相关论文: New high order relations between physical observab…
We re-evaluate the non-perturbative contribution to the thrust distribution in $e^+e^-\to$ hadrons, in the light of the latest experimental data and the recent NNLO perturbative calculation of this quantity. By extending the calculation to…
Effective field theory techniques are used to describe the interaction of heavy hadrons in a model independent way. Predictability is obtained by exploiting the symmetries of QCD. Heavy hadron chiral perturbation theory is reviewed and used…
High energy hadron-hadron collisions are discussed. It is argued that soft collisions should involve in an essential way nonperturbative QCD. A way is outlined how to calculate properties of high energy elastic hadron-hadron scattering…
The low-energy effective theory description of a confining theory, such as QCD, is constructed including local interactions between hadrons organized in a derivative expansion. This kind of approach also applies more generically to theories…
In this paper we derive relations between the cross-correlation of ambient noises recorded at two different points and the Green's function of the elastic waves in a medium with viscous damping. The Green's function allows to estimate…
We present a QCD based interpretation of heavy quark fragmentation which utilizes the heavy quark mass expansion. By distinguishing between perturbative and non-perturbative QCD effects, we show how to reliably extract mass independent…
Hadronization corrections to the predictions of perturbative QCD are reviewed. The existing models for the conversion of quarks and gluons into hadrons are summarized. The most successful models give a good description of the data on…
We discuss systematically the consistency of light gluinos with data on perturbative QCD from deep inelastic scattering, quarkonia, jets at LEP, and the total hadronic cross-section in ${e^+ e^-}$ annihilation on the $Z$ peak and elsewhere.…
We present new sets of fragmentation functions in next-to-leading order QCD that are determined from e+e- annihilation data of inclusive particle production. In addition to the O(alpha_s) unpolarized cross section the longitudinal cross…
Starting from the meson-meson Green function in 3+1 dimensional quenched lattice QCD we calculate potentials between heavy-light mesons for various light-quark mass parameters. For the valence quarks we employ the staggered scheme. The…
The model for constituent glue is presented starting from the perturbation theory in nonperturbative QCD vacuum. Green function is constructed for a system containing qqbar pair and gluon propagating in the vacuum background field, and…
We develop a second-order cosmological perturbation theory on a background geometry expressed in terms of light-cone coordinates, extending the first-order analyses available in the literature. In particular, we investigate the gauge…
Three important QCD-related aspects of the $\tau$ and $\mu$ dynamics are reviewed: the determination of the strong coupling from the hadronic tau decay width, leading to the updated value $\alpha_s(m_\tau^2) = 0.331 \pm 0.013$; the…
We perform an effective field theory analysis of the $\tau^- \to \pi^- \pi^0 \nu_\tau$ decays, that includes the most general interactions between Standard Model fields up to dimension six, assuming left-handed neutrinos. We constrain as…
The Quantum Mechanics of a point particle on a Noncommutative Plane in a magnetic field is implemented in the present work as a deformation of the algebra which defines the Landau levels. I show how to define, in this deformed Quantum…
We show that the linear dynamics of cosmological perturbations can be described by coupled wave equations, allowing their efficient numerical and, in certain limits, analytical integration directly in position space. The linear evolution of…
The hadronic decay rate of the tau lepton serves as one of the most precise determinations of the QCD coupling alpha_s. The dominant theoretical source of uncertainty at present resides in the seeming disparity of two approaches to…
We show that the Green's functions in non-linear gauge in the theory of perturbative quantum gravity is expressed as a series in terms of those in linear gauges. This formulation is also holds for operator Green's functions. We further…
The total decay widths of heavy mesons can be systematically calculated in terms of an expansion in the two parameters $1/m_Q$ and $\alpha_s(m_Q)$, where $Q=c,b$ denotes the heavy quark. The dominant contributions to meson lifetime…
We present a quantum-field-theoretical framework based on path integrals and Feynman diagrams for the investigation of the quantum-optical properties of one-dimensional waveguiding structures with embedded quantum impurities. In particular,…