DAMA detection claim is still compatible with all other DM searches

We show that the annual modulation signal observed by DAMA can be reconciled with all other negative results from dark matter searches with a conventional halo model for particle masses around 5 to 9 GeV. We also show which particular dark matter stream could produce the DAMA signal.Comment: Talk given at TAUP2005, Sept. 10-14 2005, Zaragoza (Spain). 3 pages, 4 figure

Role of spontaneous breathing trial in predicting successful extubation in premature infants

Background The ability of clinicians to predict successful extubation in mechanically ventilated premature neonates is limited. Identifying objective criteria for predicting successful extubation may reduce the incidence of failed extubation and the duration of mechanical ventilation. Objective To evaluate the validity of objective measures of lung function and spontaneous breathing trial (SBT) in predicting successful extubation among premature neonates with attempted extubations within the first 3 weeks of life. Methods Respiratory compliance (Crs) along with SBT was performed prior to elective extubations within 3 weeks of age in premature infants ≤32 weeks. Extubation was considered successful if patients remained extubated for >72 hr. Ventilator settings including mean airway pressure (MAP), set rate, and fraction of inspired oxygen (FiO 2 ) 24 hr after re‐intubation were compared with pre‐extubation settings, in patients requiring re‐intubation. Results Thirty‐nine of 49 infants (80%) were successfully extubated. Of 41 babies who passed SBT, only 5 infants failed extubation. SBT had 92% sensitivity, 50% specificity, 88% positive predictive, and 63% negative predictive value for successful extubation. Crs was comparable between infants who were successfully extubated and those who were not. Conclusions A SBT prior to extubation may be a practical objective adjunct in predicting successful extubation in ventilated premature infants. Pediatr Pulmonol. 2013; 48:443–448. © 2012 Wiley Periodicals, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/97465/1/22623_ftp.pd

Bounds on Relic Neutrino Masses in the Z-burst Model

Neutrinos from far-away sources annihilating at the Z resonance on relic neutrinos may give origin to the extreme-energy cosmic rays (EECR). If ``Z-bursts'' are responsible for the EECR events, then we show that the non-observation of cosmic ray events at energies above 2 x 10^20 eV by the AGASA Collaboration implies a lower bound around 0.3 eV on the relic neutrino mass. Since this mass exceeds the mass-squared differences inferred from oscillation physics, the bound in fact applies to all three neutrino masses. Together with the upper bound provided by comparisons of the CMB anisotropy with large-scale structure, this bound leaves only a small interval for neutrino masses around 0.3 eV, if Z-bursts are to explain the existing EECR events.Comment: 19 pages, including 4 figure

Cold dark matter in brane cosmology scenario

We analyze the dark matter problem in the context of brane cosmology. We investigate the impact of the non-conventional brane cosmology on the relic abundance of non-relativistic stable particles in high and low reheating scenarios. We show that in case of high reheating temperature, the brane cosmology may enhance the dark matter relic density by many order of magnitudes and a stringent lower bound on the five dimensional scale is obtained. We also consider low reheating temperature scenarios with chemical equilibrium and non-equilibrium. We emphasize that in non-equilibrium case, the resulting relic density is very small. While with equilibrium, it is increased by a factor of O(10^2) with respect to the standard thermal production. Therefore, dark matter particles with large cross section, which is favored by detection expirements, can be consistent with the recent relic density observational limits.Comment: 14 pages, 1 figur

Measurement of the gluon PDF at small x with neutrino telescopes

We analyze the possibility that neutrino telescopes may provide an experimental determination of the slope lambda of the gluon distribution in the proton at momentum fractions x smaller than the accelerator reach. The method is based on a linear relation between lambda and the spectral index (slope) of the down-going atmospheric muon flux above 100 TeV, for which there is no background. Considering the uncertainties in the charm production cross section and in the cosmic ray composition, we estimate the error on the measurement of lambda through this method, excluding the experimental error of the telescopes, to be ~ +/- 0.2Comment: 16 pages with 16 figures - new version, comments added, same results and figure

Anisotropy of the Cosmic Neutrino Background

The cosmic neutrino background (CNB) consists of low-energy relic neutrinos which decoupled from the cosmological fluid at a redshift z ~ 10^{10}. Despite being the second-most abundant particles in the universe, direct observation remains a distant challenge. Based on the measured neutrino mass differences, one species of neutrinos may still be relativistic with a thermal distribution characterized by the temperature T ~ 1.9K. We show that the temperature distribution on the sky is anisotropic, much like the photon background, experiencing Sachs-Wolfe and integrated Sachs-Wolfe effects.Comment: 5 pages, 2 figures / updated references, discussion of earlier wor

Sensitivity of cosmic-ray experiments to ultra-high-energy photons: reconstruction of the spectrum and limits on the superheavy dark matter

We estimate the sensitivity of various experiments detecting ultra-high-energy cosmic rays to primary photons with energies above 10^19 eV. We demonstrate that the energy of a primary photon may be significantly (up to a factor of ~ 10) under- or overestimated for particular primary energies and arrival directions. We consider distortion of the reconstructed cosmic-ray spectrum for the photonic component. As an example, we use these results to constrain the parameter space of models of superheavy dark matter by means of both the observed spectra and available limits on the photon content. We find that a significant contribution of ultra-high-energy particles (photons and protons) from decays of superheavy dark matter is allowed by all these constraints.Comment: 18 pages, 7 figure

Prompt muon contribution to the flux underwater

We present high energy spectra and zenith-angle distributions of the atmospheric muons computed for the depths of the locations of the underwater neutrino telescopes. We compare the calculations with the data obtained in the Baikal and the AMANDA muon experiments. The prompt muon contribution to the muon flux underwater due to recent perturbative QCD-based models of the charm production is expected to be observable at depths of the large underwater neutrino telescopes. This appears to be probable even at rather shallow depths (1-2 km), provided that the energy threshold for muon detection is raised above $\sim 100$ TeV.Comment: 7 pages, RevTeX, 7 eps figures, final version to be published in Phys.Rev.D; a few changes made in the text and the figures, an approximation formula for muon spectra at the sea level, the muon zenith-angle distribution table data and references adde

MeV sterile neutrinos in low reheating temperature cosmological scenarios

It is commonly assumed that the cosmological and astrophysical bounds on the mixings of sterile with active neutrinos are much more stringent than those obtained from laboratory measurements. We point out that in scenarios with a very low reheating temperature T_RH << 100 MeV at the end of (the last episode of) inflation or entropy creation, the abundance of sterile neutrinos becomes largely suppressed with respect to that obtained within the standard framework. Thus, in this case cosmological bounds become much less stringent than usually assumed, allowing sterile neutrinos to be ``visible'' in future experiments. Here, we concentrate on massive (mostly sterile) neutrinos heavier than 1 MeV.Comment: 14 pp, 7 fig