Soft gluons at large angles in hadron collisions
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In this paper, a general discussion is presented of the single logarithmic soft factor that appears in two scale QCD observables in processes involving four partons. But the authors treat it as the ''fifth form factor''', accompanying the four collinear singular Sudakov form factors attached to colliding and outgoing hard partons, and find an unexpected symmetry of the soft anomalous dimension under exchange of internal and external variables of the problem whose existence calls for explanation.Abstract:
A general discussion is presented of the single logarithmic soft factor that appears in two scale QCD observables in processes involving four partons. We treat it as the ``fifth form factor'', accompanying the four collinear singular Sudakov form factors attached to colliding and outgoing hard partons. The fifth form factor is expressed in terms of the Casimir operators (squared colour charges) of irreducible representations in the crossing t- and u-channels. As an application we revisit the problem of large angle radiation in gg→gg and give a relatively simple solution and interpretation of the results. We found an unexpected symmetry of the soft anomalous dimension under exchange of internal and external variables of the problem whose existence calls for explanation.read more
Citations
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Soft gluon resummation for the production of gluino-gluino and squark-antisquark pairs at the LHC
Anna Kulesza,L. Motyka +1 more
TL;DR: In this article, the effect of soft gluon emission in the hadroproduction of gluino-gluino and squark-antisquark pairs at the next-to-leading logarithmic accuracy within the framework of the minimal supersymmetric model was studied.
Journal ArticleDOI
Factorization constraints for soft anomalous dimensions in QCD scattering amplitudes
Einan Gardi,Lorenzo Magnea +1 more
TL;DR: In this article, the authors studied the factorization of soft and collinear singularities in dimensionally-regularized fixed-angle scattering amplitudes in massless gauge theories, and showed that the cancellation of these cusp anomalies in any multi-leg amplitude imposes all-order constraints on the kinematic dependence of the corresponding soft anomalous dimension.
Journal ArticleDOI
Two-loop soft anomalous dimension matrix and resummation at next-to-next-to-leading poles
TL;DR: In this article, the authors extended the resummation of dimensionally-regulated amplitudes to next-to-next-to leading poles, which requires the calculation of two-loop anomalous dimension matrices for color mixing through soft gluon exchange, and found that they are proportional to the corresponding one-loop matrices.
Journal ArticleDOI
Soft radiation in heavy-particle pair production: All-order colour structure and two-loop anomalous dimension
TL;DR: In this paper, the authors considered the total production cross section of heavy coloured particle pairs in hadronic collisions at the production threshold and derived an analytic expression for the two-loop soft anomalous dimension at threshold for all production processes of interest.
Journal ArticleDOI
Two-loop anomalous-dimension matrix for soft-gluon exchange.
TL;DR: The proportionality of the one- and two-loop matrices makes possible the resummation in closed form of the next-to-next- to-leading logarithms and poles in dimensional regularization for the 2-->n processes.
References
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