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Y. Becherini

Publications and source records attributed to Y. Becherini.

206 records · Page 12Linked to original sources

Time variations in the deep underground muon flux measured by MACRO

More than 30 million of high-energy muons collected with the MACRO detector at the underground Gran Sasso Laboratory have been used to search for flux variations of different natures. Two kinds of studies were carried out: search for periodic variations and for the occurrence of clusters of events. Different analysis methods, including Lomb-Scargle spectral analysis and Scan Test statistics have been applied to the data.

astro-ph↗

Search for exotic contributions to atmospheric neutrino oscillations

The energy spectrum of neutrino-induced upward-going muons in MACRO was analysed in terms of relativity principles violating effects, keeping standard mass-induced atmospheric neutrino oscillations as the dominant effect. The data disfavor these possibilities even at a sub-dominant level; stringent 90% C.L. limits are placed on the Lorentz invariance violation parameter $|Δv| < 6 \times 10^{-24}$ at $\sin 2θ_v$ = 0 and $|Δv| < 2.5 ÷5 \times 10^{-26}$ at $\sin 2θ_v$ = $\pm$1. The limits can be re-interpreted as bounds on the Equivalence Principle violation parameters.

hep-ex↗

A parameterisation of single and multiple muons in the deep water or ice

Atmospheric muons play an important role in underwater/ice neutrino detectors. In this paper, a parameterisation of the flux of single and multiple muon events, their lateral distribution and of their energy spectrum is presented. The kinematics parameters were modelled starting from a full Monte Carlo simulation of the interaction of primary cosmic rays with atmospheric nuclei; secondary muons reaching the sea level were propagated in the deep water. The parametric formulas are valid for a vertical depth of 1.5-5 km w.e. and up to 85 deg for the zenith angle, and can be used as input for a fast simulation of atmospheric muons in underwater/ice detectors.

hep-ph↗

Search for a Lorentz invariance violation contribution in atmospheric neutrino oscillations using MACRO data

Neutrino-induced upward-going muons in MACRO have been analysed in terms of relativity principles violating effects, keeping standard mass-induced atmospheric neutrino oscillations as the dominant source of nu_mu -> nu_tau transitions. The data disfavor these exotic possibilities even at a sub-dominant level, and stringent 90% C.L. limits are placed on the Lorentz invariance violation parameter |Delta v| < 6 * 10^(-24) at sin2theta_v = 0 and |Delta v| < 2.5--5 * 10^(-26) at sin2theta_v = +/-1. These limits can also be re-interpreted as upper bounds on the parameters describing violation of the Equivalence Principle.

hep-ex↗

Time correlations of high energy muons in an underground detector

We present the result of a search for correlations in the arrival times of high energy muons collected from 1995 till 2000 with the streamer tube system of the complete MACRO detector at the underground Gran Sasso Lab. Large samples of single muons (8.6 million), double muons (0.46 million) and multiple muons with multiplicities from 3 to 6 (0.08 million) were selected. These samples were used to search for time correlations of cosmic ray particles coming from the whole upper hemisphere or from selected space cones. The results of our analyses confirm with high statistics a random arrival time distribution of high energy cosmic rays.

astro-ph↗

The ANTARES neutrino telescope

The ANTARES collaboration is building a deep underwater neutrino Cerenkov telescope at 2400 m which will be located off the Mediterranean sea coast near Toulon, France. The main scientific aims of the experiment are the detection of high energy upgoing muons coming from astrophysical neutrinos, indirect dark matter searches, the study of atmospheric neutrino oscillations. The detector will be completed in the end of 2004.

hep-ph↗

Estimate of the Energy of Upgoing Muons with Multiple Coulomb Scattering

Upward throughgoing muons in underground detectors are induced by atmospheric $ν_μ$ with energies in the $1-10^4 GeV$ range. The oscillations of atmospheric muon neutrinos should affect mainly those with energy smaller than $E_ν\sim 50 GeV$, or $E_μ\le 10 GeV$ . We analyzed the MACRO upward throughgoing muons data set, using the Multiple Coulomb Scattering to estimate the energy $E_μ$ of muons crossing the detector. We analyzed the event distribution for six event subsamples with different values of $<\ell_ν/ E_ν>$. The event distribution is in agreement with the hypothesis of neutrino oscillations with $Δm^2$ few times $10^{-3} eV^2$ and maximum mixing.

hep-ex↗