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Related papers: The singular behavior of one-loop massive QCD ampl…

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We consider the process containing two quark lines and an arbitrary number of gluons in a spinor helicity framework. A current with two off-shell gluons appears in the amplitude. We first study this modified gluon current using recursion…

High Energy Physics - Phenomenology · Physics 2009-10-22 G. Mahlon , T. M. Yan , C. Dunn

In this work, we perform a lattice QCD study of the intrinsic, rapidity-independent soft function within the framework of large momentum effective theory. The computation is carried out using a gauge ensemble of $N_f=2+1+1$ clover-improved…

We discuss what happens at the end of the QCD cascades. We show that, with just a few reasonable assumptions, the emission of soft gluons is constrained to produce an ordered field in the form of a helix. We describe how to modify the Lund…

High Energy Physics - Phenomenology · Physics 2009-10-31 B. Andersson , G. Gustafson , J. Hakkinen , M. Ringner , Peter Sutton

We study QCD effects in single graviton production at the CERN Large Hadron Collider (LHC) in the Randall-Sundrum (RS) Model. We present in detail the complete next-to-leading order (NLO) QCD corrections to the inclusive total cross…

High Energy Physics - Phenomenology · Physics 2008-11-26 Qiang Li , Chong Sheng Li , Li Lin Yang

We consider the cross section for one-particle inclusive production at high transverse momentum in hadronic collisions. We present the all-order resummation formula that controls the logarithmically-enhanced perturbative QCD contributions…

High Energy Physics - Phenomenology · Physics 2013-07-25 S. Catani , M. Grazzini , A. Torre

We discuss the structure of infrared singularities in on-shell QCD amplitudes with massive partons and present a general factorization formula in the limit of small parton masses. The factorization formula gives rise to an all-order…

High Energy Physics - Phenomenology · Physics 2010-10-27 A. Mitov , S. Moch

I present results for two-loop soft anomalous dimensions for heavy quark production which control soft-gluon resummation at next-to-next-to-leading-logarithm (NNLL) accuracy. I derive an explicit expression for the exact result and study it…

High Energy Physics - Phenomenology · Physics 2009-10-08 Nikolaos Kidonakis

I present a master formula for the next-to-next-to-leading order (NNLO) soft and virtual QCD corrections for any process in hadron-hadron and lepton-hadron colliders. The formula is derived from a unified threshold resummation formalism.…

High Energy Physics - Phenomenology · Physics 2007-05-23 Nikolaos Kidonakis

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…

High Energy Physics - Phenomenology · Physics 2009-11-11 Yu. L. Dokshitzer , G. Marchesini

We use on-shell recursion relations to determine the one-loop QCD scattering amplitudes with a massless external quark pair and an arbitrary number (n-2) of positive-helicity gluons. These amplitudes are the last of the unknown infrared-…

High Energy Physics - Phenomenology · Physics 2010-11-15 Zvi Bern , Lance J. Dixon , David A. Kosower

The effective action for reggeized gluons is based on the gluodynamic Yang-Mills Lagrangian with external current for longitudinal gluons added, see [1]. On the base of classical solutions, obtained in [2], the one-loop corrections to this…

High Energy Physics - Theory · Physics 2017-10-25 S. Bondarenko , L. Lipatov , S. Pozdnyakov , A. Prygarin

We extend the generalized D-dimensional unitarity method for numerical evaluation of one-loop amplitudes by incorporating massive particles. The issues related to extending the spinor algebra to higher dimensions, treatment of external…

High Energy Physics - Phenomenology · Physics 2010-04-21 R. K. Ellis , W. T. Giele , Z. Kunszt , K. Melnikov

We discuss the structure of infrared and ultraviolet singularities in on-shell QCD and supersymmetric QCD amplitudes at one-loop order. Previous results, valid for massless partons, are extended to the case of massive partons. Using…

High Energy Physics - Phenomenology · Physics 2014-11-17 Stefano Catani , Stefan Dittmaier , Zoltan Trocsanyi

We calculate the one-loop QCD corrections for the decay of an off-shell vector boson with vector couplings into two pairs of quarks of equal or unequal flavours keeping all orders in the number of colours. These matrix elements are relevant…

High Energy Physics - Phenomenology · Physics 2008-11-26 E. W. N. Glover , D. J. Miller

We consider QCD radiative corrections to WW pair production in hadron collisions. We perform a calculation that consistently combines next-to-leading order predictions with soft-gluon resummation valid at small transverse momenta ptWW of…

High Energy Physics - Phenomenology · Physics 2009-11-11 M. Grazzini

We study the effect of soft gluon emission in the hadroproduction of gluino-gluino and squark-antisquark pairs at the next-to-leading logarithmic (NLL) accuracy within the framework of the minimal supersymmetric model. We present the…

High Energy Physics - Phenomenology · Physics 2009-11-10 A. Kulesza , L. Motyka

We present the two-loop virtual QCD corrections to the production of heavy quarks in gluon fusion. The results are exact in the limit when all kinematical invariants are large compared to the mass of the heavy quark up to terms suppressed…

High Energy Physics - Phenomenology · Physics 2010-04-05 M. Czakon , A. Mitov , S. Moch

We explain how one-loop amplitudes with massive fermions can be computed using only on-shell information. We first use the spinor-helicity formalism in six dimensions to perform generalised unitarity cuts in $d$ dimensions. We then show…

High Energy Physics - Phenomenology · Physics 2017-08-02 Simon Badger , Christian Brønnum-Hansen , Francesco Buciuni , Donal O'Connell

We compute the spectrum of gluons emitted by a highly energetic quark inside a flowing QCD medium, focusing on the soft gluon limit at first order in the opacity expansion. Specifically, we derive the leading energy-suppressed corrections…

High Energy Physics - Phenomenology · Physics 2024-06-24 Matvey V. Kuzmin , Xoán Mayo López

A "natural" model for the QCD invariant (running) coupling, free of the IR singularity, is proposed. It is based upon the hypothesis of finite gluon mass $ m_{gl}$ existence and, technically, uses an accurate treating of threshold behavior…

High Energy Physics - Phenomenology · Physics 2014-11-17 D. V. Shirkov