4 research outputs found
The KATRIN Experiment
The KArlsruhe TRitium Neutrino mass experiment, KATRIN, aims to search for
the mass of the electron neutrino with a sensitivity of 0.2 eV/c^2 (90% C.L.)
and a detection limit of 0.35 eV/c^2 (5 sigma). Both a positive or a negative
result will have far reaching implications for cosmology and the standard model
of particle physics and will give new input for astroparticle physics and
cosmology. The major components of KATRIN are being set up at the Karlsruhe
Institut of Technology in Karlsruhe, Germany, and test measurements of the
individual components have started. Data taking with tritium is scheduled to
start in 2012.Comment: 3 pages, 1 figure, proceedings of the TAUP 2009 International
Conference on Topics in Astroparticle and Underground Physics, to be
published in Journal of Physics, Conference Serie
Theory of neutrinoless double beta decay
Neutrinoless double beta decay, which is a very old and yet elusive process,
is reviewed. Its observation will signal that lepton number is not conserved
and the neutrinos are Majorana particles. More importantly it is our best hope
for determining the absolute neutrino mass scale at the level of a few tens of
meV. To achieve the last goal certain hurdles have to be overcome involving
particle, nuclear and experimental physics. Nuclear physics is important for
extracting the useful information from the data. One must accurately evaluate
the relevant nuclear matrix elements, a formidable task. To this end, we review
the sophisticated nuclear structure approaches recently been developed, which
give confidence that the needed nuclear matrix elements can be reliably
calculated. From an experimental point of view it is challenging, since the
life times are long and one has to fight against formidable backgrounds. If a
signal is found, it will be a tremendous accomplishment. Then, of course, the
real task is going to be the extraction of the neutrino mass from the
observations. This is not trivial, since current particle models predict the
presence of many mechanisms other than the neutrino mass, which may contribute
or even dominate this process. We will, in particular, consider the following
processes: (i)The neutrino induced, but neutrino mass independent contribution.
(ii)Heavy left and/or right handed neutrino mass contributions.
(iii)Intermediate scalars (doubly charged etc). (iv)Supersymmetric (SUSY)
contributions. We will show that it is possible to disentangle the various
mechanisms and unambiguously extract the important neutrino mass scale, if all
the signatures of the reaction are searched in a sufficient number of nuclear
isotopes.Comment: 104 pages, 6 tables, 25 figures.References added. To appear in ROP
(Reports on Progress in Physics), copyright RO
A UV LED-based fast-pulsed photoelectron source for time-of-flight studies
We report on spectroscopy and time-of-flight measurements using an 18 keV
fast-pulsed photoelectron source of adjustable intensity, ranging from single
photoelectrons per pulse to 5 photoelectrons per microsecond at pulse
repetition rates of up to 10 kHz. Short pulses between 40 ns and 40
microseconds in length were produced by switching light emitting diodes with
central output wavelengths of 265 nm and 257 nm, in the deep ultraviolet (or
UV-C) regime, at kHz frequencies. Such photoelectron sources can be useful
calibration devices for testing the properties of high-resolution electrostatic
spectrometers, like the ones used in current neutrino mass searches.Comment: 16 pages, 11 figure
Topical Review on "Beta-beams"
Neutrino physics is traversing an exciting period, after the important
discovery that neutrinos are massive particles, that has implications from
high-energy physics to cosmology. A new method for the production of intense
and pure neutrino beams has been proposed recently: the ``beta-beam''. It
exploits boosted radioactive ions decaying through beta-decay. This novel
concept has been the starting point for a new possible future facility. Its
main goal is to address the crucial issue of the existence of CP violation in
the lepton sector. Here we review the status and the recent developments with
beta-beams. We discuss the original, the medium and high-energy scenarios as
well as mono-chromatic neutrino beams produced through ion electron-capture.
The issue of the degeneracies is mentioned. An overview of low energy
beta-beams is also presented. These beams can be used to perform experiments of
interest for nuclear structure, for the study of fundamental interactions and
for nuclear astrophysics.Comment: Topical Review for Journal of Physics G: Nuclear and Particle
Physics, published version, minor corrections, references adde