8,910 research outputs found
Strange quark suppression from a simultaneous Monte Carlo analysis of parton distributions and fragmentation functions
We perform the first simultaneous extraction of unpolarized parton
distributions and fragmentation functions from a Monte Carlo analysis of
inclusive and semi-inclusive deep-inelastic scattering, Drell-Yan lepton-pair
production, and single-inclusive annihilation data. We use data
resampling techniques to thoroughly explore the Bayesian posterior distribution
of the extracted functions, and use -means clustering on the parameter
samples to identify the configurations that give the best description across
all reactions. Inclusion of the semi-inclusive data reveals a strong
suppression of the strange quark distribution at parton momentum fractions , in contrast with the ATLAS observation of enhanced strangeness
in and production at the LHC. Our study reveals significant
correlations between the strange quark density and the strange kaon
fragmentation function needed to simultaneously describe semi-inclusive
production data from COMPASS and inclusive spectra in
annihilation from ALEPH and SLD, as well as between the strange and light
antiquark densities in the proton.Comment: 6 pages, 4 figures; version to appear in Phys. Rev.
Towards a Comprehensive Fueling-Controlled Theory on the Growth of Massive Black Holes and Host Spheroids
We study the relation between nuclear massive black holes and their host
spheroid gravitational potential. Using AMR numerical simulations, we analyze
how gas is transported in the nuclear (central kpc) regions of galaxies. We
study the gas fueling onto the inner accretion disk (sub-pc scale) and the star
formation in a massive nuclear disk like those generally found in
proto-spheroids (ULIRGs, SCUBA Galaxies). These sub-pc resolution simulation of
gas fueling that is mainly depleted by star formation naturally satisfy the
`M_BH - $M_virial' relation, with a scatter considerably less than the observed
one. We found a generalized version of Kennicutt-Schmidt Law for starbursts is
satisfied, in which the total gas depletion rate (dot{M}_gas = dot{M}_BH +
dot{M}_SF) is the one that scales as M_gas/t_orbital. We also found that the
`M_BH - sigma' relation is a byproduct of the `M_BH - M_virial' relation in the
fueling controlled scenario.Comment: 12 pages, figures, submited to ApJ, email: [email protected]
Ab-initio molecular dynamics simulation of hydrogen diffusion in -iron
First-principles atomistic molecular dynamics simulation in the
micro-canonical and canonical ensembles has been used to study the diffusion of
interstitial hydrogen in -iron. Hydrogen to Iron ratios between
2 \times 2 \times 2$ supercell. We find that
the average optimum absorption site and the barrier for diffusion depend on the
concentration of interestitials. Iron Debye temperature decreases monotonically
for increasing concentration of interstitial hydrogen, proving that iron-iron
interatomic potential is significantly weakened in the presence of a large
number of diffusing hydrogen atoms
Health benefits and uncertainty: an experimental analysis of the effects of risk presentation on auction bids for a healthful product
Experimental subjects receive a different presentation of a food product's potential health risk reductions if eaten regularly. They are then asked to bid for the product. Results suggest that the bids vary across the groups that receive differing risk information.
Health Benefits and Uncertainty: An Experimental Analysis of the Effects of Risk Presentation on Auction Bids for a Healthful Product
Experimental subjects receive a different presentation of a food product's potential health risk reductions if people habitually eat it, and then asked to bid for the product. Results suggest that the bids vary across the groups that receive differing risk information.Health risks, experimental economics, auctions, uncertainty, Risk and Uncertainty, D81, I12,
The Effect of Risk Presentation on Product Valuation: An Experimental Analysis
We examine how people might evaluate a product with novel attribute, given various kinds of risk information. Using a product with healthful benefits, we assess subjects' willingness to pay given various kinds of health risk information conveying reduced health risks, life tradeoffs, and ambiguity. Four treatments in separate non-hypothetical experimental auctions are used to elicit willingness to pay values. Results suggest that willingness to pay vary across the groups that receive differing risk information. Specifically, willingness to pay was higher for the group that was given clear risk information and questions related to life tradeoffs than for the group given ambiguous risk information. Willingness to pay was lowest for the group that was given no risk information at all.Risk and Uncertainty,
- âŠ