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Related papers: HQET chromomagnetic interaction at two loops

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We use functional methods to compute one-loop effects in Heavy Quark Effective Theory. The covariant derivative expansion technique facilitates the efficient extraction of matching coefficients and renormalization group evolution equations.…

High Energy Physics - Phenomenology · Physics 2020-07-15 Timothy Cohen , Marat Freytsis , Xiaochuan Lu

We have studied electroweak (EW) interactions in quantum hadrodynamics (QHD) effective field theory (EFT). The Lorentz-covariant EFT contains nucleon, pion, $\Delta$, isoscalar scalar ($\sigma$) and vector ($\omega$) fields, and isovector…

Nuclear Theory · Physics 2012-03-20 Brian D. Serot , Xilin Zhang

We describe a strategy for a non-perturbative computation of the b-quark mass to leading order in 1/m in the Heavy Quark Effective Theory (HQET). The approach avoids the perturbative subtraction of power law divergencies, and the continuum…

High Energy Physics - Lattice · Physics 2011-01-27 Jochen Heitger , Rainer Sommer

Applications of HQET and NRQCD to fragmentation are briefly reviewed. The special role of the b-quark in applications of heavy quark symmetry is discussed. Predictions of HQET for semileptonic B decays to excited charmed mesons are…

High Energy Physics - Phenomenology · Physics 2009-10-30 Mark B. Wise

We consider correlation functions containing the axial current of one light and one heavy quark in the static approximation as well as in full QCD, using the lattice regularization. Up to one-loop order of perturbation theory, we study the…

High Energy Physics - Lattice · Physics 2016-09-01 ALPHA Collaboration , Martin Kurth , Rainer Sommer

We review the anomalous Chromomagnetic Dipole Moment (CMDM) of the top quark in a Two Higgs Doublet Model (2HDM). We include interactions with the involvement of the extended CKM matrix in this model, we obtain new bonds for the future…

High Energy Physics - Phenomenology · Physics 2025-05-13 T. Cisneros-Pérez , A. Ramirez-Morales , J. Montaño-Domínguez , A. Gutiérrez-Rodríguez , M. A. Hernández-Ruíz

In QCD at energies well below a heavy-quark threshold, the heavy-quark vector current can be represented via local operators made of the lighter quarks and of the gluon fields. We extract the leading perturbative matching coefficients for…

High Energy Physics - Phenomenology · Physics 2023-12-20 Harvey B. Meyer

If electro-weak symmetry is broken by a new strongly interacting sector, new physics will probably manifest itself in gauge boson scattering at the LHC. The relevant dynamics is well described in terms of an effective lagrangian. We discuss…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. Fabbrichesi , L. Vecchi

We show that by combining the static heavy quark action with the Neuberger action for the light quark, the renormalisation of the heavy-light bilinear and four-quark operators, computed on the lattice, becomes highly simplified: all the…

High Energy Physics - Lattice · Physics 2009-11-10 Damir Becirevic , Juan Reyes

We obtain the two-loop QCD corrections to the Higgs plus three-parton amplitudes with dimension-seven operators in Higgs effective field theory. This provides the two-loop S-matrix elements for Higgs plus one-jet production at the LHC with…

High Energy Physics - Phenomenology · Physics 2020-03-18 Qingjun Jin , Gang Yang

Effective field theories are useful tools to search for physics beyond the Standard Model (SM). However, effective theories can lead to non-unitary behavior with fastly growing amplitudes. This unphysical behavior may lead to large…

High Energy Physics - Phenomenology · Physics 2022-01-19 Iñigo Asiáin , Domènec Espriu , Federico Mescia

We present a broad study of collider processes that embed $2 \to 2$ scattering amplitudes involving top quarks in the Electroweak sector. We parametrise the modified interactions using the Standard Model Effective Field Theory framework and…

High Energy Physics - Phenomenology · Physics 2020-06-17 Fabio Maltoni , Luca Mantani , Ken Mimasu

We calculate the chromomagnetic dipole moment of the top quark, $\hat{\mu}_t$, in the context of the Bestest Little Higgs model. This extension of the Standard Model aims to solve the hierarchy problem without fine tuning, by introducing…

High Energy Physics - Phenomenology · Physics 2021-11-08 J. I. Aranda , T. Cisneros-Pérez , E. Cruz-Albaro , J. Montaño-Domínguez , F. Ramírez-Zavaleta

We show how heavy quark effective theory, including 1/M corrections, may be matched onto dynamical quark models by making a specific choice of K,m and v in the p=mv+K expansion. We note that Wigner rotations of heavy quark spins arise at…

High Energy Physics - Phenomenology · Physics 2010-11-01 Frank Close , Zhenping Li

The quark chromoelectric dipole (qCEDM) operator is a CP-violating operator describing, at hadronic energies, beyond-the-standard-model contributions to the electric dipole moment of particles with nonzero spin. In this paper we define…

High Energy Physics - Lattice · Physics 2022-04-15 Emanuele Mereghetti , Christopher J. Monahan , Matthew D. Rizik , Andrea Shindler , Peter Stoffer

The low energy dynamics of the general strongly interacting symmetry breaking sector can be easily described using effective chiral Lagrangians. Indeed, the enhancement in WW scattering at LHC, that would imply the existence of such an…

High Energy Physics - Phenomenology · Physics 2007-05-23 J. R. Pelaez

We present a complete calculation of the contributions to the effective leptonic weak mixing angle, sin^2theta_eff, generated by closed fermion loops at the two-loop level of the electroweak interactions. This quantity is the source of the…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. Awramik , M. Czakon , A. Freitas , G. Weiglein

In this work, we employ the heavy hadron chiral perturbation theory (HHChPT) to calculate the $\Sigma_c\bar{D}^{(*)}$ potentials to the next-to-leading order. The contact, the one-pion exchange and the two-pion exchange interactions are…

High Energy Physics - Phenomenology · Physics 2019-08-07 Lu Meng , Bo Wang , Guang-Juan Wang , Shi-Lin Zhu

This talk presents details of the calculation of two-loop corrections to heavy baryon currents containing one heavy quark in leading order of the $1/m_Q$-expansion, i.e. in the limit of Heavy Quark Symmetry (HQS). The calculations lead to…

High Energy Physics - Phenomenology · Physics 2007-05-23 Stefan Groote

We perform for the first time a direct calculation of on-shell $K\to\pi\pi$ hadronic matrix elements of chromomagnetic operators (CMO) in the Standard Model and beyond. To his end, we use the successful Dual QCD (DQCD) approach in which we…

High Energy Physics - Phenomenology · Physics 2018-08-15 Andrzej Buras , Jean-Marc Gerard