We review the use of invariant mass distributions in cascade decays to measure the masses of New Physics (NP) particles in scenarios where the final NP cascade particle is invisible. We extend earlier work by exploring further the problem of multiple solutions for the masses.
$tau$ leptons emitted in cascade decays of supersymmetric particles are polarized. The polarization may be exploited to determine spin and mixing properties of the neutralinos and stau particles involved.
Beyond the Standard Model scenarios with extensions of the Higgs sector typically predict new resonances that can undergo a series of cascade decays to detectable Standard Model particles. On one hand, sensitivity to such signatures will contribute t
o the full reconstruction of the extended Higgs potential if a new physics discovery will be made. On the other hand, such cascade decays could be dominant decay channels, thus being potentially the best motivated signatures to achieve a new physics discovery in the first place. In this work, we show how the long short-term memory that is encoded in the cascade decays phenomenology can be exploited in discriminating the signal from the background, where no such information is present. In parallel, we demonstrate for theoretically motivated scenarios that such an approach provides improved sensitivity compared to more standard analyses, where only information about the signals final state kinematics is included.
We explore how the polarization of the tau leptons in the cascade decay $tilde{q}to qtildechi^0_2to qtautildetauto qtautautildechi^0_1$ can be exploited to study mixing properties of neutralinos and staus. We present details of the analysis including
experimental effects such as transverse momentum cuts for the $tautopi u$ decay mode, and show that the di-pion invariant mass distribution provides valuable information on their properties.
A method to reconstruct sleptons in cascade-decays at the FLC is presented. It is shown that experimental mass-resolutions as low as 8.7 MeV/c^2 are attainable.
We study the pattern of gluino cascade decays in a class of supersymmetric models where R-parity is spontaneously broken. The multi-lepton and same-sign dilepton rates in these models are compared with those of the Minimal Supersymmetric Standard Mod
el. We show that these rates can be substantially enhanced in models with broken R-parity.