1,530 research outputs found
Beam-Based Alignment of the NuMI Target Station Components at FNAL
The Neutrinos at the Main Injector (NuMI) facility is a conventional
horn-focused neutrino beam which produces muon neutrinos from a beam of mesons
directed into a long evacuated decay volume. The relative alignment of the
primary proton beam, target, and focusing horns affects the neutrino energy
spectrum delivered to experiments. This paper describes a check of the
alignment of these components using the proton beam.Comment: higher resolution figures available on Fermilab Preprint Server (see
SPIRES entry), accepted for publication in Nucl. Instr. and Meth.
A large final-state interaction in the 0-0- decays of J/psi
In view of important implications in the B decay, the 0-0- decay modes of
J/psi are analyzed with broken flavor SU(3) symmetry in search for
long-distance final-state interactions. If we impose one mild theoretical
constraint on the electromagnetic form factors, we find that a large phase
difference of final-state interactions is strongly favored between the
one-photon and the gluon decay amplitudes. Measurement of the \pi+\pi- and K+K-
cross sections off the J/psi peak in e+e- annihilation can settle the issue
without recourse to theory.Comment: 9 pages with 1 eps figure in RevTe
Search for the disappearance of muon antineutrinos in the NuMI neutrino beam
We report constraints on muon antineutrino oscillation parameters that were obtained by using the two MINOS detectors to measure the 7% antineutrino component of the NuMI neutrino beam. In the Far Detector, we select 130 events in the charged-current muon antineutrino sample, compared to a prediction of 136.4 +/- 11.7(stat) ^{+10.2}_{-8.9}(syst) events under the assumption |dm2bar|=2.32x10^-3 eV^2, snthetabar=1.0. A fit to the two-flavor oscillation approximation constrains |dm2bar|<3.37x10^-3 eV^2 at the 90% confidence level with snthetabar=1.0
Measuring in Decays
We consider the possibility of measuring both and in the KM unitarity triangle using the process . This decay mode has a higher branching fraction (O(1%)) than
the mode . We use the factorization assumption and heavy
hadron chiral perturbation theory to estimate the branching fraction and
polarization. The time dependent rate for can be
used to measure and . Furthermore, examination
of the mass spectrum may be the best way to experimentally find
the broad p-wave meson.Comment: Revtex, 28 pages, 7 figures, title changed, introduction expanded,
added references, details of calculations moved to the appendi
SU(3)_flavor analysis of two-body weak decays of charmed baryons
We study two-body weak decays of charmed baryons \Lambda_c and \Xi_c into an
octet or decuplet baryon and a pseudoscalar meson employing the SU(3) flavor
symmetry. Using certain measured Cabibbo-favored modes, we fix the reduced
amplitudes and predict the branching ratios of various decays of charmed
baryons in the Cabibbo-enhanced, -suppressed and -doubly suppressed modes.Comment: 25 pages, No figure, Phys. Rev. D (to appear
Experiment Simulation Configurations Used in DUNE CDR
The LBNF/DUNE CDR describes the proposed physics program and experimental
design at the conceptual design phase. Volume 2, entitled The Physics Program
for DUNE at LBNF, outlines the scientific objectives and describes the physics
studies that the DUNE collaboration will perform to address these objectives.
The long-baseline physics sensitivity calculations presented in the DUNE CDR
rely upon simulation of the neutrino beam line, simulation of neutrino
interactions in the far detector, and a parameterized analysis of detector
performance and systematic uncertainty. The purpose of this posting is to
provide the results of these simulations to the community to facilitate
phenomenological studies of long-baseline oscillation at LBNF/DUNE.
Additionally, this posting includes GDML of the DUNE single-phase far detector
for use in simulations. DUNE welcomes those interested in performing this work
as members of the collaboration, but also recognizes the benefit of making
these configurations readily available to the wider community.Comment: 9 pages, 4 figures, configurations in ancillary file
Heightened Vulnerability to MDR-TB Epidemics after Controlling Drug-Susceptible TB
Prior infection with one strain TB has been linked with diminished likelihood of re-infection by a new strain. This paper attempts to determine the role of declining prevalence of drug-susceptible TB in enabling future epidemics of MDR-TB.A computer simulation of MDR-TB epidemics was developed using an agent-based model platform programmed in NetLogo (See http://mdr.tbtools.org/). Eighty-one scenarios were created, varying levels of treatment quality, diagnostic accuracy, microbial fitness cost, and the degree of immunogenicity elicited by drug-susceptible TB. Outcome measures were the number of independent MDR-TB cases per trial and the proportion of trials resulting in MDR-TB epidemics for a 500 year period after drug therapy for TB is introduced.MDR-TB epidemics propagated more extensively after TB prevalence had fallen. At a case detection rate of 75%, improving therapeutic compliance from 50% to 75% can reduce the probability of an epidemic from 45% to 15%. Paradoxically, improving the case-detection rate from 50% to 75% when compliance with DOT is constant at 75% increases the probability of MDR-TB epidemics from 3% to 45%.The ability of MDR-TB to spread depends on the prevalence of drug-susceptible TB. Immunologic protection conferred by exposure to drug-susceptible TB can be a crucial factor that prevents MDR-TB epidemics when TB treatment is poor. Any single population that successfully reduces its burden of drug-susceptible TB will have reduced herd immunity to externally or internally introduced strains of MDR-TB and can experience heightened vulnerability to an epidemic. Since countries with good TB control may be more vulnerable, their self interest dictates greater promotion of case detection and DOTS implementation in countries with poor control to control their risk of MDR-TB
Search for CP Violation in the decays D+ -> K_S pi+ and D+ -> K_S K+
A high statistics sample of photo-produced charm from the FOCUS(E831)
experiment at Fermilab has been used to search for direct CP violation in the
decays D+->K_S pi+ and D+ -> K_S K+. We have measured the following asymmetry
parameters relative to D+->K-pi+pi+: A_CP(K_S pi+) = (-1.6 +/- 1.5 +/- 0.9)%,
A_CP(K_S K+) = (+6.9 +/- 6.0 +/- 1.5)% and A_CP(K_S K+) = (+7.1 +/- 6.1 +/-
1.2)% relative to D+->K_S pi+. The first errors quoted are statistical and the
second are systematic. We also measure the relative branching ratios:
\Gamma(D+->\bar{K0}pi+)/\Gamma(D+->K-pi+pi+) = (30.60 +/- 0.46 +/- 0.32)%,
\Gamma(D+->\bar{K0}K+)/\Gamma(D+->K-pi+pi+) = (6.04 +/- 0.35 +/- 0.30)% and
\Gamma(D+->\bar{K0}K+)/\Gamma(D+->\bar{K0}pi+) = (19.96 +/- 1.19 +/- 0.96)%.Comment: 4 pages, 3 figure
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