1,421 research outputs found
Exclusive dimuon measurements with LHCb
International audienc
Global fit to CKM data
International audienceWe present updated results for the CKM matrix elements from a global fit to flavour physics data within the standard model theoretical context. We emphasise recent improvements on the determination of the CKM parameters l and A as well as on the angle g of the unitarity triangle
Acoustic Signal Computations in the Mediterranean Sea
4 p.International audienceWe investigate various issues related to the thermacoustic signal computation from underwater cascades in a mediterranean sea environment and discuss their implications
Simulation of Cosmic Ray neutrinos Interactions in Water
The program CORSIKA, usually used to simulate extensive cosmic ray air
showers, has been adapted to a water medium in order to study the acoustic
detection of ultra high energy neutrinos. Showers in water from incident
protons and from neutrinos have been generated and their properties are
described. The results obtained from CORSIKA are compared to those from other
available simulation programs such as Geant4.Comment: Talk presented on behalf of the ACoRNE Collaboration at the ARENA
Workshop 200
Predictions of selected flavour observables within the Standard Model
This letter gathers a selection of Standard Model predictions issued from the
metrology of the CKM parameters performed by the CKMfitter group. The selection
includes purely leptonic decays of neutral and charged B, D and K mesons. In
the light of the expected measurements from the LHCb experiment, a special
attention is given to the radiative decay modes of B mesons as well as to the
B-meson mixing observables, in particular the semileptonic charge asymmetries
a^d,s_SL which have been recently investigated by the D0 experiment at
Tevatron. Constraints arising from rare kaon decays are addressed, in light of
both current results and expected performances of future rare kaon experiments.
All results have been obtained with the CKMfitter analysis package, featuring
the frequentist statistical approach and using Rfit to handle theoretical
uncertainties.Comment: 8 pages, 1 figure, 2 tables. Typos corrected and discussion of
agreement between SM and data update
Underwater Acoustic Detection of Ultra High Energy Neutrinos
We investigate the acoustic detection method of 10^18-20 eV neutrinos in a
Mediterranean Sea environment. The acoustic signal is re-evaluated according to
dedicated cascade simulations and a complex phase dependant absorption model,
and compared to previous studies. We detail the evolution of the acoustic
signal as function of the primary shower characteristics and of the acoustic
propagation range. The effective volume of detection for a single hydrophone is
given taking into account the limitations due to sea bed and surface boundaries
as well as refraction effects. For this 'benchmark detector' we present
sensitivity limits to astrophysical neutrino fluxes, from which sensitivity
bounds for a larger acoustic detector can be derived. Results suggest that with
a limited instrumentation the acoustic method would be more efficient at
extreme energies, above 10^20 eV.Comment: 15 pages, 11 figure
Studies on muon tomography for archaeological internal structures scanning
International audienceMuon tomography is a potential non-invasive technique for internal structure scanning. It has already interesting applications in geophysics and can be used for archaeological purposes. Muon tomography is based on the measurement of the muon flux after crossing the structure studied. Differences on the mean density of these structures imply differences on the detected muon rate for a given direction. Based on this principle, Monte Carlo simulations represent a useful tool to provide a model of the expected muon rate and angular distribution depending on the composition of the studied object, being useful to estimate the expected detected muons and to better understand the experimental results. These simulations are mainly dependent on the geometry and composition of the studied object and on the modelling of the initial muon flux at surface. In this work, the potential of muon tomography in archaeology is presented and evaluated with Monte Carlo simulations by estimating the differences on the muon rate due to the presence of internal structures and its composition. The influence of the chosen muon model at surface in terms of energy and angular distributions in the final result has been also studied. 1. Introduction Among the different applications that muon tomography can have, the scanning of archaeological structures is one of the most innovative one. The principle of the method is straightforward. By detecting the muons that cross the studied object and reconstructing their directions, it is possible to identify the existence of significant differences in the muon rate for a given direction. These differences, consequence of a variation of the mean density of the object traversed by the muons, indicate the possible existence of an internal structure inside the object. The reconstruction of these internal structures by the analysis of the directions of the registered muons is frequently called inverse method. Some features of muon tomography are specially interesting for archaeology. It is a passive method since it is based on the detection of the atmospheric muons, which are naturally produced. Moreover, it is a non-invasive technique since the detector would be placed outside the object to study or, if possible, inside it if internal corridors and halls already exist, as i
Development of a radio detection array for the observation of showers induced by UHE Tau neutrinos
International audienceDevelopment of a radio detection array for the observation of showers induced by UHE Tau neutrino
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