Related papers: Allowed slepton intergenerational mixing in light …
We consider SUSY extensions of the standard model where the gravitino is the dark-matter particle and the stau is long lived. If there is a significant mass gap with squarks and gluinos, the staus produced at hadron colliders tend to be…
We present new constraints on the mass $m_{\nu_\tau}$ of the tau neutrino and its mixing with a fourth generation neutrino. From an analysis of the partial widths of tau lepton decays we obtain the following bounds at the 90% confidence…
The $^6$Li abundance observed in metal poor halo stars appears to exhibit a plateau as a function of metallicity similar to that for $^7$Li, suggesting a big bang origin. However, the inferred primordial abundance of $^6$Li is $\sim$1000…
We show that the large mixing between $\nu_\mu$ and $\nu_\tau$ observed by the SuperKamiokande collaboration is a quite natural prediction in a large class of seesaw models. This large mixing is basically due to the unparallel family…
We consider the effects of uncertainties in nuclear reaction rates on the cosmological constraints on the decays of unstable particles during or after Big-Bang nucleosynthesis (BBN). We identify the nuclear reactions due to non-thermal…
Supersymmetry (SUSY) with bilinearly broken R parity (bRPV) offers an attractive possibility to explain the origin of neutrino masses and mixings. In such scenarios, the study of neutralino decays at colliders gives access to neutrino…
We compute O(alpha_s^2) QCD corrections to the lepton invariant mass spectrum in the decay b --> u l nu_l, relevant for the determination of the CKM matrix element |V_{ub}|. Our method can also be used to evaluate moments of the lepton…
We analyze the accelerator constraints on the parameter space of the Minimal Supersymmetric extension of the Standard Model, comparing those now available from LEP II and anticipating the likely sensitivity of Tevatron Run II. The most…
We show how the spectrum of the minimal anomaly-mediated supersymmetry breaking model can be constrained from the condition that the electroweak symmetry breaking minimum of the scalar potential is the deepest point in the field space.…
In light of current constraints from supersymmetry (SUSY) searches within the LHC, as well as findings from direct dark matter detection experiments such as LUX-ZEPLIN (LZ), we revisit the three-family Pati-Salam model derived from…
A search for compositeness of electrons and muons is presented using a data sample of proton-proton collisions at a center-of-mass energy of sqrt(s) = 8 TeV collected with the CMS detector at the LHC and corresponding to an integrated…
Residual late-time dark matter particle annihilations during and after Big Bang Nucleosynthesis (BBN) may alter the predicted cosmological abundances of the light elements. Within the constrained minimal supersymmetric extension of the…
Bilinear R-parity violating supersymmetric model is a viable model which can explain the smallness of neutrino masses and the mixing pattern in the lepton sector. In this model, there is a common set of parameters which determine the…
We discuss Big Bang Nucleosynthesis constraints on maximal $\nu_\mu\leftrightarrow\nu_s$ mixing. Vacuum $\nu_\mu\leftrightarrow\nu_s$ oscillation has been proposed as one possible explanation of the Super Kamiokande atmospheric neutrino…
Results are presented of a search for compositeness in electrons and muons using a data sample of pp collisions at a center-of-mass energy sqrt(s) = 7 TeV collected with the CMS detector at the LHC and corresponding to an integrated…
Searches for charginos, neutralinos and sleptons at LEP2 centre-of-mass energies from 130 GeV to 189 GeV have been used to set lower limits on the mass of the Lightest Supersymmetric Particle and other supersymmetric particles within the…
Recently, the MiniBooNE experiment at Fermilab has updated the results with increased data and reported an excess of $560.6 \pm 119.6$ electronlike events ($4.7\sigma$) in the neutrino operation mode. In this paper, we propose a scenario to…
We propose an $SU(3)_C\times SU(2)_L\times U(1)_{Y}\times U(1)_{B-L}$ model, in which the neutrino masses and mixings can be generated via Type-I seesaw mechanism after $U(1)_{B-L}$ breaking. A light mediator emerges and enables…
We calculate cross sections and asymmetries for slepton pair production through neutral and charged electroweak currents in polarized hadron collisions for general slepton masses and including mixing of the left- and right-handed…
We focus on the use of a mu-tau interchange symmetry to explain features of lepton mixing, especially maximal atmospheric neutrino mixing. We review two models which achieve this goal and are based on the seesaw mechanism and on the soft…