Physics Opportunities for Vector-Boson Scattering at a Future 100 TeV Hadron Collider

Vector-boson scattering (VBS) processes provide particularly promising means for probing the mechanism of electroweak symmetry breaking and to search for new physics in the weak sector. In the environment of a future proton-proton collider operating at a center-of-mass energy of 100 TeV, unprecedented opportunities arise for the investigation of this important class of reactions. We highlight the prominent features of VBS processes in this energy regime and discuss how the VBS signal can be isolated in the presence of a priori large QCD backgrounds. We find excellent opportunities for the analysis of VBS reactions in a kinematic range that is inaccessible to present colliders.Comment: 26 pages, 14 figures; matches version published by Phys. Rev.

Radio Monitoring of the January 11, 1997 Gamma-Ray Burst

We report on a comprehensive radio monitoring program of the bright gamma-ray burster GRB970111. These VLA observations were made at a frequency of 1.4 GHz and span a range of post-burst timescales between 28 hours and one month. Despite extensive sampling at sub-milliJansky sensitivities, no radio source was detected above 0.5 mJy in the current best error box (~14 arcmin^2) for GRB970111. A highly unusual radio source, VLA J1528.7+1945, was seen to drop in flux density by a factor of two in our monitoring period but it lies outside the error box and thus it is unlikely to be related to GRB970111. Cosmological fireball models of gamma-ray bursts make predictions of late-time emission occurring at longer wavelengths. The absence of a flaring or fading radio counterpart to GRB970111 provides strong constraints on these models.Comment: ApJ Let (accepted

Shadowing Effects on the Nuclear Suppression Factor, R_dAu, in d+Au Interactions

We explore how nuclear modifications to the nucleon parton distributions affect production of high transverse momentum hadrons in deuteron-nucleus collisions. We calculate the charged hadron spectra to leading order using standard fragmentation functions and shadowing parameterizations. We obtain the d+Au to pp ratio both in minimum bias collisions and as a function of centrality. The minimum bias results agree reasonably well with the BRAHMS data while the calculated centrality dependence underestimates the data and is a stronger function of p_T than the data indicate.Comment: 18 pages, 3 figures, final version, Phys. Rev. C in pres

Health status of learners of educational institutions within Selebi Phikwe Ni-Cu mine area, Botswana

Published ArticleHealth effects associated with Ni-Cu mining on learners living within the mining area at Selebi Phikwe were investigated through the administration of questionnaires. Results depicted learners suffering from a wide range of different symptoms and illnesses. 70% of the learners complained of coughs, 77% had influenza / common cold, and 80% had headaches. The repeated coughing, constant influenza / common cold and persistent headaches from which learners suffered, were very significantly higher than those at the control site; and incidences of their occurrence increased with closeness to the mining area. The unusual high occurrences of these ailments and illnesses coupled with associated diseases among learners were attributed to several environmental factors including contaminated particulate air matter (PAM) (rich in sulphur and heavy metals) linked to the mining and smelting of Ni-Cu

The onset of classical QCD dynamics in relativistic heavy ion collisions

The experimental results on hadron production obtained recently at RHIC offer a new prospective on the energy dependence of the nuclear collision dynamics. In particular, it is possible that parton saturation -- the phenomenon likely providing initial conditions for the multi--particle production at RHIC energies -- may have started to set in central heavy ion collisions already around the highest SPS energy. We examine this scenario, and make predictions based on high density QCD for the forthcoming 22 GeV run at RHIC.Comment: 4 pages, 2 figures, revte

Geometric Parameterization of J/ΨJ/\Psi Absorption in Heavy Ion Collisions

We calculate the survival probability of $J/\Psi$ particles in various colliding systems using a Glauber model. An analysis of recent data has reported a $J/\Psi$-nucleon breakup cross section of 6.2$\pm$0.7 mb derived from an exponential fit to the ratio of $J/\Psi$ to Drell-Yan yields as a function of a simple, linearly-averaged mean path length through the nuclear medium. Our calculations indicate that, due to the nature of the calculation, this approach yields an apparent breakup cross section which is systematically lower than the actual value.Comment: LaTex, 7 pages, 2 figure

Lawn-watering perceptions and behaviors of residential homeowners in three Kansas (USA) cities: implications for water quantity and quality

Urbanization is increasing the land area covered with turfgrasses, which may have implications for water quantity and quality. The largest sector of turfgrass is residential lawns. Our objectives were to survey residential homeowners in three Kansas cities about their perceptions, knowledge, and behaviors when irrigating their lawns; each city has distinctive water quantity and quality issues. Surveys were mailed to 15,500 homeowners in Wichita, 10,000 in Olathe, and 5,000 in Salina; the return rate was 11-13%. Wichita residents watered more frequently than Olathe and Salina, possibly because of greater evaporative demand than Olathe, and cheaper water and less concern about water shortages than Salina; Salina and Wichita have similar evaporative demands but Salina had a recent water crisis. Salina homeowners were most concerned about keeping their water bill from getting too high, probably because of higher water costs than the other cities. Overall, 45-60% indicated it was moderately to very important their lawns looked green all the time, while 65-77% ranked water conservation at the same level of importance. Significantly, 61-63% did not know how much water their lawns required and 71-77% did not know how much water they applied to their lawns when they irrigated. About 7-9% swept or blew clippings or lawn-care products directly into streets or storm drains, which run directly into local streams or reservoirs; 9% in Wichita is ~9,000 homeowners. The homeowner’s lawn irrigation knowledge and habits must be improved to help conserve water and protect water quality

A Spectacular VHE Gamma-Ray Outburst from PKS 2155-304 in 2006

Since 2002 the VHE (>100 GeV) gamma-ray flux of the high-frequency peaked BL Lac PKS 2155-304 has been monitored with the High Energy Stereoscopic System (HESS). An extreme gamma-ray outburst was detected in the early hours of July 28, 2006 (MJD 53944). The average flux above 200 GeV observed during this outburst is ~7 times the flux observed from the Crab Nebula above the same threshold. Peak fluxes are measured with one-minute time scale resolution at more than twice this average value. Variability is seen up to ~600 s in the Fourier power spectrum, and well-resolved bursts varying on time scales of ~200 seconds are observed. There are no strong indications for spectral variability within the data. Assuming the emission region has a size comparable to the Schwarzschild radius of a ~10^9 solar mass black hole, Doppler factors greater than 100 are required to accommodate the observed variability time scales.Comment: 4 pages, 3 figures; To appear in the Proceedings of the 30th ICRC (Merida, Mexico