2,972 research outputs found
Heavy Quark Parameters and Vcb from Spectral Moments in Semileptonic B Decays
We extract the heavy quark masses and non-perturbative parameters from the
Delphi preliminary measurements of the first three moments of the charged
lepton energy and hadronic mass distributions in semileptonic B decays, using a
multi-parameter fit. We adopt two formalisms, one of which does not rely on a
1/mc expansion and makes use of running quark masses. The data are consistent
and the level of accuracy of the experimental inputs largely determines the
present sensitivity. The results allow to improve on the uncertainty in the
extraction of Vcb.Comment: 13 pages, 2 figure
Investigating The Physics Case of Running a B-Factory at the Y(5S) Resonance
We discuss the physics case of a high luminosity B-Factory running at the
Y(5S) resonance. We show that the coherence of the B meson pairs is preserved
at this resonance, and that Bs can be well distinguished from Bd and charged B
mesons. These facts allow to cover the physics program of a traditional
B-Factory and, at the same time, to perform complementary measurements which
are not accessible at the Y(4S). In particular we show how, despite the
experimental limitations in performing time-dependent measurements of Bs
decays, the same experimental information can be extracted, in several cases,
from the determination of time-integrated observables. In addition, a few
examples of the potentiality in measuring rare Bs decays are given. Finally, we
discuss how the study of Bs meson will improve the constraints on New Physics
parameters in the Bs sector, in the context of the generalized Unitarity
Triangle analysis.Comment: 47 pages, 22 figure
Post glacial readjustment, sea level variations, subsidence and erosion along the Italian coasts
Ongoing sea level variations and vertical land movements measured by tide gauges
and continuous GPS stations along the Italian coasts stem from several factors
acting on different spatiotemporal scales. Conversely to tectonics and anthropogenic
effects, which are characterized by a heterogeneous signal, the adjustment of solid
Earth and geoid to the melting of the late– Pleistocene ice sheets results in a smooth
long–wavelength pattern of sea level variation and vertical deformation across the
Mediterranean, mostly driven by the melt water load added to the basin. In this
work we define upper and lower bounds of the effects of glacial isostatic adjustment
(GIA) on current sea level variations and vertical ground movements along the
coasts of Italy. For plausible mantle viscosity profiles we explore to what extent the spatial variability of observed rates may be attributed to delayed isostatic recovery of both solid Earth and geoid. In addition, we show that long–wavelength patterns of sea level change are tuned by the effects of GIA, and that coastal retreat in Italy is broadly correlated with the expected ongoing rates of post–glacial sea level variations
Constraints on new physics from the quark mixing unitarity triangle
The status of the Unitarity Triangle beyond the Standard Model including the
most recent results on Delta m_s, on dilepton asymmetries and on width
differences is presented. Even allowing for general New Physics loop
contributions the Unitarity Triangle must be very close to the Standard Model
result. With the new measurements from the Tevatron, we obtain for the first
time a significant constraint on New Physics in the B_s sector. We present the
allowed ranges of New Physics contributions to Delta F=2 processes, and of the
time-dependent CP asymmetry in B_s to J/Psi phi decays.Comment: 5 pages, 4 figures. v2: numerical error in Delta Gamma_s/Gamma_s
corrected. Plots and tables updated. v3: update after ICHEP06, final version
published in Phys Rev Letter
Innovative Covid-19 diagnostics and testing strategies in Italy, Denmark, UK, Israel and Sweden: a comparative analysis including tests, incidence and mortality
Background and aim: Detecting SARS-CoV-2 remains a critical component in the global effort to control COVID-19, particularly with the emergence of variants. Since the outbreak, diagnostic techniques have evolved to meet different contexts and needs. Methods: In this study, we analyzed the use of these techniques in five countries (i.e. Italy, Denmark, the United Kingdom, Sweden, and Israel) based on their specific national testing and contact tracing strategies. We also examined the number of tests performed per week, the positivity rate of tests, and the mortality rate in these populations during the same time periods. These countries were chosen based on the directives of the consortium involved in the CORONADX project. Results: During the three-year period under review, Italy and Denmark adopted large-scale testing strategies over a long period of time, with different results: in Italy an average of 4.5% of the population adhered to diagnosis, in Denmark 21%, while Israel reached 6.5%. The UK prioritised mass testing for short periods, outperforming the other countries with 1,882,596,198 total swabs and an average adherence of 28.1% of the population. Despite this, it recorded the highest number of deaths related to COVID-19 (211,155), with a lethality rate of 0.87%, second only to Sweden with 0.88%, where the average adherence to diagnosis was 1.7% of the population. Significant are the data for Israel, where as deaths increased, so did testing (r = 0.62, p < 0.001). Conclusions: To control future outbreaks it’s fundamental satisfying the need for effective testing strategies and government communication, equitable healthcare access, and education in public health and hygiene principles. (www.actabiomedica.it)
The impact of SuperB on flavour physics
This report provides a succinct summary of the physics programme of SuperB,
and describes that potential in the context of experiments making measurements
in flavour physics over the next 10 to 20 years. Detailed comparisons are made
with Belle II and LHCb, the other B physics experiments that will run in this
decade. SuperB will play a crucial role in defining the landscape of flavour
physics over the next 20 years.Comment: 20 pages, 6 figure
Commissioning and operation of the Cherenkov detector for proton Flux Measurement of the UA9 Experiment
The UA9 Experiment at CERN-SPS investigates channeling processes in bent
silicon crystals with the aim to manipulate hadron beams. Monitoring and
characterization of channeled beams in the high energy accelerators environment
ideally requires in-vacuum and radiation hard detectors. For this purpose the
Cherenkov detector for proton Flux Measurement (CpFM) was designed and
developed. It is based on thin fused silica bars in the beam pipe vacuum which
intercept charged particles and generate Cherenkov light. The first version of
the CpFM is installed since 2015 in the crystal-assisted collimation setup of
the UA9 experiment. In this paper the procedures to make the detector
operational and fully integrated in the UA9 setup are described. The most
important standard operations of the detector are presented. They have been
used to commission and characterize the detector, providing moreover the
measurement of the integrated channeled beam profile and several functionality
tests as the determination of the crystal bending angle.
The calibration has been performed with Lead (Pb) and Xenon (Xe) beams and
the results are applied to the flux measurement discussed here in detail.Comment: 25 pages, 14 figure
Proteomics-based investigation in C2C12 myoblast differentiation
Skeletal muscle cell differentiation is a multistage process extensively studied over the years. Even if great improvements have been achieved in defining biological process underlying myogenesis, many molecular mechanisms need still to be clarified
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