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Related papers: Generalized Gluon Currents and Applications in QCD

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Using newly proposed BCF/BCFW recursion relations, compact formulas are obtained for tree-level n-gluon amplitudes of helicity structure --++...+. We then make an extension of these recursion relations to include fermions of multi-flavors,…

High Energy Physics - Theory · Physics 2008-11-26 Mingxing Luo , Congkao Wen

The spectrum of coherent gluon radiation from a quark-anti-quark pair experiencing multiple scatterings within a coloured medium is central for understanding in-medium parton cascades. Despite its foundational importance, current results…

The method of calculation of effective vertices of interaction of the Reggeized gluon and quark with particles in QCD in the next-to-leading order is developed. The method is demonstrated in the case of already known vertices of both…

High Energy Physics - Phenomenology · Physics 2009-11-07 V. S. Fadin , R. Fiore

The one loop gluon - W-meson amplitude is calculated by means of the gauge-invariant generalized Pauli-Villars regularization and with the help of dimensional regularization. It is shown that in the former case the amplitude satisfies…

High Energy Physics - Theory · Physics 2009-10-31 M. M. Deminov , A. A. Slavnov

We present a calculation of the planar two-loop five-gluon amplitudes. The amplitudes are obtained in a variant of the generalized unitarity approach suitable for numerical computations, which we extend for use with finite field…

High Energy Physics - Phenomenology · Physics 2018-06-27 Samuel Abreu , Fernando Febres Cordero , Harald Ita , Ben Page , Mao Zeng

I describe how the gluon chain model of QCD string formation meets a number of criteria which are required of any theory of the confining force, including: the correct center dependence and (at large-N) Casimir scaling of the string…

High Energy Physics - Lattice · Physics 2007-05-23 J. Greensite

We use supersymmetric Ward identities to relate multi-gluon helicity amplitudes involving a pair of massive quarks to amplitudes with massive scalars. This allows to use the recent results for scalar amplitudes with an arbitrary number of…

High Energy Physics - Theory · Physics 2009-11-11 Christian Schwinn , Stefan Weinzierl

We systematically compute the effective short-range potentials arising from second order QCD-diagrams related to bound states of quarks, antiquarks, and gluons. Our formalism relies on the assumption that the exchanged gluons are massless,…

High Energy Physics - Phenomenology · Physics 2008-11-26 Vincent Mathieu , Fabien Buisseret

We present a program to evaluate tree-level multi-gluon amplitudes with up to two of them off-shell. Furthermore, it evaluates squared amplitudes summed over colors and helicities for up to six external gluons. It employs both analytic…

High Energy Physics - Phenomenology · Physics 2015-06-18 M. Bury , A. van Hameren

We calculate the contribution to the gravitational form factors (GFFs) from the gluon part of the energy-momentum tensor in QCD. We take a simple spin $1/2$ composite state, namely a quark dressed with a gluon. We use the light-front…

High Energy Physics - Phenomenology · Physics 2023-06-21 Jai More , Asmita Mukherjee , Sreeraj Nair , Sudeep Saha

We analyze the structure of generalized off-diagonal and transverse-momentum dependent quark-quark and gluon-gluon correlators for a spin-1/2 hadron. Using the light-front formalism, we provide a parametrization in terms of the parton…

High Energy Physics - Phenomenology · Physics 2015-06-16 C. Lorcé , B. Pasquini

By using the background field method of QCD in a path integral approach, we derive the equation of motion for the classical chromofield and for the gluon in a system containing the gluon and the classical chromofield simultaneously. This…

High Energy Physics - Theory · Physics 2009-10-31 Qun Wang , Chung-Wen Kao , Gouranga C. Nayak , Horst Stoecker , Walter Greiner

We propose a new ``universal expansion" for one-loop amplitudes with arbitrary number of gluons in $D$ dimensions, which holds for general gauge theories with gluons/fermions/scalars in the loop, including pure and supersymmetric Yang-Mills…

High Energy Physics - Theory · Physics 2024-12-30 Qu Cao , Jin Dong , Song He , Fan Zhu

This thesis aims at providing better understanding of the perturbative expansion of gauge theories with and without supersymmetry. At tree level, the BCFW recursion relations are analyzed with respect to their validity for general off-shell…

High Energy Physics - Theory · Physics 2014-09-30 Alexander Ochirov

The amplitude for scalar Higgs boson production in a fusion of two off-shell gluons is calculated including finite (not infinite) masses of quarks in the triangle loop. In comparison to the effective Lagrangian approach, we have found a new…

High Energy Physics - Phenomenology · Physics 2009-01-07 R. S. Pasechnik , O. V. Teryaev , A. Szczurek

We consider the multi-collinear limit of multi-gluon QCD amplitudes at tree level. We use the MHV rules for constructing colour ordered tree amplitudes and the general collinear factorisation formula to derive timelike splitting functions…

High Energy Physics - Phenomenology · Physics 2007-05-23 P. Marquard , T. G. Birthwright

The process e+e- ---> q(bar) q g g where all final particles are hard is treated in a semi-analytic approach. Cuts on the invariant masses of the quark and the gluon pair can be applied. The total cross section is obtained by three…

High Energy Physics - Phenomenology · Physics 2007-05-23 M. Jack , A. Leike

We study meson-meson interactions using an extended $q^2\bar{q}^2(g)$ basis that allows calculating coupling of an ordinary meson-meson system to a hybrid-hybrid one. We use a potential model matrix in this extended basis which at quark…

High Energy Physics - Phenomenology · Physics 2015-03-18 Nosheen Akbar , Bilal Masud

The QCD evolution equations in Modified Leading Log Approximation for the factorial moments of the multiplicity distribution in quark and gluon jets are numerically solved with initial conditions at threshold by fully taking into account…

High Energy Physics - Phenomenology · Physics 2009-10-31 Sergio Lupia

We present a new procedure using on-shell recursion to determine coefficients of integral functions appearing in one-loop scattering amplitudes of gauge theories, including QCD. With this procedure, coefficients of integrals, including…

High Energy Physics - Phenomenology · Physics 2009-11-11 Zvi Bern , N. E. J. Bjerrum-Bohr , David C. Dunbar , Harald Ita