分类： 物理学 >> 基本粒子与场物理学 提交时间： 2017-08-03
摘要： New physics field content in the nature, more specifically, from spin–1 resonances sourced by the extension of the SM local gauge symmetry to the larger local group SU(2)L⊗SU(2)R⊗U(1)B−L, may induce CP–violation signalling NP effects from higher energy regimes. In this work we completely list and study all the CP–violating operators up to the p4–order in the Lagrangian expansion, for a non–linear left–right electroweak chiral context and coupled to a light dynamical Higgs. Heavy right handed fields can be integrated out from the physical spectrum, inducing thus a physical impact in the effective gauge couplings, fermionic electric dipole moment, and CP-violation in the decay h → ZZ∗ → 4 l that are briefly analysed. The final relevant set of effective operators have also been identified at low energies.
分类： 物理学 >> 基本粒子与场物理学 提交时间： 2017-08-03
摘要： All the possible CP-conserving non-linear operators up to the p4 -order in theLagrangian expansion are analysed here for the left-right symmetric model in the non-linear electroweak chiral context coupled to a light dynamical Higgs. The low energy effects will be triggered by an emerging new physics field content in the nature, more specifically, from spin-1 resonances sourced by the straightforward extension of the SM local gauge symmetry to the larger local group SU(2)L ⊗SU(2)R ⊗U(1)B−L. Low energy phenomenology will be altered by integrating out the resonances from the physical spectrum, being manifested through induced corrections onto the left handed operators. Such modifications are weighted by powers of the scales ratio implied by the symmetries of the model and will determine the size of the effective operator basis to be used. The recently observed diboson excess around the invariant mass 1.8–2 TeV entails a scale suppression that suggests to encode the low energy effects via a much smaller set of effective operators.
分类： 物理学 >> 基本粒子与场物理学 提交时间： 2017-08-02
摘要： We explore lepton-flavored electroweak baryogenesis, driven by CP-violation in leptonic Yukawa sector, using the τ −µ system in the two Higgs doublet model as an example. This setup generically yields, together with the flavor-changing decay h → τµ, a tree-level Jarlskog-invariant that can drive dynamical generation of baryon asymmetry during a first-order electroweak phase transition and results in CP-violating effect in the decay h → τ τ . We find that the observed baryon asymmetry can be generated in parameter space compatible with current experimental results for the decays h → τµ, h → τ τ The excess events reported by the ATLAS Collaboration in the W Z–final state, and by the CMS Collaboration in the e +e−jj, W h and jj–final states, may be induced by the decays of a heavy boson W0 in the 1.8–2 TeV mass range, here modelled via the larger local group SU(2)L × SU(2)R × U(1)B−L in a non–linear dynamical Higgs scenario. The W0 –production cross section at the 13 TeV LHC is around 700–1200 fb. This framework also predicts a heavy Z' boson with a mass of 2.5–4 TeV, and some decay channels testable in the LHC Run II. We determine the cross section times branching fractions for the dijet, dilepton and top–pair Z' –decay channels at the 13 TeV LHC around 2.3, 7.1, 70.2 fb respectively, for MZ' = 2.5 TeV, while one/two orders of magnitude smaller for the dijet/dilepton and top–pair modes at MZ' = 4 TeV. Non-zero contributions from the effective operators, and the underlying Higgs sector of the model, will induce sizeable enhancement in the W+W− and Zh–final states that could be probed in the future LHC Run II.and τ → µγ, as well as the present bound on the electric dipole moment of the electron. The baryon asymmetry generated is intrinsically correlated with the CP-violating decay h → τ τ and the flavor-changing decay h → τµ, which thus may serve as “smoking guns” to test lepton-flavored electroweak baryogenesis.
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