Reconstruction of τ~1\tilde{\tau}_{1} mass at the LHC

The cascade mass reconstruction approach was used for mass reconstruction of the lightest stau produced at the LHC in the cascade decay $\tilde{g} \to \tilde{b} b \to \tilde{\chi}_{2}^{0} b b \to \tilde{\tau}_{1} \tau b b \to \tilde{\chi}_{1}^{0} \tau \tau b b$. The stau mass was reconstructed assuming that masses of gluino, bottom squark and two lightest neutralinos were reconstructed in advance. SUSY data sample sets for the SU3 model point containing 160k events each were generated which corresponded to an integrated luminosity of about $8 \rm fb^{-1}$ at 14 TeV. These events were passed through the AcerDET detector simulator, which parametrized the response of a generic LHC detector. The mass of the $\tilde{\tau}_{1}$ was reconstructed with a precision of about 20% on average.Comment: 13 pages, 4 figures, corrected Table 6 and typos, added references for section

Probing lepton flavour violation in νμ+N→τ+...\nu_{\mu} + N \to \tau + ... scattering and μ→tau\mu \to tau conversion on nucleons

We study lepton flavour-violating interactions which could result in the $\tau$-lepton production in the $\nu_{\mu}N$ scattering or in $\mu \to \tau$ conversion on nucleons at high energies. Phenomenological bounds on the strength of $\bar{\tau}\nu_{\mu}\bar{q}q^{'}$ interactions are extracted from the combined result of the NOMAD and CHORUS experiments on searching for $\nu_{\mu} - \nu_{\tau}$ oscillations. Some of these bounds supersede limits from rare decays. We also propose a ``missing energy'' type experiment searching for $\mu - \tau$ conversion on nucleons. The experiment can be performed at a present accelerator or at a future neutrino factory.Comment: 13 pages, 4 figure

Registration of atmospheric neutrinos with the Baikal neutrino telescope

We present first neutrino induced events observed with a deep underwater neutrino telescope. Data from 70 days effective life time of the BAIKAL prototype telescope NT-96 have been analyzed with two different methods. With the standard track reconstruction method, 9 clear upward muon candidates have been identified, in good agreement with 8.7 events expected from Monte Carlo calculations for atmospheric neutrinos. The second analysis is tailored to muons coming from close to the opposite zenith. It yields 4 events, compared to 3.5 from Monte Carlo expectations. From this we derive a 90 % upper flux limit of 1.1 * 10^-13 cm^-2 sec^-1 for muons in excess of those expected from atmospheric neutrinos with zenith angle > 150 degrees and energy > 10GeV.Comment: 20 pages, 11 figure

Measuring diffuse neutrino fluxes with IceCube

In this paper the sensitivity of a future kilometer-sized neutrino detector to detect and measure the diffuse flux of high energy neutrinos is evaluated. Event rates in established detection channels, such as muon events from charged current muon neutrino interactions or cascade events from electron neutrino and tau neutrino interactions, are calculated using a detailed Monte Carlo simulation. Neutrino fluxes as expected from prompt charm decay in the atmosphere or from astrophysical sources such as Active Galactic Nuclei are modeled assuming power laws. The ability to measure the normalization and slope of these spectra is then analyzed. It is found that the cascade channel generally has a high sensitivity for the detection and characterization of the diffuse flux, when compared to what is expected for the upgoing- and downgoing-muon channels. A flux at the level of the Waxman-Bahcall upper bound should be detectable in all channels separately while a combination of the information of the different channels will allow detection of a flux more than one order of magnitude lower. Neutrinos from the prompt decay of charmed mesons in the atmosphere should be detectable in future measurements for all but the lowest predictions.Comment: 12 pages, 3 figure

Status of the Lake Baikal Experiment

We review the present status of the Baikal Underwater Neutrino Experiment and report on neutrino events recorded with the detector stages NT-36 and NT-96.Comment: 5 pages, 4 PostScript figures, uses here.sty and mine.sty, submitted to the Proc. of 5th Int. Workshop on Topics in Astroparticle and Underground Physics (LNGS INFN, Assergi, September 7-11, 1997

The Lake Baikal neutrino experiment

We rewiew the present status of the Baikal Neutrino Project and present the results of a search for high energy neutrinos with the detector intermediate stage NT-96.Comment: 3 pages, 2 figures, to appear in the Proceedings of Sixth International Workshop on Topics in Astroparticle and Underground Physics (TAUP99), September 6-10, 1999, Pais, Franc

Hunt for new phenomena using large jet multiplicities and missing transverse momentum with ATLAS in 4.7 fb−1 of s√=7TeV proton-proton collisions

Results are presented of a search for new particles decaying to large numbers of jets in association with missing transverse momentum, using 4.7 fb−1 of pp collision data at s√=7TeV collected by the ATLAS experiment at the Large Hadron Collider in 2011. The event selection requires missing transverse momentum, no isolated electrons or muons, and from ≥6 to ≥9 jets. No evidence is found for physics beyond the Standard Model. The results are interpreted in the context of a MSUGRA/CMSSM supersymmetric model, where, for large universal scalar mass m 0, gluino masses smaller than 840 GeV are excluded at the 95% confidence level, extending previously published limits. Within a simplified model containing only a gluino octet and a neutralino, gluino masses smaller than 870 GeV are similarly excluded for neutralino masses below 100 GeV

Expected Performance of the ATLAS Experiment - Detector, Trigger and Physics

A detailed study is presented of the expected performance of the ATLAS detector. The reconstruction of tracks, leptons, photons, missing energy and jets is investigated, together with the performance of b-tagging and the trigger. The physics potential for a variety of interesting physics processes, within the Standard Model and beyond, is examined. The study comprises a series of notes based on simulations of the detector and physics processes, with particular emphasis given to the data expected from the first years of operation of the LHC at CERN