771 research outputs found
General 2 charge geometries
Two charge BPS horizon free supergravity geometries are important in
proposals for understanding black hole microstates. In this paper we construct
a new class of geometries in the NS1-P system, corresponding to solitonic
strings carrying fermionic as well as bosonic condensates. Such geometries are
required to account for the full microscopic entropy of the NS1-P system. We
then briefly discuss the properties of the corresponding geometries in the dual
D1-D5 system.Comment: 44 page
Spatial distribution and evaluation of risk factors for bovine neosporosis in RondĂ´nia, Brazil
ABSTRACT Neospora caninum is an important worldwide parasite responsible for causing abortion in animals. Due to limited information on the occurrence of infection by this parasite in the state of RondĂ´nia, Brazil, this study aimed to determine the seroprevalence and identify the risk factors associated with the infection in slaughtered cattle, from 19 municipalities distributed in seven microregions of the state. A total of 494 samples were obtained and subjected to anti-N. caninum antibodies, using the Indirect Immunofluorescence Reaction technique. Antibodies were detected in 5.06% (25/494) of the samples, in 30.30% (10/33) of farms, in nine municipalities located in four microregions of RondĂ´nia. Of all the animals analyzed, 4.81% of the females (20/416) and 6.41% of the males (05/78) were seropositive for the parasite, with âabortion in the last 12 monthsâ being considered an important risk factor for the occurrence of infection (OR = 9.54; p = 0.01). The present study points out the prevalence of anti-N. caninum antibodies in 5.06% of slaughtered animals and abortion as the main risk factor associated with infection by N. caninum, thus contributing to the elucidation of the epidemiology of this protozoan in RondĂ´nia, Brazil
Protons in near earth orbit
The proton spectrum in the kinetic energy range 0.1 to 200 GeV was measured
by the Alpha Magnetic Spectrometer (AMS) during space shuttle flight STS-91 at
an altitude of 380 km. Above the geomagnetic cutoff the observed spectrum is
parameterized by a power law. Below the geomagnetic cutoff a substantial second
spectrum was observed concentrated at equatorial latitudes with a flux ~ 70
m^-2 sec^-1 sr^-1. Most of these second spectrum protons follow a complicated
trajectory and originate from a restricted geographic region.Comment: 19 pages, Latex, 7 .eps figure
Search for antihelium in cosmic rays
The Alpha Magnetic Spectrometer (AMS) was flown on the space shuttle
Discovery during flight STS-91 in a 51.7 degree orbit at altitudes between 320
and 390 km. A total of 2.86 * 10^6 helium nuclei were observed in the rigidity
range 1 to 140 GV. No antihelium nuclei were detected at any rigidity. An upper
limit on the flux ratio of antihelium to helium of < 1.1 * 10^-6 is obtained.Comment: 18 pages, Latex, 9 .eps figure
Spinning Strings as Small Black Rings
Certain supersymmetric elementary string states with spin can be viewed as
small black rings whose horizon has the topology of S^1 \times S^{d-3} in a
d-dimensional string theory. By analyzing the singular black ring solution in
the supergravity approximation, and using various symmetries of the \alpha'
corrected effective action we argue that the Bekenstein-Hawking-Wald entropy of
the black string solution in the full string theory agrees with the statistical
entropy of the same system up to an overall normalization constant. While the
normalization constant cannot be determined by the symmetry principles alone,
it can be related to a similar normalization constant that appears in the
expression for small black holes without angular momentum in one less
dimension. Thus agreement between statistical and macroscopic entropy of
(d-1)-dimensional non-rotating elementary string states would imply a similar
agreement for a d-dimensional elementary string state with spin. Our analysis
also determines the structure of the near horizon geometry and provides us with
a geometric derivation of the Regge bound. These studies give further evidence
that a ring-like horizon is formed when large angular momentum is added to a
small black hole.Comment: LaTeX file, 31 pages; v2: references to earlier work adde
A Study of Cosmic Ray Secondaries Induced by the Mir Space Station Using AMS-01
The Alpha Magnetic Spectrometer (AMS-02) is a high energy particle physics
experiment that will study cosmic rays in the to range and will be installed on the International Space Station
(ISS) for at least 3 years. A first version of AMS-02, AMS-01, flew aboard the
space shuttle \emph{Discovery} from June 2 to June 12, 1998, and collected
cosmic ray triggers. Part of the \emph{Mir} space station was within the
AMS-01 field of view during the four day \emph{Mir} docking phase of this
flight. We have reconstructed an image of this part of the \emph{Mir} space
station using secondary and emissions from primary cosmic rays
interacting with \emph{Mir}. This is the first time this reconstruction was
performed in AMS-01, and it is important for understanding potential
backgrounds during the 3 year AMS-02 mission.Comment: To be submitted to NIM B Added material requested by referee. Minor
stylistic and grammer change
Time-integrated luminosity recorded by the BABAR detector at the PEP-II e+e- collider
This article is the Preprint version of the final published artcile which can be accessed at the link below.We describe a measurement of the time-integrated luminosity of the data collected by the BABAR experiment at the PEP-II asymmetric-energy e+e- collider at the Ď(4S), Ď(3S), and Ď(2S) resonances and in a continuum region below each resonance. We measure the time-integrated luminosity by counting e+e-âe+e- and (for the Ď(4S) only) e+e-âÎź+Îź- candidate events, allowing additional photons in the final state. We use data-corrected simulation to determine the cross-sections and reconstruction efficiencies for these processes, as well as the major backgrounds. Due to the large cross-sections of e+e-âe+e- and e+e-âÎź+Îź-, the statistical uncertainties of the measurement are substantially smaller than the systematic uncertainties. The dominant systematic uncertainties are due to observed differences between data and simulation, as well as uncertainties on the cross-sections. For data collected on the Ď(3S) and Ď(2S) resonances, an additional uncertainty arises due to Ďâe+e-X background. For data collected off the Ď resonances, we estimate an additional uncertainty due to time dependent efficiency variations, which can affect the short off-resonance runs. The relative uncertainties on the luminosities of the on-resonance (off-resonance) samples are 0.43% (0.43%) for the Ď(4S), 0.58% (0.72%) for the Ď(3S), and 0.68% (0.88%) for the Ď(2S).This work is supported by the US Department of Energy and National Science Foundation, the Natural Sciences and Engineering Research Council (Canada), the Commissariat Ă lâEnergie Atomique and Institut National de Physique NuclĂŠaire et de Physiquedes Particules (France), the Bundesministerium fĂźr Bildung und Forschung and Deutsche Forschungsgemeinschaft (Germany), the Istituto Nazionale di Fisica Nucleare (Italy), the Foundation for Fundamental Research on Matter (The Netherlands), the Research Council of Norway, the Ministry of Education and Science of the Russian Federation, Ministerio de Ciencia e InnovaciĂłn (Spain), and the Science and Technology Facilities Council (United Kingdom). Individuals have received support from the Marie-Curie IEF program (European Union) and the A.P. Sloan Foundation (USA)
Search for a W' boson decaying to a bottom quark and a top quark in pp collisions at sqrt(s) = 7 TeV
Results are presented from a search for a W' boson using a dataset
corresponding to 5.0 inverse femtobarns of integrated luminosity collected
during 2011 by the CMS experiment at the LHC in pp collisions at sqrt(s)=7 TeV.
The W' boson is modeled as a heavy W boson, but different scenarios for the
couplings to fermions are considered, involving both left-handed and
right-handed chiral projections of the fermions, as well as an arbitrary
mixture of the two. The search is performed in the decay channel W' to t b,
leading to a final state signature with a single lepton (e, mu), missing
transverse energy, and jets, at least one of which is tagged as a b-jet. A W'
boson that couples to fermions with the same coupling constant as the W, but to
the right-handed rather than left-handed chiral projections, is excluded for
masses below 1.85 TeV at the 95% confidence level. For the first time using LHC
data, constraints on the W' gauge coupling for a set of left- and right-handed
coupling combinations have been placed. These results represent a significant
improvement over previously published limits.Comment: Submitted to Physics Letters B. Replaced with version publishe
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