The breaking of parity, a fundamental symmetry between left and right is best understood in the framework of left-right symmetric extension of the standard model. We show that the production of a heavy right-handed neutrino at the proposed Large Hadron-Electron Collider (LHeC) could give us the most simple and direct hint of the scale of this breaking in left-right symmetric theories. This production mode gives a lepton number violating signal with $Delta L=2$ which is very clean and has practically no standard model background. We highlight that the right-handed nature of $W_R$ exchange which defines the left-right symmetric theories can be confirmed by using a polarized electron beam and also enhance the production rates with relatively lower beam energy.
We explore possible signatures for right-handed neutrinos in TeV scale B-L extension of the Standard Model (SM) at the Large Hadron Collider (LHC). The studied four lepton signal has a tiny SM background. We find the signal experimentally accessible at LHC for the considered parameter regions.
We propose a model with the left-handed and right-handed continuous Abelian gauge symmetry; $U(1)_Ltimes U(1)_R$. Then three right-handed neutrinos are naturally required to achieve $U(1)_R$ anomaly cancellations, while several mirror fermions are also needed to do $U(1)_L$ anomaly cancellations. Then we formulate the model, and discuss its testability of the new gauge interactions at collider physics such as the large hadron collider (LHC) and the international linear collider (ILC). In particular, we can investigate chiral structure of the interactions by the analysis of forward-backward asymmetry based on polarized beam at the ILC.
We construct the minimal supersymmetric left-right theory and show that at the renormalizable level it requires the existence of an intermediate $B-L$ breaking scale. The subsequent symmetry breaking down to MSSM automatically preserves R-symmetry. Furthermore, unlike in the nonsupersymmetric version of the theory, the see-saw mechanism takes its canonical form. The theory predicts the existence of a triplet of Higgs scalars much lighter than the $B-L$ breaking scale.
The production rate of right-handed neutrinos from a Standard Model plasma at a temperature above a hundred GeV has previously been evaluated up to NLO in Standard Model couplings (g ~ 2/3) in relativistic (M ~ pi T) and non-relativistic regimes (M >> pi T), and up to LO in an ultrarelativistic regime (M < gT). The last result necessitates an all-orders resummation of the loop expansion, accounting for multiple soft scatterings of the nearly light-like particles participating in 1 <-> 2 reactions. In this paper we suggest how the regimes can be interpolated into a result applicable for any right-handed neutrino mass and at all temperatures above 160 GeV. The results can also be used for determining the lepton number washout rate in models containing right-handed neutrinos. Numerical results are given in a tabulated form permitting for their incorporation into leptogenesis codes. We note that due to effects from soft Higgs bosons there is a narrow intermediate regime around M ~ g^{1/2} T in which our interpolation is phenomenological and a more precise study would be welcome.
We consider an extension of the standard electroweak model with three Higgs doublets and global $B-L$ and $mathbb{Z}_2$ symmetries. Two of the scalar doublets are inert due to the $mathbb{Z}_2$ symmetry. We calculated all the mass spectra in the scalar and lepton sectors and accommodate the leptonic mixing matrix as well. We also include an analysis of the scalar sector, showing that the potential is limited from below, and we obtain the masses of the scalar sector. Furthermore we consider the effects of the model on the anaomalous magnetic dipole of charged leptons and the $muto egamma$ decay. We also present the SUSY version of the model with global $B-L$.
Subhadeep Mondal
,Santosh Kumar Rai
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(2015)
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"Polarized window for left-right symmetry and a right-handed neutrino at the Large Hadron-Electron Collider"
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Subhadeep Mondal
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