Non-perturbative approach for the time-dependent symmetry breaking

We present a variational method which uses a quartic exponential function as a trial wave-function to describe time-dependent quantum mechanical systems. We introduce a new physical variable $y$ which is appropriate to describe the shape of wave-packet, and calculate the effective action as a function of both the dispersion $\sqrt{}$ and $y$. The effective potential successfully describes the transition of the system from the false vacuum to the true vacuum. The present method well describes the long time evolution of the wave-function of the system after the symmetry breaking, which is shown in comparison with the direct numerical computations of wave-function.Comment: 8 pages, 3 figure

Supersolid Helium at High Pressure

We have measured the pressure dependence of the supersolid fraction by a torsional oscillator technique. Superflow is found from 25.6 bar up to 136.9 bar. The supersolid fraction in the low temperature limit increases from 0.6 % at 25.6 bar near the melting boundary up to a maximum of 1.5% near 55 bar before showing a monotonic decrease with pressure extrapolating to zero near 170 bar.Comment: 4 pages, 4 figure

Higgs Boson Production from Black Holes at the LHC

If the fundamental Planck scale is near a TeV, then TeV scale black holes should be produced in proton-proton collisions at the LHC where \sqrt{s} = 14 TeV. As the temperature of the black holes can be ~ 1 TeV we also expect production of Higgs bosons from them via Hawking radiation. This is a different production mode for the Higgs boson, which would normally be produced via direct pQCD parton fusion processes. In this paper we compare total cross sections and transverse momentum distributions d\sigma/dp_T for Higgs production from black holes at the LHC with those from direct parton fusion processes at next-to-next-to-leading order and next-to-leading order respectively. We find that the Higgs production from black holes can be larger or smaller than the direct pQCD production depending upon the Planck mass and black hole mass. We also find that d\sigma/dp_T of Higgs production from black holes increases as a function of p_T which is in sharp contrast with the pQCD predictions where d\sigma/dp_T decreases so we suggest that the measurement of an increase in d\sigma/dp_T as p_T increases for Higgs (or any other heavy particle) production can be a useful signature for black holes at the LHC.Comment: 20 pages latex, 5 figures, To appear in Phys. Rev.

Observation of the Cabibbo-suppressed charmed baryon decay Λ_c^+→pφ

We report the observation of the Cabibbo-suppressed decays Λ_c^+→pK^-K^+ and Λ_c^+→pφ using data collected with the CLEO II detector at CESR. The latter mode, observed for the first time with significant statistics, is of interest as a test of color suppression in charm decays. We have determined the branching ratios for these modes relative to Λ_c^+→pK^-π^+ and compared our results with theory