119361485
B ---> rho gamma decay in the large energy effective theory
The branching ratio for the $B \to \rho \gamma$ decay in the next-to-leading order (NLO) in the strong coupling $\alpha_s$ and in leading power in $\Lambda_{\rm QCD}/m_B$ is presented. The corrections are combined the hard-vertex, hard-spectator and annihilation contributions and found to be large. The theoretical expectation for the branching ratios, the isospin-violating ratio and for the direct CP-asymmetry in the $B \to \rho \gamma$ decays are presented.
13242527
MASS EFFECTS IN THE QUARK–GLUON DECAYS OF HEAVY PARAQUARKONIA
Quark–gluon decays of heavy paraquarkonia are investigated with account of the masses of final quarks. The decay widths and the energy distributions of the final quarks and gluons are calculated in dependence on the relative quark masses. The strong collinear enhancement of the gluon energy distribution at the end of the spectrum is shown to take place in all such decays of ηc and ηb mesons except the decay . The total decay width is shown to have an essential dependence on the final quark masses. The corresponding branching ratios of ηc and ηb mesons are numerically estimated with a good agreement of with experimental data on ηc decays.
125367645
Field-induced axion luminosity of photon gas via a gamma gamma interaction
116435109
Photon-axion processes in a crossed external field
119416690
MASS SHIFT OF AXION IN MAGNETIC FIELD
A mass-shift of the axion propagating in an external constant homogenious magnetic field is calculated. The contributions via an electron loop and a virtual photon are examined. It is shown that the virtual photon contribution dominates substantially over the electron-loop one. Under the conditions of the early Universe the electron-loop contribution to the massless axion mass-shift is equal to zero while the virtual photon contribution is finite and can be of order of the recent restrictions on the axion mass.