arXiv subjects

Gordon L. Kane

Publications and source records attributed to Gordon L. Kane.

41 records · Page 3Linked to original sources

arXiv1997

Sphenomenology --- An Overview, with a Focus on a Higgsino LSP World, and on Eventual Tests of String Theory

In this talk, as requested, I begin with a overview and with some basic reminders about how evidence for supersymmetry in nature might appear -- in particular, how SUSY signatures are never clear so it is difficult to search for them without major theoretical input. Models can be usefully categorized phenomenologically by naming their LSP -- that is, once the LSP is approximately fixed so is the behavior of the observables, and the resulting behavior is generally very different for different LSPs. Next I compare the three main LSP-models (gravitino, bino, higgsino). Hints from data suggest taking the higgsino-LSP world very seriously, so I focus on it, and describe its successful prediction of reported events from the 1996 LEP runs. SUSY signatures in the $\tilde h$ LSP world are very different from those that are usually studied. Then I briefly discuss how to measure the parameters of the effective Lagrangian from collider and decay data. Finally I turn to how data will test and help extract the implications of string theories.

hep-ph↗

arXiv1997

Tests and Implications of Increasing Evidence for Superpartners

Although no individual piece of experimental evidence for supersymmetry is compelling so far, several are about as good as they can be with present errors. Most important, all pieces of evidence imply the same values for common parameters --- a necessary condition, and one unlikely to hold if the hints from data are misleading. The parameters are sparticle or soft-breaking masses and $ tan β.$ For the parameter ranges reported here, there are so far no signals that should have occurred but did not. Given those parameters a number of predictions can test whether the evidence is real. It turns out that the predictions are mostly different from the conventional supersymmetry ones, and might have been difficult to recognize as signals of superpartners. They are testable at LEP2, where neutralinos and charginos will appear mainly as $γγ+$ large $\slashchar{E}$ events, $γ+$ very large $\slashchar{E}$ events, and very soft lepton pairs of same or mixed flavor. The results demonstrate that we understand a lot about how to extract an effective SUSY Lagrangian from limited data, and that we can reasonably hope to learn about the theory near the Planck scale from the data at the electroweak scale.

hep-ph↗

arXiv1997

Supersymmetric Contributions to the Decay of an Extra Z Boson

We analyse in detail the supersymmetric contributions to the decay of an extra Z boson in effective rank 5 models, including the important effect of D-terms on sfermion masses. The inclusion of supersymmetric decay channels will reduce the Z' branching ratio to standard model particles resulting in lower Z' mass limits than those often quoted. In particular, the supersymmetric parameter space motivated by the recent Fermilab $eeγγ$ event and other suggestive evidence results in a branching fraction B(Z' -> e^+ e^-)\simeq 2-4%. The expected cross sections and branching ratios could give a few events in the present data and we speculate on the connection to the three e^+e^- events observed at Fermilab with large dielectron invariant mass.

hep-ph↗

arXiv1995

Chaotic inflation and a radiatively generated intermediate scale in the supersymmetric standard model

We consider a phenomenological extension of the minimal supersymmetric standard model which incorporates chaotic inflation and a radiatively generated intermediate mass scale. Initially a period of chaotic inflation is driven by a quartic potential associated with the right-handed electron sneutrino. Supersymmetry relates the quartic coupling of the inflationary potential to the electron Majorana neutrino Yukawa coupling, $h_1$. The microwave background temperature anisotropy determines this coupling to be $h_1\simeq 10^{-7}$, which is similar in magnitude to the electron Dirac Yukawa coupling. A U$(1)$ Peccei-Quinn (PQ) symmetry is broken by radiative corrections at an intermediate scale $\simeq 10^{12}$GeV when the universe cools to a temperature $T\lesssim 10^3$GeV. This leads to an invisible axion, a weak scale $μ$-term and an electron Majorana neutrino mass $M_{N_1}\simeq 10^5$GeV. A second inflationary period can also occur via a flat-direction field. In this case the universe can be reheated to a temperature $T_{RH}\simeq 10^6$GeV, without restoring PQ symmetry. Baryogenesis will then occur via out-of-equilibrium neutrino decay.

hep-ph↗

arXiv1993

Errata for "The Higgs Hunter's Guide"

Errata are given for "The Higgs Hunter's Guide". These errata should be applied to the second printing of the book, dated 1991. The second printing has already corrected numerous errors and misprints contained in the originally published 1990 edition.

hep-ph↗