119418735
Recent results from the HiRes air fluorescence experiment
The High Resolution Fly's Eye Detector (HiRes) detects and measures properties of ultrahigh-energy cosmic rays (UHECR). The HiRes detector exploits what is known as the “air fluorescence” technique that uses the atmosphere as a calorimeter. A brief description of this technique and some recent results of the HiRes detector is given in this paper.
117245675
Ultra High Energy nt Detection Using Air Shower Fluorescence/Cerenkov Light Detector
The possibility of using air shower fluorescence/Cerenkov light detectors for ντ detection has been explored. A detector of this type is proposed to be set in the shadow of Mt. Wheeler Peak in Nevada, USA. The ντ to shower conversion probability density is calculated over an energy range from 1 PeV to 10 EeV. The number of showers converted from ντ ’s are estimated according to several models of neutrino sources.
128530951
Site Characteristics of Southern Utah Sites for Astronomical Observatories
The University of Utah has recently begun construction of a new 0.8 m optical/IR robotic telescope to be operated as a regional astronomy resource in the Intermountain West. The new Southern Utah Observatory (SUO) will require a high altitude (>3000 m) site with excellent atmospheric seeing, favorable weather conditions, and nearby infrastructure, including road, power, and high speed internet. We have explored six possible sites for the SUO telescope with favorable climate, night sky darkness and infrastructure. Since spring 2007, we have performed detailed measurements of atmospheric seeing at several of these sites, and have identified the preferred site for the SUO telescope at Frisco Peak, UT. Several large (1 sq. mile) areas of State Trust Land are nearby the new SUO telescope site. These large, flat areas may be excellent sites for large area, next generation Imaging Atmospheric Cherenkov Telescopes (IACT) arrays such as AGIS or northern CTA.
73632090
Stereo Spectrum of UHECR showers at the HiRes Detector
We present a measurement of the energy spectrum of UHECR showers. This measurement uses the two HiRes detector sites separated by 12.6 km to perform stereoscopic observations of UHECR air showers. The technique of stereoscopic reconstruction of the shower geometry and longitudinal profile is described. The resolution of reconstructed shower parameters using these techniques has been estimated using a detector simulation. Using the independently measured shower profiles from each detector site the energy resolution has also been measured. The detector aperture has been estimated by using the detector simulation. The energy distribution and resultant energy spectrum will be shown.
15877362
A fiber-optic-based calibration system for the High Resolution Fly's Eye cosmic ray observatory
Abstract This article describes the fiber-optic-based calibration system installed at the High Resolution Fly's Eye (HiRes) astro-particle physics observatory. The HiRes detectors measure ultra violet scintillation light from distant extensive air showers. This automated calibration system delivers light from a frequency tripled 355 nm YAG laser to the 10,752 photo-multiplier tubes of the 42 HiRes-II detectors.
124185401
Status of the High Altitude Water Cherenkov (HAWC) gamma ray observatory
120213557
Strong Interaction Effects in Weak Radiative $\bar{B}$ Meson Decay
Strong-interaction corrections to the effective hamiltonian for weak radiative B-meson decay (i.e., B → Xsγ, where Xs denotes a strange hadronic final state) are calculated using the leading logarithmic approximation. The inclusive rate for decays B → Xsγ, where the energy of the photon is large, is computed in the standard model with minimal particle content and in extensions of the minimal standard model with two Higgs doublets.
117938652
QCD effects in weak radiative b-meson decays
The effective Hamiltonian for B-meson decays of the form B → X xγ , where X s is a strange hadron, is found in the minimal Standard Model with strong interaction effects included. Renormalization group techniques are used to scale the coefficients of the operators in the effective Hamiltonian to find the inclusive decay rate for hard photon (E γ ~ 2GeV) emission, to leading logarithmic approximation.
118694674
Weak radiative B decays in the standard model and beyond
A discussion of the inclusive decays B → Xsγ and B → Xse+e− is given (Xs is a strange hadron), along with possible exclusive decay results from application of the Isgur‐Wise symmetry. The leading logarithmic strong interaction corrections are included. Decay rates for B → Xsγ include those predictions from the minimal standard model, the standard model with two Higgs doublets, and the minimal supersymmetric model. Decay rates for B → Xse+e− are reviewed in the standard model and the two Higgs doublet model.
119971093
Effective hamiltonian for weak radiative B-meson decay☆
Abstract The inclusive rate for decay of a B-meson to a hard photon and strange hadronic final states (i.e., B→γXs with X s = K ∗ , etc.), is likely to be dominated by short-distance physics which gives rise to an effective hamiltonian that is a magnetic-moment-type operator. Strong interaction corrections to this hamiltonian are computed in the leading logarithmic approximation.