1,016 research outputs found

    SELECTING A BUSINESS MAJOR WITHIN THE COLLEGE OF BUSINESS

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    This study employed a survey in examining the important influences that shape a student’s selection of a major in the College of Business (COB). In particular, it compared these influences, by major, to assess which items were most (and least) important to the students majoring in accounting, general business, finance, management, marketing, and MIS. The influences, totaling 37, included internal influences (e.g., interest in the field), external influences (e.g., projected salary), and interpersonal influences (influence of significant others). Some of the findings were consistent with those of prior studies. For example, interesting work was highly important for all business majors, and specific interpersonal influences such as parents, high school teachers, and peers were relatively unimportant. The findings presented herein suggest that the overall impact of interpersonal influence may have been underestimated in previous studies. Unlike many previous studies, this study showed that job availability and job security were more important to students than interest in the field. This study augments the extant literature in that the survey was conducted right after the 2009 recession, which allowed an analysis of student decision making during a period of high unemployment and lingering economic uncertainty. Implications and suggestions for further research are discussed

    Parton model versus color dipole formulation of the Drell-Yan process

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    In the kinematical region where the center of mass energy is much larger than all other scales, the Drell-Yan process can be formulated in the target rest frame in terms of the same color dipole cross section as low Bjorken-x deep inelastic scattering. Since the mechanisms for heavy dilepton production appear very different in the dipole approach and in the conventional parton model, one may wonder whether these two formulations really represent the same physics. We perform a comparison of numerical calculations in the color dipole approach with calculations in the next-to-leading order parton model. For proton-proton scattering, the results are very similar at low x_2 from fixed target to RHIC energies, confirming the close connection between these two very different approaches. We also compare the transverse momentum distributions of Drell-Yan dileptons predicted in both formulations. The range of applicability of the dipole formulation and the impact of future Drell-Yan data from RHIC for determining the color dipole cross section are discussed. A detailed derivation of the dipole formulation of the Drell-Yan process is also included.Comment: 20 pages, 5 figure

    Phonon Band Structure and Thermal Transport Correlation in a Layered Diatomic Crystal

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    To elucidate the relationship between a crystal's structure, its thermal conductivity, and its phonon dispersion characteristics, an analysis is conducted on layered diatomic Lennard-Jones crystals with various mass ratios. Lattice dynamics theory and molecular dynamics simulations are used to predict the phonon dispersion curves and the thermal conductivity. The layered structure generates directionally dependent thermal conductivities lower than those predicted by density trends alone. The dispersion characteristics are quantified using a set of novel band diagram metrics, which are used to assess the contributions of acoustic phonons and optical phonons to the thermal conductivity. The thermal conductivity increases as the extent of the acoustic modes increases, and decreases as the extent of the stop bands increases. The sensitivity of the thermal conductivity to the band diagram metrics is highest at low temperatures, where there is less anharmonic scattering, indicating that dispersion plays a more prominent role in thermal transport in that regime. We propose that the dispersion metrics (i) provide an indirect measure of the relative contributions of dispersion and anharmonic scattering to the thermal transport, and (ii) uncouple the standard thermal conductivity structure-property relation to that of structure-dispersion and dispersion-property relations, providing opportunities for better understanding of the underlying physical mechanisms and a potential tool for material design.Comment: 30 pages, 10 figure

    Thermal conductivity of one-dimensional lattices with self-consistent heat baths: a heuristic derivation

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    We derive the thermal conductivities of one-dimensional harmonic and anharmonic lattices with self-consistent heat baths (BRV lattice) from the Single-Mode Relaxation Time (SMRT) approximation. For harmonic lattice, we obtain the same result as previous works. However, our approach is heuristic and reveals phonon picture explicitly within the heat transport process. The results for harmonic and anharmonic lattices are compared with numerical calculations from Green-Kubo formula. The consistency between derivation and simulation strongly supports that effective (renormalized) phonons are energy carriers in anharmonic lattices although there exist some other excitations such as solitons and breathers.Comment: 4 pages, 3 figures. accepted for publication in JPS

    Coherence Time in High Energy Proton-Nucleus Collisions

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    Precisely measured Drell-Yan cross sections for 800 GeV protons incident on a variety of nuclear targets exhibit a deviation from linear scaling in the atomic number A. We show that this deviation can be accounted for by energy degradation of the proton as it passes through the nucleus if account is taken of the time delay of particle production due to quantum coherence. We infer an average proper coherence time of 0.4 +- 0.1 fm/c, corresponding to a coherence path length of 8 +- 2 fm in the rest frame of the nucleus.Comment: 11 pages in LaTeX. Includes 6 eps figures. Uses epsf.st

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

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    We calculate the survival probability of J/ΨJ/\Psi particles in various colliding systems using a Glauber model. An analysis of recent data has reported a J/ΨJ/\Psi-nucleon breakup cross section of 6.2±\pm0.7 mb derived from an exponential fit to the ratio of J/ΨJ/\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

    Energy loss of fast quarks in nuclei

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    We report an analysis of the nuclear dependence of the yield of Drell-Yan dimuons from the 800 GeV/c proton bombardment of 2H^2H, C, Ca, Fe, and W targets. Employing a new formulation of the Drell-Yan process in the rest frame of the nucleus, this analysis examines the effect of initial-state energy loss and shadowing on the nuclear-dependence ratios versus the incident proton's momentum fraction and dimuon effective mass. The resulting energy loss per unit path length is dE/dz=2.32±0.52±0.5-dE/dz = 2.32 \pm 0.52\pm 0.5 GeV/fm. This is the first observation of a nonzero energy loss of partons traveling in nuclear environment.Comment: 5 pages, including 4 figure

    Open and Hidden Charm Production in Heavy Ion Collisions at Ultrarelativistic Energies

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    We consider the production of the open charm and J/psi mesons in heavy ion collisions at BNL RHIC. We discuss several recently developed pictures for J/psi production and argue that a measurement at RHIC energies is crucial for disentangling these different descriptions.Comment: 19 pages, Latex, 5 PS-figures. v3: Fig.6 is adde

    Parton energy loss limits and shadowing in Drell-Yan dimuon production

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    A precise measurement of the ratios of the Drell-Yan cross section per nucleon for an 800 GeV/c proton beam incident on Be, Fe and W targets is reported. The behavior of the Drell-Yan ratios at small target parton momentum fraction is well described by an existing fit to the shadowing observed in deep-inelastic scattering. The cross section ratios as a function of the incident parton momentum fraction set tight limits on the energy loss of quarks passing through a cold nucleus
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