Related papers: Exploring Background Contributions in $H \to Z \ga…
We perform a general analysis of new physics interpretations of the recent ATLAS diboson excesses over Standard Model expectations in LHC Run I collisions. Firstly, we estimate a likelihood function for the true signal in the $WW$, $WZ$,…
By borrowing the results from a Large Hadron Collider (LHC) analysis performed with $36.1~\text{fb}^{-1}$ of Run 2 data intended to search for $A$ production followed by $ZH$ decay in turn yielding $l^+l^-b\bar b$ ($l=e,\mu$) final states…
The phenomenology of the low scale U(1)_{B-L} extension of the standard model and its implications at LHC is presented. In this model, an extra gauge boson corresponding to B-L gauge symmetry and an extra SM singlet scalar (heavy Higgs) are…
We study the enhancement of the branching ratios of the decays $h \to \gamma \gamma, \, \gamma Z$ in the Two Higgs Doublet Model Type III, assuming a four-zero Yukawa Texture and a general Higgs potential. We show that these processes are…
A search for charged lepton flavour violation in $\tau \to 3\mu$ decays is performed in $pp$ collisions at a centre-of-mass energy of 13 TeV using ATLAS data collected between 2016 and 2018, corresponding to an integrated luminosity of 137…
The most recent searches by the ATLAS and CMS Collaborations in final states with soft leptons and missing transverse energy show mild excesses predominantly associated with dilepton invariant masses of about 10-20 GeV, which can result…
The decay $K_L \to \gamma \nu \bar{\nu}$ is analyzed within the standard model. Short-distance contributions are found to dominate, yielding a branching ratio of $\sim 0.7 \times 10^{-11}$. We examine the possibility that non-standard model…
We consider implications of the diphoton excess recently observed at the LHC on the anomalous magnetic dipole moment of the muon $(g-2)_\mu = 2 a_\mu$, hypothesizing that the possible 750 GeV resonance is a (pseudo)scalar particle. The…
We have searched for the 3.55 keV line from sterile neutrino decay using 3.1 megaseconds of RXTE cluster data. A 2.5$\sigma$ excess of emission over a thermal model is found over the energy span of the 3.55 keV line in the combined spectra…
A numerical calculation of properties of finite absorbers and of intergalactic medium based on photoionization equilibrium is performed to confront alternative UV sources in addition to quasars. It is seen that a spectrum including a large…
In a recent work, we emphasized that an excess in tri-lepton events plus missing energy observed by the ATLAS experiment at the LHC could be interpreted as a signal of low energy supersymmetry. In such a scenario the lightest neutralino…
Searches for a charged Higgs boson ($H^\pm$) decaying to a charm quark and a bottom quark ($H^\pm \to cb$) have been carried out at the Large Hadron Collider (LHC) in the decay of top quarks ($t\to H^\pm b$). In a recent search by the ATLAS…
We discuss a possibility to explain the excess of $h\to\mu\tau$ at one-loop level. We introduce three generation of vector-like lepton doublet $L'$ and two singlet scalars $S_{1,2}$ which are odd under $Z_2$, while all the standard model…
Inelastic beam-gas collisions at the Large Hadron Collider (LHC), within a few hundred metres of the ATLAS experiment, are known to give the dominant contribution to beam backgrounds. These are monitored by ATLAS with a dedicated Beam…
We first show that the new WMAP 3 year data confirm the detection by Myers et al 2004 of an extended SZ signal centred on 606 Abell (ACO) clusters with richness class, R>1. Our results also show SZ decrements around APM and 2MASS groups at…
It is expounded the approach to the Z\to\gamma\Psi and Z\to\gamma\Upsilon decay study, based on the sum rules for the Z\to c\bar c\to\gamma\gamma^{\ast} and Z\to b\bar b\to\gamma\gamma^{\ast} amplitudes and their derivatives. The branching…
We present new integral-field spectroscopy in the outskirts of two nearby, edge-on, late-type galaxies to search for the H-alpha emission that is expected from the exposure of their hydrogen gas to the metagalactic ultraviolet background…
We report a remarkable over-density of high-redshift submillimetre galaxies (SMG), 4-7 times the background, around a statistically complete sample of twelve 250-micron selected galaxies at z=0.35, which were targeted by ALMA in a study of…
The ATLAS collaboration (and also CMS) has recently reported an excess over Standard Model expectations for gauge boson pair production in the invariant mass region $1.8-2.2$ TeV. In the light of these results, we argue that such signal…
We consider an extension of the lepto-specific 2HDM with an extra singlet $S$ as a dark matter candidate. Taking into account theoretical and experimental constraints, we investigate the possibility to address both the $\gamma$-ray excess…