Dihadron and isolated direct photon-hadron angular correlations are measured in p+p collisions at √s = 200 GeV. The correlations are sensitive to nonperturbative initial-state and final-state transverse momentum kT and jT in the azimuthal nearly back-to-back region ∆φ ∼ π. In this region, transverse-momentum-dependent evolution can be studied when several different hard scales are measured. To have sensitivity to small transverse momentum scales, nonperturbative momentum widths of pout, the out-of-plane transverse momentum component perpendicular to the trigger particle, are measured. These widths are used to investigate possible effects from transverse-momentum-dependent factorization breaking. When accounting for the longitudinal momentum fraction of the away-side hadron with respect to the near-side trigger particle, the widths are found to increase with the hard scale; this is qualitatively similar to the observed behavior in Drell-Yan and semi-inclusive deep-inelastic scattering interactions. The momentum widths are also studied as a function of center-of-mass energy by comparing to previous measurements at √s = 510 GeV. The nonperturbative jet widths also appear to increase with √s at a similar xT, which is qualitatively consistent to similar measurements in Drell-Yan interactions. To quantify the magnitude of any transverse-momentum-dependent factorization breaking effects, calculations will need to be performed to compare to these measurements.
|Publication status||Published - 2018 May 7|
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