相关论文: The photon spectrum in quarkonia decays

The decay rates of $c\bar{c}$ and $b\bar{b}$ through two-photon or two-gluon annihilations are obtained by using totally relativistic decay amplitudes and a sophisticated quantum-chromodynamic potential model for heavy quarkonia. Our…

An effective theory approach to heavy quarkonia decays based on the $1/m_Q$ expansion is introduced. Its application to decays in which the two heavy quarks annihilate is discussed.

The inclusive tau lepton hadronic decay is studied within Dispersive approach to QCD. The significance of effects due to hadronization is convincingly demonstrated. The approach on hand proves to be capable of describing experimental data…

Some important aspects of hadronic tau decays are reviewed: the determination of alpha_s from the inclusive tau hadronic width, the measurement of |V_{us}| through the Cabibbo-suppressed decays of the tau, and the theoretical description of…

Valuable data on quarkonia (the bound states of a heavy quark Q=c,b and the corresponding antiquark) have recently been provided by a variety of sources, mainly e+ e- collisions, but also hadronic interactions. This permits a thorough…

The theory of preasymptotic effects in inclusive decays of heavy flavors is briefly reviewed.

We report on the current status of knowledge on inclusive quarkonium production in high-energy photon-photon collisions. As a perspective for the LHC, we compute various production cross sections via direct photon-photon fusion in…

Hidden-heavy hadrons can decay into pairs of heavy hadrons through transitions from confining Born-Oppenheimer potentials to hadron-pair potentials with the same Born-Oppenheimer quantum numbers. The transitions are also constrained by…

This article summarizes results on global observables, hadron spectra, and ratios of integrated hadron yields as presented at the Quark Matter 2002 Conference.

It has long been expected that the spectrum of hadrons in QCD would be far richer and extensive than experiment has so far revealed. While there have been experimental hints of this richness for some time, it is really only in the last few…

Hadrons containing at least one heavy quark (charm or bottom) frequently have small enough natural widths that decay modes involving a single photon have detectable branching fractions. Photons of typical energy greater than 100 MeV have…

Two-photon decays of light scalar mesons are discussed within the quarkonium and tetraquark asignements: in both cases the decay rate of the sigma resonances turns out to be smaller than 1 keV.

Weak decays of charm mesons has been used for studies of light quark spectroscopy, with particular emphasis on the J^{PC}=0^{++} states. Recent results on light scalars are summarized and some conceptual issues are discussed, especially the…

The light-front wave functions of hadrons allow us to calculate a wide range of physical observables; however, the wave functions themselves cannot be measured. We discuss recent results for quarkonia obtained in basis light-front…

Relativistic constituent quark models generally describe three-quark systems with particular interactions. The corresponding invariant mass eigenvalue spectra and pertinent eigenstates should exhibit the multiplet structure anticipated for…

Recent progress in the factorization of exclusive decays of heavy quarkonia into long-distance and short-distance contributions is presented. The role of higher Fock states and colour-octet contributions is outlined.

Using non relativistic effective Lagrangian techniques, we analyze the hadronic decay of the pi+pi- atom and the strong energy-level shift of pionic hydrogen in the ground state. We derive general formulae for the width and level shift,…

The two-photon decay of a light scalar quarkonium is evaluated in a local and a nonlocal approaches. It is shown that the two-photon decay, driven by a triangle quark-loop diagram, is smaller than 1 keV for a mass below 0.7 GeV.

We study the radiative (E1 and M1) decays of P-wave quarkonia in a strong magnetic field based on the Lagrangian of potential nonrelativistic QCD. To investigate their properties, we implement a polarized wave function basis justified in…

Although the spectra of heavy quarkonium systems has been successfully explained by certain QCD motivated potential models, their strong decays are difficult to deal with. We perform a microscopic calculation of charmonium strong decays…