619 research outputs found
A search for energy deposition by neutrinos in matter
An exploratory search for an anomalous energy deposition by neutrinos in a
germanium crystal was performed in the CERN high energy neutrino beam. No
signal was found and a limit is set at a level of about 10^-12 of the normal
dE/dx for a minimum ionizing particle.Comment: 7 pages, 3 figures Paper accepted by Physics Letters B on March 4th,
199
SuperCDMS: Recent results on low-mass WIMPs
We present the rst search for weakly interacting massive particles (WIMPs) using the back- ground rejection capabilities of SuperCDMS 1. A blind analysis of data from an exposure of 577 kg-days leads to an upper limit on the spin-independent WIMP-nucleon cross section of 1:2 10????42 cm2 at 8 GeV. This result probes new parameter space for WIMP-nucleon scat- tering cross section for light WIMPs with masses < 6 GeV/c2 and is in tension with WIMP interpretations of recent experiments
MEMPHYS:A large scale water Cerenkov detector at Fr\'ejus
A water \v{C}erenkov detector project, of megaton scale, to be installed in
the Fr\'ejus underground site and dedicated to nucleon decay, neutrinos from
supernovae, solar and atmospheric neutrinos, as well as neutrinos from a
super-beam and/or a beta-beam coming from CERN, is presented and compared with
competitor projects in Japan and in the USA. The performances of the European
project are discussed, including the possibility to measure the mixing angle
and the CP-violating phase .Comment: 1+33 pages, 14 figures, Expression of Interest of MEMPHYS projec
The Drift Chambers Of The Nomad Experiment
We present a detailed description of the drift chambers used as an active
target and a tracking device in the NOMAD experiment at CERN. The main
characteristics of these chambers are a large area, a self supporting structure
made of light composite materials and a low cost. A spatial resolution of 150
microns has been achieved with a single hit efficiency of 97%.Comment: 42 pages, 26 figure
Radioscience simulations in General Relativity and in alternative theories of gravity
In this communication, we focus on the possibility to test GR with
radioscience experiments. We present a new software that in a first step
simulates the Range/Doppler signals directly from the space time metric (thus
in GR and in alternative theories of gravity). In a second step, a
least-squares fit of the involved parameters is performed in GR. This software
allows one to get the order of magnitude and the signature of the modifications
induced by an alternative theory of gravity on radioscience signals. As
examples, we present some simulations for the Cassini mission in
Post-Einsteinian gravity and with the MOND External Field Effect.Comment: 4 pages; Proceedings of "Les Rencontres de Moriond 2011 - Gravitation
session
Comparison of large-angle production of charged pions with incident protons on cylindrical long and short targets
The HARP collaboration has presented measurements of the double-differential
pi+/pi- production cross-section in the range of momentum 100 MeV/c <= p 800
MeV/c and angle 0.35 rad <= theta <= 2.15 rad with proton beams hitting thin
nuclear targets. In many applications the extrapolation to long targets is
necessary. In this paper the analysis of data taken with long (one interaction
length) solid cylindrical targets made of carbon, tantalum and lead is
presented. The data were taken with the large acceptance HARP detector in the
T9 beam line of the CERN PS. The secondary pions were produced by beams of
protons with momenta 5 GeV/c, 8 GeV/c and 12 GeV/c. The tracking and
identification of the produced particles were performed using a small-radius
cylindrical time projection chamber (TPC) placed inside a solenoidal magnet.
Incident protons were identified by an elaborate system of beam detectors.
Results are obtained for the double-differential yields per target nucleon d2
sigma / dp dtheta. The measurements are compared with predictions of the MARS
and GEANT4 Monte Carlo simulations.Comment: 43 pages, 20 figure
Absolute Momentum Calibration of the HARP TPC
In the HARP experiment the large-angle spectrometer is using a cylindrical
TPC as main tracking and particle identification detector. The momentum scale
of reconstructed tracks in the TPC is the most important systematic error for
the majority of kinematic bins used for the HARP measurements of the
double-differential production cross-section of charged pions in proton
interactions on nuclear targets at large angle. The HARP TPC operated with a
number of hardware shortfalls and operational mistakes. Thus it was important
to control and characterize its momentum calibration. While it was not possible
to enter a direct particle beam into the sensitive volume of the TPC to
calibrate the detector, a set of physical processes and detector properties
were exploited to achieve a precise calibration of the apparatus. In the
following we recall the main issues concerning the momentum measurement in the
HARP TPC, and describe the cross-checks made to validate the momentum scale. As
a conclusion, this analysis demonstrates that the measurement of momentum is
correct within the published precision of 3%.Comment: To be published by JINS
Dynamics in nonlocal linear models in the Friedmann-Robertson-Walker metric
A general class of cosmological models driven by a nonlocal scalar field
inspired by the string field theory is studied. Using the fact that the
considering linear nonlocal model is equivalent to an infinite number of local
models we have found an exact special solution of the nonlocal Friedmann
equations. This solution describes a monotonically increasing Universe with the
phantom dark energy.Comment: 18 pages, 3 figures, a few misprints in Section 5 have been correcte
The LAGUNA design study- towards giant liquid based underground detectors for neutrino physics and astrophysics and proton decay searches
The feasibility of a next generation neutrino observatory in Europe is being
considered within the LAGUNA design study. To accommodate giant neutrino
detectors and shield them from cosmic rays, a new very large underground
infrastructure is required. Seven potential candidate sites in different parts
of Europe and at several distances from CERN are being studied: Boulby (UK),
Canfranc (Spain), Fr\'ejus (France/Italy), Pyh\"asalmi (Finland),
Polkowice-Sieroszowice (Poland), Slanic (Romania) and Umbria (Italy). The
design study aims at the comprehensive and coordinated technical assessment of
each site, at a coherent cost estimation, and at a prioritization of the sites
within the summer 2010.Comment: 5 pages, contribution to the Workshop "European Strategy for Future
Neutrino Physics", CERN, Oct. 200
Beams for European Neutrino Experiments (BENE): Midterm scientific report
The activities of BENE during 2004 and 2005 are reviewed. Neutrino oscillation experiments at accelerators offer the richest possibilities of precision studies of neutrino mixing and mass differences, with the potential of important discoveries including leptonic CP or T violation. Two main options for a major initiative have been studied: 1) a high-energy Neutrino Factory coupled to a large dense magnetized detector; 2) a lower energy betabeam and conventional superbeam, coupled to a very large low-density, non-magnetic, detector. Both offer signi cant scienti c breakthroughs over other planned facilities. Much remains to be done to optimize and establish the cost, performance, and feasibility of either solution so as to allow comparison and decision. The proposal of a FP7 Design Study of a Neutrino Facility to be completed by the end of the decade is being prepared. Its success will require strong support and engagement at CERN and other European laboratories and funding agencies. International contributors are already engaged in the framework of an international scoping study. The recommendations and milestones proposed by BENE towards a complete conceptual design are summarized
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