Indirect Searches for Z′Z'-like Resonances at the LHC

We explore the possibility of indirectly observing the effects of $Z'$-like particles with electroweak strength couplings in the Drell-Yan channel at the LHC with masses above the resonance direct search reach. We find that, mostly due to statistical limitations, this is very unlikely in almost all classes of models independently of the spin of the resonance. Not unexpectedly, the one possible exception to this general result is the case of degenerate Kaluza-Klein (KK) excitations of the photon and $Z$ that occur in some extra-dimensional models. In this special case, the strong destructive interference with the Standard Model (SM) exchanges below the resonance mass leads to a well-known significant suppression of the cross section and thus increased sensitivity to this particular new physics scenario.Comment: 18 pages, 6 figs, discussion and reference adde

A screening tool to prioritize public health risk associated with accidental or deliberate release of chemicals into the atmosphere

The Chemical Events Working Group of the Global Health Security Initiative has developed a flexible screening tool for chemicals that present a risk when accidentally or deliberately released into the atmosphere. The tool is generic, semi-quantitative, independent of site, situation and scenario, encompasses all chemical hazards (toxicity, flammability and reactivity), and can be easily and quickly implemented by non-subject matter experts using freely available, authoritative information. Public health practitioners and planners can use the screening tool to assist them in directing their activities in each of the five stages of the disaster management cycle

Test of the Standard Model in high

Following the observation by H1 of unexpected events with jets, high P T leptons and large missing transverse momentum, we explore final states with similar kinematic configurations but only high P T jets in the final state. The data sample comprises all available e + p data collected in 1994 to 1997. The cross sections for two and three jet production as function of jet transverse momentum and multi-jet invariant mass are compared with QCD predictions for multi-jet events. No significant deviations from expectation are found. Abstract: 157u Parallel sessions: 1, 6 Plenary sessions: 1, 6 Electronic Access: http://www-h1.desy.de/publications/ 1 Introduction In [1] we have reported the observation of events containing an isolated charged lepton with large transverse momentum P T together with large missing transverse momentum P T;miss in e + p scattering data collected in 1994--1997 at the HERA collider. While some of the events are naturally explained by Standard Model p..

Color-Octet

We study contributions from color-octet quarkonium formation mechanisms to J=/ hadroproduction at low p ? . We include transitions of color-octet c¯c states into "direct" J=/ and into Ø 1;2 which decay radiatively into a J=/. Together with earlier work, this calculation constitutes a complete analysis of p ? -integrated J=/ production at leading twist. We find that the leading-twist contribution is not sufficient to reproduce the observed production rates and polarization of the J=/ and Ø 1;2 . Hence there must exist other important quarkonium production mechanisms at low p ? . Typeset using REVT E X I. INTRODUCTION The production and decays of heavy quarkonia have been widely studied using perturbative QCD [1]. Due to the large masses of the c and b quarks, the production or annihilation of heavy-quark--antiquark pairs takes place at a much shorter timescale than the formation of the bound state. This makes it possible to factorize the transition amplitudes. In hadroproduction re..

Diffractive

this paper, new (preliminary) HERMES experimental data on diffractive a