arXiv subjects

S. P. Das

Publications and source records attributed to S. P. Das.

10 recordsLinked to original sources

arXiv2023

A short note on Magnetized Black-hole in Non-linear Electrodynamics

We have analyzed the thermodynamic properties of magnetized black-hole in the background of non-linear electrodynamics with two parameters $β$ and $γ$. We have studied the Bekenstein-Hawking entropy, Hawking temperature, specific heats in two-dimesional surface plots as a function of event horizon ($r_{+}$) and $γ$. We showed the variation profiles of the above thermodynamic parameters for $γ$ [$ 0 \rightarrow 1$]. We identified regions of parameters for the possible phase-transitions and the stability of the black-holes.

gr-qc↗

arXiv2023

Nearly Static Magnetized Kerr Black-hole in Non-linear Electrodynamics

We have analyzed the thermodynamics of slowly rotating magnetized Kerr black-hole, with typical spin parameter $a\le 0.1$ (nearly static) in the background of non-linear electrodynamics. In particular we have studied the Bekenstein-Hawking entropy, Hawking temperature, angular momentum, specific heats and identified regions of parameters for possible phase-transitions. It turns out that once the stability lost the black-hole never come back to its original stable position.

gr-qc↗

arXiv2021

The Large Hadron-Electron Collider at the HL-LHC

The Large Hadron electron Collider (LHeC) is designed to move the field of deep inelastic scattering (DIS) to the energy and intensity frontier of particle physics. Exploiting energy recovery technology, it collides a novel, intense electron beam with a proton or ion beam from the High Luminosity--Large Hadron Collider (HL-LHC). The accelerator and interaction region are designed for concurrent electron-proton and proton-proton operation. This report represents an update of the Conceptual Design Report (CDR) of the LHeC, published in 2012. It comprises new results on parton structure of the proton and heavier nuclei, QCD dynamics, electroweak and top-quark physics. It is shown how the LHeC will open a new chapter of nuclear particle physics in extending the accessible kinematic range in lepton-nucleus scattering by several orders of magnitude. Due to enhanced luminosity, large energy and the cleanliness of the hadronic final states, the LHeC has a strong Higgs physics programme and its own discovery potential for new physics. Building on the 2012 CDR, the report represents a detailed updated design of the energy recovery electron linac (ERL) including new lattice, magnet, superconducting radio frequency technology and further components. Challenges of energy recovery are described and the lower energy, high current, 3-turn ERL facility, PERLE at Orsay, is presented which uses the LHeC characteristics serving as a development facility for the design and operation of the LHeC. An updated detector design is presented corresponding to the acceptance, resolution and calibration goals which arise from the Higgs and parton density function physics programmes. The paper also presents novel results on the Future Circular Collider in electron-hadron mode, FCC-eh, which utilises the same ERL technology to further extend the reach of DIS to even higher centre-of-mass energies.

hep-ex↗

arXiv2018

Prospects for discovering a light charged Higgs boson within the NMSSM at the FCC-eh collider

We analyze the prospects of observing relatively light charged Higgs bosons ($h^{\pm}$) in their decays via $h^{-} \to s \bar c + s \bar u$ at the upcoming Future Circular Collider in hadron-electron mode (FCC-eh) with $\sqrt s \approx 3.5$ TeV. Assuming that the intermediate Higgs boson ($h_2$) is Standard Model (SM)-like, we study the production of $e^- b \to ν_e h^{-} b$ (also $b$ could be $\bar b$ in both initial and final states) in the framework of the Next-to-Minimal Supersymmetric Standard Model (NMSSM). We consider constraints from Dark Matter (DM), super-particle and the Higgs boson data. The charged Higgs boson decays into light flavors leads to a three-jets with missing transverse energy signal with one $b$-tagged jet. Our results show that light charged Higgs bosons with mass close to, e.g., 114(121) GeV have the maximal significance of 3.2(1.8)$σ$, upon using normal cut based selections and after 1 ab$^{-1}$ of luminosity. However, we further adopt an optimization technique to enhance the latter to 4.4 (2.2)$σ$, respectively.

hep-ph↗

arXiv2016

Flavor violating signatures of lighter and heavier Higgs bosons within the Two Higgs Doublet Model Type-III at the LHeC

We analyze the prospects for observing the CP-even neutral Higgs bosons (h and H) in their decays into flavor violating $b \bar s+ c.c.$ channels at the proposed LHeC, with $\sqrt s \approx 1.3$ TeV, in the 2HDM Type-III, assuming a four-zero texture in the Yukawa matrices and a general Higgs potential. We consider theoretically consistent scenarios in agreement with current experimental data from flavor and Higgs physics. We investigate the charged current production process $ν_e ϕq$ in presence of flavor violating decays of the Higgs bosons, that lead to a 3-jets + $E\!\!\!\!/_T$ signature. We demand exactly two jets, one tagged $b$-jet and one light-flavor jet, all in the central rapidity region. The remaining jet (originated by the remanent quark $q$) is tagged in the forward or backward regions and this together with a central jet veto (not more than one light-flavor jet) are essential criterions to enhance the signal--to--background rates. We consider the most relevant Standard Model (SM) backgrounds, treating $c$-jets separately from light-flavor and gluon ones, while allowing for mis-tagging. We find that the SM-like Higgs boson, $h$, would be accessible within several parameter configurations of our model at approximately the 1-2$σ$ level with 100 fb$^{-1}$ of data. We also find that the heaviest neutral Higgs boson, $H$, with mass up to 150 GeV, would have a 1$σ$ significance for the same data sample. At the end of the LHeC running, one would have ten times data accumulation and for all the Higgs masses the significances are enhanced so as to allow for detection of both the $h$ and $H$ state. Hence, one of the most viable extensions of 2HDMs with FCNC's generated at tree level but controlled by a four-zero texture approach in the Yukawa matrices, as opposed to the adoption of ad hoc discrete symmetries, could be put under scrutiny at a future LHeC.

hep-ph↗

arXiv2015

Flavor violating signatures of neutral Higgs bosons at the LHeC

We analyze the prospect for observing the lightest and heaviest CP-even neutral Higgs bosons ($ϕ=h,\;H$) in their decays to flavor violating $b\bar{s}$ (with charge conjugate) final states at the future Large Hadron electron Collider (LHeC), in the framework of the Two Higgs Doublet Model type III (2HDM-III) assuming a four-zero texture in the Yukawa matrices and a general Higgs potential. We consider the charge current production processes $e^- p \to ν_e ϕq_f$ ($ϕ= h, \; H$), with the flavor violating decays of the Higgs bosons. We consider scenarios of the model which are consistent with current experimental data from flavor and Higgs physics. We also consider the most relevant Standard Model (SM) backgrounds. We find that the lightest (SM-like) CP-even Higgs boson $h$ and the heaviest one $ H$ (with mass up to 150 GeV) would have 1--2 $Σ$ and 1 $Σ$ significances, respectively, with 100 fb$^{-1}$ of data. At the end of the LHeC running, the significances would be increased by ten times and the detection of both Higgs bosons ($h, H$) would be guaranteed.

hep-ph↗

arXiv2012

Heavy Neutrinos and Lepton Flavour Violation in Left-Right Symmetric Models at the LHC

We discuss lepton flavour violating processes induced in the production and decay of heavy right-handed neutrinos at the LHC. Such particles appear in left-right symmetrical extensions of the Standard Model as the messengers of neutrino mass generation, and can have masses at the TeV scale. We determine the expected sensitivity on the right-handed neutrino mixing matrix, as well as on the right-handed gauge boson and heavy neutrino masses. By comparing the sensitivity of the LHC with that of searches for low energy LFV processes, we identify favourable areas of the parameter space to explore the complementarity between LFV at low and high energies.

hep-ph↗

arXiv2012

Probing neutralino properties in minimal supergravity with bilinear R-parity violation

Supersymmetric models with bilinear R-parity violation (BRPV) can account for the observed neutrino masses and mixing parameters indicated by neutrino oscillation data. We consider minimal supergravity versions of BRPV where the lightest supersymmetric particle (LSP) is a neutralino. This is unstable, with a large enough decay length to be detected at the CERN Large Hadron Collider (LHC). We analyse the LHC potential to determine the LSP properties, such as mass, lifetime and branching ratios, and discuss their relation to neutrino properties.

hep-ph↗

arXiv2010

New Physics at the LHC. A Les Houches Report: Physics at TeV Colliders 2009 - New Physics Working Group

We present a collection of signatures for physics beyond the standard model that need to be explored at the LHC. First, are presented various tools developed to measure new particle masses in scenarios where all decays include an unobservable particle. Second, various aspects of supersymmetric models are discussed. Third, some signatures of models of strong electroweak symmetry are discussed. In the fourth part, a special attention is devoted to high mass resonances, as the ones appearing in models with warped extra dimensions. Finally, prospects for models with a hidden sector/valley are presented. Our report, which includes brief experimental and theoretical reviews as well as original results, summarizes the activities of the "New Physics" working group for the "Physics at TeV Colliders" workshop (Les Houches, France, 8-26 June, 2009).

hep-ph↗

arXiv2008

Sneutrino as Lightest Supersymmetric Particle in B3 mSUGRA Models and Signals at the LHC

We consider B3 mSUGRA models where we have one lepton number violating LQD operator at the GUT scale. This can alter the supersymmetric mass spectrum leading to a sneutrino as the lightest supersymmetric particle in a large region of parameter space. We take into account the restrictions from neutrino masses, the muon anomalous magnetic moment, b -> s gamma and other precision measurements. We furthermore investigate existing restrictions from direct searches at LEP, the Tevatron and the CERN p\bar p collider. We then give examples for characteristic signatures at the LHC.

hep-ph↗