3,200 research outputs found
High precision calculations of electroweak radiative corrections for polarized Moller scattering at one loop and beyond
Parity-violating Moller scattering measurements are a powerful probe of new
physics effects, and the upcoming high-precision experiments will require a new
level of accuracy for electroweak radiative corrections (EWC). First, we
perform the updated calculations of one-loop EWC for Moller scattering
asymmetry using two different approaches: semi-automatic, precise, with
FeynArts and FormCalc as base languages, and "by hand", with reasonable
approximations. In addition, we provide a tuned comparison between the one-loop
results obtained in two different renormalization schemes: on-shell and
constrained differential renormalization. As the last step, we discuss the
two-loop EWC induced by squaring one-loop diagrams, and show that the
significant size of this partial correction indicates a need for a complete
study of the two-loop EWC in order to meet the precision goals of future
experiments.Comment: PAVI11 Workshop Proceedings (September 5-9, 2011, Rome
Beam Cooling with ionisation losses
A novel type of particle "cooling", called Ionization Cooling, is applicable
to slow (v of the order of 0.1c) ions stored in a small ring. The many
traversals through a thin foil enhance the nuclear reaction probability, in a
steady configuration in which ionisation losses are recovered at each turn by a
RF-cavity. For a uniform target "foil" the longitudinal momentum spread
diverges exponentially since faster (slower) particles ionise less (more) than
the average. In order to "cool" also longitudinally, a chromaticity has to be
introduced with a wedge shaped "foil". Multiple scattering and straggling are
then "cooled" in all three dimensions, with a method similar to the one of
synchrotron cooling, but valid for low energy ions. Particles then stably
circulate in the beam indefinitely, until they undergo for instance nuclear
processes in the thin target foil. This new method is under consideration for
the nuclear production of a few MeV/A ion beams. Simple reactions, for instance
Li 7 + D Li 8 + p, are more favourably exploited with the heavier ion colliding
against a gas-jet D2 target. Kinematics is generally very favourable, with
emission angles in a narrow angular cone and a relatively concentrated outgoing
energy spectrum which allows an efficient collection as a neutral gas in a tiny
volume with a technology at high temperatures perfected at ISOLDE. It is
however of a much more general applicability. The method appears capable of
producing a "table top" storage ring with an accumulation rate in excess of
10**14 Li-8 radioactive ion/s for possible use for radioactive beams for
physics studies (for example for beta-beams) or for therapy.Comment: 27 pages, 11 figure
White paper: CeLAND - Investigation of the reactor antineutrino anomaly with an intense 144Ce-144Pr antineutrino source in KamLAND
We propose to test for short baseline neutrino oscillations, implied by the
recent reevaluation of the reactor antineutrino flux and by anomalous results
from the gallium solar neutrino detectors. The test will consist of producing a
75 kCi 144Ce - 144Pr antineutrino source to be deployed in the Kamioka Liquid
Scintillator Anti-Neutrino Detector (KamLAND). KamLAND's 13m diameter target
volume provides a suitable environment to measure energy and position
dependence of the detected neutrino flux. A characteristic oscillation pattern
would be visible for a baseline of about 10 m or less, providing a very clean
signal of neutrino disappearance into a yet-unknown, "sterile" state. Such a
measurement will be free of any reactor-related uncertainties. After 1.5 years
of data taking the Reactor Antineutrino Anomaly parameter space will be tested
at > 95% C.L.Comment: White paper prepared for Snowmass-2013; slightly different author
lis
CeLAND: search for a 4th light neutrino state with a 3 PBq 144Ce-144Pr electron antineutrino generator in KamLAND
The reactor neutrino and gallium anomalies can be tested with a 3-4 PBq
(75-100 kCi scale) 144Ce-144Pr antineutrino beta-source deployed at the center
or next to a large low-background liquid scintillator detector. The
antineutrino generator will be produced by the Russian reprocessing plant PA
Mayak as early as 2014, transported to Japan, and deployed in the Kamioka
Liquid Scintillator Anti-Neutrino Detector (KamLAND) as early as 2015.
KamLAND's 13 m diameter target volume provides a suitable environment to
measure the energy and position dependence of the detected neutrino flux. A
characteristic oscillation pattern would be visible for a baseline of about 10
m or less, providing a very clean signal of neutrino disappearance into a
yet-unknown, sterile neutrino state. This will provide a comprehensive test of
the electron dissaperance neutrino anomalies and could lead to the discovery of
a 4th neutrino state for Delta_m^2 > 0.1 eV^2 and sin^2(2theta) > 0.05.Comment: 67 pages, 50 figures. Th. Lasserre thanks the European Research
Council for support under the Starting Grant StG-30718
The Physics of Heavy Flavours at SuperB
This is a review of the SuperB project, covering the accelerator, detector,
and highlights of the broad physics programme. SuperB is a flavour factory
capable of performing precision measurements and searches for rare and
forbidden decays of , , and
particles. These results can be used to test fundamental symmetries and
expectations of the Standard Model, and to constrain many different
hypothesised types of new physics. In some cases these measurements can be used
to place constraints on the existence of light dark matter and light Higgs
particles with masses below . The potential impact of the
measurements that will be made by SuperB on the field of high energy physics is
also discussed in the context of data taken at both high energy in the region
around the \Upsilon({\mathrm{4S}})$, and near charm threshold.Comment: 49 pages, topical review submitted to J. Phys
Validation of techniques to mitigate copper surface contamination in CUORE
In this article we describe the background challenges for the CUORE
experiment posed by surface contamination of inert detector materials such as
copper, and present three techniques explored to mitigate these backgrounds.
Using data from a dedicated test apparatus constructed to validate and compare
these techniques we demonstrate that copper surface contamination levels better
than 10E-07 - 10E-08 Bq/cm2 are achieved for 238U and 232Th. If these levels
are reproduced in the final CUORE apparatus the projected 90% C.L. upper limit
on the number of background counts in the region of interest is 0.02-0.03
counts/keV/kg/y depending on the adopted mitigation technique.Comment: 10 pages, 6 figures, 6 table
Proposal for an Enhanced Optical Cooling System Test in an Electron Storage Ring
We are proposing to test experimentally the new idea of Enhanced Optical
Cooling (EOC) in an electron storage ring. This experiment will confirm new
fundamental processes in beam physics and will demonstrate new unique
possibilities with this cooling technique. It will open important applications
of EOC in nuclear physics, elementary particle physics and in Light Sources
(LS) based on high brightness electron and ion beams.Comment: 21 pages, pdf. The number of electrons in the bunch in the example is
decreased, the volume of the paper is increased, Misprints are correcte
Conceptual design of a nonscaling fixed field alternating gradient accelerator for protons and carbon ions for charged particle therapy
Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.The conceptual design for a nonscaling fixed field alternating gradient accelerator suitable for charged particle therapy (the use of protons and other light ions to treat some forms of cancer) is described.EPSR
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