18643814
SU(3) predictions for weak decays of doubly heavy baryons, including SU(3) breaking terms
We find expressions for the weak decay amplitudes of baryons containing two b quarks (or one b and one c quark -- many relationship are the same) in terms of unknown reduced matrix elements. This project was originally motivated by the request of the FNAL Run II b Physics Workshop organizers for a guide to experimentalists in their search for as yet unobserved hadrons. We include an analysis of linear SU(3) breaking terms in addition to relationships generated by unbroken SU(3) symmetry, and relate these to expressions in terms of the complete set of possible reduced matrix elements.
54173137
Even- and odd-parity charmed meson masses in heavy hadron chiral perturbation theory
We derive mass formulae for the ground state, J P = 0 − and 1 − , and first excited even-parity, J P = 0 + and 1 + , charmed mesons including one loop chiral corrections and O(1/mc) counterterms in heavy hadron chiral perturbation theory. We show that including these counterterms is critical for fitting the current data. We find that certain parameter relations in the parity doubling model are not renormalized at one loop, providing a natural explanation for the observed equality of the hyperfine splittings of ground state and excited doublets.
56337141
Parity-violating neutron spin rotation in hydrogen and deuterium
AbstractWe calculate the (parity-violating) spin-rotation angle of a polarized neutron beam through hydrogen and deuterium targets, using pionless effective field theory up to next-to-leading order. Our result is part of a program to obtain the five leading independent low-energy parameters that characterize hadronic parity violation from few-body observables in one systematic and consistent framework. The two spin-rotation angles provide independent constraints on these parameters. Our result for np spin rotation is $$\frac{1}
{\rho }\frac{{d\varphi _{PV}^{np} }}
{{dl}} = \left[ {4.5 \pm 0.5} \right] rad MeV^{ - \frac{1}
{2}} \left( {2g^{\left( {^3 S_1 - ^3 P_1 } \right)} + g^{\left( {^3 S_1 - ^3 P_1 } \right)} } \right) - \left[ {18.5 \pm 1.9} \right] rad MeV^{ - \frac{1}
{2}} \left( {g_{\left( {\Delta {\rm I} = 0} \right)}^{\left( {^1 S_0 - ^3 P_0 } \right)} - 2g_{\left( {\Delta {\rm I} = 2} \right)}^{\left( {^1 S_0 - ^3 P_0 } \right)} } \right)$$, while for nd spin rotation we obtain $$\frac{1}
{\rho }\frac{{d\varphi _{PV}^{nd} }}
{{dl}} = \left[ {8.0 \pm 0.8} \right] rad MeV^{ - \frac{1}
{2}} g^{\left( {^3 S_1 - ^1 P_1 } \right)} + \left[ {17.0 \pm 1.7} \right] rad MeV^{ - \frac{1}
{2}} g^{\left( {^3 S_1 - ^3 P_1 } \right)} + \left[ {2.3 \pm 0.5} \right] rad MeV^{ - \frac{1}
{2}} \left( {3g_{\left( {\Delta {\rm I} = 0} \right)}^{\left( {^1 S_0 - ^3 P_0 } \right)} - 2g_{\left( {\Delta {\rm I} = 1} \right)}^{\left( {^1 S_0 - ^3 P_0 } \right)} } \right)$$, where the g(X-Y), in units of $$MeV^{ - \frac{3}
{2}}$$, are the presently unknown parameters in the leading-order parity-violating Lagrangian. Using naıve dimensional analysis to estimate the typical size of the couplings, we expect the signal for standard target densities to be $$\left| {\frac{{d\varphi _{PV} }}
{{dl}}} \right| \approx \left[ {10^{ - 7} \ldots 10^{ - 6} } \right]\frac{{rad}}
{m}$$ for both hydrogen and deuterium targets. We find no indication that the nd observable is enhanced compared to the np one. All results are properly renormalized. An estimate of the numerical and systematic uncertainties of our calculations indicates excellent convergence. An appendix contains the relevant partial-wave projectors of the three-nucleon system.
14207492
Hyperon Decays in Chiral Perturbation Theory Revisited
The discrepancies found between S-wave and P-wave fits for hyperon decays are reinvestigated using the heavy baryon chiral Lagrangian formalism. 
The agreement is found to improve through the inclusion of previously omitted diagrams. The S-waves are unaffected by this, but the P-wave predictions are modified. A correlated fit to the chiral parameters is performed and the results discussed.
120537010
Hyperons and Hypernuclei
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.
110934427
Experience in construction and testing of plastic limited streamer chambers
The manufacture and testing of multicell limited streamer chambers for use in the hadron calorimeter of the OPAL detector and LEP (Large Electron Positron Collider) are described. All operations, from chamber cathode coating to the testing of completed subassemblies, have been performed under the same roof. With reasonable care and quality control, the established technology produced chambers several meters long with an overall success rate of about 90%. Treatment of the carbon coating with Breox B-35 was effective in eliminating uncertainties in the cathode performance. >
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.
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.
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.