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

Autori
Adare, A. ; ... ; Makek, Mihael ; ... ; Vukman, Nikola ; ... ; Zou, L.

Kolaboracija
PHENIX Collaboration

Izvornik
Physical review. D. (2470-0010) 95 (2017), 7; 072002, 19

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
spin production asymmetries ; deep-inelastic scattering ; proton-proton collisions ; final-state interactions ; jet fragmentation ; boson production ; color coherence ; hard-scattering ; Drell-Yan ; PHENIX

Sažetak
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 inclusivecharged-hadron yields for different trigger-particle transverse momenta (ptrig T ). The Gaussian widths and root mean square of pout are reported as a function of the interaction hard scale ptrig T 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 ptrig T , 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.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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