UP - logo
E-viri
Celotno besedilo
Odprti dostop
  • Alfred, M; Awes, T C; Azmoun, B; Baumann, C; Beaumier, M; Beckman, S; Belmont, R; Berdnikov, A; Bok, J S; Bumazhnov, V; Butsyk, S; Cervantes, R; Chiu, M; Choi, I J; Cianciolo, V; Citron, Z; Cronin, N; Datta, A; Desmond, E J; Dion, A; Do, J H; D'Orazio, L; Esumi, S; Feege, N; Gainey, K; Garishvili, A; H Ge; R Granier de Cassagnac; Gunji, T; Hachiya, T; Hahn, K I; Hill, K; Homma, K; Ichihara, T; Imazu, Y; Isenhower, D; Z Ji; Jia, J; Johnson, B M; Joo, E; Kang, B H; Kawall, D; Kim, D J; Y -J Kim; Kistenev, E; Kleinjan, D; Koster, J; Lallow, E O; Lee, G H; Leung, Y H; Liu, M X; Makek, M; Mihalik, D E; Miller, A J; Mishra, D K; Mitchell, J T; Mitsuka, G; Miyasaka, S; Morrison, D P; Moukhanova, T V; Nagae, T; Nagamiya, S; Nagashima, K; Nagy, M I; Nakagomi, H; Nakamiya, Y; Nakamura, K R; Nouicer, R; Osborn, J D; Park, S; Patel, L; Patel, M; Phipps, M; Pisani, R P; Pun, A; Rowan, Z; Sako, H; Seidl, R; Shigaki, K; Shukla, P; Singh, V; Smith, K L; Snowball, M; Stone, M R; Sukhanov, A; Takahara, A; Timilsina, A; Todoroki, T; Towell, C L; Vazquez-Carson, S; Vazquez-Zambrano, E; Watanabe, D; Wysocki, M; Q Xu; Yamaguchi, Y L; Yoon, I; You, Z; Younus, I; Zharko, S; Zou, L

    arXiv.org, 02/2017
    Paper

    Dihadron and isolated direct photon-hadron angular correlations are measured in $p$$+$$p\( collisions at \)\sqrt{s}=510\( GeV. Correlations of charged hadrons of \)0.7<p_T<10\( GeV/\)c\( with \)\pi^0\( mesons of \)4<p_T<15\( GeV/\)c\( or isolated direct photons of \)7<p_T<15\( GeV/\)c\( are used to study nonperturbative effects generated by initial-state partonic transverse momentum and final-state transverse momentum from fragmentation. The nonperturbative behavior is characterized by measuring the out-of-plane transverse momentum component \)p_{\rm out}\( perpendicular to the axis of the trigger particle, which is the high-\)p_T\( direct photon or \)\pi^0\(. Nonperturbative evolution effects are extracted from Gaussian fits to the away-side inclusive-charged-hadron yields for different trigger-particle transverse momenta (\)p_T^{\rm trig}\(). The Gaussian widths and root mean square of \)p_{\rm out}\( are reported as a function of the interaction hard scale \)p_T^{\rm trig}\( to investigate possible transverse-momentum-dependent evolution differences between the \)\pi^0\(-h\)^\pm\( and direct photon-h\)^\pm\( correlations and factorization breaking effects. The widths are found to decrease with \)p_T^{\rm trig}\(, which indicates that the Collins-Soper-Sterman soft factor is not driving the evolution with the hard scale in nearly back-to-back dihadron and direct photon-hadron production in \)p$$+$$p$ collisions. This behavior is in contrast to Drell-Yan and semi-inclusive deep-inelastic scattering measurements.