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Related papers: Two-Loop Matching Coefficients for Heavy Quark Cur…

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We compute the three-loop QCD corrections to the massive quark-anti-quark-photon form factors $F_1$ and $F_2$ involving a closed loop of massless fermions. This subset is gauge invariant and contains both planar and non-planar…

High Energy Physics - Phenomenology · Physics 2018-04-18 Roman N. Lee , Alexander V. Smirnov , Vladimir A. Smirnov , Matthias Steinhauser

We compute the two-loop master integrals for leading-color QCD scattering amplitudes including a closed light-quark loop in $t\bar{t}H$ production at hadron colliders. Exploiting numerical evaluations in modular arithmetic, we construct a…

High Energy Physics - Phenomenology · Physics 2024-07-18 F. Febres Cordero , G. Figueiredo , M. Kraus , B. Page , L. Reina

We complete the computation of two-loop helicity amplitudes required to obtain next-to-next-to-leading order QCD corrections for three-jet production at hadron colliders, including all contributions beyond the leading-color approximation.…

High Energy Physics - Phenomenology · Physics 2024-05-15 Giuseppe De Laurentis , Harald Ita , Vasily Sotnikov

We calculate all those QCD $N$-point functions which are relevant for a three-loop QCD thermodynamics calculation with finite quark masses within the hard the thermal loop approximation. Using the effective quark propagator, we also…

High Energy Physics - Phenomenology · Physics 2018-07-16 Najmul Haque

We calculated the vector, axial-vector, scalar and pseudo-scalar two-point functions up to two-loop level in the low-energy effective field theory for three different QCD-like theories. In addition we also calculated the pseudo-scalar decay…

High Energy Physics - Phenomenology · Physics 2015-06-03 Johan Bijnens , Jie Lu

We present the implementation of relativistic coupled cluster quadratic response theory (QR-CC), following our development of relativistic equation of motion coupled cluster quadratic response theory (QR-EOMCC) [X. Yuan et al., J. Chem.…

Chemical Physics · Physics 2025-11-17 Xiang Yuan , Loïc Halbert , Lucas Visscher , André Severo Pereira Gomes

We evaluate the static QCD potential to two--loop order. Compared to a previous calculation a sizable reduction of the two--loop coefficient $a_2$ is found.

High Energy Physics - Phenomenology · Physics 2011-05-05 York Schroder

QCD with two flavours of massless colour-sextet quarks is considered as a model for conformal/walking Technicolor. If this theory possess an infrared fixed point, as indicated by 2-loop perturbation theory, it is a conformal(unparticle)…

High Energy Physics - Lattice · Physics 2014-11-20 J. B. Kogut , D. K. Sinclair

We calculate the two-loop heavy quarkonium Hamiltonian within potential-NRQCD effective field theory in the non-annihilation channel. This calculation represents the first non-trivial step towards determining the N$^4$LO Hamiltonian in the…

High Energy Physics - Phenomenology · Physics 2024-11-15 Go Mishima , Yukinari Sumino , Hiromasa Takaura

Light quark masses can be determined through lattice simulations in regularization invariant momentum-subtraction(RI/MOM) schemes. Subsequently, matching factors, computed in continuum perturbation theory, are used in order to convert these…

High Energy Physics - Phenomenology · Physics 2011-05-04 Leandro G. Almeida , Christian Sturm

We perform the two-loop matching calculation for heavy-to-light currents from QCD onto soft-collinear effective theory for the complete set of Dirac structures. The newly obtained matching coefficients enter several phenomenological…

High Energy Physics - Phenomenology · Physics 2015-05-19 G. Bell , M. Beneke , T. Huber , Xin-Qiang Li

We study the phase structure of bifundamental quantum chromodynamics (QCD(BF)), which is the $4$-dimensional $SU(N) \times SU(N)$ gauge theory coupled with the bifundamental fermion. Firstly, we refine constraints on its phase diagram from…

High Energy Physics - Theory · Physics 2024-04-26 Yui Hayashi , Yuya Tanizaki , Hiromasa Watanabe

We present the coefficient of the chromomagnetic interaction operator, the only unknown coefficient in the Heavy Quark Effective Theory (HQET) lagrangian up to the $1/m$ level, with the two-loop accuracy by matching scattering amplitudes of…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. Czarnecki , A. G. Grozin

Parameters and light fields of the QCD Lagrangian with two heavy flavours, b and c, are related to those in the low-energy effective theory without these flavours, to three-loop accuracy taking into account the exact dependence on m_c/m_b.…

High Energy Physics - Phenomenology · Physics 2012-05-29 Andrey Grozin , Maik Höschele , Jens Hoff , Matthias Steinhauser

We discuss the form and construction of general color singlet heavy particle-antiparticle pair production currents for arbitrary quantum numbers, and issues related to evanescent spin operators and scheme-dependences in nonrelativistic QCD…

High Energy Physics - Phenomenology · Physics 2008-11-26 Andre H. Hoang , Pedro Ruiz-Femenia

Heavy quarks have been instrumental for progress in our exploration of strong interactions. Quarkonium in particular, a heavy quark-antiquark nonrelativistic bound state, has been at the root of several revolutions. Quarkonium is endowed…

High Energy Physics - Phenomenology · Physics 2022-07-05 Nora Brambilla

The theory of the strong interactions, Quantum Chromodynamics (QCD), has been addressed by a variety of non-perturbative techniques over the decades since its introduction. We have investigated Hamiltonian formulations with different…

High Energy Physics - Theory · Physics 2007-05-23 J. P. Vary , T. J. Fields J. R. Spence , H. W. L. Naus , H. J. Pirner , K. S. Gupta

This talk presents some results relevant for lattice QCD at higher order in ChPT. First we discuss the finite volume corrections at two loops for the quark condensate as well as a L\"uscherlike finite volume formula for it. The latter…

High Energy Physics - Lattice · Physics 2007-05-23 Johan Bijnens , Niclas Danielsson , Karim Ghorbani , Timo Lähde

Systems with the quantum numbers of up to twelve charged and neutral pseudoscalar mesons, as well as one-, two-, and three-nucleon systems, are studied using dynamical lattice quantum chromodynamics and quantum electrodynamics (QCD+QED)…

We briefly review how nonrelativistic effective field theories give us a definition of the QCD potentials and a coherent field theory derived quantum mechanical scheme to calculate the properties of bound states made by two or more heavy…

High Energy Physics - Phenomenology · Physics 2009-01-08 Nora Brambilla