Search results for "R-Parity"
showing 10 items of 102 documents
Testing the mechanism of R-parity breaking with slepton LSP decays
2003
In supersymmetric models R-parity can be violated through either bilinear or trilinear terms in the superpotential, or both. If charged scalar leptons are the lightest supersymmetric particles, their decay properties can be used to obtain information about the relative importance of these couplings. We show that in some specific scenarios it is even possible to decide whether bilinear or trilinear terms give the dominant contribution to the neutrino mass matrix.
Neutrinoless double beta decay in supersymmetry with bilinear R-parity breaking
1998
We reanalyze the contributions to neutrinoless double beta ($\znbb$) decay from supersymmetry with explicit breaking of R-parity. Although we keep both bilinear and trilinear terms, our emphasis is put on bilinear R-parity breaking terms, because these mimic more closely the models where the breaking of R-parity is spontaneous. Comparing the relevant Feynman diagrams we conclude that the usual mass mechanism of double beta decay is the dominant one. From the non-observation of $\znbb$ decay we set limits on the bilinear R-parity breaking parameters of typically a (few) 100 $keV$. Despite such stringent bounds, we stress that the magnitude of R-parity violating phenomena that can be expected…
Supersymmetric SO(10)-inspired GUTs with sliding scales
2013
We construct lists of supersymmetric models with extended gauge groups at intermediate steps, all of which are inspired by SO(10) unification. We consider three different kinds of setups: (i) the model has exactly one additional intermediate scale with a left-right (LR) symmetric group; (ii) SO(10) is broken to the LR group via an intermediate Pati-Salam scale; and (iii) the LR group is broken into SU(3)(c) X SU(2)(L) X U(1)(R) X U(1)(B-L), before breaking to the standard model (SM) group. We use sets of conditions, which we call the "sliding mechanism," which yield unification with the extended gauge group(s) allowed at arbitrary intermediate energy scales. All models thus can have new gau…
Supersymmetry with spontaneous R-parity breaking in Z0 decays: the case of an additional Z
1991
Single production of SUSY particles in the decays of the Z0 may proceed with large rates in models with spontaneously broken R-parity. We focus on the case where there is a lepton number symmetry as part of the gauge group. In the simplest of such models there is a single additional neutral gauge boson and the strength of Rp-violating interactions is related with that of the new gauge force. We study the phenomenological implications of the model for Z0 decays, including the study of the rates for single chargino production in Z0 decays, i.e. Z0→ξ±τ±, as well as for the so-called Zen events, and find that they may be measurable at LEP. The first process, characteristics of spontaneously bro…
Probing neutralino properties in minimal supergravity with bilinear R-parity violation
2012
Supersymmetric models with bilinear R-parity violation (BRPV) can account for the observed neutrino masses and mixing parameters indicated by neutrino oscillation data. We consider minimal supergravity versions of BRPV where the lightest supersymmetric particle (LSP) is a neutralino. This is unstable, with a large enough decay length to be detected at the CERN Large Hadron Collider (LHC). We analyse the LHC potential to determine the LSP properties, such as mass, lifetime and branching ratios, and discuss their relation to neutrino properties.
Search forR-Parity Violating Decays of Sneutrinos toeμ,μτ, andeτPairs inpp¯Collisions ats=1.96 TeV
2010
7 paginas, 2 figuras, 3 tablas.-- PACS numbers: 14.80.Ly, 12.60.Jv, 13.85.Qk, 14.60.St.--CDF Collaboration: et al.
Search for the Production of Single Sleptons throughR-Parity Violation inpp¯Collisions ats=1.8 TeV
2002
We report the first search for supersymmetric particles via s-channel production and decay of smuons or muon sneutrinos at hadronic colliders. The data for the two-muon and two-jets final states were collected by the D0 experiment and correspond to an integrated luminosity of 94+/-5 pb(-1). Assuming that R parity is violated via the single coupling lambda(211)('), the number of candidate events is in agreement with expectation from the standard model. Exclusion contours are given in the (m(0),m(1/2)) and (m((χ) over bar),m((ν) over bar)) planes for lambda(211)(')=0.09, 0.08, and 0.07.
Gravitino dark matter and neutrino masses with bilinear R-parity violation
2011
Bilinear R-parity violation provides an attractive origin for neutrino masses and mixings. In such schemes the gravitino is a viable decaying dark matter particle whose R-parity violating decays lead to monochromatic photons with rates accessible to astrophysical observations. We determine the parameter region allowed by gamma-ray line searches, dark matter relic abundance and neutrino oscillation data, obtaining a limit on the gravitino mass $m_{\tilde G} \lsim$ 1-10 GeV corresponding to a relatively low reheat temperature $T_R \lsim$ few $\times 10^7-10^8$ GeV. Neutrino mass and mixing parameters may be reconstructed at accelerator experiments like the Large Hadron Collider.
Sneutrino-induced like sign dilepton signal with conservedRparity
2001
Lepton number violation could be manifest in the sneutrino sector of supersymmetric extensions of the standard model with conserved R-parity. Then sneutrinos decay partly into the ``wrong sign charged lepton'' final state, if kinematically accessible. In sneutrino pair production or associated single sneutrino production, the signal then is a like sign dilepton final state. Under favourable circumstances, such a signal could be visible at the LHC or a next generation linear collider for a relative sneutrino mass-splitting of order ${\cal O}(0.001)$ and sneutrino width of order ${\cal O}$(1 GeV). On the other hand, the like sign dilepton event rate at the TEVATRON is probably too small to be…
Invisible Higgs boson decays in spontaneously broken R parity
2004
The Higgs boson may decay mainly to an invisible mode characterized by missing energy, instead of the Standard Model channels. This is a generic feature of many models where neutrino masses arise from the spontaneous breaking of ungauged lepton number at relatively low scales, such as spontaneously broken R-parity models. Taking these models as framework, we reanalyze this striking suggestion in view of the recent data on neutrino oscillations that indicate non-zero neutrino masses. We show that, despite the smallness of neutrino masses, the Higgs boson can decay mainly to the invisible Goldstone boson associated to the spontaneous breaking of lepton number. This requires a gauge singlet su…