分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-06-24
摘要: We present a new probe of strongly coupled electroweak symmetry breaking at the 14 TeV LHC by measuring a phase shift in the event distribution of the decay azimuthal angles in massive gauge boson scattering. One generically expects a large phase shift in the longitudinal gauge boson scattering amplitude due to the presence of broad resonances. This phase shift is observable as an interference effect between the strongly interacting longitudinal modes and the transverse modes of the gauge bosons. We find that even very broad resonances of masses up to 900 GeV can be probed at 3 sigma significance with a 3000 fb(-1) run of the LHC by using this technique. We also present the estimated reach for a future 50 TeV proton-proton collider.
分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-05-09
摘要: Measuring the Higgs self-coupling is one of the crucial physics goals at the LHC Run-2 and other future colliders. In this work, we attempt to figure out the size of SUSY effects on the trilinear self-coupling of the 125 GeV Higgs boson in the MSSM and NMSSM after the LHC Run-1. Taking account of current experimental constraints, such as the Higgs data, flavor constraints, electroweak precision observables and dark matter detections, we obtain the observations: (1) In the MSSM, the ratio lambda(MSSM)(3h)/lambda(SM)(3h) has been tightly constrained by the LHC data, which can be only slightly smaller than 1 and minimally reach 97%; (2) In the NMSSM with lambda 0.7, a large enhancement or reduction -1.1 < lambda(MSSM)(3h1)/lambda(SM)(3h1) < 2 can occur, which is accompanied by a sizable change of h(1)tau(+)tau(-) coupling. The future colliders, such as the HL-LHC and ILC, will have the capacity to test these large deviations in the NMSSM. (C) 2015 The Authors. Published by Elsevier B.V.