2,085 research outputs found

    CP asymmetry in B --> phi K_S decays in left-right models and its implications on B_s decays

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    In left-right models the gluonic penguin contribution to b --> s s-bar s transition is enhanced by m_t/m_b due to the presence of (V+A) currents and by the larger values of loop functions than in the Standard Model. Together those may completely overcome the suppression due to small left-right mixing angle xi phi K_S decay amplitude appearing in a large class of left-right models may therefore modify the time dependent CP asymmetry in this decay mode by O(1) and explain the recent BaBar and Belle CP asymmetry measurements in this channel. This new physics scenario implies observable deviations from the Standard Model also in B_s decays which could be measured at upcoming Tevatron and LHC.Comment: references adde

    Hints for a non-standard Higgs boson from the LHC

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    We reconsider Higgs boson invisible decays into Dark Matter in the light of recent Higgs searches at the LHC. Present hints in the CMS and ATLAS data favor a non-standard Higgs boson with approximately 50% invisible branching ratio, and mass around 143 GeV. This situation can be realized within the simplest thermal scalar singlet Dark Matter model, predicting a Dark Matter mass around 50 GeV and direct detection cross section just below present bound. The present runs of the Xenon100 and LHC experiments can test this possibility.Comment: 6 pages, 2 figures. Final version to appear on PR

    Exponentially spread dynamical Yukawa couplings from non-perturbative chiral symmetry breaking in the dark sector

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    We propose a new paradigm for generating exponentially spread standard model Yukawa couplings from a new U(1)FU(1)_F gauge symmetry in the dark sector. Chiral symmetry is spontaneously broken among dark fermions that obtain non-vanishing masses from a non-perturbative solution to the mass gap equation. The necessary ingredient for this mechanism to work is the existence of higher derivative terms in the dark U(1)FU(1)_F theory, or equivalently the existence of Lee-Wick ghosts, that (i) allow for a non-perturbative solution to the mass gap equation in the weak coupling regime of the Abelian theory; (ii) induce exponential dependence of the generated masses on dark fermion U(1)FU(1)_F quantum numbers. The generated flavor and chiral symmetry breaking in the dark sector is transferred to the standard model Yukawa couplings at one loop level via Higgs portal type scalar messenger fields. The latter carry quantum numbers of squarks and sleptons. A new intriguing phenomenology is predicted that could be potentially tested at the LHC, provided the characteristic mass scale of the messenger sector is accessible at the LHC as is suggested by naturalness arguments.Comment: Text improved, new equations and references added, version to appear in Phys.Rev.D, 12 pages, 2 figure

    Neutrino Mass, Muon Anomalous Magnetic Moment, and Lepton Flavor Nonconservation

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    If the generating mechanism for neutrino mass is to account for both the newly observed muon anomalous magnetic moment as well as the present experimental bounds on lepton flavor nonconservation, then the neutrino mass matrix should be almost degenerate and the underlying physics be observable at future colliders. We illustrate this assertion in two specific examples, and show that Γ(μ→eγ)/mμ5\Gamma (\mu \to e \gamma)/m_\mu^5, Γ(τ→eγ)/mτ5\Gamma (\tau \to e \gamma)/m_\tau^5, and Γ(τ→μγ)/mτ5\Gamma (\tau \to \mu \gamma) /m_\tau^5 are in the ratio (Δm2)sol2/2(\Delta m^2)_{sol}^2/2, (Δm2)sol2/2(\Delta m^2)_{sol}^2 /2, and (Δm2)atm2(\Delta m^2)_{atm}^2 respectively, where the Δm2\Delta m^2 parameters are those of solar and atmospheric neutrino oscillations and bimaximal mixing has been assumed.Comment: Erratum adde

    Three Active and Two Sterile Neutrinos in an E_6 Model of Diquark Baryogenesis

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    In the U(1)_N extension of the supersymmetric standard model with E_6 particle content, the heavy singlet superfield N may decay into a quark and a diquark as well as an antiquark and an antidiquark, thus creating a baryon asymmetry of the Universe. We show how the three doublet and two singlet neutrinos in this model acquire mass from physics at the TeV scale without the benefit of using N as a heavy right-handed neutrino. Specifically, the active neutrinos get masses via the bilinear term \mu LX^c which conserves R-parity, and via the nonzero masses of the sterile neutrinos. We predict fixed properties of the extra Z' boson, as well as the new lepton doublets X and X^c, and the observation of diquark resonances at hadron colliders in this scenario.Comment: LATEX, 13 page

    Prospects for constrained supersymmetry at s=33\sqrt{s}=33 TeV and s=100\sqrt{s}=100 TeV proton-proton super-colliders

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    Discussions are underway for a high-energy proton-proton collider. Two preliminary ideas are the s=33\sqrt{s}=33 TeV HE-LHC and the s=100\sqrt{s}=100 TeV VLHC. With Bayesian statistics, we calculate the probabilities that the LHC, HE-LHC and VLHC discover SUSY in the future, assuming that nature is described by the CMSSM and given the experimental data from the LHC, LUX and Planck. We find that the LHC with 300300/fb at s=14\sqrt{s}=14 TeV has a 1515-7575% probability of discovering SUSY. Should that run fail to discover SUSY, the probability of discovering SUSY with 30003000/fb is merely 11-1010%. Were SUSY to remain undetected at the LHC, the HE-LHC would have a 3535-8585% probability of discovering SUSY with 30003000/fb. The VLHC, on the other hand, ought to be definitive; the probability of it discovering SUSY, assuming that the CMSSM is the correct model, is 100100%.Comment: 21 pages, 5 figures. Matches version published in Eur.Phys.J. C. Results and conclusions unchange
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