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Browsing by Author "Loinaz, William"

Now showing 1 - 20 of 26
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    Charge assignments in multiple-U(1) gauge theories
    Loinaz, William; Takeuchi, Tatsu (American Physical Society, 1999-12-01)
    We discuss the choice of gauge field basis in multiple-U(1) gauge theories. We find that there is a preferred basis, specified by the charge orthogonality condition, in which the U(1) gauge fields do not mix under one-loop renormalization group running. [S0556-2821(99)04219-8].
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    Charge assignments in multiple-U(1) gauge theories
    Loinaz, William; Takeuchi, Tatsu (American Physical Society, 1999-12-01)
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    Constraining new physics with vertex corrections
    Takeuchi, Tatsu; Lebedev, O.; Loinaz, William (1999)
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    Constraints on gauged B-3L(tau) and related theories
    Chang, Lay Nam; Lebedev, O.; Loinaz, William; Takeuchi, Tatsu (American Physical Society, 2001-04-01)
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    Constraints on gauged B-3L(tau) and related theories
    Chang, Lay Nam; Lebedev, O.; Loinaz, William; Takeuchi, Tatsu (American Physical Society, 2001-04-01)
    We consider extensions of the standard model with an extra U(1) gauge boson that couples to B- (alphaL(e), + betaL(mu) + gammaL(tau)) with alpha + beta + gamma =3. We show that the extra gauge boson necessarily mixes with the Z, leading to potentially significant corrections to the Zf(f) over bar vertex. The constraints on the size of this correction imposed by the Z-pole data from CERN LEP and SLD are derived.
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    Constraints on R-parity violating couplings from CERN LEP and SLAG SLD hadronic observables
    Lebedev, O.; Loinaz, William; Takeuchi, Tatsu (American Physical Society, 2000-07-01)
    We analyze the one loop corrections to hadronic Z decays in an R-parity violating extension to the minimal supersymmetric standard model. Performing a global fit to all the hadronic observables at the Z peak, we obtain stringent constraints on the R-violating coupling constants lambda' and lambda". The presence of these couplings worsens the agreement with the data relative to the standard model. The strongest constraints come from the b asymmetry parameters A(b) and A(FB)(b) From a classical statistical analysis we find that the couplings lambda'(131), lambda'(132), and lambda"(321) are ruled out at the 1 sigma level, and that lambda'(133) and lambda"(33i) are ruled out at the 2 sigma level. A Bayesian statistical analysis weakens the bounds, but the corresponding chi(2)'s are uncomfortably large, rendering the relevance of the Bayesian bounds suspect.
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    Constraints on R-parity violating couplings from CERN LEP and SLAG SLD hadronic observables
    Lebedev, O.; Loinaz, William; Takeuchi, Tatsu (American Physical Society, 2000-07-01)
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    Constraints on R-parity violating couplings from lepton universality
    Lebedev, O.; Loinaz, William; Takeuchi, Tatsu (American Physical Society, 2000-06-01)
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    Constraints on R-parity violating couplings from lepton universality
    Lebedev, O.; Loinaz, William; Takeuchi, Tatsu (American Physical Society, 2000-07-01)
    We analyze the one loop corrections to leptonic W and Z decays in an R-parity violating extension to the minimal supersymmetric standard model. We find that lepton universality violation in the Z line-shape variables alone would strengthen the bounds on the magnitudes of the lambda' couplings, but a global fit on all data leaves the bounds virtually unchanged at \lambda'(33k)\less than or equal to 0.42 and \lambda'(23k)\less than or equal to 0.50 at the 2 sigma level. Bounds from W decays are less stringent: \lambda'(33k)\less than or equal to 2.4 at 2 sigma, as a consequence of the weaker Fermilab experimental bounds on lepton universality violation in W decays. We also point out the potential of constraining R-parity violating couplings from the measurement of the Y invisible width.
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    Constraints on R-parity violation from precision electroweak measurements
    Takeuchi, Tatsu; Lebedev, O.; Loinaz, William (World Scientific, 2001-01-01)
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    Constraints on top-color assisted technicolor models from vertex corrections
    Loinaz, William; Takeuchi, Tatsu (American Physical Society, 1999-07-01)
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    Constraints on two-Higgs-doublet models at large tan beta from W and Z decays
    Lebedev, O.; Loinaz, William; Takeuchi, Tatsu (American Physical Society, 2000-09-01)
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    Constraints on two-Higgs-doublet models at large tan beta from W and Z decays
    Lebedev, O.; Loinaz, William; Takeuchi, Tatsu (American Physical Society, 2000-09-01)
    We study constraints on type-II two-Higgs-doublet models at large tan beta from CERN LEP and SLD Z-pole data and from lepton universality violation in W decay. We perform a global fit and find that, in the context of Z decay, the LEP-SLD experimental values for lepton universality violation, R-b, and A(b) all somewhat disfavor the model. Contributions from the neutral-Higgs sector can be used to constrain the scalar-pseudoscalar Higgs mass splittings. Contributions from the charged-Higgs sector allow us to constrain the charged-Higgs boson mass. For tan beta=100 we obtain the 1 sigma classical (Bayesian) bounds of m(H+/-) greater than or equal to 670 GeV (370 GeV) and 1 greater than or equal to m(h)0/m(A)0/(alpha = beta) =m(H)0/m(A)0/(alpha=0) greater than or equal to 0.68 (0.64). The 2 sigma bounds are weak. Currently, the Fermilab Tevatron experimental limits on lepton universality violation in W decay provide no significant constraint on the Higgs sector.
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    Fundamental Physics at the Intensity Frontier
    Hewett, J. L.; Weerts, H.; Brock, R.; Butler, J. N.; Casey, B. C. K.; Collar, J.; Gouvea, A. D.; Essig, R.; Grossman, Y.; Haxton, W.; Jaros, J. A.; Jung, C. K.; Lu, Z. T.; Pitts, K.; Ligeti, Z.; Patterson, J. R.; Ramsey-Musolf, M.; Ritchie, J. L.; Roodman, A.; Scholberg, K.; Wagner, C. E. M.; Zeller, Geralyn P.; Aefsky, S.; Afanasev, A.; Agashe, K.; Albright, C. H.; Alonso, J.; Ankenbrandt, C. M.; Aoki, M.; Arguelles, C. A.; Arkani-Hamed, N.; Armendariz, J. R.; Armendariz-Picon, C.; Diaz, E. A.; Asaadi, J.; Asner, D. M.; Babu, K. S.; Bailey, K.; Baker, O.; Balantekin, A. B.; Baller, B.; Bass, M.; Batell, B.; Beacham, J.; Behr, J.; Berger, N.; Bergevin, M.; Berman, E.; Bernstein, R.; Bevan, A. J.; Bishai, M.; Blanke, M.; Blessing, S.; Blondel, A.; Blum, T.; Bock, G.; Bodek, A.; Bonvicini, G.; Bossi, F.; Boyce, J.; Breedon, R.; Breidenbach, M.; Brice, S. J.; Briere, R. A.; Brodsky, S.; Bromberg, C.; Bross, A.; Browder, T. E.; Bryman, D. A.; Buckley, M.; Burnstein, R.; Caden, E.; Campana, P.; Carlini, R.; Carosi, G.; Castromonte, C.; Cenci, R.; Chakaberia, I.; Chen, M. C.; Cheng, C. H.; Choudhary, B.; Christ, N. H.; Christensen, E.; Christy, M. E.; Chupp, T. E.; Church, E.; Cline, D. B.; Coan, T. E.; Coloma, P.; Comfort, J.; Coney, L.; Cooper, J.; Cooper, R. J.; Cowan, R.; Cowen, D. F.; Cronin-Hennessy, D.; Datta, A.; Davies, G. S.; Demarteau, M.; DeMille, D. P.; Denig, A.; Dermisek, R.; Deshpande, A.; Dewey, M. S.; Dharmapalan, R.; Dhooghe, J.; Dietrich, M. R.; Diwan, M.; Djurcic, Zelimir; Dobbs, S.; Duraisamy, M.; Dutta, B.; Duyang, H.; Dwyer, D. A.; Eads, M.; Echenard, B.; Elliott, S. R.; Escobar, C. O.; Fajans, J.; Farooq, S.; Faroughy, C.; Fast, J. E.; Feinberg, B.; Felde, J.; Feldman, G.; Fierlinger, P.; Perez, P. F.; Filippone, B. W.; Fisher, P.; Fleming, B. T.; Flood, K. T.; Forty, R.; Frank, M. J.; Freyberger, A.; Friedland, A.; Gandhi, R.; Ganezer, K. S.; Garcia, A.; Garcia, F. G.; Gardiner, S.; Garrison, L.; Gasparian, A.; Geer, S.; Gehman, V. M.; Gershon, T.; Gilchriese, M.; Ginsberg, C.; Gogoladze, I.; Gonderinger, M.; Goodman, M.; Gould, H.; Graham, M.; Graham, P. W.; Gran, R.; Grange, J.; Gratta, G.; Green, J. P.; Greenlee, H.; Group, R. C.; Guardincerri, E.; Gudkov, V.; Guenette, R.; Haas, A.; Hahn, A.; Han, T.; Handler, T.; Hardy, J. C.; Harnik, R.; Harris, D. A.; Harris, F. A.; Harris, P. G.; Hartnett, J.; He, B.; Heckel, B. R.; Heeger, K. M.; Henderson, S.; Hertzog, D.; Hill, R.; Hinds, E. A.; Hitlin, D. G.; Holt, R. J.; Holtkamp, N.; Horton-Smith, Glenn A.; Huber, Patrick; Huelsnitz, W.; Imber, J.; Irastorza, I.; Jaeckel, J.; Jaegle, I.; James, C.; Jawahery, A.; Jensen, D.; Jessop, C. P.; Jones, B.; Jostlein, H.; Junk, T.; Kagan, A. L.; Kalita, M.; Kamyshkov, Y.; Kaplan, D. M.; Karagiorgi, Georgia S.; Karle, A.; Katori, T.; Kayser, B.; Kephart, R.; Kettell, S. H.; Kim, Y.-K.; Kirby, M.; Kirch, K.; Klein, J.; Kneller, J.; Kobach, A.; Kohl, M.; Kopp, J.; Kordosky, M.; Korsch, W.; Kourbanis, I.; Krisch, A. D.; Križan, P.; Kronfeld, A. S.; Kulkarni, S.; Kumar, K. S.; Kuno, Y.; Kutter, T.; Lachenmaier, Tobias; Lamm, M.; Lancaster, J.; Lancaster, M.; Lane, C.; Lang, K.; Langacker, P.; Lazarevic, S.; Le, T.; Lee, K.; Lesko, K. T.; Li, Y.; Lindgren, M.; Lindner, A.; Link, Jonathan M.; Lissauer, D.; Littenberg, L. S.; Littlejohn, B.; Liu, C. Y.; Loinaz, William; Lorenzon, W.; Louis, W. C.; Lozier, J.; Ludovici, L.; Lueking, L.; Lunardini, C.; MacFarlane, D. B.; Machado, P. A. N.; Mackenzie, P. B.; Maloney, J.; Marciano, W. J.; Marsh, W.; Marshak, M.; Martin, J. W.; Mauger, C.; McFarland, K. S.; McGrew, C.; McLaughlin, G.; McKeen, D.; McKeown, R.; Meadows, B. T.; Mehdiyev, R.; Melconian, D.; Merkel, H.; Messier, M.; Miller, J. P.; Mills, G.; Minamisono, U. K.; Mishra, S. R.; Mocioiu, I.; Sher, S. M.; Mohapatra, R. N.; Monreal, B.; Moore, C. D.; Morfin, J. G.; Mousseau, J.; Moustakas, L. A.; Mueller, G.; Mueller, P.; Muether, M.; Mumm, H. P.; Munger, C.; Murayama, H.; Nath, P.; Naviliat-Cuncin, O.; Nelson, J. K.; Neuffer, D.; Nico, J. S.; Norman, A.; Nygren, D.; Obayashi, Y.; O'Connor, T. P.; Okada, Y.; Olsen, J.; Orozco, L.; Orrell, J. L.; Osta, J.; Pahlka, B.; Paley, J.; Papadimitriou, V.; Papucci, M.; Parke, S.; Parker, R. H.; Parsa, Z.; Partyka, K.; Patch, A.; Pati, J. C.; Patterson, R. B.; Pavlovic, Z.; Paz, G.; Perdue, G. N.; Perevalov, D.; Perez, G.; Petti, R.; Pettus, W.; Piepke, A.; Pivovaroff, M. J.; Plunkett, R.; Polly, C. C.; Pospelov, M.; Povey, R.; Prakash, A.; Purohit, M. V.; Raby, S.; Raaf, J. L.; Rajendran, R.; Rajendran, S.; Rameika, G.; Ramsey, R.; Rashed, A.; Ratcliff, B. N.; Rebel, B.; Redondo, J.; Reimer, P.; Reitzner, D.; Ringer, F.; Ringwald, A.; Riordan, S.; Roberts, B. L.; Roberts, D. A.; Robertson, R.; Robicheaux, F.; Rominsky, M.; Roser, R.; Rosner, J. L.; Rott, C.; Rubin, P.; Saito, N.; Sanchez, Maria Cristina; Sarkar, S.; Schellman, H.; Schmidt, B.; Schmitt, M.; Schmitz, D. W.; Schneps, J.; Schopper, A.; Schuster, P.; Schwartz, A. J.; Schwarz, M.; Seeman, J.; Semertzidis, Y. K.; Seth, K. K.; Shafi, Q.; Shanahan, P.; Sharma, R.; Sharpe, S. R.; Shiozawa, M.; Shiltsev, V.; Sigurdson, K.; Sikivie, P.; Singh, J.; Sivers, D.; Skwarnicki, T.; Smith, N.; Sobczyk, J.; Sobel, H.; Soderberg, M.; Song, Y. H.; Soni, A.; Souder, P. A.; Sousa, A.; Spitz, Joshua; Stancari, M.; Stavenga, G. C.; Steffen, J. H.; Stepanyan, S.; Stoeckinger, D.; Stone, S.; Strait, J.; Strassler, M.; Sulai, I. A.; Sundrum, R.; Svoboda, R.; Szczerbinska, B.; Szelc, A.; Takeuchi, Tatsu; Tanedo, P.; Taneja, S.; Tang, J.; Tanner, D. B.; Tayloe, R.; Taylor, I.; Thomas, J.; Thorn, C.; Tian, X.; Tice, B. G.; Tobar, M.; Tolich, N.; Toro, N.; Towner, I. S.; Tsai, Y.; Tschirhart, R.; Tunnell, C. D.; Tzanov, M.; Upadhye, A.; Urheim, J.; Vahsen, S. E.; Vainshtein, A.; Valencia, E.; Water, R. G. V. D.; Water, RSVD; Velasco, M.; Vogel, J.; Vogel, P.; Vogelsang, W.; Wah, Y W.; Walker, D.; Weiner, N.; Weltman, A.; Wendell, R.; Wester, W.; Wetstein, M.; White, C.; Whitehead, L.; Whitmore, J.; Widmann, E.; Wiedemann, G.; Wilkerson, J.; Wilkinson, G.; Wilson, P.; Wilson, R. J.; Winter, W.; Wise, Milton B.; Wodin, J.; Wojcicki, S.; Wojtsekhowski, B.; Wongjirad, T.; Worcester, E.; Wurtele, J.; Xin, T.; Xu, J.; Yamanaka, T.; Yamazaki, Y.; Yavin, I.; Yeck, J.; Yeh, M.; Yokoyama, M.; Yoo, J.; Young, A.; Zimmerman, E.; Zioutas, K.; Zisman, M.; Zupan, J.; Zwaska, R. (2011)
    The Proceedings of the 2011 workshop on Fundamental Physics at the Intensity Frontier. Science opportunities at the intensity frontier are identified and described in the areas of heavy quarks, charged leptons, neutrinos, proton decay, new light weakly-coupled particles, and nucleons, nuclei, and atoms.
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    Monte Carlo simulation calculation of the critical coupling constant for two-dimensional continuum phi(4) theory
    Loinaz, William; Willey, R. S. (American Physical Society, 1998-10)
    We perform a Monte Carlo simulation calculation of the critical coupling constant for the continuum two-dimensional (lambda/4) phi(4) theory. The critical coupling constant we obtain is [lambda/mu(2)](crit) = 10.26(-.04)(+.08). [S0556-2821(98)07219-1].
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    NuTeV anomaly, lepton universality, and nonuniversal neutrino-gauge couplings
    Loinaz, William; Okamura, Naotoshi; Rayyan, S.; Takeuchi, Tatsu; Wijewardhana, L. C. R. (American Physical Society, 2004-12)
    In previous studies we found that models with flavor-universal suppression of the neutrino-gauge couplings are compatible with NuTeV and Z-pole data. In this paper we expand our analysis to obtain constraints on flavor-dependent coupling suppression by including lepton universality data from W, tau, pi and K decays in fits to model parameters. We find that the data are consistent with a variety of patterns of coupling suppression. In particular, in scenarios in which the suppression arises from the mixing of light neutrinos with heavy gauge singlet states (neutrissimos), we find patterns of flavor-dependent coupling suppression which are also consistent with constraints from mu-->egamma.
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    NuTeV anomaly, lepton universality, and nonuniversal neutrino-gauge couplings
    Loinaz, William; Okamura, Naotoshi; Rayyan, S.; Takeuchi, Tatsu; Wijewardhana, L. C. R. (American Physical Society, 2004-12-01)
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    NuTeV anomaly, neutrino mixing, and a heavy Higgs boson
    Loinaz, William; Okamura, Naotoshi; Takeuchi, Tatsu; Wijewardhana, L. C. R. (American Physical Society, 2003-04-01)
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    NuTeV anomaly, neutrino mixing, and a heavy Higgs boson
    Loinaz, William; Okamura, Naotoshi; Takeuchi, Tatsu; Wijewardhana, L. C. R. (American Physical Society, 2003-04)
    Recent results from the NuTeV experiment at Fermilab and the deviation of the Z invisible width, measured at CERN LEP and the SLAC Linear Collider, from its standard model (SM) prediction suggest the suppression of neutrino-Z couplings. Such suppressions occur naturally in models which mix the neutrinos with heavy gauge singlet states. We postulate a universal suppression of the Znunu couplings by a factor of (1-epsilon) and perform a fit to the Z-pole and NuTeV observables with epsilon and the oblique correction parameters S and T. Compared to a fit with S and T only, the inclusion of epsilon leads to a dramatic improvement in the quality of the fit. The values of S and T preferred by the fit can be obtained within the SM by a simple increase in the Higgs boson mass. However, if the W mass is also included in the fit, a non-zero U parameter becomes necessary which cannot be supplied within the SM. The preferred value of epsilon suggests that the seesaw mechanism may not be the reason why neutrinos are so light.
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    Phenomenology of Not-so-heavy Neutral Leptons: The NuTeV Anomaly, Lepton Universality, and Non-Universal Neutrino-Gauge Couplings
    Takeuchi, Tatsu; Loinaz, William (2004)
    Talk presented by Takeuchi at the YITP workshop "Progress in Particle Physics" 2004.