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In this article, we extend the %Weyl-van der Waerden spinor technique for calculating helicity amplitudes to general massive fields of half-integer spins. We find that the little group generators can be represented as first-order…

High Energy Physics - Theory · Physics 2012-04-09 Gang Chen , Konstantin G. Savvidy

We analyze the connections between the quark model (QM) and the description of hadrons in the low-momentum limit of heavy-baryon effective field theory in QCD. By using a three-flavor-index representation for the effective baryon fields, we…

High Energy Physics - Phenomenology · Physics 2009-11-07 Loyal Durand , Phuoc Ha , Gregory Jaczko

We present a quantitative study of vorticity formation in peripheral ultrarelativistic heavy ion collisions at sqrt(s)NN = 200 GeV by using the ECHO-QGP numerical code, implementing relativistic dissipative hydrodynamics in the causal…

We introduce a new color decomposition for multi-parton amplitudes in QCD, free of fundamental-representation matrices and structure constants. This decomposition has a physical interpretation in terms of the flow of color, which makes it…

High Energy Physics - Phenomenology · Physics 2009-11-07 F. Maltoni , K. Paul , T. Stelzer , S. Willenbrock

In this talk we discuss the results obtained in the new approach that we recently introduced to consider and include both the perturbative and nonperturbative contributions to the evolution of the gluon and quark avarage multiplicities. We…

High Energy Physics - Phenomenology · Physics 2012-11-26 P. Bolzoni

We calculate the gravitational form factors (GFFs) and pressure, shear and energy distributions for a quark state dressed with a gluon at one loop in QCD. We use the light-front Hamiltonian approach. In the light-front gauge, we use a…

High Energy Physics - Phenomenology · Physics 2022-04-06 Jai More , Asmita Mukherjee , Sreeraj Nair , Sudeep Saha

We study in this work the 2D dynamics of an experimental system of disk-shaped rotors, fluidized by turbulent upflow. Contrary to previous knowledge, our experiments show the same particle chiral geometry can produce flows with different…

We calculate the four-loop massless QCD corrections with two closed quark lines to quark and gluon form factors. The results for the gluon form factor and the singlet part of the quark form factor are given for the first time. From our…

High Energy Physics - Phenomenology · Physics 2019-07-22 Andreas von Manteuffel , Robert M. Schabinger

The contribution presents a summary of the Gauge/Gravity approach to the study of hydrodynamic flow of the quark-gluon plasma formed in heavy-ion collisions. Considering the ideal case of a supersymmetric Yang-Mills theory for which the…

High Energy Physics - Theory · Physics 2009-06-24 Michal P. Heller , Romuald A. Janik , R. Peschanski

Matrix elements of Wilson-line dressed operators play a central role in the factorization of soft and collinear modes in gauge theories. When expressed using spinor helicity variables, these so-called form factors admit a classification…

High Energy Physics - Phenomenology · Physics 2024-06-07 Timothy Cohen , Marc Riembau

We present a general formalism for simplifying manipulations of spin indices of massless and massive spinors and vectors in Feynman diagrams. The formalism is based on covariantly reducing the number of field components in the action in…

High Energy Physics - Phenomenology · Physics 2009-10-30 G. Chalmers , W. Siegel

We present the two-loop helicity amplitudes for the scattering of massless quarks and massless gauge bosons in QCD. We use projector techniques to compute the coefficients of the general tensor describing the two-quark two-boson amplitude…

High Energy Physics - Phenomenology · Physics 2010-02-03 E. W. N. Glover , M. E. Tejeda-Yeomans

The form factors for the hadron matrix element of the QCD energy-momentum tensor not only describe the coupling of the hadron with a graviton as the ``gravitational form factors'', but also serve as unique quantities for describing the…

High Energy Physics - Phenomenology · Physics 2020-01-08 Kazuhiro Tanaka

A QCD based effective action is constructed to describe the dynamics of confinement and symmetry breaking in the process of parton-hadron conversion. The deconfined quark and gluon degrees of freedom of the perturbative QCD vacuum are…

High Energy Physics - Phenomenology · Physics 2009-10-28 K. Geiger

The gravitational form factors for a hadron, the form factors for the hadron matrix element of the QCD energy-momentum tensor, not only describe the coupling of the hadron with a graviton, but also serve as unique quantities for describing…

High Energy Physics - Phenomenology · Physics 2018-08-15 Kazuhiro Tanaka

In recent years, significant progress was reached in understanding of vacuum and hadronic structure. We review recent works on the {\it point-to-point correlation functions}, comparing those obtained from phenomenology, ``instanton liquid"…

High Energy Physics - Phenomenology · Physics 2016-11-03 Edward Shuryak

Factorization is possible due to the universal behavior of Yang-Mills theories in soft and collinear limits. Here, we take a small step towards a more transparent understanding of these limits by proving a form of perturbative factorization…

High Energy Physics - Theory · Physics 2013-09-25 Ilya Feige , Matthew D. Schwartz

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

I review the formalism of loop quantum gravity, in both its real and complex formulations, and spin foam theory which is its path integral counterpart. Spin networks for non-compact groups are introduced (following hep-th/0205268) to deal…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Etera R. Livine

Processes involving electroweak vector bosons in association with jets are crucial for precision studies of the Standard Model at the Large Hadron Collider. Accurate predictions for the process $pp\rightarrow V(\rightarrow\bar\ell\ell)jj$…

High Energy Physics - Phenomenology · Physics 2024-09-25 Giuseppe De Laurentis