1,632 research outputs found

    Canonical Constraints on Leptonic Cp Violation using UHCR neutrino fluxes

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    It is shown that one can in principle constrain the CP-violating parameter delta from measurements of four independant |V_{ij}|^2, or three of them and a ratio, in the leptonic sector. To quantify our approach, using unitarity, we derive simple expressions in terms of four independant |V_{ij}|^2 for cos(delta) and an expression for sin^2(delta) from J^2. Thus, depending on the values of |V_{ij}| and their accuracy, we can set meaningful limits on |delta|. To illustrate numerically, if |V_{u1}|^2 is close to 0.1 with a 10% precision, and if |V_{e3}^2 is larger than 0.005 and for values of |V_{e2}|^2 and |V_{u3}|^2 that stay within +-0.1 of the current experimental data leads to a bound pi/2 < |delta| < pi. Alternatively, a certain combination of parameters with values of |V_{e3}|^2 larger than 0.01 leads to a closed bound of 73 < |delta| < 103. In general, we find that it is better to use |V_{u1}|^2 or |V_{t1}|^2 as the fourth independant |V_{ij}|^2 and that over most of the parameter space, delta is least sensitive to |V_{e3}|^2. With just three independant measurements (solar, atmospheric and reactor) it is impossible to set limits on the CP phase. In this respect, we study the use of ultra high energy cosmic (UHCR) neutrino fluxes as the additional fourth information. We find that within the SM, neutrino fluxes of all three flavours will be very similar but that pushing current neutrino data to their extreme values still allowed, ratios of cosmic neutrino fluxes can differ by up to 20%; such large discrepancies could imply negligibly small CP-violation. We also study a non radiative neutrino decay model and find that the neutrino fluxes can differ by a factor of up to 3 within this model and that an accuracy of 10% on the neutrino fluxes is sufficient to set interestin limits on delta.Comment: 8 pages, 2 figures, 5 table

    Extracting W Boson Couplings from the e+ee^{+}e^{-} Production of Four Leptons

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    We consider the processes e+e+ννˉe^{+}e^{-}\rightarrow \ell^{+} \ell^{\prime -}\nu \bar{\nu}^{\prime}, including all possible charged lepton combinations, with regard to measuring parameters characterizing the WW boson. We calculate at what level these processes can be used to measure anamolous triple-boson vertice coupling parameters for the cases of e+ee^{+}e^{-} colliders at 500 GeVGeV and 1 TeVTeV center of mass energies.Comment: 13 pages,OCIP/C-93-

    Preparedness to Counsel Transgender College Students: Perceptions of College Mental Health Clinicians

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    The purpose of this study was to assess the perceived preparedness levels of college mental health clinicians to counsel transgender college students. Multicultural counseling competency is required of professional counselors and transgender individuals are considered to be part of the multicultural population. A survey was completed by college mental health counselors (N = 84) from across the United States. The results showed a moderate amount of preparedness overall with no significant differences based on years of counseling experience nor graduation from a CACREP accredited program. Results did show the participants believed they do have a professional duty to be knowledgeable about gender identity issues. The majority of counselors surveyed spent between zero and five hours a week providing either individual or group counseling to transgender students, or providing consultation and collaboration on transgender student issues. Approximately two-thirds of the counselors surveyed used a trans-affirmative therapy model which is accepting and validating of all experiences of gender. Implications presented by this study include improving educational and training resources for counselor educators through additional quantitative and qualitative research into transgender counseling competencies. Additionally, providing professional development workshops for practicing professional counselors to build their knowledge and awareness of mental health issues in the transgender population will lead to increases in counselor self-efficacy

    The Measurement of Tri-Linear Gauge Boson Couplings at e+ee^+e^- Colliders

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    We describe a detailed study of the process e+eνqqˉe^+e^- \to \ell\nu_\ell q \bar{q} and the measurement of tri-linear gauge boson couplings (TGV's) at LEP200 and at a 500~GeV and 1~TeV NLC. We included all tree level Feynman diagrams contributing to the four-fermion final states including gauge boson widths and non-resonance contributions. We employed a maximum likelihood analysis of a five dimensional differential cross section of angular distributions. This approach appears to offer an optimal strategy for measurement of TGV's. LEP200 will improve existing measurements of TGV's but not enough to see loop contributions of new physics. Measurements at the NLC will be roughly 2 orders of magnitude more precise which would probe the effects of new physics at the loop level.Comment: Latex file uses aipbook.sty with revtex and psfig.sty. 2 figures (uuencoded) will be added with figures command. Full postcript version with embedded figures is available at ftp://ftp.physics.carleton.ca/pub/theory/godfrey/ocipc9504.ps To appear in the Proceedings of the International Symposium on Vector Boson Self-Interactions, UCLA, Feb. 1-3, 199

    Radiative lepton flavor violating decays in the Randall Sundrum background with localized leptons

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    We study the radiative lepton flavor violating l_i -> l_j\gamma decays in the two Higgs doublet model, respecting the Randall Sundrum scenario and estimate the contributions of the KK modes of left (right) handed charged lepton doublets (singlets) on the branching ratios. We observe that the branching ratios are sensitive to the contributions of the charged lepton KK modes.Comment: 23 pages, 10 figures, 2 table

    Supersymmetric QCD flavor changing top quark decay

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    We present a detailed and complete calculation of the gluino and scalar quarks contribution to the flavour-changing top quark decay into a charm quark and a photon, gluon, or a Z boson within the minimal supersymmetric standard model including flavour changing gluino-quarks-scalar quarks couplings in the right-handed sector. We compare the results with the ones presented in an earlier paper where we considered flavour changing couplings only in the left-handed sector. We show that these new couplings have important consequences leading to a large enhancement when the mixing of the scalar partners of the left- and right-handed top quark is included. Furthermore CP violation in the flavour changing top quark decay will occur when a SUSY phase is taken into account.Comment: 14 pages, latex, 3 figure