7,368 research outputs found

    Perturbativity constraints on U(1)B−LU(1)_{B-L} and left-right models and implications for heavy gauge boson searches

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    We derive perturbativity constraints on beyond standard model scenarios with extra gauge groups, such as SU(2)SU(2) or U(1)U(1), whose generators contribute to the electric charge, and show that there are both upper and lower limits on the additional gauge couplings, from the requirement that the couplings remain perturbative up to the grand unification theory (GUT) scale. This leads to stringent constraints on the masses of the corresponding gauge bosons and their collider phenomenology. We specifically focus on the models based on SU(2)L×U(1)I3R×U(1)B−LSU(2)_L\times U(1)_{I_{3R}} \times U(1)_{B-L} and the left-right symmetric models based on SU(2)L×SU(2)R×U(1)B−LSU(2)_L\times SU(2)_R\times U(1)_{B-L}, and discuss the implications of the perturbativity constraints for new gauge boson searches at current and future colliders. In particular, we find that the stringent flavor constraints in the scalar sector of left-right model set a lower bound on the right-handed scale vR≳10v_R \gtrsim 10 TeV, if all the gauge and quartic couplings are to remain perturbative up to the GUT scale. This precludes the prospects of finding the ZRZ_R boson in the left-right model at the LHC, even in the high-luminosity phase, and leaves only a narrow window for the WRW_R boson. A much broader allowed parameter space, with the right-handed scale vRv_R up to ≃87\simeq 87 TeV, could be probed at the future 100 TeV collider.Comment: 30 pages, 9 figures, 4 tables, minor changes, version to be published in JHE

    Human-leopard conflict in Mandi district, Himachal Pradesh, India

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    Kumar, D., Chauhan, N.P.S

    Predictions from non trivial Quark-Lepton complementarity

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    The complementarity between the quark and lepton mixing matrices is shown to provide robust predictions. We obtain these predictions by first showing that the matrix V_M, product of the quark (CKM) and lepton (PMNS) mixing matrices, may have a zero (1,3) entry which is favored by experimental data. We obtain that any theoretical model with a vanishing (1,3) entry of V_M that is in agreement with quark data, solar, and atmospheric mixing angle leads to θ13PMNS=(9−2+1)∘\theta_{13}^{PMNS}=(9{^{+1}_{-2}})^\circ. This value is consistent with the present 90% CL experimental upper limit. We also investigate the prediction on the lepton phases. We show that the actual evidence, under the only assumption that the correlation matrix V_M product of CKM and PMNS has a zero in the entry (1,3), gives us a prediction for the three CP-violating invariants J, S_1, and S_2. A better determination of the lepton mixing angles will give stronger prediction for the CP-violating invariants in the lepton sector. These will be tested in the next generation experiments. Finally we compute the effect of non diagonal neutrino mass in "l_i -> l_j gamma" in SUSY theories with non trivial Quark-Lepton complementarity and a flavor symmetry. The Quark-Lepton complementarity and the flavor symmetry strongly constrain the theory and we obtain a clear prediction for the contribution to "mu -> e gamma" and the "tau" decays "tau -> e gamma" and "tau -> mu gamma". If the Dirac neutrino Yukawa couplings are degenerate but the low energy neutrino masses are not degenerate, then the lepton decays are related among them by the V_M entries. On the other hand, if the Dirac neutrino Yukawa couplings are hierarchical or the low energy neutrino masses are degenerate, then the prediction for the lepton decays comes from the CKM hierarchy.Comment: 15 pages, 5 figures, ws-ijmpa class included, Proceedings of the CTP Symposium on Sypersymmetry at LH

    SOME RESULTS ON THE DESIGN OF EXPERIMENTS FOR COMPARING UNREPLICATED TREATMENTS

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    In early generation variety trials, large numbers of new varieties may be compared, and little seed is usually available for each variety. A so-called unreplicated trial has each new variety on just one plot at a site, but includes several (often around 5) replicated check or control (or standard) varieties. The total proportion of check plots is usually between 10% and 20%. The aim of the trial is to choose some (around 1/3) good performing varieties to go on for further testing, rather than precise estimation of their mean yield. Now that spatial analyses of data from field experiments are becoming more common, there is interest in an efficient layout of an experiment given a proposed spatial analysis. Some possible design criteria are discussed, and efficient layouts under spatial dependence are considered
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