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Related papers: Use of Recursion Relations to Compute One-Loop Hel…

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Light cone perturbation theory has become an essential tool to calculate cross sections for various small-$x$ dilute-dense processes such as deep inelastic scattering and forward proton-proton and proton-nucleus collisions. Here we set out…

High Energy Physics - Phenomenology · Physics 2017-04-05 Tuomas Lappi , Risto Paatelainen

We propose an approach to compute one-loop corrections to the four-point amplitude in the higher spin gravities that are holographically dual to free $O(N)$, $U(N)$ and $USp(N)$ vector models. We compute the double-particle cut of one-loop…

High Energy Physics - Theory · Physics 2020-01-29 Dmitry Ponomarev , Ergin Sezgin , Evgeny Skvortsov

We present complete analytical ${\mathcal O}(\epsilon^2)$ results on the one-loop amplitudes relevant for the NNLO quark-parton model description of the hadroproduction of heavy quarks as given by the so-called loop-by-loop contributions.…

High Energy Physics - Phenomenology · Physics 2016-08-16 J. G. Körner , Z. Merebashvili , M. Rogal

The self-couplings of the electroweak gauge bosons are probed at hadron colliders through the production of a massive gauge boson and a photon. To extend the theoretical description of this type of final states towards…

High Energy Physics - Phenomenology · Physics 2020-12-09 Thomas Gehrmann , Lorenzo Tancredi

We describe methods for evaluating one-loop integrals in $4-2\e$ dimensions. We give a recursion relation that expresses the scalar $n$-point integral as a cyclicly symmetric combination of $(n-1)$-point integrals. The computation of such…

High Energy Physics - Phenomenology · Physics 2008-11-26 Z. Bern , L. Dixon , D. A. Kosower

We recently presented a new method for the evaluation of one-loop amplitude of arbitrary scattering processes, in which the reduction to scalar integrals is performed at the integrand level. In this talk, we review the main features of the…

High Energy Physics - Phenomenology · Physics 2007-09-17 Giovanni Ossola

In a previous paper a new approach has been introduced for computing, recursively and numerically, one-loop tensor integrals. Here we describe a few modifications of the original method that allow a more efficient numerical implementation…

High Energy Physics - Phenomenology · Physics 2007-05-23 R. Pittau

We calculate one loop scattering amplitudes for arbitrary number of positive helicity on-shell gluons and one off-shell gluon treated within the quasi-multi Regge kinematics. The result is fully gauge invariant and possesses the correct…

High Energy Physics - Phenomenology · Physics 2021-03-05 Etienne Blanco , Andreas van Hameren , Piotr Kotko , Krzysztof Kutak

We compute the part of the two-loop virtual amplitude for the process $gg \to V_1 V_2 \to (l_1 \bar l'_{1}) (l_2 \bar l'_2)$, where $V_{1,2}$ are arbitrary electroweak gauge bosons, that receives contributions from loops of massless quarks.…

High Energy Physics - Phenomenology · Physics 2015-04-02 Fabrizio Caola , Johannes M. Henn , Kirill Melnikov , Alexander V. Smirnov , Vladimir A. Smirnov

We develop the formal tools needed to construct helicity amplitudes for massive gravitino in N=1 SUGRA. We start by considering the helicity states for massive spin-3/2 particles, which involves the solutions of Rarita-Schwinger equation.…

High Energy Physics - Phenomenology · Physics 2017-11-28 J. Lorenzo Diaz-Cruz , Bryan O. Larios

We review recent progress in calculations of one-loop QCD amplitudes. By imposing the consistency requirements of unitarity and correct behavior as the momenta of two legs become collinear, we construct ansatze for one-loop amplitudes with…

High Energy Physics - Phenomenology · Physics 2008-02-03 Z. Bern , L. Dixon , D. Dunbar , D. A. Kosower

Hadron decay chains constitute one of the main sources of information on the QCD spectrum. We discuss the differences between several partial wave analysis formalisms used in the literature to build the amplitudes. We match the helicity…

We calculate one-loop 2-point tachyon amplitudes in unoriented open-closed string field theory, and determine all the coupling constants of the interaction vertices in the theory. It is shown that the planar, nonplanar and nonorientable…

High Energy Physics - Theory · Physics 2009-10-31 Tsuguhiko Asakawa , Taichiro Kugo , Tomohiko Takahashi

We compute the helicity amplitudes for the processes $gg\to Zg$ and $gg\to Z\gamma$ to two loops in massless QCD. The perturbative expansion of these processes starts only at the one-loop level, such that our results are a crucial…

High Energy Physics - Phenomenology · Physics 2023-08-21 Thomas Gehrmann , Lorenzo Tancredi , Erich Weihs

In this paper, we study three applications of recursion to problems in coding and random permutations. First, we consider locally recoverable codes with partial locality and use recursion to estimate the minimum distance of such codes. Next…

Combinatorics · Mathematics 2020-12-22 Ghurumuruhan Ganesan

We present a conjecture for the $n$-gluon one-loop amplitudes with maximal helicity violation. The conjecture emerges from the powerful requirement that the amplitudes have the correct behavior in the collinear limits of external momenta.…

High Energy Physics - Phenomenology · Physics 2010-11-15 Z. Bern , G. Chalmers , L. Dixon , D. A. Kosower

We present the one-loop QCD corrections to the helicity amplitudes for the processes $q\qb \to W^+ W^-, Z Z, W^\pm Z, W^\pm \gamma$, or $Z \gamma$, including the subsequent decay of each massive vector boson into a pair of leptons. We also…

High Energy Physics - Phenomenology · Physics 2010-11-15 L. Dixon , Z. Kunszt , A. Signer

Many search strategies for the Standard Model Higgs boson apply specific selection criteria on hadronic jets observed in association with the Higgs boson decay products, either in the form of a jet veto, or by defining event samples…

High Energy Physics - Phenomenology · Physics 2015-06-03 T. Gehrmann , M. Jaquier , E. W. N. Glover , A. Koukoutsakis

We study the recursive relations for a quiver gauge theory with the gauge group $SU(N_1)\times SU(N_2)$ with bifundamental fermions transforming as $(N_1,\bar{N_2})$. We work out the recursive relation for the amplitudes involving a pair of…

High Energy Physics - Theory · Physics 2009-11-11 Jaemo Park , Woojoo Sim

We present the first numerical results for the two-loop helicity amplitudes for the scattering of four partons and a W-boson in QCD. We use a finite field sampling method to reduce directly from Feynman diagrams to the coefficients of a set…

High Energy Physics - Phenomenology · Physics 2019-07-01 Heribertus Bayu Hartanto , Simon Badger , Christian Brønnum-Hansen , Tiziano Peraro