Rolling Tachyon Solution in Vacuum String Field Theory

We construct a time-dependent solution in vacuum string field theory and investigate whether the solution can be regarded as a rolling tachyon solution. First, compactifying one space direction on a circle of radius R, we construct a space-dependent solution given as an infinite number of *-products of a string field with center-of-mass momentum dependence of the form e^{-b p^2/4}. Our time-dependent solution is obtained by an inverse Wick rotation of the compactified space direction. We focus on one particular component field of the solution, which takes the form of the partition function of a Coulomb system on a circle with temperature R^2. Analyzing this component field both analytically and numerically using Monte Carlo simulation, we find that the parameter b in the solution must be set equal to zero for the solution to approach a finite value in the large time limit x^0\to\infty. We also explore the possibility that the self-dual radius R=\sqrt{\alpha'} is a phase transition point of our Coulomb system.Comment: 39 pages, 17 figures, v3: references adde

Boron abundance and solar neutrino spectrum distortion

The presence of neutrinos from Boron decay in the flux observed on Earth is attested by the observation of their energy spectrum. Possible distortions of the spectrum investigated in current detectors are often interpreted in terms of evidence in favour or against various schemes of neutrino oscillations. We stress here that a distortion of the spectrum at high energies could also result from an increase in the ratio of neutrinos originating from ($^3$He+p) and $^8$B reactions. While a $^8$B neutrino depletion would contribute to this effect, an increase in the Hep contribution seems also needed to reproduce the preliminary data.Comment: 8 pages, 2 figures; abstract and introduction rewritten to match the conclusions bette

Predicting Big Bang Deuterium

We present new upper and lower bounds to the primordial abundances of deuterium and helium-3 based on observational data from the solar system and the interstellar medium. Independent of any model for the primordial production of the elements we find (at the 95\% C.L.): $1.5 \times 10^{-5} \le (D/H)_P \le 10.0 \times 10^{-5}$ and $(^3He/H)_P \le 2.6\times 10^{-5}$. When combined with the predictions of standard big bang nucleosynthesis, these constraints lead to a 95\% C.L. bound on the primordial abundance of deuterium: $(D/H)_{best} = (3.5^{+2.7}_{-1.8})\times 10^{-5}$. Measurements of deuterium absorption in the spectra of high redshift QSOs will directly test this prediction. The implications of this prediction for the primordial abundances of helium-4 and lithium-7 are discussed, as well as those for the universal density of baryons.Comment: Revised version of paper to reflect comments of the referee and reply to suggestions of Copi, Schramm, and Turner regarding the overall analysis and treatment of chemical evolution of D and He-3. Best-fit D/H abundance changes from (2.3 + 3.0 - 1.0)x10^{-5} to (3.5 +2.7 - 1.8) x10^{-5}. See also hep-ph/950531

The Perturbative Spectrum of the Dressed Sliver

We analyze the fluctuations of the dressed sliver solution found in a previous paper, hep-th/0311198, in the operator formulation of Vacuum String Field Theory. We derive the tachyon wave function and then analyze the higher level fluctuations. We show that the dressing is responsible for implementing the transversality condition on the massless vector. In order to consistently deal with the singular $k=0$ mode we introduce a string midpoint regulator and we show that it is possible to accommodate all the open string states among the solutions to the linearized equations of motion. We finally show how the dressing can give rise to the correct ratio between the energy density of the dressed sliver and the brane tension computed via the three-tachyons-coupling.Comment: 52 pages, v2: comment added in sec. 5, v3: one appendix added, comments added in introduction and conclusion, to appear on PR

Probability of a Solution to the Solar Neutrino Problem Within the Minimal Standard Model

Tests, independent of any solar model, can be made of whether solar neutrino experiments are consistent with the minimal Standard Model (stable, massless neutrinos). If the experimental uncertainties are correctly estimated and the sun is generating energy by light-element fusion in quasi-static equilibrium, the probability of a standard-physics solution is less than 2%. Even when the luminosity constraint is abandoned, the probability is not more than 4%. The sensitivity of the conclusions to input parameters is explored.Comment: PRL, Revtex, 1 figure, 5 page

Prosomal-width-to-weight relationships in American horseshoe crabs (Limulus polyphemus): examining conversion factors used to estimate landings

Horseshoe crabs (Limulus polyphemus) are valued by many stakeholders, including the commercial fishing industry, biomedical companies, and environmental interest groups. We designed a study to test the accuracy of the conversion factors that were used by NOAA Fisheries and state agencies to estimate horseshoe crab landings before mandatory reporting that began in 1998. Our results indicate that the NOAA Fisheries conversion factor consistently overestimates the weight of male horseshoe crabs, particularly those from New England populations. Because of the inaccuracy of this and other conversion factors, states are now mandated to report the number (not biomass) and sex of landed horseshoe crabs. However, accurate estimates of biomass are still necessary for use in prediction models that are being developed to better manage the horseshoe crab fishery. We recommend that managers use the conversion factors presented in this study to convert current landing data from numbers to biomass of harvested horseshoe crabs for future assessments

Linking Conformation Change to Hemoglobin Activation Via Chain-Selective Time-resolved Resonance Raman Spectroscopy on Protoheme/Mesoheme Hybrids

Time-resolved Resonance Raman spectra are reported for Hb tetramers, in which the αand β chains are selectively substituted with mesoheme. The Soret absorption band shift in meso- relative to protoheme permits chain-selective excitation of heme RR spectra. The evolution of these spectra following HbCO photolysis show that geminate recombination rates and yields are the same for the two chains, consistent with recent results on 15N-heme isotopomer hybrids. The spectra also reveal systematic shifts in the deoxy-heme ν4 and νFe-His) RR bands, which are anti-correlated. These shifts are resolved for the successive intermediates in the protein structure, which have previously been determined from time-resolved UVRR spectra. Both chains show Fe-His bond compression in the immediate photoproduct, which relaxes during the formation of the first intermediate, Rdeoxy (0.07 μs), in which the proximal F-helix is proposed to move away from the heme. Subsequently, the Fe-His bond weakens, more so for the α than the β chains. The weakening is gradual for the β chains, but abrupt for the α chains, coinciding with completion of the R-T quaternary transition, at 20μs. Since the transition from fast- to slow-rebinding Hb also occurs at 20μs, the drop in the α chain νFe-His supports the localization of ligation restraint to tension in the Fe-His bond, at least in the α-chains. The mechanism is more complex in the β chains

Open String on Symmetric Product

We develop some basic properties of the open string on the symmetric product which is supposed to describe the open string field theory in discrete lightcone quantization (DLCQ). After preparing the consistency conditions of the twisted boundary conditions for Annulus/M\"obius/Klein Bottle amplitudes in generic non-abelian orbifold, we classify the most general solutions of the constraints when the discrete group is $S_N$. We calculate the corresponding orbifold amplitudes from two viewpoints -- from the boundary state formalism and from the trace over the open string Hilbert space. It is shown that the topology of the world sheet for the short string and that of the long string in general do not coincide. For example the annulus sector for the short string contains all the sectors (torus, annulus, Klein bottle, M\"obius strip) of the long strings. The boundary/cross-cap states of the short strings are classified into three categories in terms of the long string, the ordinary boundary and the cross-cap states, and the ``joint'' state which describes the connection of two short strings. We show that the sum of the all possible boundary conditions is equal to the exponential of the sum of the irreducible amplitude -- one body amplitude of long open (closed) strings. This is typical structure of DLCQ partition function. We examined that the tadpole cancellation condition in our language and derived the well-known gauge group $SO(2^{13})$.Comment: 56 pages, 11 figures, Late

Time Dependent Solution in Cubic String Field Theory

We study time dependent solutions in cubic open string field theory which are expected to describe the configuration of the rolling tachyon. We consider the truncated system consisting of component fields of level zero and two, which are expanded in terms of cosh n x^0 modes. For studying the large time behavior of the solution we need to know the coefficients of all and, in particular, large n modes. We examine numerically the coefficients of the n-th mode, and find that it has the leading n-dependence of the form (-\beta)^n \lambda^{-n^2} multiplied by a peculiar subleading part with peaks at n=2^m=4,8,16,32,64,128,.... This behavior is also reproduced analytically by solving simplified equations of motion of the tachyon system.Comment: 22 pages, 12 figures, LaTeX2e, v3:minor correction