Comparison of predictions for nuclear effects in the Marteau model with the NUX+FLUKA scheme

Nuclear effects in neutrino-nucleus reactions simulated by means of the NUX+FLUKA Monte Carlo generator are compared with the theoretical predictions of the Marteau model. Pion absorption in NUX+FLUKA and non-pionic Delta decays in the Marteau model differ by about 30%. The fraction of pions produced due to the re-interactions after primary quasi-elastic vertex is in the NUX+FLUKA scheme much higher then provided by the Marteau model.Comment: 6 pages, 8 figures, Presented by J.A. Nowak at the 3rd International Workshop on Neutrino-Nucleus Interactions in the Few-GeV Region, 17-21 March, Gran Sasso(Italy),to appear in the Proceeding

On the theory of large amplitude Alfven waves

Large amplitude Alfvenic disturbances of arbitrary spatial shape and polarization are described by MHD equations, without resort to the usual assumption of planarity. However, because of their nonplanar nature, the direction of propagation of these disturbances cannot, in general, be determined by looking for minima in a variance matrix constructed from observed field fluctuations. When such minima exist, one is observing that subset of interplanetary Alfven waves that is essentially planar

Possible approach to improve sensitivity of a Michelson interferometer

We propose a possible approach to achieve an 1/N sensitivity of Michelson interferometer by using a properly designed random phase modulation. Different from other approaches, the sensitivity improvement does not depend on increasing optical powers or utilizing the quantum properties of light. Moreover the requirements for optical losses and the quantum efficiencies of photodetection systems might be lower than the quantum approaches and the sensitivity improvement is frequency independent in all detection band.Comment: 8 pages, 3 figures, new versio

Using Full Information When Computing Modes of Post-Newtonian Waveforms From Inspiralling Compact Binaries in Circular Orbit

The increasing sophistication and accuracy of numerical simulations of compact binaries (especially binary black holes) presents the opportunity to test the regime in which post-Newtonian (PN) predictions for the emitted gravitational waves are accurate. In order to confront numerical results with those of post-Newtonian theory, it is convenient to compare multipolar decompositions of the two waveforms. It is pointed out here that the individual modes can be computed to higher post-Newtonian order by examining the radiative multipole moments of the system, rather than by decomposing the 2.5PN polarization waveforms. In particular, the dominant (l = 2, m = 2) mode can be computed to 3PN order. Individual modes are computed to as high a post-Newtonian order as possible given previous post-Newtonian results.Comment: 15 page

Coherent States and N Dimensional Coordinate Noncommutativity

Considering coordinates as operators whose measured values are expectations between generalized coherent states based on the group SO(N,1) leads to coordinate noncommutativity together with full $N$ dimensional rotation invariance. Through the introduction of a gauge potential this theory can additionally be made invariant under $N$ dimensional translations. Fluctuations in coordinate measurements are determined by two scales. For small distances these fluctuations are fixed at the noncommutativity parameter while for larger distances they are proportional to the distance itself divided by a {\em very} large number. Limits on this number will lbe available from LIGO measurements.Comment: 16 pqges. LaTeX with JHEP.cl

Single Pion Production in Neutrino Reactions and Estimates for Charge-Exchange Effects

We calculate single pion production by neutrinos in the resonance region. We consider both charged and neutral current reactions on free protons and neutrons. We present differential and total cross sections which can be compared with experiments. Then we use these results to calculate the spectra of the emerging pions including the Pauli suppression factor and rescattering corrections for reactions in heavy nuclei. Our results will be useful for studying single pion production and for investigating neutrino oscillations in future experiments.Comment: 20 pages, 16 figure

One Tile to Rule Them All: Simulating Any Tile Assembly System with a Single Universal Tile

In the classical model of tile self-assembly, unit square tiles translate in the plane and attach edgewise to form large crystalline structures. This model of self-assembly has been shown to be capable of asymptotically optimal assembly of arbitrary shapes and, via information-theoretic arguments, increasingly complex shapes necessarily require increasing numbers of distinct types of tiles. We explore the possibility of complex and efficient assembly using systems consisting of a single tile. Our main result shows that any system of square tiles can be simulated using a system with a single tile that is permitted to flip and rotate. We also show that systems of single tiles restricted to translation only can simulate cellular automata for a limited number of steps given an appropriate seed assembly, and that any longer-running simulation must induce infinite assembly

Negatively Charged Strangelet Search using the E864 Spectrometer at the AGS

We provide a status report on the progress of searching for negatively charged strangelets using the E864 spectrometer at the AGS. About 200 million recorded events representing approximately 14 billion 10% central interactions of Au + Pt at 11.5 GeV/c taken during the 1996-1997 run of the experiment are used in the analysis. No strangelet candidates are seen for charges Z=-1 and Z=-2, corresponding to a 90% confidence level for upper limits of strangelet production of ~1 x 10^{-8} and ~4 x 10^{-9} per central collision respectively. The limits are nearly uniform over a wide range of masses and are valid only for strangelets which are stable or have lifetimes greater than ~50 ns.Comment: 6 pages, 4 figures; Talk at SQM'98, Padova, Italy (July 20-24, 1998

Thermoelastic Noise and Homogeneous Thermal Noise in Finite Sized Gravitational-Wave Test Masses

An analysis is given of thermoelastic noise (thermal noise due to thermoelastic dissipation) in finite sized test masses of laser interferometer gravitational-wave detectors. Finite-size effects increase the thermoelastic noise by a modest amount; for example, for the sapphire test masses tentatively planned for LIGO-II and plausible beam-spot radii, the increase is less than or of order 10 per cent. As a side issue, errors are pointed out in the currently used formulas for conventional, homogeneous thermal noise (noise associated with dissipation which is homogeneous and described by an imaginary part of the Young's modulus) in finite sized test masses. Correction of these errors increases the homogeneous thermal noise by less than or of order 5 per cent for LIGO-II-type configurations.Comment: 10 pages and 3 figures; RevTeX; submitted to Physical Review

Super-Kamiokande atmospheric neutrinos: Status of subdominant oscillations

In the context of the recent (79.5 kTy) Super-Kamiokande atmospheric neutrino data, we concisely review the status of muonic-tauonic flavor oscillations and of the subdominant electron or sterile neutrino mixing, in schemes with three or four families and one dominant mass scale. In the three-family case, where we include the full CHOOZ spectral data, we also show, through a specific example, that ``maximal'' violations of the one-dominant mass scale approximation are not ruled out yet.Comment: 8 pages + 10 figure