},
  url          = {{http://dx.doi.org/10.1103/PhysRevD.95.072002}},
  doi          = {{10.1103/PhysRevD.95.072002}},
  volume       = {{95}},
  year         = {{2017}},
}