6,730 research outputs found
Transverse Enhancement Model and MiniBooNE Charge Current Quasi-Elastic Neutrino Scattering Data
Recently proposed Transverse Enhancement Model of nuclear effects in Charge
Current Quasi-Elastic neutrino scattering [A. Bodek, H. S. Budd, and M. E.
Christy, Eur. Phys. J. C{\bf 71} (2011) 1726] is confronted with the MiniBooNE
high statistics experimental data. It is shown that the {\it effective} large
axial mass model leads to better agreement with the data.Comment: 4 pages, 6 figure
Charged Dual String Vacua from Interacting Rotating Black Holes Via Discrete and Nonlinear Symmetries
Using the stationary formulation of the toroidally compactified heterotic
string theory in terms of a pair of matrix Ernst potentials we consider the
four-dimensional truncation of this theory with no U(1) vector fields excited.
Imposing one time-like Killing vector permits us to express the stationary
effective action as a model in which gravity is coupled to a matrix Ernst
potential which, under certain parametrization, allows us to interpret the
matter sector of this theory as a double Ernst system. We generate a web of
string vacua which are related to each other via a set of discrete symmetries
of the effective action (some of them involve S-duality transformations and
possess non-perturbative character). Some physical implications of these
discrete symmetries are analyzed and we find that, in some particular cases,
they relate rotating black holes coupled to a dilaton with no Kalb--Ramond
field, static black holes with non-trivial dilaton and antisymmetric tensor
fields, and rotating and static naked singularities. Further, by applying a
nonlinear symmetry, namely, the so-called normalized Harrison transformation,
on the seed field configurations corresponding to these neutral backgrounds, we
recover the U(1)^n Abelian vector sector of the four-dimensional action of the
heterotic string, charging in this way the double Ernst system which
corresponds to each one of the neutral string vacua, i.e., the stationary and
the static black holes and the naked singularities.Comment: 19 pages in latex, added referenc
Dielectric Characterization of Breast Biopsied Tissues as Pre-Pathological Aid in Early Cancer Detection: A Blinded Feasibility Study
Dielectric characterization has significant potential in several medical applications, providing valuable insights into the electromagnetic properties of biological tissues for disease diagnosis, treatment planning, and monitoring of therapeutic interventions. This work presents the use of a custom-designed electromagnetic characterization system, based on an open-ended coaxial probe, for discriminating between benign and malignant breast tissues in a clinical setting. The probe’s development involved a well-balanced compromise between physical feasibility and its combined use with a reconstruction algorithm known as the virtual transmission line model (VTLM). Immediately following the biopsy procedure, the dielectric properties of the breast tissues were reconstructed, enabling tissue discrimination based on a rule-of-thumb using the obtained dielectric parameters. A comparative analysis was then performed by analyzing the outcomes of the dielectric investigation with respect to conventional histological results. The experimental procedure took place at Complejo Hospitalario Universitario de Toledo—Hospital Virgen de la Salud, Spain, where excised breast tissues were collected and subsequently analyzed using the dielectric characterization system. A comprehensive statistical evaluation of the probe’s performance was carried out, obtaining a sensitivity, specificity, and accuracy of 81.6%, 61.5%, and 73.4%, respectively, compared to conventional histological assessment, considered as the gold standard in this investigation
The combination of high-fat diet-induced obesity and chronic ulcerative colitis reciprocally exacerbates adipose tissue and colon inflammation
<p>Abstract</p> <p>Background</p> <p>This study evaluated the relationship between ulcerative colitis and obesity, which are both chronic diseases characterized by inflammation and increases in immune cells and pro-inflammatory cytokines.</p> <p>Methods</p> <p>Mice with chronic ulcerative colitis induced by 2 cycles of dextran sodium sulfate (DSS) in the first and fourth week of the experiment were fed a high-fat diet (HFD) to induce obesity by 8 weeks. The animals were divided into 4 groups (control, colitis, HFD and colitis + HFD).</p> <p>Results</p> <p>Obesity alone did not raise histopathology scores, but the combination of obesity and colitis worsened the scores in the colon compared to colitis group. Despite the reduction in weight gain, there was increased inflammatory infiltrate in both the colon and visceral adipose tissue of colitis + HFD mice due to increased infiltration of macrophages, neutrophils and lymphocytes. Intravital microscopy of VAT microvasculature showed an increase in leukocyte adhesion and rolling and overexpression of adhesion molecules compared to other groups. Moreover, circulating lymphocytes, monocytes and neutrophils in the spleen and cecal lymph nodes were increased in the colitis + HFD group.</p> <p>Conclusion</p> <p>Our results demonstrated the relationship between ulcerative colitis and obesity as aggravating factors for each disease, with increased inflammation in the colon and adipose tissue and systemic alterations observed in the spleen, lymph nodes and bloodstream.</p
Second-order corrections to neutrino two-flavor oscillation parameters in the wave packet approach
We report about an analytic study involving the {\em intermediate} wave
packet formalism for quantifying the physically relevant information which
appear in the neutrino two-flavor conversion formula and help us to obtain more
precise limits and ranges for neutrino flavor oscillation. By following the
sequence of analytic approximations where we assume a strictly peaked momentum
distribution and consider the second-order corrections in a power series
expansion of the energy, we point out a {\em residual} time-dependent phase
which, coupled with the {\em spreading/slippage} effects, can subtly modify the
neutrino oscillation parameters and limits. Such second-order effects are
usually ignored in the relativistic wave packet treatment, but they present an
evident dependence on the propagation regime so that some small modifications
to the oscillation pattern, even in the ultra-relativistic limit, can be
quantified. These modifications are implemented in the confront with the
neutrino oscillation parameter range (mass-squared difference \Delta m^{\2}
and the mixing-angle ) where we assume the same wave packet parameters
previously noticed in the literature in a kind of {\em toy model} for some
reactor experiments. Generically speaking, our analysis parallels the recent
experimental purposes which concern with higher precision parameter
measurements. To summarize, we show that the effectiveness of a more accurate
determination of \Delta m^{\2} and depends on the wave packet width
and on the averaged propagating energy flux which still
correspond to open variables for some classes of experiments. \Comment: 25 pages, 5 figure
Simple models for the top asymmetry: constraints and predictions
We perform a comprehensive study of the allowed range for the Tevatron t tbar
forward-backward asymmetries in six representative new physics models: a
flavour-changing Z' boson, a scalar isodoublet, a W' boson, a heavy axigluon, a
colour-triplet and a colour-sextet scalar. We devote special attention to the
constraints from the t tbar tail at LHC on the parameter space, which will be
dramatic if the measurements agree with the SM prediction, specially for Z' and
W' bosons. We also study the predictions for the charge asymmetries at LHC and
compare several proposed definitions.Comment: LaTeX 27 pages. Version to appear in JHE
Top quark forward-backward asymmetry in R-parity violating supersymmetry
The interaction of bottom squark-mediated top quark pair production,
occurring in the R-parity violating minimal supersymmetric standard model
(MSSM), is proposed as an explanation of the anomalously large
forward-backward asymmetry (FBA) observed at the Tevatron. We find that this
model can give a good fit to top quark data, both the inclusive and invariant
mass-dependent asymmetries, while remaining consistent (at the 2-
level) with the total and differential production cross-sections. The scenario
is challenged by strong constraints from atomic parity violation (APV), but we
point out an extra diagram for the effective down quark-Z vertex, involving the
same coupling constant as required for the FBA, which tends to weaken the APV
constraint, and which can nullify it for reasonable values of the top squark
masses and mixing angle. Large contributions to flavor-changing neutral
currents can be avoided if only the third generation of sparticles is light.Comment: 24 pages, 7 figures. v3: included LHC top production cross section
data; model still consistent at 2 sigma leve
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