7,947 research outputs found

    Parity-Violating Electron Scattering as a Probe of Supersymmetry

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    We compute the one-loop supersymmetric (SUSY) contributions to the weak charges of the electron (QWeQ_W^e) and proton (QWpQ_W^p) using the Minimal Supersymmetric Standard Model (MSSM). These q2=0q^2=0 vector couplings of the Z0Z^0-boson to fermions will be determined in two fixed-target, parity-violating electron scattering experiments. The SUSY loop contributions to QWpQ_W^p and QWeQ_W^e can be substantial, leading to several percent corrections to the Standard Model values for these quantities. We show that the relative signs of the SUSY loop effects on QWeQ_W^e and QWpQ_W^p are correlated and positive over nearly all of the MSSM parameter space, whereas inclusion of R-parity nonconserving interactions can lead to opposite sign relative shifts in the weak charges. Thus, a comparison of QWpQ_W^p and QWeQ_W^e measurements could help distinguish between different SUSY scenarios.Comment: 4 pages, 2 figure

    Probing Supersymmetry with Neutral Current Scattering Experiments

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    We compute the supersymmetric contributions to the weak charges of the electron and proton in the framework of Minimal Supersymmetric Standard Model. We also consider the ratio of neutral current to charged current cross sections, R_nu and R_nubar at nu (nubar)-nucleus deep inelastic scattering, and compare the supersymmetric corrections with the deviations of these quantities from the Standard Model predictions implied by the recent NuTeV measurement.Comment: 4 pages, contribution to the proceedings of CIPANP 2003 (May, 2003), New York Cit

    Radiative corrections in neutrino-deuterium disintegration

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    The radiative corrections of order alpha for the charged- and neutral-current neutrino-deuterium disintegration for energies relevant to the SNO experiment are evaluated. Particular attention is paid to the issue of the bremsstrahlung detection threshold. It is shown that the radiative corrections to the total cross section for the charged current reaction are independent of that threshold, as they must be for consistency, and amount to a slowly decreasing function of the neutrino energy E-nu, varying from about 4% at low energies to 3% at the end of the B-8 spectrum. The differential cross section corrections, on the other hand, do depend on the bremsstrahlung detection threshold. Various choices of the threshold are discussed. It is shown that for a realistic choice of the threshold and for the actual electron energy threshold of the SNO detector, the deduced B-8 nu(e) flux should be decreased by about 2%. The radiative corrections to the neutral-current reaction are also evaluated

    A Computer Program for Calculating Three-Dimensional Compressible Laminar and Turbulent Boundary Layers on Arbitrary Wings

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    A computer program for calculating three dimensional compressible laminar and turbulent boundary layers on arbitrary wings is described and presented. The computer program consists of three separate programs, namely, a geometry program to represent the wing analytically, a velocity program to compute the external velocity components from a given experimental pressure distribution and a finite difference boundary layer method to solve the governing equations for compressible flows. To illustrate the usage of the computer program, three different test cases are presented and the preparation of the input data as well as the computed output data is discussed in some detail

    Fabrication of Nano-Gapped Single-Electron Transistors for Transport Studies of Individual Single-Molecule Magnets

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    Three terminal single-electron transistor devices utilizing Al/Al2O3 gate electrodes were developed for the study of electron transport through individual single-molecule magnets. The devices were patterned via multiple layers of optical and electron beam lithography. Electromigration induced breaking of the nanowires reliably produces 1-3 nm gaps between which the SMM can be situated. Conductance through a single Mn12(3-thiophenecarboxylate) displays the coulomb blockade effect with several excitations within +/- 40 meV.Comment: 10 pages, 5 figure

    Pion Leptonic Decays and Supersymmetry

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    We compute supersymmetric contributions to pion leptonic (\pi_{l2}) decays in the Minimal Supersymmetric Standard Model (MSSM). When R-parity is conserved, the largest contributions to the ratio R_{e/\mu} = \Gamma[ \pi^+ \to e^+ \nu_e(\gamma)]/\Gamma[ \pi^+ \to \mu^+ \nu_\mu(\gamma)] arise from one-loop (V-A)x(V-A) corrections. These contributions can be potentially as large as the sensitivities of upcoming experiments; if measured, they would imply significant bounds on the chargino and slepton sectors complementary to current collider limits. We also analyze R-parity violating interactions, which may produce a detectable deviation in R_{e/\mu} while remaining consistent with all other precision observables.Comment: 12 pages, 11 figures; included additional electroweak constraints in analysis, simplified abstract, ref. adde

    A Comparison of Personality Traits of Female Athletes with a High Incidence of Injury to Those with a Low Incidence of Injury

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    The purpose of this study was to determine if there is a significant difference in the personality traits of collegiate female athletes with a high incidence of injury when compared to female athletes with a low incidence of injury. Fourteen female intercollegiate athletes completed a personal information questionnaire and Cattell\u27s Sixteen Personality Factor Questionnaire during a one hour session of testing. The mean raw scores of the two groups were analyzed to determine if they differed statistically. The mean raw scores were then converted to mean sten scores under the recommendations of Cattell. A visual depiction of the mean sten scores was also completed to identify any possible trends. The results of this study indicate that there is a significant difference between those athletes with a high and low incidence of injury on the primary personality factor B. Factor B indicates an individuals reasoning abilities. The findings of this study indicate that athletes with a high incidence of injury are more concrete thinkers, while those athletes with a low incidence of injury tend to be more abstract thinkers. However, this finding may not be as profound because the mean sten scores of both groups fall within the average range of the population. A visual inspection of the data also seems to indicate with more subjects there may have been a significant difference in the personality traits of warmth, dominance, and independence. It was also found that there seems to be a relationship between the number of high school injuries and collegiate injuries. After review of the personal information questionnaires, it was found that all but one individual that was classified as having a high incidence of injury in college would also have been classified similarly in high school. The findings of this study indicate that the use of a personality inventory may be helpful to some degree in determining the incidence of injury in collegiate female athletes. This may help coaches, and athletic trainers to better help such athletes whether it be in prevention or rehabilitation. This study also seems to indicate that more studies should be done in this area. However, future studies should address a wider variety of issues associated with injury such as exposures, and type of equipment available to the athletes

    Hadron Spin Dynamics

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    Spin effects in exclusive and inclusive reactions provide an essential new dimension for testing QCD and unraveling hadron structure. Remarkable new experiments from SLAC, HERMES (DESY), and the Jefferson Laboratory present many challenges to theory, including measurements at HERMES and SMC of the single spin asymmetries in pion electroproduction, where the proton is polarized normal to the scattering plane. This type of single spin asymmetry may be due to the effects of rescattering of the outgoing quark on the spectators of the target proton, an effect usually neglected in conventional QCD analyses. Many aspects of spin, such as single-spin asymmetries and baryon magnetic moments are sensitive to the dynamics of hadrons at the amplitude level, rather than probability distributions. I illustrate the novel features of spin dynamics for relativistic systems by examining the explicit form of the light-front wavefunctions for the two-particle Fock state of the electron in QED, thus connecting the Schwinger anomalous magnetic moment to the spin and orbital momentum carried by its Fock state constituents and providing a transparent basis for understanding the structure of relativistic composite systems and their matrix elements in hadronic physics. I also present a survey of outstanding spin puzzles in QCD, particularly the double transverse spin asymmetry A_{NN} in elastic proton-proton scattering, the J/psi to rho-pi puzzle, and J/psi polarization at the Tevatron.Comment: Concluding theory talk presented at SPIN2001, the Third Circum-Pan-Pacific Symposium on High Energy Physics, October, 2001, Beijin
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