Related papers: Quark mass effects in double parton distributions
QCD Laplace transform sum rules, involving the axial-vector current divergences, are used in order to determine the strange quark mass. The two-point function is known in QCD up to four loops in perturbation theory, and up to dimension-six…
The dependence of the top-quark mass measurement in top-quark production on the parton distribution functions is explored through the differential distribution of the invariant mass of the top-antitop system in top-quark pair production at…
Far above threshold the production process e^+e^-to t t-bar can be analyzed using effective field theories. In this talk we consider the invariant mass distribution of top-jets and report about our computation of the two-loop heavy quark…
Generalized parton distributions provide a unified parameterization of hadron structure and allow one to combine information from many different observables. Lattice QCD calculations already provide important input to determine these…
We present recent results on the first moments of parton distributions using gauge configurations generated with two degenerate flavors of light twisted mass quarks with pion mass fixed approximately to its physical value. We also present a…
The calculation of the quartic mass terms at order \alpha_s^3 to the hadronic R ratio is described. It is based on the operator product expansion for the quark current correlator, combined with an application of the renormalization group…
The effects induced by the quark masses in three-jet observables have been studied in this thesis. In particular, we have explored a new method: the study of three-jet observables at LEP, different from QCD Sum Rules and Lattice…
Results from inclusive and differential measurements of the production cross sections for top quarks in proton-proton collisions at center-of-mass energies of 7 and 8 TeV are compared to predictions at next-to-leading and…
Covariant version of the quark-parton model is studied. Dependence of the structure functions and parton distributions on the 3D quark intrinsic motion is discussed. The important role of the quark orbital momentum, which is a particular…
In order to overcome the shortcoming of nonconservation of nuclear momentum existing in the original $Q^2$-rescaling model(O$Q^2$RM) and avoid introducing nuclear shadowing factor, we proposed a double $Q^2$-rescaling model(D$Q^2$RM) for…
We study the double parton interaction process in collisions between highly virtual $q{\bar q}$ pairs in the BFKL regime. Explicit expressions for the double parton distributions are obtained both in the case of direct coupling of the BFKL…
We report on recent calculations of the differential cross section for top-quark pair production at hadron colliders. The results are differential with respect to the top-pair invariant mass and to the partonic scattering angle. In these…
Heavy baryon chiral perturbation theory is extended to include the effects of quenching. In this framework the leading nonanalytic dependence of the heavy baryon masses on the light quark masses is studied. The size of quenching effects is…
The mass splittings of the pseudoscalar and vector D and B light-heavy quark systems have been calculated using the method of QCD sum rules. Electromagnetic, quark mass, and nonperturbative QCD effects are all included. The results are in…
The dependence of the top-quark mass measurement in top-quark pair production on the parton distribution functions (PDF) is explored through differential mass distributions in $t\bar{t}$ and $t\bar{t}j$ production at the LHC and a future…
We derive double distributions for the proton in a simple model that contains scalar as well as axial-vector diquark correlations. The model parameters are tuned so that the experimentally measured electromagnetic form factors are…
We derive the formal expressions needed to discuss the change of the twist-two parton distribution functions when a hadron is placed in a medium with relativistic scalar and vector mean fields
I discuss radiative corrections due to the emission of photons from quarks which contribute to deep inelastic lepton--nucleon scattering as well as to $pp$ collisions at high energies. These corrections are dominated by quark-mass…
We present the CTEQ6HQ parton distribution set which is determined in the general variable flavor number scheme which incorporates heavy flavor mass effects; hence, this set provides advantages for precision observables which are sensitive…
We discuss a few examples of rich newly developing field of double parton scattering. We start our presentation from production of two pairs of charm quark-antiquark and argue that it is the golden reaction to study the double parton…