相关论文: A one-loop study of matching conditions for static…

Leptonic and semileptonic meson decays that proceed via flavour-changing neutral currents provide excellent probes of physics of the standard model and beyond. We present explicit results for the Wilson coefficients of the weak effective…

We present our analysis of B physics quantities using non-perturbatively matched Heavy Quark Effective Theory (HQET) in Nf= 2 lattice QCD on the CLS ensembles. Using all-to-all propagators, HYP-smeared static quarks, and the Generalized…

We present the three-loop calculations of the nonrelativistic QCD (NRQCD) current renormalization constants and corresponding anomalous dimensions, and the matching coefficients for the spatial-temporal tensor and spatial-spatial…

In highly improved staggered quark (HISQ) simulations by the HPQCD, MILC, and Fermilab Lattice collaborations, both the light quarks and the charm quark are staggered. We extend chiral perturbation theory for staggered quarks to include…

We compute the one-loop (hard) matching correction to heavy-to-light transition currents in soft-collinear effective theory (SCET) to sub-leading power in the SCET expansion parameter for an arbitrary Dirac structure of the QCD weak…

We study charged lepton flavor-violating (LFV) transitions in the color octet model that generates neutrino mass and lepton mixing at one loop. By taking into account neutrino oscillation data and assuming octet particles of TeV scale mass,…

We show the three-loop calculation of the matching coefficients $\mathcal{C}_J$ for the four heavy flavor-changing currents in nonrelativistic Quantum Chromodynamics effective theory and confirm the surprising observation of the…

Heavy Quark Effective Theory (HQET) is a new approach to QCD problems involving a heavy quark. In the leading approximation, the heavy quark is considered as a static source of the gluon field; 1/m corrections can be systematically included…

We present analytical next-to-leading order results for the correlator of baryonic currents at the three-loop level with one finite mass quark. We obtain the massless and the HQET limits of the correlator as particular cases from the…

QCD/HQET matching for the heavy-quark field and heavy-light quark currents with three-loop accuracy is discussed.

Within the framework of non-relativistic QCD (NRQCD) factorization, we compute the matching coefficients between full Quantum Chromodynamics (QCD) and NRQCD for the heavy flavor-changing vector, axial-vector, scalar and pseudo-scalar…

We perform a loop-level analysis of charged-current (CC) processes involving light leptons and quarks within the Standard Model Effective Field Theory (SMEFT). This work is motivated by the high precision reached in experiment and Standard…

We compute semi-leptonic $B_s$ decay form factors using Heavy Quark Effective Theory on the lattice. To obtain good control of the $1/m_b$ expansion, one has to take into account not only the leading static order but also the terms arising…

Mirror Twin Higgs(MTH) models always contain heavy gauge bosons and extra Higgses. Besides, to accommodate tiny neutrino masses via seesaw mechanism, new heavy neutrinos can also be introduced in MTH extension models. Such new particles and…

We analyze the compatibility of the hypothesis of third-family quark-lepton unification at the TeV scale with electroweak precision data, lepton flavor universality tests, and high-$p_T$ constraints. We work within the framework of the UV…

We show that the different ways of deriving the Heavy Quark Effective Theory (HQET) lead to equivalent theories. The equivalence can be established through a careful redefinition of the field variables. We demonstrate the equivalence to…

We explain how the strategy of solving renormalization problems in HQET non-perturbatively by a matching to QCD in finite volume can be implemented to include dynamical fermions. As a primary application, some elements of an HQET…

In this work, we compile the necessary and sufficient conditions a theory has to fulfill in order to ensure general lepton flavour conservation, in the spirit of the Glashow-Weinberg criteria for the absence of flavour-changing neutral…

If low energy supersymmetry is realized in nature it is possible that a first generation linear collider will only have access to some of the superpartners with electroweak quantum numbers. Among these, sleptons can provide sensitive probes…

The baryon axial vector current is computed in heavy baryon chiral perturbation theory in the large-$N_c$ limit, where $N_c$ is the number of color charges. One-loop nonanalytic corrections of order $m_q \ln m_q$ are comprised in the…