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Related papers: Two-loop QCD corrections to massless quark-gluon s…

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The complete two-loop correction to the quark propagator, consisting of the spider, rainbow, gluon bubble and quark bubble diagrams, is evaluated in the noncovariant light-cone gauge (lcg). (The overlapping self-energy diagram had already…

High Energy Physics - Theory · Physics 2015-06-26 George Leibbrandt , Jimmy D. Williams

We consider the radiation of a soft gluon ($g$) and a soft quark-antiquark ($q{\bar q}$) pair in QCD hard scattering. In the soft limit the scattering amplitude has a singular behaviour that is factorized and controlled by a soft current,…

High Energy Physics - Phenomenology · Physics 2023-02-01 Stefano Catani , Leandro Cieri , Dimitri Colferai , Francesco Coradeschi

We have computed the even-$N$ moments $N \leq 20$ of the gluon-to-quark splitting function $P_{\rm qg}$ at the fourth order of perturbative QCD via the renormalization of off-shell operator matrix elements. Our results, derived analytically…

High Energy Physics - Phenomenology · Physics 2024-04-16 G. Falcioni , F. Herzog , S. Moch , A. Vogt

We study two-loop corrections to the scattering amplitude of four massive leptons in quantum electrodynamics. These amplitudes involve previously unknown elliptic Feynman integrals, which we compute analytically using the differential…

High Energy Physics - Phenomenology · Physics 2023-11-14 Maximilian Delto , Claude Duhr , Lorenzo Tancredi , Yu Jiao Zhu

We find that scattering amplitudes in massive scalar QCD can manifest the duality between color and kinematics at loop-level. Specifically we construct the one-loop integrands for four-point scattering between two distinct massive scalars,…

High Energy Physics - Theory · Physics 2021-02-10 John Joseph M. Carrasco , Ingrid A. Vazquez-Holm

We calculate the two-loop virtual, UV renormalized corrections at order \alpha^4 (N_F=1) in QED to the Bhabha scattering differential cross section, for arbitrary values of the squared c.m. energy s and momentum transfer t, and on-shell…

High Energy Physics - Phenomenology · Physics 2009-11-10 R. Bonciani , A. Ferroglia , P. Mastrolia , E. Remiddi , J. J. van der Bij

At small momentum transfer, the quark-gluon scattering cross section d{\sigma}/dt has a power-law divergence in the backward scattering region where the outgoing quark is nearly collinear to the incoming gluon. In this Regge limit |t|<< s,…

High Energy Physics - Phenomenology · Physics 2022-03-02 Arindam Bhattacharya , Aneesh V. Manohar , Matthew D. Schwartz

The high-energy factorization of gauge theory scattering amplitudes in terms of universal impact factors and a Reggeized exchange in the $t$-channel, corresponding to a Regge pole in the angular momentum plane, is know to conflict with the…

High Energy Physics - Phenomenology · Physics 2013-12-19 Vittorio Del Duca , Giulio Falcioni , Lorenzo Magnea , Leonardo Vernazza

The loop-tree duality (LTD) theorem establishes that loop contributions to scattering amplitudes can be computed through dual integrals, which are build from single cuts of the virtual diagrams. In order to build a complete LTD…

High Energy Physics - Phenomenology · Physics 2017-11-22 N. Selomit Ramírez-Uribe , Roger J. Hernández-Pinto , Germán Rodrigo

We present the two-loop pure gauge contribution to the gluon-gluon scattering amplitude with maximal helicity violation. Our construction of the amplitude does not rely directly on Feynman diagrams, but instead uses its analytic properties…

High Energy Physics - Phenomenology · Physics 2011-06-27 Z. Bern , L. Dixon , D. A. Kosower

We obtain a simple relation between massless and massive scattering amplitudes in gauge theories in the limit where all kinematic invariants are large compared to particle masses. We use this relation to derive the two-loop QED corrections…

High Energy Physics - Phenomenology · Physics 2009-11-13 Thomas Becher , Kirill Melnikov

The sophistication of current predictions for $Z+$jet production at hadron colliders necessitates a re-evaluation of any approximations inherent in the theoretical calculations. In this paper we address one such issue, the inclusion of mass…

High Energy Physics - Phenomenology · Physics 2017-02-01 John M. Campbell , R. Keith Ellis

We present an analytical calculation of the two-loop QCD corrections to the electromagnetic form factor of heavy quarks. The two-loop contributions to the form factor are reduced to linear combinations of master integrals, which are…

High Energy Physics - Phenomenology · Physics 2009-07-29 J. Gluza , A. Mitov , S. Moch , T. Riemann

The resummation of soft gluon exchange for QCD hard scattering requires a matrix of anomalous dimensions. We compute this matrix directly for arbitrary 2 to n massless processes for the first time at two loops. Using color generator…

High Energy Physics - Phenomenology · Physics 2009-04-06 S. Mert Aybat , Lance J. Dixon , George Sterman

We calculate the one-loop non-factorizable QCD corrections to the production and decay of pairs of top quarks at various collider experiments. These non-factorizable corrections interconnect the different production and decay stages of the…

High Energy Physics - Phenomenology · Physics 2009-10-31 W. Beenakker , F. A. Berends , A. P. Chapovsky

We consider the leading post-Newtonian and quantum corrections to the non-relativistic scattering amplitude of charged scalars in the combined theory of general relativity and scalar QED. The combined theory is treated as an effective field…

High Energy Physics - Theory · Physics 2009-11-07 N. E. J. Bjerrum-Bohr

We present the result for the two-loop and the one-loop squared virtual QCD corrections to the W boson pair production in the quark-anti-quark-annihilation channel in the limit where all kinematical invariants are large compared to the mass…

High Energy Physics - Phenomenology · Physics 2009-01-26 G. Chachamis , M. Czakon , D. Eiras

In this paper we compute the QCD corrections for the triple Higgs boson production cross section via gluon fusion, within the heavy-top approximation. We present, for the first time, analytical results for the next-to-leading order…

High Energy Physics - Phenomenology · Physics 2017-03-08 Daniel de Florian , Javier Mazzitelli

Lattice QCD studies of hadron-hadron interactions are performed by computing the energy levels of the system in a finite box. The shifts in energy levels proportional to inverse powers of the volume are related to scattering parameters in a…

High Energy Physics - Lattice · Physics 2014-11-17 Paulo F. Bedaque , Ikuro Sato , Andre Walker-Loud

We present a semi-numerical algorithm to calculate one-loop virtual corrections to scattering amplitudes. The divergences of the loop amplitudes are regulated using dimensional regularization. We treat in detail the case of amplitudes with…

High Energy Physics - Phenomenology · Physics 2008-11-26 R. K. Ellis , W. T. Giele , G. Zanderighi