118502677
Spontaneous R-symmetry Breaking with Multiple Pseudomoduli
We examine generalized O’Raifeartaigh models that feature multiple tree-level flat directions and only contain fields with R-charges 0 or 2. We show that spontaneous R-breaking at up to one-loop order is impossible in such theories. Specifically, we prove that the R-symmetric origin of field space is always a local minimum of the one-loop Coleman-Weinberg potential, generalizing an earlier result for the case of a single flat direction. This result has consequences for phenomenology and helps elucidate the behavior of various models of dynamical SUSY breaking.
118736479
Direct detection with dark mediators
We introduce dark mediator Dark matter (dmDM) where the dark and visible sectors are connected by at least one light mediator carrying the same dark charge that stabilizes DM. is coupled to the Standard Model via an operator qq =, and to dark matter via a Yukawa coupling y c . Direct detection is
15753083
Singlet-Stabilized Minimal Gauge Mediation
We propose Singlet Stabilized Minimal Gauge Mediation as a simple ISS-based model of Direct Gauge Mediation which avoids both light gauginos and Landau poles. The hidden sector is a massive s-conning SQCD that is distinguished by a minimal SU(5) avor group. The uplifted vacuum is stabilized by coupling the meson to an additional singlet sector with its own U(1) gauge symmetry via non-renormalizable interactions suppressed by a higher scale UV in the electric theory. This generates a nonzero VEV for the singlet meson via the inverted hierarchy mechanism, but requires tuning to a precision ( = UV ) 2 , which is 10 4 . In the course of this analysis we also outline some simple model-building rules for stabilizing uplifted ISS models, which lead us to conclude that meson deformations are required (or at least heavily favored) to stabilize the adjoint component of the magnetic meson.
119232932
Leptogenesis with composite neutrinos
Models with composite singlet neutrinos can give small Majorana or Dirac masses to the active neutrinos. The mechanism is based on the fact that conserved chiral symmetries give massless neutrinos at the renormalizable level. Thus, they acquire very small masses due to non-renormalizable terms. We investigate such models in two aspects. First, we find UV completions for them and then we investigate the possibility of giving leptogenesis. We find that these models offer new possibilities for leptogenesis. Models with Majorana masses can exhibit standard leptogenesis. Models with Dirac masses can provide a realization of Dirac type leptogenesis with mass scale that can be as low as 10 TeV.
51428350
Soft RPV through the baryon portal
A bstractSupersymmetric (SUSY) models with R-parity generically predict sparticle decays with invisible neutralinos, which yield distinctive missing energy events at colliders. Since most LHC searches are designed with this expectation, the putative bounds on sparticle masses become considerably weaker if R-parity is violated so that squarks and gluinos decay to jets with large QCD backgrounds. Here we introduce a scenario in which baryonic R-parity violation (RPV) arises effectively from soft SUSY breaking interactions, but leptonic RPV remains accidentally forbidden to evade constraints from proton decay and FCNCs. The model features a global R-symmetry that initially forbids RPV interactions, a hidden R-breaking sector, and a heavy mediator that communicates this breaking to the visible sector. After R-symmetry breaking, the mediator is integrated out and an effective RPV A-term arises at tree level; RPV couplings between quarks and squarks arise only at loop level and receive additional suppression. Although this mediator must be heavy compared to soft masses, the model introduces no new hierarchy since viable RPV can arise when the mediator mass is near the SUSY breaking scale. In generic regions of parameter space, a light thermally-produced gravitino is stable and can be a viable dark matter candidate.
119194513
Neutralino Oscillations at the LHC
We study a supersymmetric phenomenon that can give spectacular signals at the LHC: oscillations of neutralinos. Such oscillations can be naturally realised in Rsymmetric models, where additional elds are introduced as Dirac mass partners of gauginos and Higgsinos. Majorana masses for gauginos, necessarily generated from anomaly mediation, can create tiny mass splittings between degenerate mass eigenstates, causing states produced at the LHC to oscillate between neutralinos and their Dirac partner elds. Scenarios where such states decay with displaced vertices can lead to striking signatures at the LHC, where the oscillation can be visible directly in the distribution of displaced vertex lengths. We elaborate on the theory and LHC phenomenology of this feature within a specic scenario of a Higgsino decaying with a displaced vertex into a gravitino and a Z boson.
119110843
Bayesian implications of current LHC supersymmetry and dark matter detection searches for the constrained MSSM
We investigate the impact of recent limits from LHC searches for supersymmetry and from direct and indirect searches for dark matter on global Bayesian inferences of the parameter space of the Constrained Minimal Supersymmetric Standard Model (CMSSM). In particular we apply recent exclusion limits from the CMS \alpha_T analysis of 1.1/fb of integrated luminosity, the current direct detection dark matter limit from XENON100, as well as recent experimental constraints on \gamma-ray fluxes from dwarf spheroidal satellite galaxies of the Milky Way from the FermiLAT telescope, in addition to updating values for other non-LHC experimental constraints. We extend the range of scanned parameters to include a significant fraction of the focus point/hyperbolic branch region. While we confirm earlier conclusions that at present LHC limits provide the strongest constraints on the model's parameters, we also find that when the uncertainties are not treated in an excessively conservative way, the new bounds from dwarf spheroidal have the power to significantly constrain the focus point/hyperbolic branch region. Their effect is then comparable, if not stronger, to that from XENON100. We further analyze the effects of one-year projected sensitivities on the neutrino flux from the Sun in the 86-string IceCube+DeepCore configuration at the South Pole. We show that data on neutrinos from the Sun, expected for the next few months at IceCube and DeepCore, have the potential to further constrain the same region of parameter space independently of the LHC and can yield additional investigating power for the model.
18956502
Global fits of the Non-Universal Higgs Model
We examine the Non-Universal Higgs Model (NUHM) with the help of a Markov Chain Monte Carlo scanning technique and Bayesian statistics. The method allows us to reveal more fully the remarkably rich and complex structure of the model and also some new interesting features. In particular we find that, for large ranges of parameters, the neutralino dark matter in the model is higgsino-like with mass close to 1 TeV. This feature does depend to some extent on the prior but generically results from a mild focussing effect in the running of one of the Higgs masses that we also point out. On the other hand, the usual bino-like neutralino is also present, and in some sense is favored by a more robust prior and a better average chi–square. In spite of experimental constraints often favoring different regions of parameter space than in the Constrained MSSM, most observational consequences appear fairly similar, which will make it challenging to experimentally distinguish the two models.
125490747
Decay Correlations of Heavy Leptons in e+ e- ---> Lepton+ Lepton-
123425178
The signature of sequential charged leptons
I am honored to be invited to give a talk on this occasion to celebrate Martin Perl`s 65th birthday. John Jaros, the organizer of this occasion, wanted me to recollect several things, especially: what motivated me to write my 1971 Physical Review paper on the heavy lepton entitled ``Decay Correlations of Heavy Lepton in e{sup minus} + e{sup +} = {ell}{sup -} + {ell}+;`` why did I think of muon-electron coincidence; and what were the contributions of Thacker and Sakurai. In this paper I answer his requests and add something else later.
120043110
Bayesian implications of collider and SUSY dark matter direct and indirect searches
In this talk we present our recent Bayesian analyses of the Constrained MSSM in which the model's parameter space is constrained by the CMS αT 1.1/fb data at the LHC, the XENON100 dark matter direct detection data, and Fermi-LAT γ-ray data from dwarf spheroidal galaxies (dSphs). We also show that the projected one-year sensitivities for annihilation-induced neutrinos from the Sun in the 86-string configuration of IceCube/DeepCore have the potential to yield additional constraining power on the parameter space of the CMSSM.