Search results for "Standard Model"
showing 10 items of 1206 documents
Search for new physics using QUAERO: A general interface to D0 Event data
2001
We describe Quaero, a method that i) enables the automatic optimization of searches for physics beyond the standard model, and ii) provides a mechanism for making high energy collider data generally available. We apply Quaero to searches for standard model WW, ZZ, and ttbar production, and to searches for these objects produced through a new heavy resonance. Through this interface, we make three data sets collected by the D0 experiment at sqrt(s)=1.8 TeV publicly available.
Right Handed Sneutrino Dark Matter in Inverse and Linear seesaw scenarios
2012
We consider supersymmetric models in which the right-handed sneutrino is a viable WIMP dark matter candidate. These are either simple extensions of the Minimal Supersymmetric Standard Model or models with the addition of an extra U(1) group. All of them can explain small neutrino masses, through either the Inverse or the Linear Seesaw mechanism. We investigate the properties of the dark matter candidate naturally arising in these scenarios. We check for phenomenological bounds, such as correct relic abundance, consistency with direct detection cross section limits and laboratory constraints. Especially, we comment on limitations of the model space due to lepton flavour violating charged lep…
Associated production of weak bosons at the LHC with the ATLAS detector
2009
The study of the associated production of weak vector bosons at the LHC allows to search for New Physics through the measurement of possible deviations of the weak boson self-couplings from the expectation within the Standard Model. The sensitivity of the ATLAS experiment to Standard Model diboson (W+ W-, Wplusmn; Z0, Z0 Z0, W± γ, and Z0 γ) production in pp collisions at = 14 TeV, using final states containing electrons, muons and photons, is presented. These studies use Monte Carlo data sets with full detector simulation from the ATLAS Computer System Commissioning, which furthermore include detailed trigger information as well as effects of detector calibration and alignment corrections. …
CP-violating MSSM Higgs at Tevatron and LHC
2010
talk presented at PASCOS 2010 (Valencia) and SUSY 10 (Bonn)
Simultaneous analysis of neutrinoless double beta decay and LHC pp-cross sections: limits on the left-right mixing angle
2015
The extension of the Standard Model of electroweak interactions, to accommodate massive neutrinos and/or right-handed currents, is one of the fundamental questions to answer in the cross-field of particle and nuclear physics. The consequences of such extensions would reflect upon nuclear decays, like the very exotic nuclear double-beta-decay, as well as upon high-energy proton-proton reactions of the type performed at the LHC accelerator. In this talk we shall address this question by looking at the results reported by the ATLAS and CMS collaborations, where the excitation and decay of a heavy-mass boson may be mediated by a heavy-mass neutrino in proton-proton reactions leading to two jets…
Long-Lived Slepton in the Coannihilation Region and Measurement of Lepton Flavour Violation at LHC
2009
When the mass difference between the lightest slepton and the lightest neutralino is smaller than the tau mass, the lifetime of the lightest slepton in the constrained Minimal Supersymmetric Standard Model (MSSM) increases in many orders of magnitude with respect to typical lifetimes of other supersymmetric particles. In a general MSSM, the lifetime of the lightest slepton is inversely proportional to the square of the intergenerational mixing in the slepton mass matrices. Such a long-lived slepton would produce a distinctive signature at LHC and a measurement of its lifetime would be relatively simple. Therefore, the long-lived slepton scenario offers an excellent opportunity to study lept…
Implications of new generations on neutrino masses
2011
We explore the possible implications that new families, that are being searched for at the LHC, would have on neutrino masses. In particular, we have explored the possibility that the smallness of the observed neutrino masses is naturally understood in a modified version of the Standard Model (SM) with complete extra generations of fermions, i.e., that have right-handed neutrinos, in which neutrino masses are generated at two loops. With one extra family it is not possible to fit the observed spectrum of masses and mixings. However, the radiative mass generated provides an important constraint in these kind of models, so the neutrino masses do not exceed their cosmological bound. Within the…
New limits on neutrino magnetic moments from low energy neutrino data
2016
Here we give a brief review on the current bounds on the general Majorana transition neutrino magnetic moments (TNMM) which cover also the conventional neutrino magnetic moments (NMM). Leptonic CP phases play a key role in constraining TNMMs. While the Borexino experiment is the most sensitive to the TNMM magnitudes, one needs complementary information from reactor and accelerator experiments in order to probe the complex CP phases.
An A4 model for neutrinos
2010
Proceedings of PASCOS 2010, the 16th International Symposium on Particles, Strings and Cosmology. 19 - 23 July 2010. Valencia (Spain)
Search for sterile neutrinos at radioactive ion beam facilities
2013
We propose applications of Radioactive Ion Beam facilities to investigate physics beyond the Standard Model. In particular, we focus upon the search for sterile neutrinos by means of a low energy beta-beam with a Lorentz boost factor of 1. In the considered setup, collected 8Li radioactive ions are sent inside a 4? detector filled with a liquid scintillator, with inverse-beta decay as neutrino detection channel. We provide exclusion curves for the sterile neutrino mixing parameters, based upon the 3+1 formalism, depending upon the achievable ion intensity. The proposed experiment represents a possible alternative to clarify the current anomalies observed in neutrino experiments.