Modern Physics Letters A

In this document we will review the current status of reactor neutrino oscillation experiments and present their physics potentials for measuring the θ₁₃ neutrino mixing angle. The neutrino mixing angle θ₁₃ is currently a high-priority topic in the field of neutrino physics. There are currently three different reactor neutrino experiments, DOUBLE CHOOZ, DAYA BAY and RENO and a few accelerator neutrino experiments searching for neutrino oscillations induced by this angle. A description of the reactor experiments searching for a nonzero value of θ₁₃ is given, along with a discussion of the sensitivities that these experiments can reach in the near future.

The properties of bottomonia are investigated in detail in the constituent quark model. The wave functions of bottomonia are obtained by solving Dirac equation and Schrödinger equation. The potentials between quark and antiquark include color confinement (linear and quadratic) and one-gluon-exchange. Based on the obtained wave functions, the electromagnetic and two-photon decay, electric dipole transition, and hadronic width of bottomonia are calculated. The calculated results are in a good agreement with the experimental data. The results also show that the nonrelativistic and relativistic version of quark model can all describe the properties of bottomonia.

The DAEMONs (DArk Electric Matter Objects) have been suggested as a possible exotic component in cosmic rays able to contribute to the Dark Matter; they belong to the wide class of the Elementary Black Holes (EBH) deeply discussed in literature. A preliminary possible DAEMONs direct detection, at ≃3σ C.L., was originally suggested by the sea-level St. Petersburg experiment (SPb); a DAEMONs flux: (1.0±0.3) DAEMONs/(days m² sr) can be derived. Here the results obtained by the sea-level NEMESIS experiment, which has exploited the same detection approach, are presented; they restrict the DAEMONs flux to be less than 0.32 DAEMONs/(days m² sr) at 90% C.L.

The Belle collaboration has reported for the inclusive decay . Recently, the LHCb and the CMS collaboration has released the combined limit . The standard model results of the and are found to be within the 1σ of the experimental result. Taking a conservative viewpoint, we use these decays to constrain the braneworld Randall–Sundrum model. The stabilized radion in the Randall–Sundrum model, which is an electro-weak singlet, can cause the flavor changing neutral current (FCNC) b →s transition at the oneloop level. We investigate the possible impact of a stabilized radion on the above two decays and obtain the possible constraints on the radion vev 〈ϕ〉 for an ultra-light radion.

We study the extremal rotating spacetimes with a NUT twist in the context of recently proposed Kerr/CFT correspondence. The Kerr/CFT correspondence states that the near-horizon states of an extremal four (or higher) dimensional black hole could be identified with a certain chiral conformal field theory. The corresponding Virasoro algebra is generated with a class of diffeomorphism which preserves an appropriate boundary condition on the near-horizon geometry. We combine the calculated central charges with the expected form of the temperature, using the Cardy formula to obtain the microscopically entropy of the extremal rotating spacetimes with a NUT twist. All results are in agreement with the macroscopic entropy of the extremal spacetimes.

The effect of quark mass on the Regge trajectory is analyzed. Modifications in the equations of Regge trajectories are shown for mesonic as well as baryonic systems. For mesonic systems, the Regge trajectories get modified, but still remain linear. Contrary to the mesonic case, the Regge trajectories for baryonic systems indicate nonlinearity. It is shown that in low mass and angular momentum region two hadrons with different quark compositions can have same mass and angular momentum.

We consider the quantum capture of nonrelativistic massive particle by the moving infinite curve (cosmic string in wire approximation). It is shown that the cusp appearing on a string at a certain point due to the string dynamics can make the wave function collapse at this point irrespective of the caption place.