A5030494842- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Quantum Chromodynamics and Particle Interactions
- Dark Matter and Cosmic Phenomena
- Cosmology and Gravitation Theories
- Particle Detector Development and Performance
- Galaxies: Formation, Evolution, Phenomena
- Black Holes and Theoretical Physics
- Neutrino Physics Research
- Computational Physics and Python Applications
- Astrophysics and Cosmic Phenomena
- Cold Atom Physics and Bose-Einstein Condensates
- Nuclear reactor physics and engineering
- Radiation Detection and Scintillator Technologies
- Gamma-ray bursts and supernovae
- Quantum and electron transport phenomena
- Solar and Space Plasma Dynamics
- Electron and X-Ray Spectroscopy Techniques
- Atomic and Subatomic Physics Research
- Impact of Light on Environment and Health
- Distributed and Parallel Computing Systems
- Physics of Superconductivity and Magnetism
Indian Association for the Cultivation of Science
2018-2024
Saha Institute of Nuclear Physics
2015-2019
University of Pittsburgh
2016-2018
Institute of High Energy Physics
2016-2017
The University of Tokyo
2013-2016
Kavli Institute for the Physics and Mathematics of the Universe
2013-2015
University of Arizona
2014
Harish-Chandra Research Institute
2010-2012
We enumerate the set of simplified models which match onto complete gauge invariant effective operators up to dimension six describing interactions a singlet-like Majorana fermion dark matter with standard model. Tree level matching conditions for each case are worked out in large mediator mass limit, defining one correspondence between operator coefficients and model parameters weakly interacting models. Utilizing such mapping, we compute annihilation rate early universe, as well other...
The inclusion of higher-dimensional gauge invariant operators induces new Lorentz structures in Higgs couplings with electroweak boson pairs. This principle affects the kinematics production and decay, thereby modifying efficiencies experimental cuts compared to what simulations based on standard model interactions yield. Taking some sample cases, we perform a rigorous analysis how differ for various strengths additional operator vis-\`a-vis interactions, scanning over values both them....
We explore a singlet Majorana fermion dark matter candidate using an effective field theory (EFT) framework, respecting the relations imposed by standard model $SU(3)_C \times SU(2)_L U(1)_Y$ gauge invariance among different couplings. All operators of dimension-5 and dimension-6, forming complete basis, are taken into account at same time, keeping in view ultraviolet completions which can give rise to more than one operator time. If addition CP-conservation is assumed, remaining parameter...
A bstract Using the upper bound on inelastic reaction cross-section implied by S-matrix unitarity, we derive thermally averaged maximum dark matter (DM) annihilation rate for general k → 2 number-changing reactions, with ≥ 2, taking place either entirely within sector, or involving standard model fields. This translates to a mass of particle saturating observed DM abundance, which, dominantly s -wave annihilations, is obtained be around 130 TeV, 1 GeV, 7 MeV and 110 keV, = , 3 4 5,...
We show that in studies of light quark- and gluon-initiated jet discrimination, it is important to include the information on softer reconstructed jets (associated jets) around a primary hard jet. This particularly relevant while adopting small radius parameter for reconstructing hadronic jets. The probability having an associated as function transverse momentum (p T ) radius, minimum p association computed up next-to-double logarithmic accuracy (NDLA), predictions are compared with results...
It has recently been pointed out that a component of the observed gamma-ray emission in low latitudes Fermi bubbles spectral shape can be explained by 10 GeV dark matter (DM) annihilating to tau leptons with cross section $2\ifmmode\times\else\texttimes\fi{}1{0}^{\ensuremath{-}27}\text{ }\text{ }{\mathrm{cm}}^{3}/\mathrm{s}$. Motivated this possibility, we revisit annihilation neutralino DM MSSM via stau exchange. The required masses and mixing, consistent LEP direct search electroweak...
We revisit the current LHC constraints on electroweak-ino sector parameters in minimal supersymmetric standard model (MSSM) that are relevant to explaining $(g-2)_\mu$ anomaly via dominant chargino and muon sneutrino loop. Since bounds electroweak-inos become weaker if they decay an intermediate stau or a tau instead of first two generation sleptons, we perform detailed analysis scenario with bino as lightest particle (LSP) light next-to-lightest one (NLSP). Even this scenario, MSSM can...
In a large class of scenarios, dark matter (DM) particles that belong to multiplet the standard model (SM) weak interactions are challenging probe in direct detection experiments due loop-suppressed cross-sections. Direct production at colliders is thus crucial look for such DM candidates, and under current estimates, future runs 14-TeV LHC projected masses around 300 GeV belonging an SU(2) doublet (Higgsino-like), 900 triplet (wino-like). We examine how far this mass reach can be extended...
The initial density of dark matter (DM) particles, otherwise secluded from the standard model (SM), may be generated at reheating, with an temperature ratio for internal thermalizations, <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:msub><a:mi>ξ</a:mi><a:mi>i</a:mi></a:msub><a:mo>=</a:mo><a:msub><a:mi>T</a:mi><a:mrow><a:mi>DM</a:mi><a:mo>,</a:mo><a:mi...
We study the impact of including quark- and gluon-initiated jet discrimination in search for strongly interacting supersymmetric particles at LHC. Taking example gluino pair production, considerable improvement is observed LHC reach on substructure observables to standard kinematic variables within a multivariate analysis. In particular, quark gluon separation has higher region intermediate mass-gap between lightest neutralino, as difference signal model background distributions reduced this...
Examining the Higgs sector at high energy scales through off-shell production can potentially shed light on naturalness problem of boson mass. We propose such a study LHC by utilizing representative model with new scalar field (S) coupled to standard doublet (H) in form |S|^{2}|H|^{2}. In process pp→h^{*}→ZZ, dominant momentum-dependent part one-loop singlet corrections, especially above threshold 2m_{S}, leads measurable deviation differential distribution Z-pair invariant mass, accordance...
We study the off-shell production of Higgs boson at LHC to probe physics higher energy scales utilizing process $g g \rightarrow h^{*} ZZ$. focus on scale dependence propagation, and top quark Yukawa coupling, $y_t (Q^2)$. Extending our recent in arXiv:1710.02149, we first discuss threshold effects propagator due existence new states, such as a gauge singlet scalar portal, possible continuum states conformal limit, both which would be difficult discover other traditional searches. then...
We study the implications of premise that any new, relativistic, highly energetic neutral particle interacts with quarks and gluons would create cascade-like events in IceCube (IC) detector. Such be observationally indistinguishable from current deep-inelastic (DIS) scattering due to neutrinos. Consequently, one reason for deviations, breaks or excesses expected astrophysical power-law neutrino spectrum could flux such a particle. Motivated by features recent 1347-day high energy starting...
A bstract We evaluate the impact of one-loop electroweak corrections to spin-independent dark matter (DM) scattering cross-section with nucleons ( σ SI ), in models a so-called blind spot for direct detection, where leading-order prediction relevant DM coupling Higgs boson, and therefore , are vanishingly small. Adopting simple illustrative scenario which state results from mixing singlet doublet fermions, we compute higher order scalar effective operator contributions stemming both triangle...
Post-inflationary reheating is a widely discussed mechanism for non-thermal production of dark matter (DM). In this scenario the momentum distribution produced DM particles usually taken to be one obtained at reheating, red-shifted later times due expansion Universe. However, since in such both and standard model (SM) fields couple inflaton, necessarily undergo self-scatterings, as well elastic inelastic scattering reactions with SM bath, all which proceed through $s-$channel or $t-$channel...
The LHC search for nearly degenerate gluinos and neutralinos, which can occur, example, in SUSY axion models, is limited by the reduced missing transverse momentum effective mass events. We propose use of kinematic correlations between jets coming from initial state radiation (ISR) gluino pair production events at 13 TeV LHC. A significant improvement signal to background ratio obtained highly compressed gluino-neutralino search, using cuts on rapidity azimuthal angle separation tagged with...
Gas Electron Multipliers (GEM) are a proven position sensitive gas detector technology which nowadays is becoming more widely used in High Energy Physics. GEMs offer an excellent spatial resolution and high particle rate capability, with close to 100% detection efficiency. In view of the luminosity phase CERN Large Hadron Collider, these aforementioned features make suitable candidates for future upgrades Compact Muon Solenoid (CMS) detector. particular, CMS GEM Collaboration proposes cover...
A bstract We show that a general semi-annihilation scenario, in which pair of dark matter (DM) particles annihilate to an anti-DM, and unstable state can mix with or decay standard model states, lead particle anti-particle asymmetry the DM sector. The present abundance, including CP-violation sector resulting are determined entirely by single process at next-to-leading order. For large this process, we find nearly complete be obtained sector, observed density being dominated (anti-)DM...
We point out that same-sign multilepton events, not given due attention yet for new physics search, can be extremely useful at the Large Hadron Collider. After showing easy reducibility of standard model backgrounds, we demonstrate viability trilepton signals R-parity breaking supersymmetry, both 7 and 14 TeV. find four-leptons, too, have appreciable rates. Same-sign trileptons are also expected, example, in Little Higgs theories with T-parity broken by anomaly terms.
Under rather generic assumptions, we show that in the asymmetric dark matter (ADM) scenario, sign of B-L asymmetry stored sector and standard model are always same. One particularly striking consequence this result is that, when decays or annihilates present universe, resulting final state involves an anti-neutrino. As a concrete example this, construct composite ADM explore feasibility detecting such anti-neutrino signal atmospheric neutrino detectors.
In the context of Grand Unified Theories (GUT) baryogenesis models, a well-known theorem asserts that $CPT$ conservation and unitarity S matrix require lowest order contribution leads to generation nonzero net $CP$ violation via decay heavy particle must be $\mathcal{O}({\ensuremath{\alpha}}_{\overline{)B}}^{3})$, where ${\ensuremath{\alpha}}_{\overline{)B}}$ is baryon number (B) violating coupling. We revisit this [which holds for lepton (L) violation, hence leptogenesis as well] examine...
We study the prospects of measuring CP property Higgs (h) coupling to tau leptons using vector boson fusion (VBF) production mode at high-luminosity LHC. Utilizing previously proposed angle between planes spanned by momentum vectors (π + π 0) and − pairs originating in τ ± decays as CP-odd observable, we perform a detailed Monte Carlo analysis, taking into account relevant standard model backgrounds, well detector resolution effects. find that excluding pure C $$ \mathcal{O}\left(400\...