Modern Physics Letters A

Since nine years, experiments have been observing a host of exotic states decaying into heavy quarkonia. The interpretation of most of them still remains uncertain and, in some cases, controversial, notwithstanding a considerable progress has been made on the quality of the experimental information available and a number of ideas and models have been put forward to explain the observations.

In this mini-review we will summarize the measurements, with the most recent updates and list the useful ones yet to be done. We will discuss the problem of the spin of the X, which could hide some major surprise on its interpretation, and review some more phenomenological issues debated in the field.

Cosmological models in Lyra's geometry are constructed and investigated with the assumption of a minimal interaction of matter with the displacement vector field and the dynamical Λ-term. Exact solutions of the model equations are obtained for the different equations of state of the matter, that fills the universe, and for the certain assumptions on the decaying law for Λ.

We give sum rules for tetraquark decay coupling constants, taking into account the SU(3) symmetry breaking interactions to first order.

Motivated by the μ-problem and the axion solution to the strong CP-problem, we extend the MSSM with one more chiral singlet field X_ew. The underlying PQ-symmetry allows only one more renormalizable term X_ew H_u H_d in the superpotential. The spectrum of the Higgs system includes a light pseudoscalar a_X (in addition to the standard CP-even Higgs boson), predominantly decaying to two photons: a_X →γγ. Both Higgs bosons might be in the range accessible to current LHC experiments.

The neutron single-particle bound states as solutions of radial Schrödinger equation for the central Woods–Saxon potential together with spin-orbit interaction and centrifugal terms have been obtained analytically. By introducing new variable and using Taylor expansion, the differential equation has been transformed to solvable hypergeometric type. This differential equation has also been solved using Nikiforov–Uvarov (NU) method. Neutron single-particle states have been derived as self-adjoint form of hypergeometric series. By means of boundary conditions, which implies eigenvalue condition as complicated relation between energy eigenvalues and parameters of nuclear potential, the neutron single-particle energy eigenvalues have been derived using graphical method. To examine method, numerical results in special cases of S states are evaluated. Results obtained using this method are in satisfactory agreements with available numerical solutions.

We show that flow anisotropies in relativistic heavy-ion collisions can be analyzed using a certain technique of shape analysis of excursion sets recently proposed by us for CMBR fluctuations to investigate anisotropic expansion history of the universe. The technique analyzes shapes (sizes) of patches above (below) certain threshold value for transverse energy/particle number (the excursion sets) as a function of the azimuthal angle and rapidity. Modeling flow by imparting extra anisotropic momentum to the momentum distribution of particles from HIJING, we compare the resulting distributions for excursion sets at two different azimuthal angles. Angles with maximum difference in the two distributions identify the event plane, and the magnitude of difference in the two distributions relates to the magnitude of momentum anisotropy, i.e. elliptic flow.

In this paper, we calculate the heat flux passing through the horizon TS|_rh and the difference of energy between the Einstein and Møller prescription within the region , in which is the region between outer horizon and inner horizon , for the modified GHS solution, KLOPP solution and CLH solution. The formula TS is obeyed for the mGHS solution and the KLOPP solution, but not for the CLH solution. Also, we suggest a RN-like stringy dyonic black hole solution, which comes from the KLOPP solution under a dual transformation, and its thermodynamical properties are the same as the KLOPP solution.