The Gluon Sivers Distribution in D Production at Rhic
نویسنده
چکیده
The single transverse spin asymmetry in D meson production at RHIC can provide a clean measure of the gluon Sivers distribution function. At intermediate rapidity, D production is largely dominated by the elementary gg → cc̄ channel, where there cannot be any transverse spin transfer. Therefore, any transverse single spin asymmetry observed for D’s produced in pp interactions can only originate from the Sivers effect in the gluon distribution functions. A sizeable transverse single spin asymmetry measured by PHENIX or STAR experiments would then give direct information on the size of the gluon Sivers distribution function.
منابع مشابه
ar X iv : h ep - p h / 06 12 20 9 v 1 1 8 D ec 2 00 6 Constraints on Gluon Sivers Distribution from RHIC Results
We consider the recent RHIC data on the transverse single spin asymmetry (SSA) AN , measured in p↑p → π0 X processes at mid-rapidity by the PHENIX Collaboration. We analyze this experimental information within a hard scattering approach based on a generalized QCD factorization scheme, with unintegrated, transverse momentum dependent (TMD), parton distribution and fragmentation functions. In thi...
متن کاملar X iv : h ep - p h / 06 11 37 6 v 1 2 9 N ov 2 00 6 Gluon saturation effects on single spin asymmetries 1
We consider forward pion production in p p collisions at RHIC energies, which probes the so-called Extended Geometric Scaling region. Upon inclusion of small-x effects via an anomalous dimension within the Color Glass Condensate formalism at leading order in αs, a good description of the cross section as a function of the transverse momentum of the produced pion is obtained. The latter is essen...
متن کاملJet Production in Polarized pp Collisions at RHIC
One of the primary goals of the RHIC spin program is to determine the gluon polarization distribution within the proton. At leading order, pp collisions at RHIC involve a mixture of quark-quark (qq), quark-gluon (qg), and gluon-gluon (gg) scattering processes, with qg and gg contributions dominating. This makes RHIC an ideal place to study gluon polarization. For the past several years, the STA...
متن کاملRecent results from the STAR spin program at RHIC
The STAR experiment uses polarized p+p collisions at RHIC to determine the contributions to the spin of the proton from gluon spin and from orbital angular momentum of the quarks and gluons. Selective STAR measurements of the longitudinal double spin asymmetry for inclusive jet and inclusive hadron production are presented here. In addition, we report measurements of the transverse spin asymmet...
متن کاملTransverse single spin asymmetries in photon production
Transverse single-spin asymmetries (SSA) in inclusive reactions are now considered to be directly related to the transverse momentum kT of the fundamental partons involved in the process. We find that the ideal probe to extract information on the gluon Sivers function is the transverse SSA of prompt photon production pp → γX, at large pT . The following related processes, pp → γ + jet + X, pp →...
متن کامل