625 research outputs found
Heavy quark studies with nuclear emulsions
Emulsions have started particle physics with the discovery of natural
radioactivity by Becquerel in 1896. The development of the ``nuclear
emulsions'' made it possible to detect tracks of single particle and to perform
detailed measurements of their interactions. The discovery of the pion in 1947
was the first, spectacular demonstration of their unique features for the
direct observation of the production and decay of short-lived particles, with
negligible or very low background. In particular, these features are now
exploited for studies of heavy quark physics in experiments where nuclear
emulsions are combined with electronic detectors and profit is taken of the
remarkable technological progress in automated analysis. In these experiments,
neutrinos provide a selective probe for specific quark flavors. Interesting
results on charm production and decay are expected in the very near future.Comment: To be published on the book for the eightieth birthday of Roberto
Salmeron, World Scientifi
Future neutrino oscillation facilities
The recent discovery that neutrinos have masses opens a wide new field of
experimentation. Accelerator-made neutrinos are essential in this program.
Ideas for future facilities include high intensity muon neutrino beams from
pion decay (`SuperBeam'), electron neutrino beams from nuclei decays (`Beta
Beam'), or muon and electron neutrino beams from muon decay (`Neutrino
Factory'), each associated with one or several options for detector systems.
Each option offers synergetic possibilities, e.g. some of the detectors can be
used for proton decay searches, while the Neutrino Factory is a first step
towards muon colliders.
A summary of the perceived virtues and shortcomings of the various options,
and a number of open questions are presented.Comment: Originally written for the CERN Strategy Grou
The inclusive reaction pp=pX at the CERN ISR
Experiments at the CERN ISR have given evidence for proton single-dissociation processes where the missing mass of the system X, measured on the proton which is observed in the reaction p + p â p + X, presents a distribution extending up to large values , in the 10 GeV range. These processes globally account for âŒ15% of the inelastic p-p cross section. Evidence for such a distinct class of inelastic phenomena is also provided by long-range rapidity correlations and clustering. The nature of these processes appears to be predominantly diffractive. The physics which emerges from ISR observations is discussed , together with a presentation of present and planned lines of experimental investigation at the ISR
Sensitivity on Earth Core and Mantle densities using Atmospheric Neutrinos
Neutrino radiography may provide an alternative tool to study the very deep
structures of the Earth. Though these measurements are unable to resolve the
fine density layer features, nevertheless the information which can be obtained
are independent and complementary to the more conventional seismic studies. The
aim of this paper is to assess how well the core and mantle averaged densities
can be reconstructed through atmospheric neutrino radiography. We find that
about a 2% sensitivity for the mantle and 5% for the core could be achieved for
a ten year data taking at an underwater km^3 Neutrino Telescope. This result
does not take into account systematics related to the details of the
experimental apparatus.Comment: 11 pages, 11 figures, accepted for publication in JCA
Stand-alone Low Power Consumption FEE and DAQ for the Readout of Silicon Photomultipliers
We developed a front end electronics (FEE) and data acquisition (DAQ) system with a low power consumption, especially intended for stand-alone applications in unattended environments without standard electricity supply. The system works autonomously thanks to dedicated algorithms that are embedded. The FEE is based on the EASIROC chip, designed for the readout of Silicon photomultipliers (SiPMs). It digitizes the amplitude of the signals and provides time information with time of flight capability. The trigger logic is programmable and physical and accidental coincidences rates can be measured. The SiPMs temperature is controlled by thermoelectric cells. Thanks to a network of temperature and humidity sensors, a real-time software sets the optimal operating point of the SiPMs depending on external conditions and if necessary halts the system to avoid damage to the electronics. The system has been used in several muon radiography experiments
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
Response to electrons and pions of the calorimeter for the CHORUS experiment
We built and tested on charged particle beams the high energy-resolution calorimeter for the CHORUS experiment, which searches for nu(mu)-nu(tau) oscillations in the CERN Wide Band Neutrino Beam. This calorimeter is longitudinally divided into three sectors: one electromagnetic and two hadronic. The first two upstream sectors are made of lead and plastic scintillating fibers in the volume ratio of 4/1, and they represent the first large scale application of this technique for combined electromagnetic and hadronic calorimetry. The third sector is made of a sandwich of lead plates and scintillator strips and complements the measurement of the hadronic energy flow. In this paper, we briefly describe the calorimeter design and we show results on its response to electrons and pions, obtained from tests performed at the CERN SPS and PS. An energy resolution of sigma(E)/E=(32.3+/-2.4)%/root E(GeV)+(1.4+/-0.7)% was achieved for pions, and sigma(E)/E=(13.8+/-0.9)%/root V(GeV)+(-0.2+/-0.4)% for electrons
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