Is cosmology compatible with sterile neutrinos?

By combining data from cosmic microwave background (CMB) experiments (including the recent WMAP third year results), large scale structure (LSS) and Lyman-alpha forest observations, we constrain the hypothesis of a fourth, sterile, massive neutrino. For the 3 massless + 1 massive neutrino case we bound the mass of the sterile neutrino to m_s<0.26eV (0.44eV) at 95% (99.9%) c.l.. These results exclude at high significance the sterile neutrino hypothesis as an explanation of the LSND anomaly. We then generalize the analysis to account for active neutrino masses (which tightens the limit to m_s<0.23eV 0.42eV) and the possibility that the sterile abundance is not thermal. In the latter case, the contraints in the (mass, density) plane are non-trivial. For a mass of >1eV or <0.05eV the cosmological energy density in sterile neutrinos is always constrained to be omega_nu <0.003 at 95 c.l.. However, for a sterile neutrino mass of ~0.25eV, omega_nu can be as large as 0.01.Comment: 5 pages, 3 figures; v2: update datasets to WMAP3, new Lyman Alpha, Baryonic oscillations; confidence limits tightened by a factor ~2, results unchanged; v3 minor changes, version accepted by PR

A Standard format for Les Houches event files

A standard file format is proposed to store process and event information, primarily output from parton-level event generators for further use by general-purpose ones. The information content is identical with what was already defined by the Les Houches Accord five years ago, but then in terms of Fortran commonblocks. This information is embedded in a minimal XML-style structure, for clarity and to simplify parsing

Improved Method for CKM Constraints in Charmless Three-body B and Bs Decays

Recently Ciuchini, Pierini and Silvestrini proposed a method for constraining CKM parameters in B {yields} K{pi}{pi} and B{sub s} {yields} K{pi}{pi} through phase measurements of amplitudes involving I = 3/2 K*{pi} final states. We show that complementary information on CKM parameters may be obtained by studying the phases of {Delta}I = 1 B {yields} (K*{pi}){sub I = 1/2}, B{sub s} {yields} (K* {bar K}){sub l=1} and B{sub s} {yields} ({bar K}* K){sub I=1} amplitudes. Hadronic uncertainties in these constraints from electroweak penguin operators O{sub 9} and O{sub 10}, studied using flavor SU(3), are shown to be very small in B {yields} K{pi}{pi} and B{sub s} {yields} K{pi}{pi} and somewhat larger in B{sub s} {yields} K{bar K}{pi}. The first processes imply a precise linear relation between {bar {rho}} and {bar {eta}}, with a measurable slope and an intercept at {bar {eta}} = 0 involving a theoretical error of 0.03. The decays B{sub s} {yields} K{pi}{pi} permit a measurement of involving a theoretical error below a degree. We note that while time-dependence is required when studying B{sup 0} decays at the {Upsilon}(4S), it is not needed when studying B{sub s} decays at hadronic colliders

Statistical Properties of Blue Horizontal Branch Stars in the Spheroid: Detection of a Moving Group approximately 50 kpc from the Sun

A new moving group comprising at least four Blue Horizontal Branch (BHB) stars is identified at (l; b) = (65{sup o}; 48{sup o}). The horizontal branch at g{sub 0} = 18.9 magnitude implies a distance of 50 kpc from the Sun. The heliocentric radial velocity is &lt;V{sub r}&gt; = -157 {+-} 4 km s{sup -1}, corresponding to V{sub gsr} = -10 km s{sup -1}; the dispersion in line-of-sight velocity is consistent with the instrumental errors for these stars. The mean metallicity of the moving group is [Fe/H] {approx} -2.4, which is significantly more metal poor than the stellar spheroid. We estimate that the BHB stars in the outer halo have a mean metallicity of [Fe/H]=-2.0, with a wide scatter and a distribution that does not change much as a function of distance from the Sun. We explore the systematics of SDSS DR7 surface gravity metallicity determinations for faint BHB stars, and present a technique for estimating the significance of clumps discovered in multidimensional data. This moving group cannot be distinguished in density, and highlights the need to collect many more spectra of Galactic stars to unravel the merger history of the Galaxy

Averages of B-Hadron, C-Hadron, and Tau-Lepton Properties as of Early 2012

This report talks about Averages of B-Hadron, C-Hadron, and Tau-Lepton Properties as of Early 201