相关论文: Two-loop form factors for $P$-wave quarkonium prod…

The computation of two-loop amplitudes for the production of multiple Higgs and electroweak gauge bosons via gluon fusion with exact dependence on quark masses relies primarily on numerical methods. We propose a framework that enables their…

We compute the ${\mathcal O}(\alpha_s^2)$ corrections to the exclusive channels $e^+e^-\to J/\psi+\chi_{cJ}$ ($J=0,1,2$) at $\sqrt{s}=10.58$ GeV within the nonrelativistic QCD (NRQCD) factorization framework. The validity of NRQCD…

We perform an analytic calculation of the one-loop amplitude for the W-boson mediated process 0 \to d u-bar Q Q-bar l-bar l, retaining the mass for the quark Q. The momentum of each of the massive quarks is expressed as the sum of two…

A short summary of a NLO QCD calculation for the top-quark pair production with a jet in the dilepton decay channel is presented. The calculation takes into account all double, single, non-resonant and interference contributions. Thus, NLO…

The self-couplings of the electroweak gauge bosons are probed at hadron colliders through the production of a massive gauge boson and a photon. To extend the theoretical description of this type of final states towards…

We accomplish the complete two-loop computation of the leading-twist contribution to the photon-pion transition form factor $\gamma \, \gamma^{\ast} \to \pi^0$ by applying the hard-collinear factorization theorem together with modern…

We compute fragmentation corrections to hadroproduction of the quarkonium states $J/\psi$, $\chi_{cJ}$, and $\psi(2S)$ at leading power in $m_c^2/p_T^2$, where $m_c$ is the charm-quark mass and $p_T$ is the quarkonium transverse momentum.…

Using overlap as well as Wilson fermions, we have computed the one-loop renormalization factors of ten non-singlet operators which measure the third moment of quark momentum and helicity distributions (the lowest two having been computed in…

Like the two-photon and two-gluon decays of the $P$-wave $\chi_{c0,2}$ and $\chi_{b0,2}$ charmonium state for which the Born term produces a very simple decgays amplitude in terms of an effective Lagrangian with two-quark local operator,…

We compute the three-loop form factors for $gg\to HH$ in the limit of vanishing transverse momentum of the Higgs boson which provides a reasonable approximation of the cross section. In our calculations we adopt the large-$N_c$ limit, which…

We compute the four-loop contributions to the photon quark and Higgs quark form factors involving two closed fermion loops. We present analytical results for all non-planar master integrals of the two non-planar integral families which…

We present an analytic expression for the two-loop QCD corrections to the decay process b -> u W^*, where b and u are a massive and massless quark, respectively, while W^* is an off-shell charged weak boson. Since the W-boson can…

In the QCD energy-momentum tensor $T^{\mu\nu}$, the terms that contribute to physical matrix elements are expressed as the sum of the gauge-invariant quark part and gluon part. Each part undergoes the renormalization due to the interactions…

We follow up on our discussion of the exact quark-mass dependence of the Higgs-gluon form factor at three loops in QCD (arXiv:2001.03008) and turn our attention to the closely related Higgs-photon form factor. Similarly to our previous…

We test the nonrelativistic QCD factorization conjecture for inclusive quarkonium production at two loops by carrying out a covariant calculation of the nonrelativistic quantum chromodynamics (NRQCD) long-distance matrix element (LDME) for…

We compute the form factors of the photon-quark-anti-quark vertex and the effective vertex of a Higgs boson and two gluons to three-loop order within massless perturbative Quantum Chromodynamics. These results provide building blocks for…

In the QCD energy-momentum tensor $T^{\mu\nu}$, the terms that contribute to physical matrix elements are expressed as the sum of the gauge-invariant quark part and gluon part. Each part undergoes the renormalization due to the interactions…

The form factors relevant to $B_{q}\to D^{\ast}_{q}(J^{P}=1^{-})\ell\nu$ $(q=s, d, u)$ decays are calculated in the framework of the three point QCD sum rules approach. The heavy quark effective theory prediction of the form factors are…

We present analytical results on the two-loop anomalous dimensions of currents for baryons, containing two heavy quarks $J = [Q^{iT}C\Gamma\tau Q^j]\Gamma' q^k\epsilon_{ijk}$ with arbitrary Dirac matrices $\Gamma$ and $\Gamma'$ in the…

We compute the two-loop QCD corrections to $q g \to H q$ and $q \bar{q} \to H g$ amplitudes mediated by loops of nearly massless quarks. These amplitudes provide the last missing ingredient required to compute the NLO QCD corrections to the…