Related papers: Mass Determination in SUSY-like Events with Missin…
In the collider phenomenology of extensions of the Standard Model with partner particles, cascade decays occur generically, and they can be challenging to discover when the spectrum of new particles is compressed and the signal cross…
Supersymmetry (SUSY) proposed as an elementary symmetry for physics beyond the Standard Model has found important applications in various areas outside high-energy physics. Here, we systematically implement supersymmetric quantum mechanics…
The four-lepton final state, rare in standard model processes, is an attractive channel for new physics searches at the LHC. In supersymmetry (SUSY), charged leptons may arise from R-Parity conserving (RPC) cascade decays of SUSY particles…
Three-step cascade decays into two invisible particles and two visible particles via two intermediate on-shell particles develop cusped peak structures in several kinematic distributions. We study the basic properties of the cusps and…
The measurements of kinematical endpoints, in cascade decays of supersymmetric particles, in principle allow for a determination of the masses of the unstable particles. However, in this procedure ambiguities often arise. We here illustrate…
After successful discovery of the Higgs boson, the Large Hadron Collider (LHC) would confront the major challenge in searching for new physics and new particles. Any such observation necessitates the determination of mass and other quantum…
New particles $\phi$ in the MeV-GeV range produced at colliders and escaping detection can be searched for at operating $b-$ and $\tau-$factories such as Belle II. A typical search topology involves pair-produced $\tau$s (or mesons), one of…
Based on the idea that electromagnetism is responsible for the mass differences within isotopic multiplets, and possibly also for the whole mass of the electron, a supersymmetric gauge theoretical model based on the group $SU(2)_{L} \times…
Searches for supersymmetry (SUSY) models with a compressed mass spectrum are theoretically motivated but also pose experimental challenges. Two recent searches from the CMS Collaboration targeting leptonic final states that can originate…
We propose ways to distinguish between different mechanisms behind the collider signals of TeV-scale seesaw models for neutrino masses using kinematic endpoints of invariant mass variables. We particularly focus on two classes of such…
We present an analysis of new physics searches in $Z\,h$ with missing energy final states at the Large Hadron Collider considering $Z \to l^+ l^-$ (where $l^\pm = e^\pm, \mu^\pm$) and $h \to b\bar b$ decay modes. For this analysis we…
Fermion masses and mixing angles are studied in an SUSY $SO(10)\times \Delta (48)\times U(1)$ model with small $\tan\beta$. Thirteen parameters involving masses and mixing angles in the quark and charged lepton sector are successfully…
Three case studies are presented of slepton pair production followed by two-body or quasi-two-body decays at a muon collider. Precision mass measurements are possible using a variety of kinematic fitting methods. Standard Model and…
We propose a new method to resolve combinatorial ambiguities in hadron collider events involving two invisible particles in the final state. This method is based on the kinematic variable MT2 and on the MT2-assisted-on-shell reconstruction…
The production of a charged lepton (e/mu) pair with a large missing energy at a linear collider is discussed as a means of distinguishing the minimal supersymmetry (MSSM) scenario from that with large extra dimensions (ADD) for parameter…
We study supersymmetric (SUSY) models in which the muon $g-2$ discrepancy and the dark matter relic abundance are simultaneously explained. The muon $g-2$ discrepancy, or a 3$\sigma$ deviation between the experimental and theoretical…
Neutrinoless double beta decay ($\znbb$) induced by superparticle exchange is investigated. Such a supersymmetric (SUSY) mechanism of $\znbb$ decay arises within SUSY theories with R-parity non-conservation (\rp). We consider the minimal…
We present a search for new physics using events with two same-sign isolated leptons with/out the presence of b-jets in the final state, targetting two very different SUSY scenarios, one dominated by strong production of squarks and gluinos…
We outline a general strategy for measuring spins, couplings and mixing angles in the case of a heavy partner decay chain terminating in an invisible particle. We consider the common example of a new scalar or fermion D decaying…
We present a set of Lorentz invariant kinematic variables for reconstructing mass of semi-invisible decaying particles pair-produced at lepton colliders, $m_{\rm RC}^{\rm min}$, $m_{\rm RC}^{\rm max}$ and $m_{\rm LSP}^{\rm max}$, with…