4,449 research outputs found
Searching for Antiproton Decay at the Fermilab Antiproton Accumulator
This paper describes an experimental search for antiproton decay at the
Fermilab Antiproton Accumulator. The E868 (APEX) experimental setup is
described. The APEX data is expected to be sensitive to antiproton decay if the
antiproton lifetimes is less than a few times 100 000 years.Comment: http://fnapx1.fnal.gov/talks/eps_preprint.p
A New Limit on CPT Violation
A search for antiproton decay has been made at the Fermilab Antiproton
Accumulator. Limits are placed on fifteen antiproton decay modes. The results
are used to place limits on the characteristic mass scale Mx that could be
associated with CPT-violation accompanied by baryon number violation.Comment: 11 pages, 1 figure. Submitted to Phys. Rev. Let
Comparison of LMA and LOW Solar Solution Predictions in an SO(10) GUT Model
Within the framework of an SO(10) GUT model that can accommodate both the LMA
and LOW solar neutrino mixing solutions by appropriate choice of the
right-handed Majorana matrix elements, we present explicit predictions for the
neutrino oscillation parameters \Delta m^2_{21}, \sin^2 2\theta_{12}, \sin^2
2\theta_{23}, \sin^2 2\theta_{13}, and \delta_{CP}. Given the observed near
maximality of the atmospheric mixing, the model favors the LMA solution and
predicts that \delta_{CP} is small. The suitability of Neutrino Superbeams and
Neutrino Factories for precision tests of the two model versions is discussed.Comment: Title, abstract and emphasis changed, references adde
Summary of the Superconducting RF Linac for Muon Collider and Neutrino Factory
Project-X is a proposed project to be built at Fermi National Accelerator
Laboratory with several potential missions. A primary part of the Project-X
accelerator chain is a Superconducting linac, and In October 2009 a workshop
was held to concentrate on the linac parameters. The charge of the workshop was
to "..focus only on the SRF linac approaches and how it can be used...". The
focus of Working Group 2 of this workshop was to evaluate how the different
linac options being considered impact the potential realization of Muon
Collider (MC) and Neutrino Factory (NF) applications. In particular the working
group charge was, "to investigate the use of a multi-megawatt proton linac to
target, phase rotate and collect muons to support a muon collider and neutrino
factory". To focus the working group discussion, three primary questions were
identified early on, to serve as a reference: 1) What are the proton source
requirements for muon colliders and neutrino factories? 2) What are the issues
with respect to realizing the required muon collider and neutrino factory
proton sources? a. General considerations b. Considerations specific to the two
linac configurations identified by Project-X. 3) What things need to be done
before we can be reasonably confident that ICD1/ICD2 can be upgraded to provide
the neutrino factory / muon collider needs? A number of presentations were
given, and are available at the workshop web-site. This paper does not
summarize the individual presentations, but rather addresses overall findings
as related to the three guiding questions listed above.Comment: 6 pp. Workshop on Applications of High Intensity Proton Accelerators
19-21 Oct 2009: Batavia, Illinoi
A multiple scales approach to sound generation by vibrating bodies
The problem of determining the acoustic field in an inviscid, isentropic fluid generated by a solid body whose surface executes prescribed vibrations is formulated and solved as a multiple scales perturbation problem, using the Mach number M based on the maximum surface velocity as the perturbation parameter. Following the idea of multiple scales, new 'slow' spacial scales are introduced, which are defined as the usual physical spacial scale multiplied by powers of M. The governing nonlinear differential equations lead to a sequence of linear problems for the perturbation coefficient functions. However, it is shown that the higher order perturbation functions obtained in this manner will dominate the lower order solutions unless their dependence on the slow spacial scales is chosen in a certain manner. In particular, it is shown that the perturbation functions must satisfy an equation similar to Burgers' equation, with a slow spacial scale playing the role of the time-like variable. The method is illustrated by a simple one-dimenstional example, as well as by three different cases of a vibrating sphere. The results are compared with solutions obtained by purely numerical methods and some insights provided by the perturbation approach are discussed
Exploring Neutrino Oscillations with Superbeams
We consider the medium- and long-baseline oscillation physics capabilities of
intense muon-neutrino and muon-antineutrino beams produced using future
upgraded megawatt-scale high-energy proton beams. In particular we consider the
potential of these conventional neutrino ``superbeams'' for observing
\nu_\mu\to\nu_e oscillations, determining the hierarchy of neutrino mass
eigenstates, and measuring CP-violation in the lepton sector. The physics
capabilities of superbeams are explored as a function of the beam energy,
baseline, and the detector parameters. The trade-offs between very large
detectors with poor background rejection and smaller detectors with excellent
background rejection are illustrated. We find that it may be possible to
observe \nu_\mu\to\nu_e oscillations with a superbeam provided that the
amplitude parameter \sin^2 2\theta_{13} is larger than a few \times 10^{-3}. If
\sin^2 2\theta_{13} is of order 10^{-2} or larger, then the neutrino mass
hierarchy can be determined in long-baseline experiments, and if in addition
the large mixing angle MSW solution describes the solar neutrino deficit then
there is a small region of parameter space within which maximal CP-violation in
the lepton sector would be observable in a low-energy medium-baseline
experiment. We explicitly consider massive water Cherenkov and liquid argon
detectors at superbeams with neutrino energies ranging from 1 GeV to 15 GeV,
and baselines from 295 km to 9300 km. Finally, we compare the oscillation
physics prospects at superbeams with the corresponding prospects at neutrino
factories. The sensitivity at a neutrino factory to CP violation and the
neutrino mass hierarchy extends to values of the amplitude parameter \sin^2
2\theta_{13} that are one to two orders of magnitude lower than at a superbeam.Comment: Revtex (singlespaced), 41 pages, uses epsf.sty, 12 postscript
figures. Minor corrections and notation changes, expanded discussions, x-axis
numbers added to Fig.9(a),(c). To be published in Phys. Rev.
Future accelerator-based neutrino facilities and program
Near-future and proposed longer-term accelerator-based neutrino experiments are described and discussed
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