29905749
Polarization-dependent bending of light by the axion hair of black holes.
We study the deflection of light by the pseudoscalar "axion" hair of black holes. Because of the $P$- and $T$-violating interaction ${\mathcal{L}}_{\mathcal{I}}=\ensuremath{\lambda}\mathrm{aF}\stackrel{\ifmmode \tilde{}\else \~{}\fi{}}{F}$ between axions and photons, light signals of opposite circular polarization propagating through the axion medium will be deflected through different angles. There will be a twofold splitting of the image of the source with an angular separation which is determined by the static configuration of the axion field outside the black hole horizon and could be an unambiguous signature of axionic black holes.
117886121
Field-theoretical treatment of neutrino oscillations
We discuss the field-theoretical approach to neutrino oscillations. This approach includes the neutrino source and detector processes and allows to obtain the neutrino transition or survival probabilities as cross sections derived from the Feynman diagram of the combined source -- detection process. In this context, the neutrinos which are supposed to oscillate appear as propagators of the neutrino mass eigenfields, connecting the source and detection processes.
15412351
Production process dependence of neutrino flavor conversion
We perform a covariant wave-packet analysis of neutrino oscillations taking into account the lifetime of the neutrino production process . We find that flavor oscillations in space are washed out when the neutrinos are produced from long lived resonances - and what may be observed in appearance/disappearance experiments is a uniform conversion probability independent of distance. The lifetime of the resonance which produces the neutrinos acts as the the effective baseline of the experiment. 
For this reason the LSND experiment where neutrinos are produced from muon decay has two orders of magnitude more sensitivity to neutrino mass square difference than other experiments where the neutrinos are produced from pion or kaon decays.
121168530
Quantum cosmology of the superstring universe
Abstract We study the quantum cosmology of the string universe obtained by embedding the Robertson-Walker metric in the non-linear model of Antoniadis, Bachas, Ellis and Nanopoulos (ABEN). We find that the quantum model has some unusual features not seen in the classical model. Initially, the universe exists in a series of metastable bound states with scale factor taking discrete values. Then the universe tunnels through a barrier and comes out in an inflationary state. This tunneling (or evolution in imaginary time) also has the effect of heating up the matter field so that we have the conditions of chaotic inflation. Our asymptotic solutions agree with those obtained from the classical Einstein equations by ABEN.
11918846
Neutrino and astroparticle physics: Working group report
The contributions made to the Working Group activities on neutrinos and astrophysics are summarized in this article. The topics discussed were inflationary models in Raman-Sundrum scenarios, ultra high energy cosmic rays and neutrino oscillations in 4 flavour and decaying neutrino models.
118059039
Determination of the age of the earth from Kamland measurement of geo-neutrinos
The low energy component of the antineutrino spectrum observed in the recent Kamland experiment has significant contribution from the radioactive decay of $^{238}U$ and $^{232}Th$ in the crust and mantle of the earth. By taking the ratio of the antineutrino events obeserved in two different energy ranges we can determine the present value $[Th/U]$ independent of the U,Th distribution in the earth. Comparing with the r-process initial value of $[Th/U]_0$ we determine the age of the earth as a function of $\Delta m^2$ and $Sin^2 2 \theta$. We find that the age of the earth determined from KamLAND data matches the age of solar system ($4.5 Gyrs$ from meteorites) for the LMA-I solution. For the LMA-II solution the age of the earth does not match the solar system age at 90 % C.L.
35500264
Intermittency in quark-gluon-plasma phase transition.
Intermittency properties of the multiplicity fluctuations in high energy heavy ion collisions have been studied on the basis of Landau mean field approach. A universal scaling exponent for hadron phase is found which does not depend on whether the transition is of first or second order. It is further shown that the multiplicity distributions at different rapidity intervals carry more discriminating information about the nature of the phase transition.