Related papers: Charge sum rules for quark fragmentation functions
We use local quark-hadron duality to calculate the nucleon structure function as seen by neutrino and muon beams. Our result indicates a possible signal of charge symmetry violation at the parton level in the very large x region.
QCD sum rules for D and B mesons embedded in cold nuclear matter are evaluated. We quantify the mass splitting of D - D-bar and B - B-bar mesons as a function of the nuclear matter density; extrapolated to saturation density it is in the…
Lattice sum rules are checked using lattice perturbation theory. The action sum rule gives a relation between the quark-antiquark potential, its logarithmic derivative with respect to distance and the expectation value of the action; the…
The nature of the electron gas is characterized, above all, by its multi-particle correlations. The conserving sum rules for the electron gas have been thoroughly studied for many years, and their centrality to the physics of metallic…
We study heavy-hadron semileptonic decays proceeding via $b \to c$ transition, such as $B \to D^{(*)}\tau\bar{\nu}_\tau$ and $\Lambda_b \to \Lambda_c\tau\bar{\nu}_\tau$. In the heavy-quark limit, where the heavy-quark symmetry holds, we…
The factorization theorem for organizing multiple electroweak boson emissions at future colliders with energy far above the electroweak scale is formulated. Taking the inclusive muon-pair production in electron-positron collisions as an…
The NJL-jet model provides a sound framework for calculating the fragmentation func- tions in an effective chiral quark theory, where the momentum and isospin sum rules are satisfied without the introduction of ad hoc parameters [1].…
Achievements in the heavy quark theory over the last decade are reviewed, with the main emphasis put on dynamical methods which quantify nonperturbative effects via application of the Operator Product Expansion. These include the total weak…
Model independent sum rules are applied to recent measurements of heavy c-baryon and d-baryon masses. The sum rules are generally satisfied to the same degree as for the light (u,d,s) baryons.
We analyze the isospin-breaking corrections to quark condensates within one-loop SU(2) and SU(3) Chiral Perturbation Theory including $m_u\neq m_d$ as well as electromagnetic (EM) contributions. The explicit expressions are given and…
Properties of doubly charged scalar tetraquarks $bb\overline{c}\overline{c}$ are investigated in the framework of the QCD sum rule method. We model them as diquark-antidiquark states $X_{\mathrm{1}}$ and $X_{\mathrm{2}}$ built of…
A surprisingly large charge symmetry violation of the sea quarks in the nucleon has been proposed in a recent article by Boros et al. as an explanation of the discrepancy between neutrino (CCFR) and muon (NMC) nucleon structure function…
The moments of the heavy quark-parton distribution functions in a heavy pseudoscalar meson are calculated from QCD sum rules. Expanding these sum rules in the inverse heavy quark mass we obtain the heavy-mass limits of the moments.…
We classify the meson and baryon long lived resonances considering quarks with electric charge 5/3 and $-4/3$ (in units of $\vert e\vert$) predicted by some 3-3-1 models. Some of these exotic resonances have the usual electric charges…
Physical quark-number charges of dyons are determined, via a formula which generalizes that of Witten for the electric charge, in N=2 supersymmetric theories with $SU(2) \times U(1)^{N_f} $ gauge group. The quark numbers of the massless…
We consider (for the first time) the ratios of doubly heavy baryon masses (spin 3/2 over spin 1/2 and SU(3) mass-splittings) using double ratios of sum rules (DRSR), which are more accurate than the usual simple ratios often used in the…
The mass formulas and decay constants of electrically charged and strange pseudoscalar mesons are analyzed within the combined framework of Nambu -- Jona-Lasinio model and the $1/N_c$ expansion up to $\mathcal O(1/N_c^2)$. The light quark…
The asymmetry in the angular distribution of n p --> d pi^0 due to Charge Symmetry Breaking is calculated using Heavy Baryon Chiral Perturbation Theory. Recent developments in power counting have proven successful in describing total cross…
Fragmentation functions represent a key ingredient to address the proton spin structure in semi-inclusive deep-inelastic scattering and proton-proton collisions. They can not be determined from perturbative Quantum Chromodynamics and have…
This research summarizes work done by myself (Nucl.Phys.{\bf A641} (1998)461), or in collaboration with R. M. Davidson (Phys.Lett.{\bf B348}(1995)163) and H. Weigel and L. Gamberg (Nucl.Phys.{\bf B560}(1999)xx). I will discuss several…