Searches for Long-lived particles with the ATLAS experiment

The discovery of a new type of a heavy long-lived particle (LLP) would be of fundamental significance due to their existence in many beyond the Standard Model scenarios. LLPs are anticipated in a wide range of physics models which extend the Standard Model, such as Supersymmetry and Universal Extra Dimensions. Since LLPs produced in 7 TeV pp collisions at the CERN LHC can be slow (beta << 1) and penetrating, time-of-flight and anomalous dE/dx energy loss measurements are promising ways to search for LLPs. In some cases these heavy objects may lose all of their energy and come to rest within the densest parts of the detector volume, decaying later, potentially out-of-time with collisions from the LHC. We present searches for LLPs using the ATLAS experiment, describing the techniques used and the results achieved to date.Comment: 3 pages, 6 figures, Proceedings of the XXXI Physics in Collision Conference, Vancouver, Canada, August 28 - September 1, 201

The Space Shuttle Columbia Catastrophe

On February 1, 2003, the space shuttle Columbia and its crew were tragically lost over East Texas upon re-entry from a two-week mission. Immediately following the explosion, another mission ensued; an unprecedented search and recovery effort by agency officials and the local community. Dr. Paul Jackson (School of Agricultural Sciences and Forestry) will share information about the shuttle crew along with his experience as a recovery team official for five weeks following the disaster

Influence of Container Color, Media Depth, and Subsequent Light Availability on Stem Elongation of Longleaf Pine

Nathan G. Bolner is an undergraduate student in the School of Agricultural Sciences and Forestry at Louisiana Tech University. D. Paul Jackson is an Assistant Professor in the School of Agricultural Sciences and Forestry at Louisiana Tech Universit

Contact-less measurements of Shubnikov-de Haas oscillations in the magnetically ordered state of CeAgSb2_2 and SmAgSb2_2 single crystals

Shubnikov - de Haas oscillations were measured in single crystals of highly metallic antiferromagnetic SmAgSb$_{2}$ and ferromagnetic CeAgSb$_{2}$ using a tunnel diode resonator. Resistivity oscillations as a function of applied magnetic field were observed via measurements of skin depth variation. The effective resolution of $\Delta\rho\simeq20$ p$\Omega$ allows a detailed study of the SdH spectra as a function of temperature. The effects of the Sm long - range magnetic ordering as well as its electronic structure ($4f$-electrons) on the Fermi surface topology is discussed

A Search for B+ to K+ Nu Anti-Nu

A search for the rare, flavour-changing neutral current decay B{sup +} {yields} K{sup +} {nu}{bar {nu}} is presented using 81.9 fb{sup -1} of data collected at the {Upsilon}(4S) resonance by the BABAR experiment. Signal candidate events are selected through the identification of a high momentum charged kaon and significant missing energy, where the companion B{sup -} in the event has decayed semileptonically via B{sup -} {yields} D{sup 0}{ell}{sup -}{bar {nu}} X and X is kinematically constrained to be either nothing or a low momentum transition photon or {pi}{sup 0}. The analysis was performed blind and 6 candidates were selected with a background expectation of 3.4 {+-} 1.2. This leads to a limit on the branching fraction of {Beta} (B{sup +} {yields} K{sup +} {nu}{bar {nu}}) &lt; 7.2 x 10{sup -5} at 90% confidence level. We also search for the reaction B{sup +} {yields} {pi}{sup +}{nu}{bar {nu}} and extract a limit on the branching fraction of {Beta}(B{sup +} {yields} {pi}{sup +}{nu}{bar {nu}}) &lt; 2.5 x 10{sup -4} at 90% confidence level

Validity of effective material parameters for optical fishnet metamaterials

Although optical metamaterials that show artificial magnetism are mesoscopic systems, they are frequently described in terms of effective material parameters. But due to intrinsic nonlocal (or spatially dispersive) effects it may be anticipated that this approach is usually only a crude approximation and is physically meaningless. In order to study the limitations regarding the assignment of effective material parameters, we present a technique to retrieve the frequency-dependent elements of the effective permittivity and permeability tensors for arbitrary angles of incidence and apply the method exemplarily to the fishnet metamaterial. It turns out that for the fishnet metamaterial, genuine effective material parameters can only be introduced if quite stringent constraints are imposed on the wavelength/unit cell size ratio. Unfortunately they are only met far away from the resonances that induce a magnetic response required for many envisioned applications of such a fishnet metamaterial. Our work clearly indicates that the mesoscopic nature and the related spatial dispersion of contemporary optical metamaterials that show artificial magnetism prohibits the meaningful introduction of conventional effective material parameters

Negative vaccine attitudes and intentions to vaccinate against Covid-19 in relation to smoking status: a population survey of UK adults

INTRODUCTION: We examined differences in negative attitudes towards vaccines in general, and intentions to vaccinate against Covid-19 specifically, by smoking status in a large sample of adults in the UK. METHOD: Data were from 29,148 adults participating in the Covid-19 Social Study in September-October 2020. Linear regression analyses examined associations between smoking status (current/former/never) and four types of general negative vaccine attitudes: mistrust of vaccine benefit, worries about unforeseen effects, concerns about commercial profiteering, and preference for natural immunity. Multinomial logistic regression examined associations between smoking status and uncertainty and unwillingness to be vaccinated for Covid-19. Covariates included sociodemographic characteristics and diagnosed health conditions. RESULTS: Relative to never and former smokers, current smokers reported significantly greater mistrust of vaccine benefit, were more worried about unforeseen future effects, had greater concerns about commercial profiteering, and had a stronger preference for natural immunity (Badjs 0.16-0.36, p<0.001). Current smokers were more likely to be uncertain (27.6% vs. 22.7% of never smokers: RRadj 1.43 [95%CI 1.31-1.56]; vs. 19.3% of former smokers: RRadj 1.55 [1.41-1.73]) or unwilling (21.5% vs. 11.6% of never smokers: RRadj 2.12 [1.91-2.34]; vs. 14.7% of former smokers: RRadj 1.53 [1.37-1.71]) to receive a Covid-19 vaccine. CONCLUSIONS: Current smokers hold more negative attitudes towards vaccines in general, and are more likely to be undecided or unwilling to vaccinate against Covid-19, compared with never and former smokers. With a disproportionately high number of smokers belonging to socially clustered and disadvantaged socioeconomic groups, lower vaccine uptake in this group could also exacerbate health inequalities. IMPLICATIONS: These results suggest that without intervention, smokers will be less likely than non-smokers to take up the offer of a Covid-19 vaccine when offered. Targeted policy action may be required to ensure low uptake of Covid-19 vaccination programmes does not compound health inequalities between smokers and non-smokers

Improved Constraints on Isotropic Shift and Anisotropies of the Speed of Light using Rotating Cryogenic Sapphire Oscillators

We demonstrate that Michelson-Morley tests, which detect direction-dependent anisotropies in the speed of light, can also be used to place limits upon isotropic deviations of the vacuum speed of light from $c$, as described by the photon sector Standard Model Extension (SME) parameter $\tilde{\kappa}_{tr}$. A shift in the speed of light that is isotropic in one inertial frame implies anisotropic shifts in others. Using observer Lorentz covariance, we derive the time-dependent variations in the relative resonance frequencies of a pair of electromagnetic resonators that would be generated by such a shift in the rest frame of the Sun. A new analysis of a recent experimental test of relativity using this result constrains $\tilde{\kappa}_{tr}$ with a precision of $7.4\times10^{-9}$. This represents the first constraint on $\tilde{\kappa}_{tr}$ by a Michelson-Morley experiment and the first analysis of a single experiment to simultaneously set limits on all nine non-birefringent terms in the photon sector of the SME