123899161
NEUTRINOS AND MUONS IN AREA 1.
38997255
Prototype detector for ultrahigh energy neutrino detection
Abstract Necessary technical experience is being gained from successful construction and deployment of current prototype detectors to search for UHE neutrinos in Antarctica, Lake Baikal in Russia, and the Mediterranean. The prototype detectors have also the important central purpose of determining whether or not UHE neutrinos do in fact exist in nature by observation of at least a few UHE neutrino-induced leptons with properties that are not consistent with expected backgrounds. We discuss here the criteria for a prototype detector to accomplish that purpose in a convincing way even if the UHE neutrino flux is substantially lower than predicted at present.
118973535
Some Recent Advances in Neutrino Physics
One answer to questions concerning the subject matter of elementary particle physics and its position within the physical sciences is that particle physics is the study of creation. To justify this idea, at least in part, consider the “big bang” model of creation of the universe. In that model the primeval fireball involved very high temperatures, estimated to be greater than 1011 degrees Kelvin (°K), which is to be compared with the interior temperature of the sun at about 107 degrees Kelvin. We believe the sun to be a nuclear furnace, generating its energy by individual nuclear interactions in the million electron volt (MeV) energy range. In the “big bang” the energies involved in the individual particle interactions would have been more than 104 times larger than in the sun, and thus in the tens of giga-electron volts (GeV). This is precisely the energy region of present-day high energy or elementary particle physics laboratory experiments. In this sense, then, laboratory experiments that study, even indirectly, lepton-lepton scattering or quark-quark interactions are revisiting creation.
122124216
Neutrino oscillations and the number of neutrino types
A brief treatment of neutrino oscillations, generalized to an arbitrary number of neutrino types, is given as the basis for design of a feasible experiment to search for neutrino oscillations using the neutrino beam produced at a high-energy proton accelerator.
121246612
Scaling-variable distributions in high-energy inelastic neutrino interactions
118712243
Comments on the letter «Limits on the electromagnetic production of heavy leptons»
122239911
Maximumvs. Critical temperature in a superfluid approach to strong interactions
18649329
Generation of single-mode intelligent states and an analytic approach to their quantum statistical properties
We discuss a scheme for generation of single-mode photon states associated with the two-photon realization of the SU(1,1) algebra. This scheme is based on the process of non-degenerate down-conversion with the signal prepared initially in the squeezed vacuum state and with a measurement of the photon number in one of the output modes. We focus on the generation and properties of single-mode SU(1,1) intelligent states which minimize the uncertainty relations for Hermitian generators of the group. Properties of the intelligent states are studied by using a `weak' extension of the analytic representation in the unit disc. Then we are able to obtain exact analytical expressions for expectation values describing quantum statistical properties of the SU(1,1) intelligent states. Attention is mainly devoted to the study of photon statistics and linear and quadratic squeezing.
119280331
Calorimeter-Based Triggers at the ATLAS Detector for Searches for Supersymmetry in Zero-Lepton Final States
This thesis consists of three closely related parts. An analysis of data recorded by the ATLAS detector in 2010 in proton-proton collisions at a center-of-mass energy of 7 TeV with an integrated luminosity of 33.4 pb-1 is performed, searching for supersymmetric final states containing jets and missing transverse energy and no electrons or muons (zero-lepton channel). No excess over the Standard Model background expectation is observed. Using the CLs and PLR methods, exclusion limits are set in a minimal supergravity model with tan β = 3, A0 = 0 GeV and μ > 0 and in a simplified supergravity model. These considerably extend the excluded parameter ranges from earlier experiments. The analysis validates the official analysis carried out within the ATLAS Supersymmetry group and additionally takes into account the uncertainty from pile-up effects.The rates and efficiencies of triggers based on combined signatures with jets plus missing transverse energy in ATLAS are studied, which are the primary triggers for the search for Supersymmetry in the zero-lepton channel. Methods to measure the efficiencies on data are tested and optimized to obtain sufficient statistics. For the measurement of the efficiencies in data collected in 2010 and 2011, the bootstrap method is applied to correct for the sample trigger bias. Different sample triggers based on jets and missing transverse energy are compared and their efficiencies are measured. A reweighting approach is studied and used to correct for the bias from the propagation of the uncertainties in the bootstrap method. The resulting efficiency estimates for the primary triggers allow to determine the onset of the plateau of the two-dimensional turn-on curves and are input to the official analyses in the ATLAS Supersymmetry group in 2010 and 2011.A universal model is developed to describe the contribution of fake missing transverse energy from resolution effects to the rates of missing transverse energy triggers as function of the level of in-time pile-up, i.e. the number of concurrent proton-proton interactions. The input parameters to tune the model to the properties of the ATLAS triggers are determined, and the model predictions are compared to measurements of trigger rates in ATLAS. Good agreement is found for missing transverse energy triggers with low thresholds for which the rates are dominated by resolution effects, whereas the rates for higher thresholds are underestimated due to additional sources of fake and real missing transverse energy which are not incorporated in the model.
8636737
The universal sampling ADC readout system of the COMPASS experiment
The COMPASS experiment (COmpact Muon Proton Apparatus for Structure and Spectroscopy) is a fixed target experiment located at the CERN Super Proton Synchrotron. The physics program is focused on the study of hadron structure and hadron spectroscopy with high intensity muon and hadron beams, up to 160 GeV/c for muons and 190 GeV/c for hadrons respectively. To allow the tracking of charged particles with very low and as well very high momentum, COMPASS comprises two magnetic spectrometer stages extending to a total length of 60 m. From the data acquisition point of view, about 200000 analog detector channels have to be read along the complete experiment. Depending on the detector signal characteristics and the number of channels, this task is realized by frontend electronics using either dedicated ASICs and/or sampling analog-to-digital (ADC) or time-to-digital (TDC) components. The sampling ADC based readout system of the COMPASS experiment comprises today over 127k channels equipped with the APV25 frontend ASIC and 5728 direct sampling channels. An important feature from the beginning was the combination of data transfer, clock and trigger distribution and configuration access within a standardized serial interface between the different ADC modules and the first stage of data concentrator modules. By choosing between a copper or fiber realization for this interface, either a low cost interconnect or a link with galvanic decoupling can be realized. The ongoing development of the sampling ADC electronics is focused on the migration toward the Advanced Telecom Computing Architecture (ATCA) crate standard, to overcome the backplane bandwidth limitations in VME systems. In addition, the ATCA standard provides better cooling and monitoring capabilities. To simplify the transition to ATCA, the MSADC module was already realized as a mezzanine card, which can be mounted on an ATCA based carrier card as well. In addition, the MSADC card fits also to the MicroTCA form factor, which allows to provide a handy building block for laboratory based data acquisition systems.
120390393
Study of Neutrino Interactions in Hydrogen and Deuterium. 1. Description of the Experiment and Study of the Reaction Neutrino d --> mu- p p(s)
This paper gives a detailed description of an experiment which studies the interactions of muon-type neutrinos in hydrogen and deuterium. The experiment was performed at the Zero Gradient Synchrotron using the wide-band neutrino beam incident on the Argonne 12-foot bubble chamber filled with hydrogen and deuterium. The neutrino energy spectrum peaks at 0.5 GeV and has a tail extending to 6 GeV. The shape and intensity of the flux is determined using measurements of pion yields from beryllium. The produced pions are focused by one or (for the latter part of the experiment) two magnetic horns. A total of 364000 pictures were taken with a hydrogen filling of the bubble chamber and 903 000 with a deuterium filling. The scanning and other analyses of the events are described. The most abundant reaction occurs off neutrons and is quasi-elastic scattering $\ensuremath{\nu}d\ensuremath{\rightarrow}{\ensuremath{\mu}}^{\ensuremath{-}}p{p}_{s}$. The separation of these events from background channels is discussed. The total and differential cross sections are analyzed to obtain the axial-vector form factor of the nucleon. Our result, expressed in terms of a dipole form factor, gives an axial-vector mass of 0.95\ifmmode\pm\else\textpm\fi{}0.09 GeV. A comparison is made to previous measurements using neutrino beams, and also to determinations based upon threshold pion electroproduction experiments. In addition, the data are used to measure the weak vector form factor and so check the conserved-vector-current hypothesis.