977 research outputs found
Z', new fermions and flavor changing processes, constraints on E models from --> eee
We study a new class of flavor changing interactions, which can arise in
models based on extended gauge groups (rank 4) when new charged fermions are
present together with a new neutral gauge boson. We discuss the cases in which
the flavor changing couplings in the new neutral current coupled to the
are theoretically expected to be large, implying that the observed
suppression of neutral flavor changing transitions must be provided by heavy
masses together with small - mixing angles.
Concentrating on E models, we show how the tight experimental limit on implies serious constraints on the mass and mixing
angle. We conclude that if the value of the flavor changing parameters is
assumed to lie in a theoretically natural range, in most cases the presence of
a much lighter than 1 TeV is unlikely.Comment: plain tex, 22 pages + 2 pages figures in PostScript (appended after
`\bye'), UM-TH 92-1
Side Arm Homicide in the Italian Province of Trieste between 1953 and 2002
The authors present a complete overview of the phenomenon of side arm homicide, basing the study on the data collected at the Forensic Pathology Unit of the University Of Trieste School Of Medicine. Side arms are the most frequently used homicidal method in the town and province of Trieste in a considered study period of 50 years from 1953 to 2002. The analysis of the collected data shows that the town and province of Trieste are communities still very well disjoined from a reality in which crimes against life are yet very uncommon occurrences. This conclusion is well supported by the fact that it has not been possible to define a category of potential victims, which is on the contrary quite easy among societies where organized crime is consistent and widespread. The popularity of side arm as homicide method in our province supports the hypothesis that these crimes are often not aforethought murders, perpetrated by subjects often afflicted by recorded mental health problems, acting during an insanity raptus. Knives are not only actually the easiest weapons to obtain in a household, but are very easily used as well, even by the subjects not accustomed to handle weapons
Variations in Function and Vocal Acoustic Characteristics After Orthognathic Surgery: Preliminary Results
Objective: To determine the effects of orthognathic surgery on oral function and vocal quality in order to assess the need for speech therapy after surgery. Material and Methods: Thirty-seven patients scheduled for mono-jaw surgery, specifically maxillary (G1:15 patients), mandibular advancement (G2:10 patients) or mandibular set-back (G3:12 patients), were recruited for this prospective cohort study. Evaluation of oral functions, video recordings of speech articulation and audio recordings of voice were obtained before surgery (T0), and at 1 (T1) and 6 months (T2) after surgery. Spectrographic analysis and self-evaluation questionnaire regarding the vocal performance (VAPP) were performed. Both qualitative and quantitative statistical analysis was performed, mainly using generalized linear models for dichotomous data (p<0.05). Results: The formant frequencies (F1 and F2) of the main vowels vary after orthognathic surgery according to the type of surgery. Before surgery, 84% of patients analyzed showed difficulties in breathing and positioning the tongue both at rest and swallowing. Thanks to surgical correction of the malocclusion, the major part of these issues were resolved within 6 months. In 25% of cases, a change in the voice and/or articulation had occurred. Conclusion: Vocality improves after orthognathic surgery and it changes in relation to the type of surgery. However, vocality did not normalize completely. Speech assessment should be considered after surgery in order to offer adequate speech therapy if necessary
Chapter RoCKIn@Home: Domestic Robots Challenge
Service robots performing complex tasks involving people in houses or public environments are becoming more and more common, and there is a huge interest from both the research and the industrial point of view. The RoCKIn@Home challenge has been designed to compare and evaluate different approaches and solutions to tasks related to the development of domestic and service robots. RoCKIn@Home competitions have been designed and executed according to the benchmarking methodology developed during the project and received very positive feedbacks from the participating teams. Tasks and functionality benchmarks are explained in detail
Events with Isolated Charged Leptons and Large Missing Transverse Momentum at HERA
Striking events with isolated charged leptons, large missing transverse
momentum and large transverse momentum of the hadronic final state were
observed at the electron proton collider HERA in a data sample corresponding to
a luminosity of about 130 pb-1. The H1 collaboration observed 11 events with
isolated electrons or muons and with transverse momentum above 25 GeV. Only
3.4+-0.6 events were expected from Standard Model (SM) processes. Six of these
events have a transverse momentum of greater than 40 GeV, while 1.3+-0.3 events
were expected. The ZEUS collaboration observed good agreement with the SM.
However, ZEUS found two events with a similar event topology, but tau leptons
instead of electrons or muons in the final state. Only 0.2+-0.05 events were
expected from SM processes. For various hypotheses the compatibility of the
experimental results was investigated with respect to the SM and with respect
to possible explanations beyond the SM. Prospects for the high-luminosity
HERA-II data taking period are given
RoCKIn@Home: Domestic Robots Challenge
Service robots performing complex tasks involving people in houses or public environments are becoming more and more common, and there is a huge interest from both the research and the industrial point of view. The RoCKIn@Home challenge has been designed to compare and evaluate different approaches and solutions to tasks related to the development of domestic and service robots. RoCKIn@Home competitions have been designed and executed according to the benchmarking methodology developed during the project and received very positive feedbacks from the participating teams. Tasks and functionality benchmarks are explained in detail
Anatomy of F_D-Term Hybrid Inflation
We analyze the cosmological implications of F-term hybrid inflation with a
subdominant Fayet--Iliopoulos D-term whose presence explicitly breaks a
D-parity in the inflaton-waterfall sector. This scenario of inflation, which is
called F_D-term hybrid model for brevity, can naturally predict lepton number
violation at the electroweak scale, by tying the mu-parameter of the MSSM to an
SO(3)-symmetric Majorana mass m_N, via the vacuum expectation value of the
inflaton field. We show how a negative Hubble-induced mass term in a
next-to-minimal extension of supergravity helps to accommodate the present CMB
data and considerably weaken the strict constraints on the theoretical
parameters, resulting from cosmic string effects on the power spectrum P_R. The
usual gravitino overabundance constraint may be significantly relaxed in this
model, once the enormous entropy release from the late decays of the ultraheavy
waterfall gauge particles is properly considered. As the Universe enters a
second thermalization phase involving a very low reheat temperature, which
might be as low as about 0.3 TeV, thermal electroweak-scale resonant
leptogenesis provides a viable mechanism for successful baryogenesis, while
thermal right-handed sneutrinos emerge as new possible candidates for solving
the cold dark matter problem. In addition, we discuss grand unified theory
realizations of F_D-term hybrid inflation devoid of cosmic strings and
monopoles, based on the complete breaking of an SU(2) subgroup. The F_D-term
hybrid model offers rich particle-physics phenomenology, which could be probed
at high-energy colliders, as well as in low-energy experiments of lepton
flavour or number violation.Comment: 73 pages, LaTeX, minor rewordings, references added, to appear in
JHE
Leptonic CP violation: zero, maximal or between the two extremes
Discovery of the CP-violation in the lepton sector is one of the challenges
of the particle physics. We search for possible principles, symmetries and
phenomenological relations that can lead to particular values of the
CP-violating Dirac phase, . In this connection we discuss two extreme
cases: the zero phase, , and the maximal CP-violation, , and relate them to the peculiar pattern of the neutrino mixing. The
maximal CP-violation can be related to the reflection
symmetry. We study various aspects of this symmetry and introduce a generalized
reflection symmetry that can lead to an arbitrary phase that depends on the
parameter of the symmetry transformation. The generalized reflection symmetry
predicts a simple relation between the Dirac and Majorana phases. We also
consider the possibility of certain relations between the CP-violating phases
in the quark and lepton sectors.Comment: 34 pages, no figures; v3: version appeared in JHE
Low-Energy Thermal Leptogenesis in an Extended NMSSM Model
Thermal leptogenesis in the canonical seesaw model in supersymmetry suffers
from the incompatibility of a generic lower bound on the mass scale of the
lightest right-handed neutrino and the upper bound on the reheating temperature
of the Universe after inflation. This is resolved by adding an extra singlet
superfield, with a discrete symmetry, to the NMSSM (Next to Minimal
Supersymmetric Standard Model). This generic mechanism is applicable to any
supersymmetric model for lowering the scale of leptogenesis.Comment: 16 pages, revtex, 9 eps figure
Management strategies for newly diagnosed immune thrombocytopenia in Italian AIEOP Centres: Do we overtreat? Data from a multicentre, prospective cohort study
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