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Related papers: One-loop amplitudes with an off-shell gluon

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Within the effective QCD action for the Regge kinematics amplitudes for virtual gluon emission are studied in collision of a projectile with two and three targets. It is demonstrated that all un- Feynman singularities cancel between induced…

High Energy Physics - Phenomenology · Physics 2017-09-13 M. A. Braun , M. Yu. Salykin

We present experimental evidence for a first-order freezing/melting phase transition in a nonequilibrium system -- an oscillated two-dimensional isobaric granular fluid. The steady-state transition occurs between a gas and a crystal and is…

Soft Condensed Matter · Physics 2007-05-23 M. D. Shattuck

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

We consider the on-shell amplitudes in N=(1,1) SYM in D=6 dimensions within the spinor helicity and on-shell superspace formalism. This leads to an effective and straightforward technique reducing the calculation to a set of scalar master…

High Energy Physics - Theory · Physics 2015-06-16 L. V. Bork , D. I. Kazakov , D. E. Vlasenko

Knowledge of two-loop QCD amplitudes for processes $q\bar q \to V_1 V_2 \to (l_1\bar l'_1)(l_2 \bar l'_2)$ is important for improving the theoretical description of four-lepton production in hadron collisions. In this paper we compute these…

High Energy Physics - Phenomenology · Physics 2015-06-22 Fabrizio Caola , Johannes M. Henn , Kirill Melnikov , Alexander V. Smirnov , Vladimir A. Smirnov

We derive the analytic expression of the two one-loop dipole contributions to the elastic 4-gluon amplitude in QCD for arbitrary transverse momentum. The first one corresponds to the double QCD pomeron exchange, the other to an order…

High Energy Physics - Phenomenology · Physics 2007-05-23 H. Navelet , R. Peschanski

We present a new method for computing complete one-loop amplitudes, including their rational parts, in non-supersymmetric gauge theory. This method merges the unitarity method with on-shell recursion relations. It systematizes a…

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

It is shown that off-forward parton distributions for $\zeta =0$, i.e. where the initial and final state differ only in their transverse momenta, can be interpreted as a simultaneous measurement of the longitudinal momentum and transverse…

High Energy Physics - Phenomenology · Physics 2014-11-17 Matthias Burkardt

Motivated by recent findings on the separability of optical potentials that are derived from folding off-shell densities with off-shell nucleon-nucleon amplitudes, we study the off-shell character of one-body density matrices created within…

Nuclear Theory · Physics 2026-03-13 J. Foy , Ch. Elster , P. Maris , S. P. Weppner , S. K. Bogner

A simplest case, where a contribution to a color ordered multi-gluon amplitude, describing a three body partonic interaction, can split into two weakly correlated two-body gluon scattering amplitudes and may thus contribute to a Double…

High Energy Physics - Phenomenology · Physics 2016-02-16 Daniele Treleani , Giorgio Calucci

We report on the calculation of the three-loop polarized and unpolarized flavor non-singlet and the polarized singlet anomalous dimensions using massless off-shell operator matrix elements in a gauge-variant framework. We also reconsider…

High Energy Physics - Phenomenology · Physics 2022-07-19 J. Blümlein , P. Marquard , C. Schneider , K. Schönwald

One of the methods to calculate tree-level multi-gluon scattering amplitudes is to use the Berends-Giele recursion relation involving off-shell currents or off-shell amplitudes, if working in the light cone gauge. As shown in recent works…

High Energy Physics - Phenomenology · Physics 2016-08-24 Piotr Kotko , Mirko Serino , Anna M. Stasto

We study the decay process of the Z boson to a photon and a graviton. The most general form of the on-shell amplitude, subject to the constraints due to the conservation of the electromagnetic and the energy-momentum tensor, is determined.…

High Energy Physics - Phenomenology · Physics 2009-11-11 Jose F. Nieves , Palash B. Pal

In this work we obtain all the allowed values of the angular momentum and parity for two massless non-Abelian fields. In particular, we show that, unlike the two photons system, two gluons can be in a state with $J^P=1^\pm$, $(2k)^-$, and…

High Energy Physics - Phenomenology · Physics 2018-02-05 V. Pleitez

We show that, in analyzing differential equations obeyed by one-loop gauge theory amplitudes, one must take into account a certain holomorphic anomaly. When this is done, the results are consistent with the simplest twistor-space picture of…

High Energy Physics - Theory · Physics 2010-04-07 Freddy Cachazo , Peter Svrcek , Edward Witten

We give the light-cone gauge calculation of the one-loop on-shell scattering amplitudes for gluon-gluon scattering which violate helicity conservation. We regulate infrared divergences by discretizing the p^+ integrations, omitting the…

High Energy Physics - Theory · Physics 2009-11-11 D. Chakrabarti , J. Qiu , C. B. Thorn

We present the first calculation of two-quark and five-gluon tree amplitudes using on-shell recursion relations. These amplitudes are needed for tree level 5-jet cross-section and an essential ingredient for next-to-leading order 4-jet and…

High Energy Physics - Phenomenology · Physics 2015-06-25 Daniel de Florian , Jose Zurita

We investigate the gluon Wigner distributions for unpolarized, longitudinally polarized and transversely polarized target state. Instead of a nucleon, we take the target state to be a quark dressed with a gluon at one loop and investigate…

High Energy Physics - Phenomenology · Physics 2018-05-25 Jai More , Asmita Mukherjee , Sreeraj Nair

Magnetospheres of pulsars are thought to be filled with plasma, and variations in plasma supply can affect both pulsar emission properties and spin-down rates. A number of recently discovered "intermittent" pulsars switch between two…

High Energy Astrophysical Phenomena · Physics 2015-06-03 Jason Li , Anatoly Spitkovsky , Alexander Tchekhovskoy

We elaborate on the presence of a nonvanishing totally antisymmetric (super)torsion, equivalent to an axial vector, and higher forms in the "new minimal" and "old minimal" off-shell formulations of $\mathcal{N}=1$, $D=4$ supergravity. We…

High Energy Physics - Theory · Physics 2024-04-29 Lucrezia Ravera