Related papers: Calculating Fragmentation Functions from Definitio…
A new class of fragmentation functions, arising from the interference of different hadron production channels, is analyzed. Their symmetry properties with respect to naive time-reversal transformations allow for the exploration of…
We present MAPFF1.0_Lambda, the first global analysis at next-to-next-to-leading order in perturbative QCD of the collinear unpolarised fragmentation functions of Lambda hyperons. The fit is based on data from single-inclusive…
We present a heavy quark fragmentation mechanism based on a modified version of the standard model of quark fragmentation, taking into account peculiarities of the Regge trajectories of quarkonia containing heavy quarks. The modified model…
Hadron form factors are calculated using the Lorentz contracted wave functions, determined in the arbitrary dynamical scheme with the instantaneous interaction. It is shown that the large $Q$ asymptotics of the form factors is defined by…
Structure functions are a measure of the partonic structure of hadrons, which is important for any process which involves colliding hadrons. They are a key ingredient for deriving partons distributions in nucleons. In recent years dramatic…
We report on the status an ab initio computation of the time-like splitting functions at next-to-next-to-leading order in QCD. Time-like splitting functions govern the collinear kinematics of inclusive hadron production in $e^+e^-$…
Spin dependent fragmentation functions are an important tool to understand the spin structure of the nucleon. The Collins fragmentation function for example describes the fragmentation of a transversely polarized quark into a hadron via the…
We relate the fragmentation functions of partons into mesons and baryons in the framework of recombination of shower partons. The results are in reasonable agreement with the data. The implication is that the meson and baryon fragmentation…
The NJL-jet model provides a framework for calculating fragmentation functions without the introduction of ad hoc parameters. We develop the NJL-jet model to investigate dihadron fragmentation functions (DFFs) of the form $D^{h_1…
COMPASS final results on multiplicities of charged hadrons and of identified pions and kaons produced in the deep inelastic muon scattering off an isoscalar target are presented and compared to HERMES results. Measurements are done in bins…
Processes involving heavy quarks are a crucial component of the LHC physics program, both by themselves and as backgrounds for Higgs physics and new physics searches. In this work, we critically reconsider the validity of the widely-adopted…
Direct photons associated with jets provide a direct measurement of the effects of energy loss on the fragmentation of the parton as it propagates through the medium. Perturbative QCD calculations describe the direct photon cross section…
In the fragmentation of a heavy quark into a heavy meson whose light degrees of freedom have angular momentum $3/2$, all the helicity probabilities are completely determined in the heavy quark limit up to a single probability $w_{3/2}$. We…
It is shown that the azimuthal dependence of the distribution of hadrons in a quark jet is a probe of the transverse spin of the quark initiating the jet. This results in a new spin-dependent fragmentation function that acts at the twist-2…
We compute the contributions due to gluon and heavy-quark fragmentation to quarkonium production at large transverse momentum in $\bar p p$ and $p p$ collisions. For inclusive $J/\psi$ production, there is a large contribution from the $g…
We present results from two different methods for the calculation of hadron spectra in QCD and SUSY QCD with large primary energies $\sqrt{s}$ up to $10^{16}$ GeV. The two methods considered are a Monte Carlo (MC) simulation and the…
We calculate the spin density matrix of the hadron $h$ created via quark fragmentation in the process $e^-e^+ \to q\bar q \to h + X$. In the case of $h=\Lambda$ the experimental data could possibly elucidate the problem of $s$-quark…
Parton distribution functions (PDFs) describe the structure of hadrons as composed of quarks and gluons. They are needed to make predictions for short-distance processes in high-energy collisions and are determined by fitting to cross…
The fragmentation functions of $D^0$, $D^{\pm}$, $D_s^{\pm}$, $D^{*o}$, $D^{*\pm}$ and $\Lambda_c^{\pm}$ at $\sqrt{s}$$\simeq$10.6 GeV are measured with a data set of 102.7 fb$^{-1}$. Fragmentation model parametrizations (Peterson,…
The physics of heavy quarks becomes a very reach area of study thanks to an excellent operation of hadron colliders and $B$-factories and exciting results from them. Experimental data obtained allows to get some information about the heavy…