Research Interest
Neutrino Physics:
Neutrino physics is a very active field now,
both experimentally and theoretically. The results of observations toward
the existence of neutrino oscillations serve as one of the few experimental
indications of the incompleteness of the Standard Model. The smallness of
neutrino mass is very likely related to existence of new, yet unexplored
mass scales in particle physics. At present we are involved in realizing the
neutrino mass and mixing pattern based on different flavor symmetry.
Dark Matter:
It has been established that the constituents of our
universe are predominantly not the ordinary matter, rather the dark matter which
occupies a substantial part of it. Particle physics plays an important role in
describing the period of Big Bang Nucleosynthesis, and can also provide new
candidates for dark matter once we go beyond the Standard Model. We are interested
in studying various possible candidates for dark matter which can be explored
in future experiments. More specifically, we work on those candidates of DM
which also carry some interesting involvement in solving various problems, e.g.
related to the neutrino mass generation, part of the inflationary set-up etc.
Matter-antimatter asymmetry of the Universe:
The origin of the
excess of baryons over anti-baryons in the Universe remains one of the
fascinating problems of particle physics and cosmology. One of the possibilities
could be that the baryon asymmetry has originated through the physics in the
lepton sector, called leptogenesis. This involves the neutrinos as well.
Therefore we are interested in exploring this asymmetry in connection with
the models of neutrino mass in different flavor-symmetric framework. This
involves an understanding of CP-violation in the lepton sector.
Issues related with Higgs vacuum stability:
The discovery of the Higgs boson undoubtedly establishes the credibility of the
Standard Model (SM) as a successful theory of fundamental interactions in nature.
While the Higgs boson was the only particle in the SM that remained to be discovered
until recently, its finding does not necessarily indicate the end for the hunt
of particle physics. On the contrary, the discovery opens up several questions
regarding the Higgs sector of the SM. In particular, the study of the Higgs potential
turns out to be quite intriguing in view of the fact that the Higgs quartic coupling
becomes negative at high energies indicating a possible instability of the electroweak
(EW) vacuum. At present we are studying the fate of the EW vacuum from
the new physics point of view those are required to accommodate some of the un-answered
problems within the SM, e.g. neutrino mass and mixing, inflation, dark matter etc..
Early Universe Inflation and Connection with Particle Physics:
Our
current knowledge of the Cosmic Microwave Background Radiation (CMB),
combined with other data suggests that the universe can be well described by
an early period of inflation, followed by a hot big bang. We are also involved
in developing models of inflation (mostly in supersymmetric or supergravity
framework) so as accommodate the present data from PLANCK etc.
Supersymmetry breaking and its mediation:
If there is a supersymmetry,
it has to be broken. However the origin of the supersymmetry breaking scale is
mysterious. We work on the theory of dynamical supersymmetry breaking and study
its phenomenological implications.
Few recent publications:
[2017]
Study of Electroweak Vacuum Stability from Extended Higgs Portal of Dark Matter and Neutrinos;
by Purusottam Ghosh, Abhijit Kumar Saha and Arunansu Sil, arXiv:1706.04931
Flavor origin of dark matter and its relation with
leptonic nonzero theta_{13} and Dirac CP phase; by Subhaditya Bhattacharya, Biswajit Karmakar,
Narendra Sahu, and Arunansu Sil; JHEP 1705 (2017) 068.
An A4 realization of inverse seesaw: neutrino masses, theta_{13} and leptonic non-unitarity;
by Biswajit Karmakar and Arunansu Sil; Phys. Rev. D 96, no. 1, 015007 (2017).
Higgs Vacuum Stability and Modified Chaotic Inflation; by Abhijit Kumar Saha and Arunansu Sil; Phys. Lett. B 765, 244 (2017).
[2016]
Unifying the flavor origin of dark matter with leptonic nonzero theta_{13}; by Subhaditya Bhattacharya, Biswajit Karmakar,
Narendra Sahu, and Arunansu Sil; Phys. Rev. D 93, no. 11, 115041 (2016).
Spontaneous CP violation in lepton-sector: A common origin for theta_{13}, the Dirac CP phase,
and leptogenesis; by Biswajit Karmakar and Arunansu Sil; Phys. Rev. D 93, no. 1, 013006 (2016).
Neutrino masses and deviation from tribimaximal mixing in Delta(27) model with inverse seesaw mechanism;
by Mohammed Abbas, Shaaban Khalil, Ahmed Rashed and Arunansu Sil; Phys. Rev. D 93, no. 1, 013018 (2016).
[2015]
A Dynamic Modification to Sneutrino Chaotic Inflation; by Abhijit Kumar Saha and Arunansu Sil; JHEP 1511, 118 (2015).
Nonzero theta-13 and leptogenesis in a type-I seesaw model with A4 symmetry, by Biswajit Karmakar and Arunansu Sil;
Phys. Rev. D 91, 013004 (2015).
Warm dark matter in a $B-L$ inverse seesaw scenario, by Amr El-Zant, Shaaban Khalil and Arunansu Sil;
Phys. Rev. D 91, 035030 (2015).
For a complete list of publications, check spires [https://inspirehep.net/].
Ph.D. Students:
Biswajit Karmakar [completed]
Abhijit Kumar Saha [continuing]
Rishav Roshan [continuing]
Postdoc:
Dr. Amit Dutta Banik [National Postdoctoral Fellow (NPDF), Ph.D. from SINP, Kolkata]