Related papers: Gluonia in QCD with massless quarks

After discussing the intrinsic ambiguity in determining the light quark mass ratio $m_u/m_d$, we reexamine the recent proposal that this ambiguity can be resolved by applying the QCD multipole expansion for the heavy quarkonium decays. It…

We extend the Gunion Bertsch calculation of gluon radiation in single scattering to the case of finite mass quarks. This case applies to the radiative energy-loss of heavy quarks of intermediate energies propagating in a quark gluon plasma.…

Using the trace anomaly and low energy relations, as well as the Witten-Veneziano formula for the mass of the $\eta'$ meson, we have developed a formalism which makes it possible to express the gluon condensate, the topological…

In supersymmetric theories, the top quark can decay into its scalar partner plus a neutralino, with an appreciable rate. We calculate the $O(\alpha_s)$ QCD corrections to this decay mode in the minimal supersymmetric extension of the…

Suppression of open heavy quarks and quarkonia in heavy-ion collisions are among the most informative probes of quark-gluon plasma (QGP). Interpreting the full wealth of data obtained from the collision events requires a precise theoretical…

The calculations of masses and decay constants of the radial excitations of light pseudoscalar and scalar mesons within QCD sum rules method are briefly reviewed. The predictions are based on the $1/N_c$-supported model spectra, which…

The radiative transitions $\phi \to \eta \gamma$ and $\phi \to \eta^\prime \gamma$ are analysed using QCD sum-rules. The results we obtain for ${\cal B}(\phi \to \eta \gamma)=(1.15 \pm 0.2) 10^{-2}$ and ${\cal B}(\phi \to \eta^\prime…

I review recent new lattice QCD results on a few selected topics which are relevant to the heavy ion physics community. Special emphasis is put on the QCD phase diagram towards the chiral limit and at nonzero baryon density as well as the…

We discuss how the spectral changes of quarkonia at T_c can reflect the ``critical'' behaviour of QCD phase transition. Starting from the temperature dependencies of the energy density and pressure from lattice QCD calculation, we extract…

We study the effect of squark-generation mixing on gluino decays in the Minimal Supersymmetric Standard Model (MSSM). We show that due to the effect the quark-flavor violating (QFV) gluino decay branching ratio B(gluino -> c bar{t} (t…

We report about a recent calculation of the heavy quarkonium mass and decay width in a quark-gluon plasma, whose temperature T and screening mass m_D satisfy the hierarchy m alpha_s >> pi T >> m alpha_s^2 >> m_D, m being the heavy-quark…

We derive the analogue of the QCD low energy theorems for the scalar and pseudoscalar gluonic correlators in nuclear matter. We find that the scalar correlations are depleted while the pseudoscalar correlations are enhanced to leading order…

The $SU(3)$-violating decays $\Phi^{2S} \goto \Phi^{1S} X$, where $X = \pi^0$ or $\eta$ and $\Phi = J/\psi$ or $\Upsilon$ have been recently proposed as a means of probing the light quark masses beyond leading order in chiral perturbation…

We perform a QCD analysis for the radiative decay of a heavy $^3S_1$ quarkonium into the tensor meson $f_2(1270)$. We make an attempt to separate the nonperturbative effect related to the quarkonium and that related to the tensor meson, the…

Although eta-eta' mixing is qualitatively well understood as a consequence of the U(1)_A anomaly in QCD together with a broken SU(3) flavor symmetry, until recently the values of decay and mixing parameters of the eta and eta' were only…

Recently CDF and D0 collaborations observed several bottom baryons. In this work we perform a systematic study of the masses of bottom baryons up to $1/m_Q$ in the framework of heavy quark effective field theory (HQET) using the QCD sum…

We calculate the heavy quarkonium energy levels and decay widths in a quark-gluon plasma, whose temperature T and screening mass m_D satisfy the hierarchy m alpha_s >> T >> m alpha_s^2 >> m_D (m being the heavy-quark mass), at order m…

The QCD finite energy sum rules method is used to show that the parameter of the K^0-\bar{K}_0 mixing \hat{B} is mainly determined by the value of g m_s< \bar{d} G_{\mu\nu} \sigma_{\mu\nu} d > and the vacuum expectation values of four-quark…

Using the trace anomaly relation, low-energy theorem and Witten-Veneziano formula, we have developed an analytical formalism which allows one to calculate the gluon condensate, the topological susceptibility and the mass of the $\eta'$…

We study the two-body decays of the gluino at full one-loop level in the Minimal Supersymmetric Standard Model with quark-flavour violation (QFV) in the squark sector. The renormalization is done in the $\overline{\rm DR}$ scheme. The gluon…