Subhendu Rakshit

R-parity violating trilinear couplings and recent neutrino data

The nontrivial structure of the neutrino mass matrix, suggested by the recent Super-Kamiokande results and data from other neutrino experiments, can be reproduced in

Constraints on inert dark matter from the metastability of the electroweak vacuum

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Some low energy effects of a light stabilized radion in the Randall–Sundrum model

-parity-violating supersymmetric theories. This requires sets of products of

Trilinear neutral gauge boson couplings

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Muon anomalous magnetic moment confronts exotic fermions and gauge bosons

-parity-violating trilinear couplings to take appropriately chosen values. It is shown that the existing constraints on these couplings are satisfied by these choices.

Radiative production of invisible charginos in photon photon collisions

The inert scalar doublet model of dark matter can be valid up to the Planck scale. We briefly review the bounds on the model in such a scenario and identify parameter spaces that lead to absolute stability and metastability of the electroweak vacuum.

Working group report: Neutrino and astroparticle physics

Abstract In this paper we study some of the low energy effects of a light stabilized radion field in the Randall–Sundrum scenario. We find that the NLC 500 with its projected precision level will be able to probe the radion contribution to κ v and λ v for values of 〈 φ 〉 up to 500 GeV. On the other hand the BNL E821 experiment will be able to test the radion contribution to a μ for 〈 φ 〉= 1 TeV and m φ ≤ m μ . We have also shown that the higgs-radion mixing induces a 2.6% correction in the WWh coupling. Finally by comparing the radionstralung process with the higgsstralung process we have found that the LEPI bound of 60 GeV on the higgs mass based on Z→hl l decay mode suggests a lower bound of about 35 GeV on the radion mass.

Beyond the standard model: working group report

We study the CP even trilinear neutral gauge boson vertices at one-loop in the context of the Standard Model and the Minimal Supersymmetric Standard Model, assuming two of the vector bosons are on-shell. We also study the changes in the form-factors when these two bosons are off-shell.

Cosmological constraints on R-parity violation from neutrino decay

Abstract We investigate the status of models containing exotic fermions or extra ( Z -like) neutral gauge bosons in the light of the recent data on anomalous magnetic moment of the muon. We find that it is possible to extract interesting bounds on the parameters characterizing such models. The bounds are particularly strong if the new flavour-changing neutral currents are axial vector-like.

Are We Looking at Neutrino Absorption Spectra at IceCube

If, in a supersymmetric model, the lightest chargino is nearly degenerate with the lightest neutralino, the former can decay into the latter alongwith a soft pion (or a lepton-neutrino pair). Near degeneracy of the chargino and neutralino masses can cause the other decay products (the pion or the lepton) to be almost invisible. Photon-photon colliders offer a possibility of clean detection of such an event through a hard photon tag.