Low-mass lepton pair production at large transverse momentum
Low-mass lepton pair production at large transverse momentum
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DOI：
10.1103/physrevd.79.054007
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发表时间：
2008-10
影响因子：
5
通讯作者：
Z. Kang;J. Qiu;W. Vogelsang
中科院分区：
文献类型：
--
作者：
Z. Kang;J. Qiu;W. Vogelsang
We study the transverse momentum distribution of low-mass lepton pairs produced in hadronic scattering, using the perturbative QCD factorization approach. We argue that the distribution at large transverse momentum, Q{sub T}>>Q, with the pair's invariant mass Q as low as Q{approx}{lambda}{sub QCD}, can be systematically factorized into universal parton-to-lepton pair fragmentation functions, parton distributions, and perturbatively calculable partonic hard parts evaluated at a short-distance scale {approx}O(1/Q{sub T}). We introduce a model for the input lepton pair fragmentation functions at a scale {mu}{sub 0}{approx}1 GeV, which are then evolved perturbatively to scales relevant at the Relativistic Heavy Ion Collider. Using the evolved fragmentation functions, we calculate the transverse momentum distributions in hadron-hadron, hadron-nucleus, and nucleus-nucleus collisions at the Relativistic Heavy Ion Collider. We also discuss the sensitivity of the transverse momentum distribution of low-mass lepton pairs to the gluon distribution.
We study the transverse momentum distribution of low-mass lepton pairs produced in hadronic scattering, using the perturbative QCD factorization approach. We argue that the distribution at large transverse momentum, Q{sub T}>>Q, with the pair's invariant mass Q as low as Q{approx}{lambda}{sub QCD}, can be systematically factorized into universal parton-to-lepton pair fragmentation functions, parton distributions, and perturbatively calculable partonic hard parts evaluated at a short-distance scale {approx}O(1/Q{sub T}). We introduce a model for the input lepton pair fragmentation functions at a scale {mu}{sub 0}{approx}1 GeV, which are then evolved perturbatively to scales relevant at the Relativistic Heavy Ion Collider. Using the evolved fragmentation functions, we calculate the transverse momentum distributions in hadron-hadron, hadron-nucleus, and nucleus-nucleus collisions at the Relativistic Heavy Ion Collider. We also discuss the sensitivity of the transverse momentum distribution of low-mass lepton pairs to the gluon distribution.