arXiv:hep-ph/0406135·v2·High Energy Physics — Phenomenology
The spread of the gluon k_t-distribution and the determination of the saturation scale at hadron colliders in resummed NLL BFKL
V. A. Khoze🇬🇧 · A. D. Martin🇬🇧 · M. G. Ryskin🇬🇧 · W. J. Stirling🇬🇧
Abstract
The transverse momentum distribution of soft hadrons and jets that accompany central hard-scattering production at hadron colliders is of great importance, since it has a direct bearing on the ability to separate new physics signals from Standard Model backgrounds. We compare the predictions for the gluonic k_t-distribution using two different approaches: resummed NLL BFKL and DGLAP evolution. We find that as long as the initial and final virtualities (k_t) along the emission chain are not too close to each other, the NLL resummed BFKL results do not differ significantly from those obtained using standard DGLAP evolution. The saturation momentum Q_s(x), calculated within the resummed BFKL approach, grows with 1/x even slower than in the leading-order DGLAP case.
Comments: 24 pages, 8 figures, An improved, slightly more precise NLL resummation is used and the figures are updated accordingly. The conclusions are unchanged