17890704
Optimum long baseline for the next generation neutrino oscillation experiments
For high-energy long baseline neutrino oscillation experiments, we propose a figure of merit criterion to compare the statistical quality of experiments at various baseline lengths under the condition of identical detectors and a given neutrino beam. We take into account all possible experimental errors under general consideration. In this way, the figure of merit is closely related to the usual statistical criterion of number of sigmas. We use a realistic neutrino beam for an entry-level neutrino factory and a possible superbeam from a meson source and a 100 kt detector for the calculation. We consider in detail four baseline lengths\char22{}300 km, 700 km, 2100 km, and 3000 km in the neutrino energy range of 0.5\char21{}20 GeV for a 20 GeV entry-level neutrino factory and a 50 GeV superbeam. We find that the very long baselines of 2100 km and 3000 km are preferred for the neutrino factory according to the figure of merit criterion. Our results also show that, for a neutrino factory, lower primary muon energies such as 20 GeV are preferred rather than higher ones such as 30 or 50 GeV. For the superbeam, the combination of a long baseline such as 300 km and a very long baseline such as 2100 km will form a complete measurement of the oscillation parameters in addition to the $\mathrm{CP}$ phase. To measure the $\mathrm{CP}$ phase in a superbeam, a larger detector (a factor 3 beyond what is considered in this paper) and/or a higher intensity beam will be needed to put some significant constraints on the size of the $\mathrm{CP}$ angle.
122214277
A water Cherenkov calorimeter for long baseline neutrino oscillation experiments
Abstract We propose a water-based large homogeneous calorimeter as the next generation neutrino detector for ν factories and/or conventional ν beams. The Cherenkov light produced in water is sufficient to have good energy resolution, and the pattern recognition is realized by a modular water tank structure. Monte Carlo simulations show that the detector performance is excellent for identifying neutrino CC events while rejecting backgrounds.
125677069
TUBE CHAMBERS FOR THE MUON FILTER OF THE L3 DETECTOR
18893994
The mass production and quality control of RPCs for the Daya Bay experiment
Abstract Resistive plate chambers will be used in the Daya Bay reactor neutrino experiment to help veto backgrounds created by cosmic-ray muons. The mass production of RPCs began in 2008 and by the end of 2009, 1600 RPCs (3500 m 2 ) had been produced and tested. This paper describes the production and quality control procedures, and quality assurance using cosmic-ray testing.
56005177
Inclusive J production in Z0 decays
Abstract Inclusive J production in Z0 decays is observed via the leptonic decay mode J → l+l− (l = e,μ). We measure the branching ratio Br(Z0 → J + X) = (4.1 ± 0.7 (stat.) ± 0.3 (sys.)) × 10−3. We have calculated the fraction of the J mesons from b-hadron decay and find a branching ratio of Br(b → J + X)= (1.3±0.2(stat.)±0.2(sys.)) × 10−2. We determine the average fractional energy of bottom hadrons 〈XE > = 0.70±0.03 (stat.)+0.02−0.01 (sys.) using the momentum spectrum of the J mesons. From a study of the angle between the J and the most energetic jet, we set an upper limit on the branching ratio Br ( Z 0 → q q g ∗ ; g ∗ → J + X ) −4 at 90% confidence level.
118039047
Physics of tau and charm
The physics of tau and charm started in early 70's after J/$\psi$ and $\tau$ were discovered. Since then several dedicated accelerators and experiments were built with increasing luminosities and studies on light hadron spectroscopy, charmonium, electroweak and QCD were never interupted. New interests and surprises are not rare in this area. With the newly built BEPCII/BESIII, an even brighter future is foreseen.
119981129
Interactions of fast ions with carbon nanotubes: Self-energy and stopping power
The interactions of charged particles with carbon nanotubes are studied by means of the linearized hydrodynamic theory for electronic excitations on the nanotube surface. General expressions are derived for the induced potential, the self-energy, and the stopping power for a charged particle moving paraxially in a nanotube. Numerical results are obtained showing the influence of the damping factor, the nanotube radius, and the particle position on its self-energy and the stopping power. Results for stopping power in the linearized hydrodynamic model are compared with those obtained by means of the dielectric formalism in random-phase approximation, showing a close agreement between the two approaches for high speeds of charged particles.
18463747
THE LIQUID SCINTILLATOR NEUTRINO DETECTOR AND LAMPF NEUTRINO SOURCE
Abstract A search for neutrino oscillations of the type ν μ → ν c has been conducted at the Los Alamos Meson Physics Facility using ν μ from muon decay at rest. Evidence for this transition has been reported previously. This paper discusses in detail the experimental setup, detector operation and neutrino source, including aspects relevant to oscillation searches in the muon decay-at-rest and pion decay in flight channels.
1436143
A stochastic measure for eternal inflation
We use the stochastic approach to investigate a measure for slow roll eternal inflation. The probability for the universe to have a given Hubble radius can be calculated in this framework. In a solvable model, it is shown that the probability for the universe to evolve from a state with a smaller Hubble radius to one with a larger Hubble radius is dominated by the classical probability without the stochastic source, while the probability for the universe to evolve from a state with a larger Hubble radius to one with a smaller one is suppressed by exp(-Delta S), where the de Sitter entropy S arises naturally in this stochastic approach.
118449992
Inflation, Cosmic Perturbations and Non-Gaussianities
We review the theory of inflationary perturbations. Perturbations at both linear and nonlinear orders are reviewed. We also review a variety of inflation models, emphasizing their signatures on cosmic perturbations.
118640758
Neutrino constraints from future nearly all-sky spectroscopic galaxy surveys
We examine whether future, nearly all-sky galaxy redshift surveys, in combination with CMB priors, will be able to detect the signature of the cosmic neutrino background and determine the absolute neutrino mass scale. We also consider what constraints can be imposed on the effective number of neutrino species. In particular we consider two spectroscopic strategies in the near-IR, the so-called ``slitless'' and ``multi-slit'' approaches, whose examples are given by future space-based galaxy surveys, as EUCLID for the slitless case, or SPACE, JEDI, and possibly WFIRST in the future, for the multi-slit case. We find that, in combination with Planck, these galaxy probes will be able to detect at better than 3-sigma level and measure the mass of cosmic neutrinos: a) in a cosmology-independent way, if the sum of neutrino masses is above 0.1 eV; b) assuming spatial flatness and that dark energy is a cosmological constant, otherwise. We find that the sensitivity of such surveys is well suited to span the entire range of neutrino masses allowed by neutrino oscillation experiments, and to yield a clear detection of non-zero neutrino mass. The detection of the cosmic relic neutrino background with cosmological experiments will be a spectacular confirmation of our model for the early Universe and a window into one of the oldest relic components of our Universe.