6,626 research outputs found

    Direct searches of Type III seesaw triplet fermions at high energy e+ee^+e^- collider

    Full text link
    The signatures of heavy fermionic triplets (Σ\Sigma) arising in scenarios like Type III seesaw model are probed through their direct production and subsequent decay at high energy electron-positron collider. Unlike the case of LHC, the production process has strong dependence on the mixing parameter (Ve,μV_{e,\mu}), making the leptonic collider unique to probe such mixing. We have established that with suitably chosen kinematic cuts, a 1 TeV e+ee^+e^- collider could probe the presence of Σ\Sigma of mass in the range of 500 GeV having Ve=0.05V_e=0.05 with a few inverse femto barn luminosity through single production. The cross section is found to be not sufficient to probe the case of triplet-muon mixing through single triplet production. On the other hand, the pair production considered at 2 TeV centre of mass energy is capable of probing both the mixing scenarios efficiently. Studying the mass reach, presence of charged fermionic triplets upto a mass of about 980 GeV could be established at 3σ3\sigma level through single production at a 1 TeV e+ee^+e^- collider with moderate luminosity of 100 fb1^{-1}, assuming Ve=0.05V_e = 0.05 . The pair production case requires larger luminosity, as the cross section is smaller in this case. With an integrated luminosity of 300 fb1^{-1}, the mass reach in this case is close to 1 TeV with triplet-muon mixing, while it is slightly lower at about 950 GeV in the case of Vμ=0.05V_\mu = 0.05.Comment: 26 pages, 5 Figure

    Dielectric Properties of Antimony Trioxide Films

    Get PDF

    Laser phase modulation approaches towards ensemble quantum computing

    Full text link
    Selective control of decoherence is demonstrated for a multilevel system by generalizing the instantaneous phase of any chirped pulse as individual terms of a Taylor series expansion. In the case of a simple two-level system, all odd terms in the series lead to population inversion while the even terms lead to self-induced transparency. These results also hold for multiphoton transitions that do not have any lower-order photon resonance or any intermediate virtual state dynamics within the laser pulse-width. Such results form the basis of a robustly implementable CNOT gate.Comment: 10 pages, 4 figures, PRL (accepted

    On the absence of the usual weak-field limit, and the impossibility of embedding some known solutions for isolated masses in cosmologies with f(R) dark energy

    Get PDF
    This version deposited at arxiv 02-10-12 arXiv:1210.0730v1. Subsequently published in Physical Review D as Phys. Rev. D 87, 063517 (2013) http://link.aps.org/doi/10.1103/PhysRevD.87.063517. Copyright American Physical Society (APS).11 pages11 pages11 pages11 pagesThe problem of matching different regions of spacetime in order to construct inhomogeneous cosmological models is investigated in the context of Lagrangian theories of gravity constructed from general analytic functions f(R), and from non-analytic theories with f(R)=R^n. In all of the cases studied, we find that it is impossible to satisfy the required junction conditions without the large-scale behaviour reducing to that expected from Einstein's equations with a cosmological constant. For theories with analytic f(R) this suggests that the usual treatment of weak-field systems may not be compatible with late-time acceleration driven by anything other than a constant term of the form f(0), which acts like a cosmological constant. For theories with f(R)=R^n we find that no known spherically symmetric vacuum solutions can be matched to an expanding FLRW background. This includes the absence of any Einstein-Straus-like embeddings of the Schwarzschild exterior solution in FLRW spacetimes

    TeV Scale Left-Right Symmetry and Large Mixing Effects in Neutrinoless Double Beta Decay

    Full text link
    We analyze various contributions to neutrinoless double beta decay (0νββ0\nu\beta\beta) in a TeV-scale Left-Right Symmetric Model (LRSM) for type-I seesaw dominance. We find that the momentum-dependent effects due to WLWRW_L-W_R exchange (λ\lambda-diagram) and WLWRW_L-W_R mixing (η\eta-diagram) could give dominant contributions to the 0νββ0\nu\beta\beta amplitude in a wide range of the LRSM parameter space. In particular, for a relatively large WLWRW_L-W_R mixing, the η\eta-contribution by itself could saturate the current experimental limit on the 0νββ0\nu\beta\beta half-life, thereby providing stringent constraints on the relevant LRSM parameters, complementary to the indirect constraints derived from lepton flavor violating observables. In a simplified scenario parametrized by a single light-heavy neutrino mixing, the inclusion of the λ\lambda and η\eta contributions leads to significantly improved 0νββ0\nu\beta\beta constraints on the light-heavy neutrino mixing as well as on the WLWRW_L-W_R mixing parameters. We also present a concrete TeV-scale LRSM setup, where the mixing effects are manifestly enhanced, and discuss the interplay between 0νββ0\nu\beta\beta, lepton flavor violation and electric dipole moment constraints.Comment: 33 pages, 7 figures, 2 table
    corecore