2,373 research outputs found
A variety of lepton number violating processes related to Majorana neutrino masses
A Majorana type of the neutrino mass matrix induces a class of lepton number
violating processes. Cross sections of these reactions are given in terms of
the neutrino mass matrix element, and a semi-realistic event rate is estimated.
These processes provide mass and mixing parameters not directly accessible by
the neutrino oscillation experiments. If these processes are discovered with a
larger rate than given here, it would imply a new physics of the lepton number
violation not directly related to the Majorana neutrino mass, such as R-parity
violating operators in SUSY models.Comment: 15 pages, 1 figur
Two-frequency heating technique at the 18 GHz electron cyclotron resonance ion source of the National Institute of Radiological Sciences
The two-frequency heating technique was studied to increase the beam
intensities of highly charged ions provided by the high-voltage extraction
configuration (HEC) ion source at the National Institute of Radiological
Sciences (NIRS). The observed dependences on microwave power and frequency
suggested that this technique improved plasma stability but it required precise
frequency tuning and more microwave power than was available before 2013.
Recently, a new, high-power (1200 W) wide bandwidth (17.1-18.5 GHz)
travelling-wave-tube amplifier (TWTA) was installed. After some single tests
with klystron and TWT amplifiers the simultaneous injection of the two
microwaves has been successfully realized. The dependence of highly charged
ions (HCI) currents on the superposed microwave power was studied by changing
only the output power of one of the two amplifiers, alternatively. While
operating the klystron on its fixed 18.0 GHz, the frequency of the TWTA was
swept within its full limits (17.1-18.5 GHz), and the effect of this frequency
on the HCI-production rate was examined under several operation conditions. As
an overall result, new beam records of highly charged argon, krypton, and xenon
beams were obtained at the NIRS-HEC ion source by this high-power two-frequency
operation mode
Effective Autonomic Nerve Treatmentsin Female Patient with Migraine and Tension-Type Headache (TTH)
Authors have been involved in rehabilitation, sports medicine, and psychosomatic problems.
Case presentation: The patient is 40-year-old female, who suffers from migraine and tension-type headache (TTH) for 10 years.Autonomic nerve exam showed decreased function of sympathetic and parasympathetic nerves with tachycardia as 103/min. We continued a series of autonomic nerve treatments, and then pulse was decreased to 90’s, 80’s, 70’s in 1,3,6 months. After treatments, she showed improved autonomic function and stress resilience.
Discussion and Conclusion: The treatments suggest efficacy for recovery of autonomic nerve function. They may become useful reference for novel methods for future developmen
Phase effects from the general neutrino Yukawa matrix on lepton flavor violation
We examine contributions from Majorana phases to lepton flavor violating
processes in the framework of the minimal supersymmetric standard model with
heavy right-handed neutrinos. All phases in the complex neutrino Yukawa matrix
are taken into account in our study. We find that in the scenario with
universal soft-breaking terms sizable phase effects can appear on the lepton
flavor violating processes such as , , and
. In particular, the branching ratio of
can be considerably enhanced due to the Majorana phases, so that it can be much
greater than that of .Comment: 14 pages, 4 eps figures, revtex
Enhancement of lepton flavor violation in a model with bi-maximal mixing at the grand unification scale
We study phenomenological predictions in the scenario with the
quasi-degenerate relation among neutrino Dirac masses, m_D1 simeq m_D2 < m_D3,
assuming the bi-maximal mixing at the grand unification scale in supersymmetric
standard models with right-handed neutrinos. A sufficient lepton number
asymmetry can be produced for successful leptogenesis. The lepton flavor
violating process mu to e gamma can be enhanced due to the Majorana phase, so
that it can be detectable at forthcoming experiments. The processes tau to e
gamma and tau to mu gamma are suppressed because of the structure of neutrino
Dirac masses, and their branching ratios are smaller than that of mu to e
gamma.Comment: 15 pages, 5 figure
New Leptoquark Mechanism of Neutrinoless Double Beta Decay
A new mechanism for neutrinoless double beta (\znbb) decay based on
leptoquark exchange is discussed. Due to the specific helicity structure of the
effective four-fermion interaction this contribution is strongly enhanced
compared to the well-known mass mechanism of \znbb decay. As a result the
corresponding leptoquark parameters are severely constrained from
non-observation of \znbb-decay. These constraints are more stringent than
those derived from other experiments.Comment: LaTeX, 6 pages, 1 figur
Sister chromatid telomere fusions, but not NHEJ-mediated inter-chromosomal telomere fusions, occur independently of DNA ligases 3 and 4
Telomeres shorten with each cell division and can ultimately become substrates for non-homologous end-joining repair, leading to large-scale genomic rearrangements of the kind frequently observed in human cancers. We have characterised over 1400 telomere fusion events at the single-molecule level, using a combination of high-throughput sequence analysis together with experimentally-induced telomeric double-stranded DNA breaks. We show that a single chromosomal dysfunctional telomere can fuse with diverse non-telomeric genomic loci, even in the presence of an otherwise stable genome, and that fusion predominates in coding regions. Fusion frequency was markedly increased in the absence of TP53 checkpoint control and significantly modulated by the cellular capacity for classical, versus alternative, non-homologous end joining (NHEJ). We observed a striking reduction in inter-chromosomal fusion events in cells lacking DNA ligase 4, in contrast to a remarkably consistent profile of intra-chromosomal fusion in the context of multiple genetic knockouts, including DNA ligase 3 and 4 double-knockouts. We reveal distinct mutational signatures associated with classical NHEJ-mediated inter-chromosomal, as opposed to alternative NHEJ-mediated intra-chromosomal telomere fusions and evidence an unanticipated sufficiency of DNA ligase 1 for these intra-chromosomal events. Our findings have implications for mechanisms driving cancer genome evolution
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