Sukanta Dutta

Trilinear neutral gauge boson couplings

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.

Bounds on the neutrino magnetic moment from SN 1987 A

Abstract We examine the emission of wrong helicity neutrinos from SN 1987 A due to neutrino magnetic moment (μv). We consider the case when the core of nascent neutron star is on the verge of pion condensation. The relevant processes are the p + π − → n + ν l,r ν l,r and πν l ( ν r ) → πν r ( ν l ) . We have also studied the case where the core is assumed to have undergone a phase transition to quark matter. The important process here is q + ν l ( ν r ) → q + ν r ( ν l ) . By imposing a bound on νr luminosity, we get a limit on μv≲(0.3−0.05)×10−12 μb depending on the temperature and composition of the core.

Searches for the appearance of \(\nu_\tau\) using neutrino beams from muon storage rings

Abstract. We study the possibilities offered by muon storage rings for

Constraints on astro-unparticle physics from SN 1987A

\nu_\tau

Anomalous X-ray galactic signal from 7.1 keV spin-3/2 dark matter decay

appearance experiments in order to determine masses and mixing angles for the

Working group report: High energy and collider physics

\nu_\mu \rightarrow \nu_\tau

Top quark physics in the vector color-octet model

and

Summary of the Activities of the Working Group I on High Energy and Collider Physics

\bar\nu_e \rightarrow \bar\nu_\tau

Neutrino, photon interaction in unparticle physics

oscillations. The dependence of tau event rates on baseline, forward peaking of decay neutrinos with increasing energies, and average fluxes intercepted by detectors of various sizes is discussed. It is found that the baseline length does not significantly affect the rates for oscillations of such magnitudes as are suggested by the current atmospheric neutrino data. Subsequently, the effects of cuts on hadronic and wrong sign leptonic modes are computed and used to plot 90% CL contours for the parameter regions that can be explored in such experiments. The results show that even for modest muon beam energies, convincing coverage and verification of the Super Kamiokande parameters is possible. In addition, a very significant enlargement of present day bounds on the mixing parameters for neutrino oscillations of all types is guaranteed by these types of searches.

Investigating perturbative unitarity in the presence of anomalous couplings

SN 1987A observations have been used to place constraints on the interactions between standard model particles and unparticles. In this study we calculate the energy loss from the supernovae core through scalar, pseudo-scalar, vector, and pseudo-vector unparticle emission from nuclear bremsstrahlung for degenerate nuclear matter interacting through one pion exchange. In order to examine the constraints on we considered the emission of scalars, pseudo-scalars, vectors, pseudo-vectors and tensors through the pair annihilation process . In addition we have re-examined other pair annihilation processes. The most stringent bounds on the dimensionless coupling constants for and are obtained from the nuclear bremsstrahlung process for the pseudo-scalar and pseudo-vector couplings , and for tensor interaction, the best limit on dimensionless coupling is obtained from and we get .