Related papers: Two-loop Resummation in Fractional Analytic Pertur…
This is the second paper on semiclassical approach based on the density matrix given by the Euclidean time path integral with fixed coinciding endpoints. The classical path, interpolating between this point and the classical vacuum, called…
Threshold resummation for factorizable cross sections in hadron-hadron collisions has a number of applications and extensions. We discuss factorization scale dependence, resummation at nonleading power in the moment variable, and the…
We study the prediction for the Higgs transverse momentum distribution in gluon fusion and focus on the problem of matching fixed- and all-order perturbative results. The main sources of matching ambiguities on this distribution are…
We review soft-collinear effective theory (SCET), and apply it to discuss quark electromagnetic form factor, then present the resumed transverse momentum distribution of Higgs-boson production via gluon fusion under this framework, where we…
Three-loop propagator diagrams in HQET can be reduced, using integration by parts, to 8 basis integrals: 5 trivial ones, two expressible via 3F2, and one only known up to \epsilon^0. Calculation of the heavy-quark propagator in HQET is…
We defend the Fock-space Hamiltonian truncation method, which allows to calculate numerically the spectrum of strongly coupled quantum field theories, by putting them in a finite volume and imposing a UV cutoff. The accuracy of the method…
Quark mass effects in ${\cal O}(\alpha_s^2)$ QCD corrections to the decay rates of intermediate Higgs bosons are studied. The total hadronic rate and the partial decay rate into bottom quarks are analyzed for the Standard (scalar) Higgs…
The two--loop ${\cal O}(\alpha_s G_F m_t^2)$ corrections to the $b\bar b$ decay rate of the Standard Model Higgs boson as well as its production via $e^+e^- \to ZH$ will be presented. These QCD corrections are obtained by using a low-energy…
In this thesis, we study the three-loop QCD form factors. After an introduction and a discussion of the physics motivation, we generate the quark form factor using Qgraf. We then show how to bring the Feynman integrals into a unique form by…
We study a finite temperature two-loop resummed effective potential in the Abelian gauge theory. A tractable calculation scheme without using a high-temperature expansion is devised. We apply it to the Abelian-Higgs model and its extension…
Within the framework of nonrelativistic QCD (NRQCD) factorization, we compute the three-loop QCD corrections to the decay constant of $B_c$. We reconstruct the analytical expressions for the three-loop renormalization constant and the…
Higher orders in perturbation theory require the calculation of Feynman integrals at multiple loops. We report on an approach to systematically solve Feynman integrals by means of symbolic summation and discuss the underlying algorithms.…
Hamiltonian Truncation Methods are a useful numerical tool to study strongly coupled QFTs. In this work we present a new method to compute the exact corrections, at any order, in the Hamiltonian Truncation approach presented by Rychkov et…
Perturbative cross-sections in QCD are beset by logarithms of kinematic invariants, whose arguments vanish when heavy particles are produced near threshold. Contributions of this type often need to be summed to all orders in the coupling,…
One-loop radiative corrections to the charged Higgs coupling to two fermions and to the charged Higgs fermionic decay are studied. A renormalization scheme is proposed including the definition of the parameter $\tan\beta$ through the…
We propose a modified procedure for extracting the numerical value for the strong coupling constant $\alpha_s$ from the $\tau$ lepton hadronic decay rate into non-strange particles in the vector channel. We employ the concept of the…
We compute the perturbative component of the fragmentation function of the $b$ quark to the best of the present theoretical knowledge. The fixed-order calculation to order $\alpha_s^2$ of the fragmentation function at the initial scale is…
The resummed expression for the quark form factor illustrates the fact that dimensional continuation provides a regularization not only for ultraviolet and infrared singularities of fixed order QCD amplitudes, but also for the Landau pole…
We investigate the QCD resummation for the Higgs boson plus a high $P_T$ jet production with large rapidity separations in proton-proton collisions at the LHC. The relevant Balitsky-Fadin-Kuraev-Lipatov (BFKL) and Sudakov logs are…
I discuss the motivation for resummation of the effects of initial-state soft gluon radiation, to all orders in the strong coupling strength, for processes in which the near-threshold region in the partonic subenergy is important. I…