Search

The deviations of the recent measurements of the muon magnetic moment and the $W-$boson mass from their SM predictions hint to new physics beyond the SM. In this article, we address the observed discrepancies in the $W$-boson mass and muon anomalous magnetic moment in the Inert Two Higgs Doublet Model (I2HDM) extended by a complex scalar field singlet under the SM gauge group. The model is constrained from the existing LEP data and the measurements of partial decay widths to gauge bosons at LHC. It is shown that a large subset of this constrained parameter space of the model can simultaneously accommodate the $W$-boson mass and also explain the muon $g-2$ anomaly., Comment: 15 pages, 5 figures

We investigate self-conjugate Dark Matter (DM) particles that primarily interact with standard model electroweak gauge bosons within an effective field theoretical framework. Our analysis focuses on effective contact interactions, invariant under the standard model gauge group, between Majorana fermions, and real scalar DM, with SM neutral electroweak gauge bosons. We calculate the Wilson coefficients for interaction terms up to dimension-8 and establish constraints on the theory's parameters. These constraints are derived from the observed relic density, and indirect detection observations. We discuss the potential for dark matter-nucleon scattering in direct detection experiments. Additionally, we utilize low-energy LEP data to assess sensitivity to the pair production of low-mass ($\leq$ 80 GeV) DM particles. Furthermore, we highlight the potential of the proposed International Linear Collider (ILC) in probing effective operators through the pair production of DM particles with masses $\geq$ 50 GeV in association with mono-photons., Comment: 14 pages, 8 figures

We address the observed discrepancies in the anomalous magnetic dipole moments (MDM) of the muon and electron by extending the inert two Higgs Doublet Model (2HDM) with SM gauge singlet complex scalar field and singlet Vector-like Lepton (VLL) field. We obtain the allowed parameter space constrained from the Higgs decays to gauge Bosons at LHC, LEP II data and electro-weak precision measurements. The muon and electron MDM's are then explained within a common parameter space for different sets of allowed couplings and masses of the model particles., Comment: 25 pages, 10 figures

We study the self conjugate dark matter (DM) particles interacting primarily with the standard model leptons in an effective field theoretical frame work. We consider SM gauge invariant effective contact interactions between the Majorana fermion, real scalar and a real vector DM with leptons by evaluating the Wilson coefficients appropriate for interaction terms upto dimension-8 and obtain constraints on the parameters of the theory from the observed relic density, indirect detection observations and from the DM-electron scattering cross-sections in the direct detection experiments. Low energy LEP data has been used to study sensitivity in the pair production of such low mass $\le$ 80 GeV DM particles. Pair production of DM particles of mass $\ge$ 50 GeV in association with mono-photons at the proposed ILC has rich potential to probe such effective operators., Comment: 21 pages, 10 figures. To be published in Chinese Physics C. arXiv admin note: text overlap with arXiv:1901.00192

We study the effective interactions of the fermionic, scalar and vector dark matter (DM) with leptons and neutral electroweak gauge Bosons induced by the higher dimensional effective twist-2 tensor operators. We constrain these lepto-philic, $\tau^\pm$-philic and $U(1)_Y$ gauge Boson B-philic effective interactions of DM with the visible world from the WMAP and Planck data. The thermally averaged indirect DM pair annihilation cross-section and the DM-electron direct-detection cross-section for such DM candidates are observed to be consistent with the respective experimental data. Constraining coefficients of the effective operators from the low energy LEP data for the DM $\le$ 80 GeV, we further study their sensitivities in the pair production of such DM $\ge$ 50 GeV in association with mono-photon at the proposed ILC and perform the $\chi^2$ analysis to obtain the 99.73\% C.L. acceptance contours in the $m_{\rm DM}-\Lambda_{\rm eff}$ plane from the two dimensional differential distributions of the kinematic observables. We observe that ILC has rich potential to probe the contribution of such effective operators., Comment: 24 pages and 8 figures

We present a detailed V-band photometric light curve modeling of 30 eclipsing binaries using the data from Pietrukowicz et al. (2009) collected with the European Southern Observatory Very Large Telescope (ESO VLT) of diameter 8-m. The light curve of these 30 eclipsing binaries were selected out of 148 of them available in the database on the basis of complete phase coverage, regular and smooth phased light curve shapes. Eclipsing binaries play pivotal role in the direct measurement of astronomical distances more accurately simply from their geometry of light curves. The accurate value of Hubble constant (H0) which measures the rate of expansion of the Universe heavily relies on extragalactic distance scale measurements. Classification of the selected binary stars in the sample were done, preliminarily on the basis of Fourier parameters in the a2-a4 plane and final classification was obtained from the Roche lobe geometry. Out of these 30 eclipsing binaries, only one was found to be detached binary system while the rest 29 of them belong to the contact binary systems. These contact binaries were further classified into the A-type and W-type based on their mass ratios. Since spectroscopic mass ratio measurements were not available for any of these binary stars, we determined the mass ratios through photometric light curve modeling with the aid of Wilson-Devinney code as implemented in PHOEBE. Various geometrical parameters and physical parameters of astrophysical importance viz., mass, radius and luminosity were obtained from the light curves of the selected stars., Comment: 19 pages, 6 figures, 7 tables. Accepted for publication in DU Journal of Undergraduate Research and Innovation (DUJURI) http://journals.du.ac.in/ugresearch/