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Lalit Kumar Saini

Publications and source records attributed to Lalit Kumar Saini.

6 recordsLinked to original sources

Boosted four-top production at the LHC : a window to Randall-Sundrum or extended color symmetry

Scenarios seeking to address the issue of electroweak symmetry breaking often have heavy colored gauge bosons coupling preferentially to the top quark. Considering the bulk Randall-Sundrum as a typical example, we consider the prospects of the first Kaluza-Klein mode ($G^{(1)}$) of the gluon being produced at the LHC in association with a $t \bar{t}$ pair. The enhanced coupling not only dictates that the dominant decay mode would be to a $t \bar{t}$ pair, but also to a very large $G^{(1)}$ width, necessitating the use of a renormalised $G^{(1)}$ propagator. This, alongwith the presence of large backgrounds (specially $t \bar{t} j j$), renders a conventional cut-based analysis ineffective, yielding only marginal significances of only around 2$σ$. The use of Machine Learning (ML) techniques alleviates this problem to a great extent. In particular, the use of Artificial Neural Networks helps us identify the most discriminating observables, thereby allowing a significance in excess of 4$σ$ for $G^{(1)}$ masses of $\sim$ 4 TeV.

hep-ph

Anomalous gauge couplings vis-$\grave{a}$-vis $(g-2)_μ$ and flavor observables

We reassess non-standard triple gauge couplings in the light of the recent $(g-2)_μ$ measurement at FNAL, the new lattice theory result of $(g-2)_μ$ and the updated measurements of several $B$-decay modes. In the framework of SMEFT, three bosonic dimension-6 operators are invoked to parametrize physics beyond the Standard Model and their contributions to such low-energy observables computed. Constraints on the corresponding Wilson coefficients are then derived from fits to the current experimental bounds on the observables and compared with the most stringent ones available from the 13 TeV LHC data in the $W^+ W^-$ and $W^\pm Z$ production channels.

hep-ph

Limiting the Heavy-quark and Gluon-philic Real Dark Matter

We investigate the phenomenological viability of real spin half, zero and one dark matter candidates, which interact predominantly with third generation heavy quarks and gluons via the twenty-eight gauge invariant higher dimensional effective operators. The corresponding Wilson coefficients are constrained one at a time from the relic density $Ω^{\rm DM} h^2$ $\approx$ 0.1198. Their contributions to the thermal averaged annihilation cross-sections are shown to be consistent with the FermiLAT and H.E.S.S. experiments' projected upper bound on the annihilation cross-section in the $b\,\bar b$ mode. The tree-level gluon-philic and one-loop induced heavy-quark-philic DM-nucleon direct-detection cross-sections are analysed. The non-observation of any excess over expected background in the case of recoiled Xe-nucleus events for spin-independent DM-nucleus scattering in XENON-1T sets the upper limits on the eighteen Wilson coefficients. Our analysis validates the real DM candidates for the large range of accessible mass spectrum below 2 TeV for all but one interaction induced by the said operators.

hep-ph

Spin-$0^\pm$ portal induced Dark Matter

Standard model (SM) spin-zero singlets are constrained through their di-Bosonic decay channels via an effective coupling induced by a vector-like quark (VLQ) loop at the LHC for $\sqrt{s}$ = 13 TeV. These spin-zero resonances are then considered as portals for scalar, vector or fermionic dark matter particle interactions with SM gauge bosons. We find that the model is validated with respect to the observations from LHC data and from cosmology, indirect and direct detection experiments for an appreciable range of scalar, vector and fermionic DM masses greater than 300 GeV and VLQ masses $\ge$ 400 GeV, corresponding to the three choice of portal masses 270 GeV, 500 GeV and 750 GeV respectively.

hep-ph

A Survey of Digital Watermarking Techniques and its Applications

Digital media is the need of a people now a day as the alternate of paper media.As the technology grown up digital media required protection while transferring through internet or others mediums.Watermarking techniques have been developed to fulfill this requirement.This paper aims to provide a detailed survey of all watermarking techniques specially focuses on image watermarking types and its applications in today world.

cs.MM

Analysis of Attacks on Hybrid DWT-DCT Algorithm for Digital Image Watermarking With MATLAB

Watermarking algorithms needs properties of robustness and perceptibility. But these properties are affected by different -2 types of attacks performed on watermarked images. The goal of performing attacks is destroy the information of watermark hidden in the watermarked image. So every Algorithms should be previously tested by developers so that it would not affected by attacks.

cs.CR