arXiv subjects

A. Mtchedilishvili

Publications and source records attributed to A. Mtchedilishvili.

3 recordsLinked to original sources

arXiv2020

Search for lepton flavour violating muon decay mediated by a new light particle in the MEG experiment

We present the first direct search for lepton flavour violating muon decay mediated by a new light particle X, $μ^+ \to \mathrm{e}^+\mathrm{X}, \mathrm{X} \to γγ$. This search uses a dataset resulting from $7.5\times 10^{14}$ stopped muons collected by the MEG experiment at the Paul Scherrer Institut in the period 2009--2013. No significant excess is found in the mass region 20--45 MeV/c$^2$ for lifetimes below 40 ps, and we set the most stringent branching ratio upper limits in the mass region of 20--40 MeV/c$^2$, down to $\mathcal{O}(10^{-11})$ at 90\% confidence level.

hep-ex↗

arXiv2018

Results from Pilot Run for MEG II Positron Timing Counter

The MEG II experiment at Paul Scherrer Institut in Switzerland will search for the lepton flavour violating muon decay, $μ^+\to e^+γ$, with a sensitivity of $4\times10^{-14}$ improving the existing limit of an order of magnitude. In 2016, we finished the construction of the MEG II Timing Counter, the subdetector dedicated to the measurement of the positron emission time. The first one-fourth of it was installed in the experimental area and we performed a pilot run with the MEG~II beam of $7\times10^{7}μ^+/$s. The timing resolution reached the design value improving by a factor of two compared to MEG.

physics.ins-det↗

arXiv2018

The design of the MEG II experiment

The MEG experiment, designed to search for the mu+->e+ gamma decay at a 10^-13 sensitivity level, completed data taking in 2013. In order to increase the sensitivity reach of the experiment by an order of magnitude to the level of 6 x 10-14 for the branching ratio, a total upgrade, involving substantial changes to the experiment, has been undertaken, known as MEG II. We present both the motivation for the upgrade and a detailed overview of the design of the experiment and of the expected detector performance.

physics.ins-det↗