735789
Final results of magnetic monopole searches with the MACRO experiment
We present the final results obtained by the MACRO experiment in the search for GUT magnetic monopoles in the penetrating cosmic radiation, for the range \(4\times 10^{-5}< \beta < 1\). Several searches with all the MACRO sub-detectors (i.e. scintillation counters, limited streamer tubes and nuclear track detectors) were performed, both in stand alone and combined ways. No candidates were detected and a 90% Confidence Level (C.L.) upper limit to the local magnetic monopole flux was set at the level of \(1.4\times 10^{-16}\) cm-2 s-1 sr-1. This result is the first experimental limit obtained in direct searches which is well below the Parker bound in the whole \(\beta\) range in which GUT magnetic monopoles are expected.
8791824
Detection of high energy cosmic rays with the resonant gravitational wave detectors NAUTILUS and EXPLORER
Abstract The cryogenic resonant gravitational wave detectors NAUTILUS and EXPLORER, made of an aluminum alloy bar, can detect cosmic ray showers. At temperatures above 1 K, when the material is in the normal-conducting state, the measured signals are in good agreement with the expected values based on the cosmic rays data and on the thermo-acoustic model. When NAUTILUS was operated at the temperature of 0.14 K, in superconductive state, large signals produced by cosmic ray interactions, more energetic than expected, were recorded. The NAUTILUS data in this case are in agreement with the measurements done by a dedicated experiment on a particle beam. The biggest recorded event was in EXPLORER and excited the first longitudinal mode to a vibrational energy of ∼670 K, corresponding to ∼360 TeV absorbed in the bar. Cosmic rays can be an important background in future acoustic detectors of improved sensitivity. At present, they represent a useful tool to verify the gravitational wave antenna performance.
122862116
EXPLORER and NAUTILUS gravitational wave detectors: a status report
The two cryogenic resonant bar detectors of the ROG Collaboration, EXPLORER and NAUTILUS, have been taking data continuously with a high duty cycle for several years. We report here on the status of recent analysis of the data and in particular on the results of the burst searches in the year 2004.
59335104
RAP: thermoacoustic detection at the DAΦNE beam test facility
In order to investigate the anomalous response at ultra-low temperatures of the resonant-mass gravitational wave detector NAUTILUS, the RAP experiment has been planned to measure the vibrations in a small cylindrical aluminium bar when hit by 105 510 MeV electrons from the DAΦNE beam test facility, corresponding to the energies released by typical extensive air showers. The results of the measurement at low temperature and in the superconducting regime are crucial to understand the interaction of ionizing particles with bulk superconductors and to confirm the results on the thermoacoustic model of the past experiments. The first run of RAP experiment is scheduled for the end of June. The scheme of operation and the preliminary results at room temperature will be presented.
118375535
Comparison of muon and neutrino times from decays of mesons in the atmosphere
We propose a test to compare the speed of muons and muon neutrinos produced in the same bundles in the atmosphere. By comparing the arrival times of primary muons and muons induced by neutrinos, experiments such as Super-Kamiokande, IceCube and ANTARES could verify recent hints on the possibility that neutrinos have a velocity larger than the speed of light. For smaller detectors such as MINOS and OPERA, where it may be challenging to recognize downgoing muons induced by neutrinos inside the active volume, another measurement may be possible thanks to the ns-time resolution. The arrival times of muons in a bundle produced by one cosmic ray interaction in the atmosphere should return a value compatible with the time resolution, while if neutrinos have larger velocity than muons some of the muons may arrive slightly earlier in a bundle of particles than others.
121773371
Muon tracking underground
SummaryWe present a new design of plastic streamer tubes, optimized to match the experimental requirements of large-area under-ground detectors, where muon identification is needed with good angular resolution.RiassuntoSi descrive un nuovo disegno di tubi a streamer in plastica, ottimizzati per le esigenze sperimentali di apparati sotterranei di grande area, dove si richiede l'identificazione di muoni con buona risoluzione angolare.РзюмеПредлагается новый проект пластических стримерных трубок, оптимально согласованный с эксперименталыми требованиями подэемных детекторов на большой площади, когда небходима идентификция мюоноб с высокими угловым разрешением.
124381391
Track Reconstruction with Cosmic Ray Data at the Tracker Integration Facility
The subsystems of the CMS silicon strip tracker were integrated and commissioned at the Tracker Integration Facility (TIF) in the period from November 2006 to July 2007. As part of the commissioning, large samples of cosmic ray data were recorded under various running conditions in the absence of a magnetic field. Cosmic rays detected by scintillation counters were used to trigger the readout of up to 15 % of the final silicon strip detector, and over 4.7 million events were recorded. This document describes the cosmic track reconstruction and presents results on the performance of track and hit reconstruction as from dedicated analyses. t) Now at University of California, Los Angeles, California, USA
116966286
Search for a $W^\prime$ or Techni-$\rho$ Decaying into $WZ$ in $pp$ Collisions at $\sqrt{s}=7$ TeV
A search is performed in pp collisions at √s=7  TeV for exotic particles decaying via WZ to final states with electrons and muons. The data sample corresponds to an integrated luminosity of approximately 5  fb^(-1). No significant excess is observed in the data above the expected standard model background. Upper bounds at 95% confidence level are set on the production cross section of the W′ boson described by the sequential standard model and on the W′ WZ coupling. W′ bosons with masses below 1143 GeV are excluded. Limits are also set in the context of low-scale technicolor models, under a range of assumptions concerning the model parameters.
54755032
Spatial resolution in Micromegas detectors
The performance of a telescope of Micromegas detectors has been studied in a pion beam at the CERN PS. With a gas "lling of CF and 20% isobutane and with a strip pitch of 100m an accuracyof 14 $3m on the spatial resolution has been measured at normal incidence. A simulation demonstrates that the resolution is limited bythe size of the holes of the mesh of the detector and could be reduced to 11m in the same conditions with smaller holes. Even further improvement down to 8.5m is feasible for the same gas with an optimized 75m strip pitch. 2001 Elsevier Science B.V. All rights reserved.
9430917
Likelihood functions for supersymmetric observables in frequentist analyses of the CMSSM and NUHM1
On the basis of frequentist analyses of experimental constraints from electroweak precision data, (g−2)μ, B-physics and cosmological data, we investigate the parameters of the constrained MSSM (CMSSM) with universal soft supersymmetry-breaking mass parameters, and a model with common non-universal Higgs masses (NUHM1). We present χ2 likelihood functions for the masses of supersymmetric particles and Higgs bosons, as well as BR(b→sγ), BR(Bs→μ+μ−) and the spin-independent dark-matter scattering cross section, σpSI. In the CMSSM we find preferences for sparticle masses that are relatively light. In the NUHM1 the best-fit values for many sparticle masses are even slightly smaller, but with greater uncertainties. The likelihood functions for most sparticle masses are cut off sharply at small masses, in particular by the LEP Higgs mass constraint. Both in the CMSSM and the NUHM1, the coannihilation region is favored over the focus-point region at about the 3-σ level, largely but not exclusively because of (g−2)μ. Many sparticle masses are highly correlated in both the CMSSM and NUHM1, and most of the regions preferred at the 95% C.L. are accessible to early LHC running, though high-luminosity running would be needed to cover the regions allowed at the 3-σ levels. Some slepton and chargino/neutralino masses should be in reach at the ILC. The masses of the heavier Higgs bosons should be accessible at the LHC and the ILC in portions of the preferred regions in the (MA,tan β) plane. In the CMSSM, the likelihood function for BR(Bs→μ+μ−) is peaked close to the Standard Model value, but much larger values are possible in the NUHM1. We find that values of σpSI>10−10 pb are preferred in both the CMSSM and the NUHM1. We study the effects of dropping the (g−2)μ, BR(b→sγ), Ωχh2 and Mh constraints, demonstrating that they are not in tension with the other constraints.
5543619
Tracking and Alignment in the CMS Detector
This Report summarises the alignment strategy of the CMS detector. Track reconstruction in the silicon tracker and muon chambers is briefly described. We then present the different sources of alignment information, in particular alignment algorithms using reconstructed tracks.