Related papers: gamma* gamma -> pi pi at large Q^2
A heavy quark placed in the medium modifies its specific heat. Using a renormalization group argument we show a low energy theorem in terms of the defect in the trace of the energy-momentum tensor which allows the unambiguous determination…
The low energy mass spectrum of QCD in the large $N_C$ limit is computed. The low-lying states in the meson spectrum are explicitly evaluated up to the fourth order in the strong coupling perturbative expansion. The 't Hooft limit is smooth…
We investigate the soft handbag contribution to two-photon annihilation into pion or kaon pairs at large energy and momentum transfer. The amplitude is expressed as a hard gamma gamma -> q qbar subprocess times a form factor describing the…
The meson-photon transition form factors $\gamma\gamma^*\to P$ ($P$ stands for $\pi$, $\eta$ and $\eta'$) provide strong constraints on the distribution amplitudes of the pseudoscalar mesons. In this paper, these transition form factors are…
The process gamma gamma to ZH first arises at the 1-loop level, and as such it provides remarkable tests of the structure of the electroweak Higgs sector. These tests are complementary to those in the gauge sector involving gamma gamma to…
The QCD-vacuum is characterized by the Higgs phenomenon for colored scalar fields. In this dual picture the gluons appear as the octet of vector mesons. Also quarks and baryons are identified. Gluon-meson and quark-baryon duality can…
Quark-hadron phase transition is simulated by an event generator that incorporates the dynamical properties of contraction due to QCD confinement forces and randomization due to the thermal behavior of a large quark system on the edge of…
I review recent progress in the theory of gamma gamma annihilation into meson or baryon pairs at large energy, and of the process gamma* gamma* -> pi0 at large photon virtuality.
We review recent advances in the theory of strong-interaction effects and final-state interactions in hadronic weak decays of heavy mesons. In the heavy-quark limit, the amplitudes for most nonleptonic, two-body B decays can be calculated…
Analysis of the isoscalar S- and D-waves of processes pi-pi-> pi-pi, K-Kbar, eta-eta is carried out aimed at studying the status and QCD nature of scalar and tensor mesons below 2 GeV and 2.3 GeV, respectively. Assignment of these mesons to…
We consider the non-relativistic limit of the QCD Hamiltonian in the Coulomb gauge, to describe radiative transitions between conventional charmonium states and from the lowest multiplet of $c\bar{c}$ hybrids to charmonium mesons. The…
Exclusive hadron production processes in photon-photon collisions provide important tests of QCD at the amplitude level, particularly as measures of hadron distribution amplitudes and skewed parton distributions. The determination of the…
Ultrarelativistic heavy-ion collisions are considered ideal environments for exploring the QCD phase diagram and probing the properties of the QGP as functions of temperature and baryon chemical potential. At the highest energies, such as…
We present for the first time a determination of the energy dependence of the isoscalar $\pi\pi$ elastic scattering phase-shift within a first-principles numerical lattice approach to QCD. Hadronic correlation functions are computed…
The study of charmless two-body decays of B mesons is currently one of the hottest topics in B physics. QCD factorization provides the theoretical framework for a systematic analysis of such decays. A global fit to B->pi K,pi pi branching…
The chiral phase transition at finite temperature is investigated in the linear sigma model, which is regarded as a low energy effective theory of QCD with three momentum cutoff, in the variational method with the Gaussian approximation in…
We calculate the QCD equation of state for temperatures corresponding to the transition region with physical mass values for two degenerate light quark flavors and a strange quark using an improved staggered fermion action (p4-action) on…
The recently discovered sharp peak in the K+/pi+ ratio is discussed in the framework of the statistical model. In this model a rapid change is expected as the hadronic gas undergoes a transition from a baryon-dominated to a meson-dominated…
The 't Hooft model for the two-dimensional QCD in the limit of infinite number of colours is studied in the axial gauge. The mass-gap and the bound-state equations are derived using the two consequent Bogoliubov-like transformations. Chiral…
We develop a description of the equation of state of QCD matter with restored chiral symmetry, which is in thermal and chemical equilibrium with the hadronic phase. The hadron gas is described with thermodynamically consistent volume…