Padua Infn

Observations of MilkyWay Dwarf Spheroidal galaxies with the Fermi-LAT detector and

We report on the observations of 14 dwarf spheroidal galaxies with the Fermi Gamma-Ray Space Telescope taken during the first 11 months of survey mode operations. The Fermi telescope provides a new opportunity to test particle dark matter models through the expected gamma-ray emission produced by pair annihilation of weakly interacting massive particles (WIMPs). Local Group dwarf spheroidal galaxies, the largest galactic substructures predicted by the cold dark matter scenario, are attractive targets for such indirect searches for dark matter because they are nearby and among the most extreme dark matter dominated environments. No significant gamma-ray emission was detected above 100 MeV from the candidate dwarf galaxies. We determine upper limits to the gamma-ray flux assuming both power-law spectra and representative spectra from WIMP annihilation. The resulting integral flux above 100 MeV is constrained to be at a level below around 10^-9 photons cm^-2 s^-1. Using recent stellar kinematic data, the gamma-ray flux limits are combined with improved determinations of the dark matter density profile in 8 of the 14 candidate dwarfs to place limits on the pair annihilation cross-section of WIMPs in several widely studied extensions of the standard model. With the present data, we are able to rule out large parts of the parameter space where the thermal relic density is below the observed cosmological dark matter density and WIMPs (neutralinos here) are dominantly produced non-thermally, e.g. in models where supersymmetry breaking occurs via anomaly mediation. The gamma-ray limits presented here also constrain some WIMP models proposed to explain the Fermi and PAMELA e^+e^- data, including low-mass wino-like neutralinos and models with TeV masses pair-annihilating into muon-antimuon pairs. (Abridged)

A Study of

The e(+)e(-) -> p (p) over bar cross section is determined over a range of p (p) over bar masses, from threshold to 4.5 GeV/c(2), by studying the e(+)e(-)-> p (p) over bar gamma process. The data set corresponds to an integrated luminosity of 232 fb(-1), collected with the BABAR detector at the PEP-II storage ring, at an e(+)e(-) center-of-mass energy of 10.6 GeV. The mass dependence of the ratio of electric and magnetic form factors, vertical bar G(E)/G(M)vertical bar, is measured for p (p) over bar masses below 3 GeV/c(2); its value is found to be significantly larger than 1 for masses up to 2.2 GeV/c(2). We also measure J/psi -> p (p) over bar and psi(2S) -> p (p) over bar branching fractions and set an upper limit on Y(4260) -> p (p) over bar production and decay.

e^ + e^ - \to p \bar p

Dark matter (DM) particle annihilation or decay can produce monochromatic gamma rays readily distinguishable from astrophysical sources. gamma-ray line limits from 30 to 200 GeV obtained from 11 months of Fermi Large Area Space Telescope data from 20-300 GeV are presented using a selection based on requirements for a gamma-ray line analysis, and integrated over most of the sky. We obtain gamma-ray line flux upper limits in the range 0.6-4.5x10{-9} cm{-2} s{-1}, and give corresponding DM annihilation cross-section and decay lifetime limits. Theoretical implications are briefly discussed.

using initial state radiation with BABAR

We present a measurement of the

Fermi LAT Search for Photon Lines from 30 to 200 GeV

\ttbar

First Measurement of the t anti-t Differential Cross Section d sigma/dM(t anti-t) in p anti-p Collisions at s**(1/2)=1.96-TeV

differential cross section with respect to the

Study of B to X \gamma Decays and Determination of |V_{td}/V_{ts}|

\ttbar

Inclusive Search for Squark and Gluino Production in p anti-p Collisions at s**(1/2) = 1.96-TeV

invariant mass, dSigma/dMttbar, in

Measurement of Cross Sections for

\ppbar

b

collisions at