Related papers: Factorization analysis for the fragmentation funct…
Heavy hadron production in $e^+e^-$ annihilation is studied in the framework of heavy-quark recombination mechanism. This mechanism predicts a new type of 3-jet event such as $b\bar{b}q$ or $b\bar{b}\bar{q}$, which is power-suppressed…
The structure function of a heavy quark in a heavy hadron in electroproduction is calculated from QCD. Its deviation from the parton model prediction (a delta function) is shown to be governed by a shape function, similar to the one…
QCD factorization approach in the field-theoretic description of the semi-inclusive hadronic processes in the large Bjorken $x$ approximation implies extraction of the three-dimensional parton distribution functions as a convolution of a…
We propose a factorized approach to QED radiative corrections for inclusive and semi-inclusive deep-inelastic scattering to systematically account for QED and QCD radiation contributions to both processes on equal footing. This is achieved…
Different ``analytization'' procedures for the factorized pion form factor are discussed in comparison with the standard QCD perturbation theory at NLO. It is argued that demanding the analyticity of the exclusive amplitude as a…
In this contribution, we make use of the QCD perturbative fragmentation function formalism to describe the one-particle inclusive fragmentation of a heavy quark produced in $e^+e^-$ annihilation at $\mathcal{O}(\alpha_S^2)$. We perform the…
Heavy Quark Effective Theory (HQET) is a new approach to QCD problems involving a heavy quark. In the leading approximation, the heavy quark is considered as a static source of the gluon field; 1/m corrections can be systematically included…
I present new results on the quark distribution in an on-shell heavy quark in perturbative QCD and explore its all-order relations with heavy-quark fragmentation. I first compute the momentum distribution function to all orders in the…
The fragmentation functions D_{a -> H}(x,mu^2) of a heavy hadron H, with mass m_H, satisfy the phase-space constraint D_{a - > H}(x,mu^2)=0 for x < m_H^2/mu^2, which is violated by the naive mu^2 evolution equations. Using appropriately…
We point out a problem with the formulation and derivations of sum rules for quark fragmentation functions that impacts their validity in QCD, but which potentially points toward an improved understanding of final states in inclusive hard…
To identify some way to measure the quark transversity, this thesis analyzes one-particle and two-particle inclusive deep inelastic scattering, where one and two of the outgoing hadrons are detected in coincidence with the electron. It is…
This talk discusses the effective field theory view of deep inelastic scattering. In such an approach, the standard factorization formula of a hard coefficient multiplied by a parton distribution function arises from matching of QCD onto an…
We study the radiative decay B -> gamma l nu_l in the framework of QCD factorization. We demonstrate explicitly that, in the heavy-quark limit and at one-loop order in perturbation theory, the amplitude does factorize, i.e. that it can be…
Using methods of effective field theory, factorized expressions for arbitrary B -> X_u l nu decay distributions in the shape-function region of large hadronic energy and moderate hadronic invariant mass are derived. Large logarithms are…
Fragmentation functions are determined for pions, kaons, and nucleons by a global analysis of charged-hadron production data in electron-positron annihilation. The optimum functions are obtained in both leading order (LO) and…
Factorization, in the sense defined for inclusive hard scattering, is discussed for diffractive hard scattering. A factorization theorem similar to its inclusive counterpart is presented for diffractive DIS. For hadron-hadron diffractive…
The perturbative QCD fragmentation functions can be applied phenomenologically as a model for charm and bottom quark fragmentation into heavy-light mesons. The predictions by this model on the observables $P_V$ and $\langle z \rangle$ for…
We have derived the coefficients of the highest three 1/x-enhanced small-x logarithms of all timelike splitting functions and the coefficient functions for the transverse fragmentation function in one-particle inclusive e^+e^- annihilation…
Using heavy quark effective theory a factorized form for inclusive production rate of a heavy meson can be obtained, in which the nonperturbative effect related to the heavy meson can be characterized by matrix elements defined in the heavy…
We develop a formalism for resumming threshold double logarithms that appear in fragmentation functions for production of heavy quarkonia. Threshold singularities appear in fixed-order calculations of quarkonium fragmentation functions in…