G Rajasekaran
Articles written in Pramana – Journal of Physics
Volume 2 Issue 2 February 1974 pp 62-72 Nuclear And Particle Physics
Analysis of the neutral-current interaction in the inclusive neutrino reactions
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 strength
Volume 2 Issue 4 April 1974 pp 225-225 Erratum
Analysis of the neutral-current interaction in the inclusive neutrino reaction
Volume 2 Issue 6 June 1974 pp 1- Erratum
Analysis of the neutral-current interaction in the inclusive neutrino reaction
Volume 3 Issue 1 July 1974 pp 44-55 Particle Physics
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 {(
Volume 4 Issue 5 May 1975 pp 222-228 Nuclear And Particle Physics
Effect of gluons on neutral-current interactions in deep inelastic neutrino scattering
The contribution of neutral spin-1 gluons to the deep inelastic neutral-current processes
Volume 5 Issue 2 August 1975 pp 78-86 Nuclear And Particle Physics
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 (
Volume 5 Issue 6 December 1975 pp 303-327 Nuclear And Particle Physics
Colour gluons and scaling in a unified gauge model
Deep inelastic weak and electromagnetic processes are considered within the parton framework taking the partons to be integrally charged quarks and coloured gluons. Despite the participation of the spin-one gluons in these processes, scaling is shown to be maintained by treating the problem in a unified gauge model based on the group
Volume 6 Issue 1 January 1976 pp 29-33 Nuclear And Particle Physics
Radiative decays, photoproduction and total cross section of the
K (xxxV) L Sarma G Rajasekaran J Pasupathy
It is pointed out that the coupling characterizing the
Volume 7 Issue 3 September 1976 pp 194-222 Nuclear And Particle Physics
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.
Volume 9 Issue 3 September 1977 pp 239-247 Nuclear And Particle Physics
Renormalizable theories from nonrenormalizable interactions
By using Kikkawa’s method the equivalence of the nonrenormalizable pair interaction$$\bar \psi \psi \phi ^2 $$ to a renormalizable theory is proved. Equivalence relationships between a few other nonrenormalizable and renormalizable interactions are also indicated.
Volume 10 Issue 1 January 1978 pp 33-45 Nuclear And Particle Physics
Generation of gluons from quark confinement
We study a model of quark confinement defined by the vanishing of colour currents. The model is shown to be equivalent to quantum chromodynamics and this equivalence is interpreted as due to the compositeness of the colour gluons. The Green’s functions of the theory are found to contain nontrivial structure only for colour singlet composites which can be identified with hadrons.
Volume 11 Issue 5 November 1978 pp 609-617 Nuclear and Particle Physics
Neutral current cross-sections for neutrinos on protons
Defining the ratios
Volume 11 Issue 6 December 1978 pp 739-743 Particle Physics
Classical solutions of a model of quark confinement
We find the classical solutions of a model of quark confinement defined by the vanishing of colour currents. Both plane-wave type of solutions extending all over space as well as string-type of solutions confined to restricted regions of space are found.
Volume 12 Issue 4 April 1979 pp 397-417 Particle Physics
Neutral currents in left-right symmetric gauge models
Jatinder K Bajaj G Rajasekaran
We analyse all the neutral-current phenomena following from the general class of gauge models based on the group SU(2)_{L} ⊗ SU(2)_{R} ⊗ U(1). It is found that the neutral-current couplings in these models bear a remarkable similarity to those in the standard Weinberg-Salam gauge model. The parameter which plays the role of sin^{2}ϑ_{w} is found to lie between 0 and 1/2. Comparison with experimental data shows that even a model with the ratio of the masses of the two
Volume 13 Issue 2 August 1979 pp 183-204 Nuclear And Particle Physics
General relations among observables in neutral-current phenomena mediated by one or two
If
Volume 14 Issue 5 May 1980 pp 395-409 Particle Physics
The electroweak mixing angle in unified gauge theories
Jatinder K Bajaj G Rajasekaran
We study in detail the factors that influence the unification relations among the coupling parameters of strong and electroweak interactions. We find that the factor that decides the unification relations in a theory is the fermion content of the theory. The specific ‘observed’ group of strong and electroweak interactions used and the specific unification group in which these interactions are embedded are largely irrelevant. In particular, we find that the unification value of the electroweak mixing angle is the same for almost all models of interest. We also explicitly illustrate that the canonical value 3/8 of the mixing angle is a characteristic result of the currently popular sequential doublets scheme of fermions. Addition of extra fermion singlets reduces the mixing angle to 1/4. We propose this sequential triplets scheme of fermions as an interesting alternative to the current scheme.
Volume 14 Issue 5 May 1980 pp 411-422 Particle Physics
The electroweak mixing angle in unified gauge theories—the renormalisation effects
Jatinder K Bajaj G Rajasekaran
A general analysis of the renormalisation corrections to the unification results for the coupling constants of strong and electroweak interactions is attempted. In particular, the effects of introducing an energy scale intermediate between the unification energy and the low-energy regions are studied and found to be important. This analysis is applied to unification schemes of both kinds, namely, unification at superhigh energies, and unification at accessible energies.
Volume 19 Issue 4 October 1982 pp 315-321 Particle Physics
Non-renormalization of the weak vertex in gauge theories with integrally charged quarks
We give current algebra arguments to show that to
Volume 24 Issue 3 March 1985 pp 423-427 Particle Physics
Decays of
S Lakshmibala G Rajasekaran S D Rindani
The two-gluonic decay modes of
Volume 24 Issue 3 March 1985 pp 435-442 Particle Physics
Fields with vanishing colour-currents
G Rajasekaran V Srinivasan M S Sri Ram
We consider spinor, scalar and vector fields with colour degrees of freedom and find the classical solutions when the constraint of vanishing colour currents is imposed. We find that there are no non-trivial
Volume 26 Issue 1 January 1986 pp 21-41 Particle Physics
Validity of the equivalent-photon approximation for the production of massive spin-1 particles
T Jayaraman G Rajasekaran S D Rindani
We point out that the equivalent-photon approximation (
We also discuss how the extra conditions are altered when the vector bosons are incorporated in a spontaneously broken gauge theory. Examples of
Volume 27 Issue 3 September 1986 pp 371-382 Particle Physics
Higgs couplings in the integer-charge quark model
Colour SU(3) symmetry is broken spontaneously by the introduction of coloured Higgs scalars in the standard SU(3)×SU(2)×U(1) model, so as to make the quarks integrally charged. The resulting couplings of the Higgs bosons with the gauge bosons are worked out.
Volume 33 Issue 6 December 1989 pp 639-649 Particle Physics
Interpretation of the recent Kolar events
A S Joshipura G Rajasekaran V Gupta K V L Sarma
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^{−9}s) particle. We show that it is possible to accommodate the particle in the standard model as a fourth generation neutrino, or in
Volume 34 Issue 3 March 1990 pp 183-192
We show how the position and residue of the
Volume 36 Issue 5 May 1991 pp 537-555 Research Articles
Algebra for fermions with a new exclusion principle
We construct the algebra of the creation and destruction operators for spin 1/2 particles obeying a new exclusion principle which is “more exclusive” than Pauli’s exclusion principle: an orbital state shall not contain more than one particle, whether spin up or spin down. The consequences of this algebra are studied and applications to the Hubbard model in condensed matter physics are indicated.
Volume 37 Issue 5 November 1991 pp 455-455 Erratum
Volume 38 Issue 4 April 1992 pp 1- Rapid Communication
New forms of quantum statistics
We propose a new two-parameter deformation of the algebra of creation and destruction operators, which allows the construction of a new family of Hillbert spaces with positive definite inner product. This provides a continuous interpolation between two new forms of statistics named orthofermi and orthobose statistics. Positivity of the inner product over the two-parameter region is discussed.
Volume 40 Issue 3 March 1993 pp 149-176
Algebras of creation and destruction operators
A general analysis of bilinear algebras of creation and destruction operators is performed. Generalizing the earlier work on the single-parameter
Volume 45 Issue 2 August 1995 pp 91-139
Generalized Fock spaces, new forms of quantum statistics and their algebras
We formulate a theory of generalized Fock spaces which underlies the different forms of quantum statistics such as ‘infinite’, Bose-Einstein and Fermi-Dirac statistics. Single-indexed systems as well as multi-indexed systems that cannot be mapped into single-indexed systems are studied. Our theory is based on a three-tiered structure consisting of Fock space, statistics and algebra. This general formalism not only unifies the various forms of statistics and algebras, but also allows us to construct many new forms of quantum statistics as well as many algebras of creation and destruction operators. Some of these are: new algebras for infinite statistics,
Volume 55 Issue 1-2 July 2000 pp 19-32
Phenomenology of neutrino oscillations
The phenomenology of solar, atmospheric, supernova and laboratory neutrino oscillations is described. Analytical formulae for matter effects are reviewed. The results from oscillations are confronted with neutrinoless double beta decay.
Volume 55 Issue 1-2 July 2000 pp 347-355
Discussion on a possible neutrino detector located in India
MVN Murthy Urjit A Yajnik KRS Balaji G Bhattacharyya Amol Dighe Shashikant Dugad ND Hari Dass PK Kabir Kamales Kar D Indumathi John G Learned Debasish Majumdar NK Mondal MVN Murthy SN Nayak Sandip Pakvasa Amitava Raychaudhuri RS Raghavan G Rajasekaran R Ramachandran Alak K Ray Asim K Ray Saurabh Rindani HS Sharatchandra Rahul Sinha Nita Sinha S Umasankar Urjit A Yajnik
We have identified some important and worthwhile physics opportunities with a possible neutrino detector located in India. Particular emphasis is placed on the geographical advantage with a stress on the complimentary aspects with respect to other neutrino detectors already in operation.
Volume 88 Issue 4 April 2017 Article ID 0060 Research Article
Corrigendum: ‘Anomalous Kolar events revisited: Dark matter?’
Some unusual and unexplained events (the so-called Kolar events) were interpreted in $\it{Pramana – J. Phys}$. $\bf{82}$, 609 (2014). This article is a corrigendum to it.
Volume 88 Issue 5 May 2017 Article ID 0079 Research Article
Physics potential of the ICAL detector at the India-based Neutrino Observatory (INO)
A KUMAR A M VINOD KUMAR ABHIK JASH AJIT K MOHANTY ALEENA CHACKO ALI AJMI AMBAR GHOSAL AMINA KHATUN AMITAVA RAYCHAUDHURI AMOL DIGHE ANIMESH CHATTERJEE ANKIT GAUR ANUSHREE GHOSH ASHOK KUMAR ASMITA REDIJ B SATYANARAYANA B S ACHARYA BRAJESH C CHOUDHARY C RANGANATHAIAH C D RAVIKUMAR CHANDAN GUPTA D INDUMATHI DALJEET KAUR DEBASISH MAJUMDAR DEEPAK SAMUEL DEEPAK TIWARI G RAJASEKARAN GAUTAM GANGOPADHYAY GOBINDA MAJUMDER H B RAVIKUMAR J B SINGH J S SHAHI JAMES LIBBY JYOTSNA SINGH K RAVEENDRABABU K K MEGHNA K R REBIN KAMALESH KAR KOLAHAL BHATTACHARYA LALIT M PANT M SAJJAD ATHAR M V N MURTHY MANZOOR A MALIK MD NAIMUDDIN MOHAMMAD SALIM MONOJIT GHOSH MOON MOON DEVI NABA K MONDAL NAYANA MAJUMDAR NITA SINHA NITALI DASH POMITA GHOSHAL POONAM MEHTA PRAFULLA BEHERA R KANISHKA RAJ GANDHI RAJESH GANAI RASHID HASAN S KRISHNAVENI S M LAKSHMI S K SINGH S S R INBANATHAN S UMA SANKAR SADIQ JAFER SAIKAT BISWAS SANJEEV KUMAR SANJIB KUMAR AGARWALLA SANDHYA CHOUBEY SATYAJIT SAHA SHAKEEL AHMED SHIBA PRASAD BEHERA SRUBABATI GOSWAMI SUBHASIS CHATTOPADHYAY SUDEB BHATTACHARYA SUDESHNA BANERJEE SUDESHNA DASGUPTA SUMANTA PAL SUPRATIK MUKHOPADHYAY SUSHANT RAUT SUVENDU BOSE SWAPNA MAHAPATRA TAPASI GHOSH TARAK THAKORE V K S KASHYAP V S SUBRAHMANYAM VENKTESH SINGH VINAY B CHANDRATRE VIPIN BHATNAGAR VIVEK M DATAR WASEEM BARI Y P VIYOGI
The upcoming 50 kt magnetized iron calorimeter (ICAL) detector at the India-based Neutrino Observatory (INO) is designed to study the atmospheric neutrinos and antineutrinos separately over a wide range of energies andpath lengths. The primary focus of this experiment is to explore the Earth matter effects by observing the energy and zenith angle dependence of the atmospheric neutrinos in the multi-GeV range. This study will be crucial toaddress some of the outstanding issues in neutrino oscillation physics, including the fundamental issue of neutrino mass hierarchy. In this document, we present the physics potential of the detector as obtained from realistic detector simulations.We describe the simulation framework, the neutrino interactions in the detector, and the expected responseof the detector to particles traversing it. The ICAL detector can determine the energy and direction of the muons to a high precision, and in addition, its sensitivity to multi-GeV hadrons increases its physics reach substantially. Itscharge identification capability, and hence its ability to distinguish neutrinos from antineutrinos, makes it an efficient detector for determining the neutrino mass hierarchy. In this report, we outline the analyses carried out for the determination of neutrino mass hierarchy and precision measurements of atmospheric neutrino mixing parameters at ICAL, and give the expected physics reach of the detector with 10 years of runtime. We also explore the potential of ICAL for probing new physics scenarios like CPT violation and the presence of magnetic monopoles.
Current Issue
Volume 93 | Issue 2
August 2019
© 2017-2019 Indian Academy of Sciences, Bengaluru.