18 research outputs found
Resonant particle production at hadron colliders
We present a method to compute off-shell effects for processes involving
resonant particles at hadron colliders with the possibility to include
realistic cuts on the decay products. The method is based on an effective
theory approach to unstable particle production and, as an example, is applied
to t-channel single top production at the LHC.Comment: 6 pages, to appear in the proceedings of the 9th International
Symposium on Radiative Corrections (RADCOR 2009), October 25-30 2009, Ascona,
Switzerlan
Threshold expansion of the gg(qq) -> QQ+X cross section at O(alpha_s^4)
We derive the complete set of velocity-enhanced terms in the expansion of the
total cross section for heavy-quark pair production in hadronic collisions at
next-to-next-to-leading order. Our expression takes into account the effects of
soft-gluon emission as well as that of potential-gluon exchanges. We prove that
there are no enhancements due to subleading soft-gluon couplings multiplying
the leading Coulomb singularity.Comment: 11 pages, 2 figures, published erratum included at the end of the
paper, updated attached Mathematica fil
BFKL at Next-to-Next-to-Leading Order
We determine an approximate expression for the O(alpha_s^3) contribution
chi_2 to the kernel of the BFKL equation, which includes all collinear and
anticollinear singular contributions. This is derived using recent results on
the relation between the GLAP and BFKL kernels (including running-coupling
effects to all orders) and on small-x factorization schemes. We present the
result in various schemes, relevant both for applications to the BFKL equation
and to small-x evolution of parton distributions.Comment: 34 pages, 6 figures, TeX with harvmac. Various small typos corrects,
in particular first term in eq D.3. Final version to be published in Nucl.
Phys.