Related papers: Heavy-quark QCD vacuum polarisation function: anal…
We present calculations of the one-loop vacuum polarization contribution (Uehling potential) for the two-center problem in the NRQED formalism. The cases of hydrogen molecular ions ($Z_1=Z_2=1$) as well as antiprotonic helium ($Z_1=2$,…
In this article we discuss the calculation of single top-quark production in the t channel at two-loop order in QCD. In particular we present the decomposition of the amplitude according to its spin and colour structure and present complete…
We have computed the even-$N$ moments $N \leq 20$ of the gluon-to-quark splitting function $P_{\rm qg}$ at the fourth order of perturbative QCD via the renormalization of off-shell operator matrix elements. Our results, derived analytically…
Collective modes within a hot Quantum Chromodynamics (QCD) medium are obtained from the polarization tensor, considering both constant and time-varying electromagnetic fields. In both scenarios, five complex modes emerge, reliant on the…
Study of the polarized heavy quarkonium production in recently proposed QCD factorization formalism requires knowledge of a large number of input fragmentation functions (FFs) from a single parton or a heavy quark-antiquark pair to a…
We numerically evaluate the two-loop QCD squared matrix element for in $q\bar{q}\to Z$ and $q\bar{q}\to Z\gamma$ with heavy top and bottom quarks circulating in a triangular fermion loop, by simultaneously subtracting infrared, ultraviolet,…
The one-loop QCD heavy quark potential is computed to order v^2 in the color singlet and octet channels. Several errors in the previous literature are corrected. To be consistent with the velocity power counting, the full dependence on |p'…
Contents: 1. The Thermodynamics of Quarks and Gluons 2. Hard Probes: Colour Deconfinement 3. Electromagnetic Probes: Chiral Symmetry Restoration 4. Soft Probes: Equilibration and Expansion 5. Conclusions
This is a review of strong coupling approaches to grasp the nature of the phase transition in finite temperature and density QCD. We commence with classics of the center symmetry and the Polyakov loop in pure gauge theories. The effective…
In this paper the three-loop polarization functions \Pi(q^2) are calculated for the cases of an external vector, axial-vector, scalar or pseudo-scalar current. Results are presented for the imaginary part which directly leads to the cross…
We review the recent progress in formulating a quantum kinetic theory for the polarization of spin-$\frac{1}{2}$ massive quarks from the leading-log order of perturbative QCD.
I present results for the resummation of soft and collinear gluon contributions to QCD hard-scattering cross sections at two loops. This requires the calculation of UV and IR divergences through two loops and the construction of soft…
Vacuum of Quantum Chromodynamics in very strong (hadron-scale) magnetic fields exhibits many interesting nonperturbative effects. Some of these effects can be studied with the help of lattice simulations in quenched QCD. We review our…
We discuss results for heavy quark correlations in next-to-leading order QCD in deep inelastic electroproduction.
We calculate the complete set of two-loop leading-colour QCD helicity amplitudes for $\gamma \gamma j$-production at hadron colliders. Our results are presented in a compact, fully-analytical form.
We calculate the two-loop pressure of a plasma of quarks and gluons at finite temperature and chemical potential using the hard thermal loop perturbation theory (HTLpt) reorganization of finite temperature/density quantum chromodynamics.…
The fragmentation function of vector particle into possible bound S-wave states with a heavy antiquark is calculated in the leading order of perturbative QCD for the high energy processes at large transverse momenta with the different…
We report about recent progress in computing four-loop massive correlators. The expansion of these correlators in the external momentum leads to vacuum integrals. The calculation of these vacuum integrals can be used to determine Taylor…
I present the two-loop QCD corrections to the production of a massive quark-anti-quark pair in the massless quark-anti-quark annihilation channel. The result is obtained as a combination of a deep expansion in the mass around the high…
We survey results in lattice quantum chromodynamics from groups in the USQCD Collaboration. The main focus is on physics, but many aspects of the discussion are aimed at an audience of computational physicists.