A Method to Unambiguously Determine the Parity of the Theta+ Pentaquark

With the recent discovery of the $\Theta(1540)$ pentaquark, the question of its parity is paramount since this will constrain the correct description of its internal structure. We show that the measurement of the spin singlet and triplet cross sections for the reaction $\vec{p}\vec{p} \to \Sigma^+ \Theta^+$ will unambiguously determine the parity of the $\Theta^+$.Comment: 3 page

Exploring the practical knowledge of eccentric resistance training in high-performance strength and conditioning practitioners

Habitual use of eccentric exercise has been recognised to increase strength and power; however, the current body of knowledge has limited potential to understand the application of such resistance training in athletic populations. In order to develop appropriate applied research, that relates to elite athletic populations, it is vital to appreciate the practical knowledge of strength and conditioning practitioners operating in high-performance environments. This study summarised the questionnaire responses from 100 strength and conditioning practitioners operating in performance sport relating to questions such as the training effects to various eccentric resistance training regimes, the rationale for the use of these techniques and the knowledge supporting its application. The combination of closed and open-ended questions enabled a thematic analysis to be conducted. There was evidence that practitioners employed a variety of eccentric training methodologies; however, there was interest in gaining greater understanding of the training dose to bring about the optimal adaptive changes, and importantly how this might translate to sport-specific performance. In addition, practitioners would welcome recommendations associated with eccentric training, whilst concurrently minimising the issues of excessive fatigue, muscle damage and soreness. The training effects of interest included neural, architectural and morphological adaptations and, importantly, translation to performance of sports-specific skills. Collectively, these responses called for more practically relevant research to be conducted within the high-performance environment, alongside more opportunities for professional development through learning and knowledge-sharing opportunities. The outcomes summarised in this work should inform future applied research projects and educational content relating to eccentric training

1-1.4 Micron Spectral Atlas of Stars

We present a catalog of J-band (1.08 um to 1.35 um) stellar spectra at low resolution (R ~ 400). The targets consist of 105 stars ranging in spectral type from O9.5 to M7 and luminosity classes I through V. The relatively featureless spectra of hot stars, earlier than A4, can be used to remove the atmospheric features which dominate ground-based J-band spectroscopy. We measure equivalent widths for three absorption lines and nine blended features which we identify in the spectra. Using detailed comparison with higher resolution spectra, we demonstrate that low resolution data can be used for stellar classification, since several features depend on the effective temperature and gravity. For example The CN index (1.096 - 1.104 um) decreases with temperature, but the strength of a blended feature at 1.28 um (consisting of primarily P beta) increases. The slope of a star's spectrum can also be used to estimate its effective temperature. The luminosity class of a star correlates with the ratio of the Mg I (1.1831 um) line to a blend of several species at 1.16 um. Using these indicators, a star can be classified to within several subclasses. Fifteen stars with particularly high and low metal abundances are included in the catalog and some spectral dependence on metal abundance is also found.Comment: 35 pages, 10 figures (3a-e are in gif format. For complete high resolution figures, go to http://www.astro.ucla.edu/~malkan/newjspec/) ; Accepted for published in ApJS; For associated spectra files, see http://www.astro.ucla.edu/~malkan/newjspec

Experimental Outlook for the Pentaquark

A critical look is taken at both positive and null evidence for the $\Theta^+$ pentaquark. Potential problems with experiments will be discussed and the question of what conclusion can be drawn from both the positive and the null results is examined. First the question of existence of the $\Theta^+$ pentaquark is considered, followed by a discussion of new experiments that are either planned or in progress to answer questions about its mass, width and isospin. Finally, indirect evidence for the parity of the $\Theta^+$ is examined, and suggestions for experiments to measure its parity directly are given.Comment: MESON2004 conference proceedings, 10 pages, 1 figur

Comment on The Evidence for a Pentaquark and Kinematic Reflections

The Regge exchange model used by Dzierba et al. is shown to be questionable, since the pion pole term is not allowed. Hence the Regge amplitudes in their calculation are exaggerated. The amount of kinematic reflection in the mass spectrum of the (nK+) system, which is one decay channel of a possible pentaquark, is not well justified in the fitting procedure used by Dzierba et al., as shown by comparison with the (K+K-) invariant mass spectrum, which is one decay channel of the a_2 and f_2 tensor mesons. While kinematic reflections are still a concern in some papers that have presented evidence for the pentaquark, better quantitative calculations are needed to demonstrate the significance of this effect.Comment: Comment submitted to Phys. Rev. D (no figures

Make me think! Exploring library UX through the lens of (critical) information literacy

While (critical) information literacy (IL) acknowledges the political, economic, and social forces that shape complex information environments, library user experience (UX) typically centers efficiency and ‘seamlessness,’ ignoring the power structures and values that condition learning. In this paper, we explore the tensions between IL and UX values and practices, with the aim of starting a conversation about how these two related fields can become more closely aligned

A Study of Self-Esteem and Grade Point Average (GPA) Among College Students

The study examined the possible relationship between self-esteem and grade point average (GPA) held by college students. One hundred forty college students completed a survey, through the Human Subject Pool, as well as at the end of five separate classes, to determine their level of self-esteem as well as to obtain their permission to view their GPA anonymously. Results suggest that there is a positive relationship between selfesteem and grade point averag

Cross sections for the gamma p -\u3e K*(+)Lambda and gamma p -\u3e K*(+)Sigma(0) reactions measured at CLAS

The first high-statistics cross sections for the reactions gamma p -\u3e K*(+)Lambda and gamma p -\u3e K*(+)Sigma(0) were measured using the CLAS detector at photon energies between threshold and 3.9 GeV at the Thomas Jefferson National Accelerator Facility. Differential cross sections are presented over the full range of the center-of-mass angles, and then fitted to Legendre polynomials to extract the total cross section. Results for the K*(+)Lambda final state are compared with two different calculations in an isobar and a Regge model, respectively. Theoretical calculations significantly underestimate the K*(+)Lambda total cross sections between 2.1 and 2.6 GeV, but are in better agreement with present data at higher photon energies

Pyrolysis of switchgrass (\u3ci\u3ePanicum virgatum\u3c/i\u3e) harvested at several stages of maturity

The pyrolysis of switchgrass (Panicum virgatum) of the cultivar, ‘‘Cave-in-Rock’’ harvested at three stages of physiological maturity was studied in a PY–GC/MS system at the 600–1050 °C temperature range. Under these conditions, the decomposition was complete within 20 s yielding char, and two sets of pyrolysis gas, condensable and non-condensable. The former consisted of acetaldehyde (CH3CHO), acetic acid (CH3COOH) and higher molecular weight compounds possibly from the hydroxyl group and from the methoxy groups of the cell wall components. The non-condensable gases were mainly CO, CO2 and C1–C3 hydrocarbons. For these, there was a 900 °C temperature boundary where dramatic change occurred in their evolution rates. Below this temperature, CO2 decreased but CO and the C1–C3 hydrocarbons increased almost linearly with temperature. Above this temperature boundary, the hydrocarbons leveled off but there was a rapid rise in CO and CO2 evolution at a constant CO/CO2 ratio. These suggest the appearance of secondary or tertiary pyrolysis reactions involving rearrangement and release of CO and hydrocarbons prior to this temperature boundary and the release of CO and CO2 from the tightly bond oxygen functionalities including C–C bonds thereafter. At \u3c750 \u3e°C, there were modest increases in condensable gas yield and decrease in non-condensable gas due to differences in plant maturity at harvest. However, the effect of switchgrass physiological maturity on gas yield was statistically insignificant at high temperatures. The energy content of the non-condensable gas measured was about 68% of the gross energy content of the biomass for the early harvest crop and 80% for the mature crop. The activation energy for the decomposition, estimated assuming first order reaction kinetics, showed a linear increasewith plant physiological maturity. The results demonstrate that physiological maturity at harvest of switchgrass biomass can result in different concentrations of pyrolysis products at different temperatures. These results also demonstrate the need for additional research with a broader array of herbaceous biomass materials to develop a better understanding of the synergies of crop cultivation, harvesting and processing of dedicated herbaceous biomass energy crops during their thermochemical conversion