3,098 research outputs found
Why the Water Bridge does not collapse
In 2007 an interesting phenomenon was discovered: a thread of water, the
so-called water bridge (WB), can hang between two glass beakers filled with
deionized water if voltage is applied to them. We analyze the available
explanations of the WB stability and propose a completely different one: the
force that supports the WB is the surface tension of water and the role of
electric field is not to allow the WB to reduce its surface energy by means of
breaking into separate drops.Comment: 4 pages, 3 figure
DNA waves and water
Some bacterial and viral DNA sequences have been found to induce low
frequency electromagnetic waves in high aqueous dilutions. This phenomenon
appears to be triggered by the ambient electromagnetic background of very low
frequency. We discuss this phenomenon in the framework of quantum field theory.
A scheme able to account for the observations is proposed. The reported
phenomenon could allow to develop highly sensitive detection systems for
chronic bacterial and viral infections.Comment: Invited talk at the DICE2010 Conference, Castiglioncello, Italy
September 201
Pure Gravity Mediation with m_{3/2} = 10-100TeV
Recently, the ATLAS and CMS collaborations reported exciting hints of a
Standard Model-like Higgs boson with a mass around 125GeV. Such a Higgs boson
mass can be easily obtained in the minimal supersymmetric Standard Model based
on the "pure gravity mediation model" where the sfermion masses and the Higgs
mass parameters are in tens to hundreds TeV range while the gauginos are in the
hundreds GeV to TeV range. In this paper, we discuss detalis of the gaugino
mass spectrum in the pure gravity mediation model. We also discuss the signals
of the model at the current and future experiments such as cosmic ray
observations and the LHC experiments. In particular, we show that the parameter
space which is consistent with the thermal leptogenesis can be fully surveyed
experimentally in the foreseeable future.Comment: 21 pages, 7 figure
More Visible Effects of the Hidden Sector
There is a growing appreciation that hidden sector dynamics may affect the
supersymmetry breaking parameters in the visible sector (supersymmetric
standard model), especially when the dynamics is strong and superconformal. We
point out that there are effects that have not been previously discussed in the
literature. For example, the gaugino masses are suppressed relative to the
gravitino mass. We discuss their implications in the context of various
mediation mechanisms. The issues discussed include anomaly mediation with
singlets, the mu (B mu) problem in gauge and gaugino mediation, and distinct
mass spectra for the superparticles that have not been previously considered.Comment: 25 pages; small clarifications and corrections, version to appear in
Phys. Rev.
Neutrino Masses in Split Supersymmetry
We investigate the possibility to generate neutrino masses in the context of
Split supersymmetric scenarios where all sfermions are very heavy. All relevant
contributions coming from the R-parity violating terms to the neutrino mass
matrix up to one-loop level are computed, showing the importance of the Higgs
one-loop corrections. We conclude that it is not possible to generate all
neutrino masses and mixings in Split SUSY with bilinear R-Parity violating
interactions. In the case of Partial Split SUSY the one-loop Higgs
contributions are enough to generate the neutrino masses and mixings in
agreement with the experiment. In the context of minimal SUSY SU(5) we find new
contributions which help us to generate neutrino masses in the case of Split
SUSY.Comment: 33 pages, 6 figures, to appear in Physical Review
Quark-antiquark pair production in space-time dependent fields
Fermion-antifermion pair-production in the presence of classical fields is
described based on the retarded and advanced fermion propagators. They are
obtained by solving the equation of motion for the Dirac Green's functions with
the respective boundary conditions to all orders in the field. Subsequently,
various approximation schemes fit for different field configurations are
explained. This includes longitudinally boost-invariant forms. Those occur
frequently in the description of ultrarelativistic heavy-ion collisions in the
semiclassical limit. As a next step, the gauge invariance of the expression for
the expectation value of the number of produced fermion-antifermion pairs as a
functional of said propagators is investigated in detail. Finally, the
calculations are carried out for a longitudinally boost-invariant model-field,
taking care of the last issue, especially.Comment: 32 pages, 8 figures, revised versio
Direct Detection of the Wino- and Higgsino-like Neutralino Dark Matters at One-Loop Level
The neutralino-nucleon (\tilde{\chi}^0-N) scattering is an important process
for direct dark matter searches. In this paper we discuss one-loop
contributions to the cross section in the wino-like and Higgsino-like LSP
cases. The neutralino-nucleon scattering mediated by the Higgs
\tilde{\chi}^0\tilde{\chi}^0 and Z\tilde{\chi}^0\tilde{\chi}^0 couplings at
tree level is suppressed by the gaugino-Higgsino mixing at tree level when the
neutralino is close to a weak eigenstate. The one-loop contribution to the
cross section, generated by the gauge interaction, is not suppressed by any
SUSY particle mass or mixing in the wino- and Higgsino-like LSP cases. It may
significantly alter the total cross section when \sigma_{\tilde{\chi}^0 N}\sim
10^{-45} cm^2 or less.Comment: 26 pages, 9 figures. Version to be published in Physical Review
The Minimal Model for Dark Matter and Unification
Gauge coupling unification and the success of TeV-scale weakly interacting
dark matter are usually taken as evidence of low energy supersymmetry (SUSY).
However, if we assume that the tuning of the higgs can be explained in some
unnatural way, from environmental considerations for example, SUSY is no longer
a necessary component of any Beyond the Standard Model theory. In this paper we
study the minimal model with a dark matter candidate and gauge coupling
unification. This consists of the SM plus fermions with the quantum numbers of
SUSY higgsinos, and a singlet. It predicts thermal dark matter with a mass that
can range from 100 GeV to around 2 TeV and generically gives rise to an
electric dipole moment that is just beyond current experimental limits, with a
large portion of its allowed parameter space accessible to next generation EDM
and direct detection experiments. We study precision unification in this model
by embedding it in a 5-D orbifold GUT where certain large threshold corrections
are calculable, achieving gauge coupling and b-tau unification, and predicting
a rate of proton decay just beyond current limits.Comment: 20 pages, 10 figures. v2: Minor typos and Reference errors corrected.
Modified explanation of the KK mode contribution to runnin
COVID-19 and the impact on the cranio-oro-facial trauma care in Italy: An epidemiological retrospective cohort study
The coronavirus disease 2019 (COVID-19) has deeply modified the organization of hospitals, health care centers, and the patient’s behavior. The aim of this epidemiological retrospective cohort study is to evaluate if and how the COVID-19 pandemic has determined a modification in cranio-oro-facial traumatology service. Methods: The dataset included hospital emergency room access of a six-month pre-pandemic period and six months into pandemic outbreak. The variables collected were: patient age, gender, type of emergency access with relative color code, Glasgow Coma Scale Score, type of discharge. Results: 537 vs 237 (pre-pandemic vs pandemic) patients accessed the hospital emergency room and the mean age decreased from 60.79 ± 25.34 to 56.75 ± 24.50 year. Yellow and green code access went from 28.9% and 66.1% to 37.5% and 57.7% (pre-pandemic vs pandemic). Glasgow Coma Scale (GCS) shows an increase of 16.6% vs 27.8% of 15 grade score, a 28.7% vs 28.5% of the 14 grade score and reduction of 13 and 12 grade 40.2% and 14.5% vs 37.1 and 9.7% (pre-pandemic vs pandemic). Conclusions: Since the COVID-19 outbreak continues, epidemiological data are still necessary to perform public health intervention strategies and to appropriately predict the population needs, in order to properly manage the COVID-19 related to oral pathologies as well as the most common health problems
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