K.V.L. Sarma

Interpretation of the new particle of the cosmic ray neutrino experiment

In order to reconcile the life time of the new particle observed in the cosmic ray neutrino experiment with its production rate, it is proposed that the particle has a new quantum number (κ) which may be assigned to leptons and hadrons. In the production of the new particle, assumed to be a heavy charged lepton,κ is conserved by creating an associated lepton-hadron pair. Suppression of theκ-violating interaction is invoked to interpret the long life time of this particle.

General bounds on the isovector coupling constants of the weak neutral current

We show that experimental data on inclusive neutrino reactions can be used to obtain general bounds on the coupling constants of the isovector part of the hadronic weak neutral current provided this isovector current is related to the charged current by isospin rotation. These bounds are free from the assumption of a specific model for the neutral current as well as any dynamical assumption on the hadronic structure functions. We derive upper bounds on the coupling constants which involve only the cross sections for isospin-averaged nucleon target as well as lower bounds which require a knowledge of the cross sections for proton and neutron separately.

Implications of accelerator experiments for models of the Kolar gold mine particles

Abstract The significance of accelerator searches for the new particles discovered in the Kolar Gold Mine experiments depends on the characteristics of the models of these particles. Models that could give cosmic ray neutrinos a great advantage over accelerator neutrinos are presented. The new particles should be produced in e + e - colliding beams, but the cross-section is model dependent.

Bounds on the coupling constants of the neutral current

Abstract We derived bounds on the coupling constants which characterize the strengths of the various pieces of the weak hadronic neutral current using isospin invariance of strong interactions alone. For the numerical evaluation of the bounds with present experimental data Bjorken scaling also has been used.

Analysis of the neutral-current interaction in the inclusive neutrino reaction

We attempt a general phenomenological analysis of the neutral weak current in the inclusive neutrino reactions using the parton model as a tool. From the recently reported data on these processes we determine the strengthH of the neutral-current interaction as well as the amount of theVA interference. We find (H/G)2=0·54±0·06 whereG is the Fermi coupling constant and theVA interference contribution turns out to be 33±23%. We also discuss the comparison of the data with various models for the neutral hadronic current.

Model-independent analysis of the neutral-current interaction in the inclusive neutrino reactions

On the basis of some general assumptions on the deep inelastic structure functions, such as scaling and chiral symmetry we determine the values of {(HV3)2+(HA3)2}+η{(HV0)2+(HA0)2} andHV3HA3+ηHV0HA0 whereHV3,0 andHA3,0 are the four coupling constants characterizing the hadronic neutral current andη is the ratio of the isoscalar to isovector structure functions. General expressions are given for the kinematical averages 〈v〉 and 〈Q2〉 for the neutral-current reactions in terms of the coupling constants. This analysis does not depend on the validity of the quark-parton model.

ANALYSIS OF THE DATA IN HEAVY FLAVOUR DECAYS

The charmed and bottom hadron decays have been analyzed phenomenologically, keeping both the spectator and nonspectator contributions to the total decay rates. A sum rule relating the total decay widths of the four low-lying charmed baryons is given. It is pointed out that all the data which have become recently available can be understood in all cases with negligible Pauli interference effects but with important exchange- mechanism contributions. Predictions for the lifetimes of and together with the expected lifetime hierarchy for the bottom hadrons are given. The corresponding semileptonic branching ratios, where possible, are also predicted.

Interpretation of the recent Kolar events

We give plausible interpretations of the unusual events seen in the proton decay detector at Kolar Gold Fields indicating the existence of a massive (≳2GeV) long lived (10−8−10−9s) particle. We show that it is possible to accommodate the particle in the standard model as a fourth generation neutrino, or inE6 grand unified theory as a neutral fermion occurring in27 representation or in supersymmetric theory as a scalar neutrino. However, there is a difficulty in explaining the large production rate for the particle.

Effective baryon-lepton coupling and the proton decay modes

We present a simple model for the phenomenology of baryon-number violating nucleon decays in which the basic process is taken to be a direct conversion of a baryon into a lepton or an antilepton. A large number of branching modes are found to be correlated, independently of any specific grand unification scheme.

Is there a new type of hadron with mass around 90 GeV

Abstract It is suggested that the observed l l γ events in the Z0 mass region could actually be due to the decay and a new neutral massive hadron, ζ, with JPC = 0±-. Interestingly, the other decay modes of ζ can give rise to events with a hard photon or a monojet and missing transverse energy, similar to the ones recently observed at the p p collider.