1,676 research outputs found
The Schr\"odinger Wave Functional and S-branes
In this paper we will consider the minisuperspace approach to S-branes
dynamics in the Schr\"odinger picture description. Time-evolution of vacuum
wave functional for quantum field theory on S-brane is studied. Open string
pair production is calculated. The analysis of density matrix for mixed states
is also performed.Comment: 27 page
Deconfinement transition and string tensions in SU(4) Yang-Mills Theory
We present results from numerical lattice calculations of SU(4) Yang-Mills
theory. This work has two goals: to determine the order of the finite
temperature deconfinement transition on an lattice and to study the
string tensions between static charges in the irreducible representations of
SU(4). Motivated by Pisarski and Tytgat's argument that a second-order
SU() deconfinement transition would explain some features of the SU(3)
and QCD transitions, we confirm older results on a coarser, , lattice.
We see a clear two-phase coexistence signal, characteristic of a first-order
transition, at on a lattice, on which we also
compute a latent heat of . Computing
Polyakov loop correlation functions we calculate the string tension at finite
temperature in the confined phase between fundamental charges, ,
between diquark charges, , and between adjoint charges . We
find that , and our result for the adjoint string
tension is consistent with string breaking.Comment: 10 pages with included figures. For version 2: New calculation and
discussion of latent heat added; 2 new figures and 1 new table. Typo in
abstract corrected for v3. To appear in Physical Review
Particle Production on Half S-brane
In this paper we will study quantum field theory of fluctuation modes around
the rolling tachyon solution on non-BPS D-brane effective action. The goal of
this paper is to study particle production during the decay of non-BPS D-brane
and explore possible relation with minisuperspace calculation. We find that the
number of particles produced on half S-brane exponentially grows for large time
which suggests that linearised approximation breaks down and also that
backreaction of fluctuation field on classical solution should be taken into
account.Comment: 24 pages,v1.references adde
The all-particle spectrum of primary cosmic rays in the wide energy range from 10^14 eV to 10^17 eV observed with the Tibet-III air-shower array
We present an updated all-particle energy spectrum of primary cosmic rays in
a wide range from 10^14 eV to 10^17 eV using 5.5 times 10^7 events collected in
the period from 2000 November through 2004 October by the Tibet-III air-shower
array located at 4300 m above sea level (atmospheric depth of 606 g/cm^2). The
size spectrum exhibits a sharp knee at a corresponding primary energy around 4
PeV. This work uses increased statistics and new simulation calculations for
the analysis. We performed extensive Monte Carlo calculations and discuss the
model dependences involved in the final result assuming interaction models of
QGSJET01c and SIBYLL2.1 and primary composition models of heavy dominant (HD)
and proton dominant (PD) ones. Pure proton and pure iron primary models are
also examined as extreme cases. The detector simulation was also made to
improve the accuracy of determining the size of the air showers and the energy
of the primary particle. We confirmed that the all-particle energy spectra
obtained under various plausible model parameters are not significantly
different from each other as expected from the characteristics of the
experiment at the high altitude, where the air showers of the primary energy
around the knee reaches near maximum development and their features are
dominated by electromagnetic components leading to the weak dependence on the
interaction model or the primary mass. This is the highest-statistical and the
best systematics-controlled measurement covering the widest energy range around
the knee energy region.Comment: 19 pages, 20 figures, accepted by Ap
- …