arXiv subjects

Bruce A. Campbell

Publications and source records attributed to Bruce A. Campbell.

21 records · Page 2Linked to original sources

arXiv1994

Neutrino Mass Effects in a Minimally Extended Supersymmetric Standard Model

We consider an extension of the supersymmetric standard model which includes singlet Higgs superfield representations (in three generations) to generate neutrino masses via the see-saw mechanism. The resulting theory may then exhibit R-parity violation in the couplings of the singlets, inducing $R$-parity violating effective interactions among the standard model superfields, as well as inducing decay of the lightest neutralino, which otherwise would compose a stable LSP. We compute the rates for the resulting neutralino decays, depending on the particular superpotential couplings responsible for the violation of R-parity. We compare to astrophysical constraints on the decay of massive particles.

hep-ph↗

arXiv1993

Model independent constraints on leptoquarks from rare processes

We present model independent constraints on the masses and couplings to fermions of $B$ and $L$ conserving leptoquarks. Such vector or scalar particles could have masses below 100 GeV and be produced at HERA; we list the generation dependent bounds that can be calculated from rare lepton and meson decays, meson-anti-meson mixing and various electroweak tests. PLEASE NOTE: this file does not contain tables and figures, so is not very useful. Complete paper available (by mail) from sacha@physics.berkeley.edu.

hep-ph↗

arXiv1993

Toponium Tests Of Top-Quark Higgs Bags

Recently it has been suggested that top quarks, or very massive fourth generation quarks, might surround themselves with a Higgs "bag" of deformation of the Higgs expectation value from its vacuum magnitude. In this paper we address the question of whether such nonlinear Higgs-top interaction effects are subject to experimental test. We first note that if top quarks were necessarily accompanied by Higgs "bags", then top quark weak decay would involve the sudden disruption of the Higgs "bag", with copious production of physical Higgs particles accompanying the decay. We then examine the effects that such Higgs "bags" would produce on the spectrum of toponium, where the two bound top (anti)quarks, and their "bags", overlap. We numerically evaluate the effects that the nonlinear feedback in the Higgs-toponium system would have on the energy level splittings of the toponium bound states, and find that for allowed values of the top and Higgs mass the effect is negligible, thus indicating that even in this favourable circumstance Higgs "bag" formation around top quarks does not observably occur. Finally, we consider the case of a second Higgs doublet, allowing the possibility of enhanced couplings for one of the physical Higgs to top. Even in this nonstandard scenario the effects are minimal, and we infer the general absence of observable effects at any level that might suggest the utility of considering top quarks to be accompanied by Higgs "bags".

hep-ph↗