The continuous beam provided by the TTT-3 accelerator of the University of Naples have to be pulsed with 5 ns length bunch to allow experiments in many fields of the fundamental and applied physics. ...The characteristics of the first low energy chopper prototype and the results obtained during preliminary test with the beam are presented.
Measurement of the Λ c + Lifetime Abudinén, F.; Aggarwal, L.; Aihara, H. ...
Physical review letters,
02/2023, Letnik:
130, Številka:
7
Journal Article
Recenzirano
Odprti dostop
An absolute measurement of the $\Lambda^{+}_c$ lifetime is reported using $\Lambda_c^+\rightarrow pK^-\pi^+$ decays in events reconstructed from data collected by the Belle II experiment at the ...SuperKEKB asymmetric-energy electron-positron collider. The total integrated luminosity of the data sample, which was collected at center-of-mass energies at or near the $\Upsilon(4S)$ resonance, is $207.2~\mbox{fb}^{-1}$. The result, $\tau(\Lambda^{+}_c) = 203.20 \pm 0.89 \,\mathrm{(stat)} \pm 0.77 \,\mathrm{(syst)}$ fs, is the most precise measurement to date and is consistent with previous determinations.
The OPERA neutrino detector in the underground Gran Sasso Laboratory (LNGS) has been designed to perform the first detection of neutrino oscillations in direct appearance mode through the study of ...the νμ→ντ channel. The hybrid apparatus consists of an emulsion/lead target complemented by electronic detectors and it is placed in the high energy long-baseline CERN to LNGS beam (CNGS) 730 km away from the neutrino source. Runs with CNGS neutrinos were successfully carried out in 2008 and 2009. After a brief description of the beam, the experimental setup and the procedures used for the analysis of the neutrino events, we describe the topology and kinematics of a first candidate ντ charged-current event satisfying the kinematical selection criteria. The background calculations and their cross-check are explained in detail and the significance of the event is assessed.
We present the first comprehensive tests of light-lepton universality in the angular distributions of semileptonic $B^0$-meson decays to charged spin-1 charmed mesons. We measure five ...angular-asymmetry observables as functions of the decay recoil that are sensitive to lepton-universality-violating contributions. We use events where one neutral $B$ is fully reconstructed in $\Upsilon\left(4S\right)\to{}B \overline{B}$ decays in data corresponding to $189~\mathrm{fb}^{-1}$ integrated luminosity from electron-positron collisions collected with the Belle II detector. We find no significant deviation from the standard model expectations.
We measure the tau-to-light-lepton ratio of inclusive B -meson branching fractions R ( X τ / ℓ ) ≡ B ( B → X τ ν ) / B ( B → X ℓ ν ) , where ℓ indicates an electron or muon, and thereby test the ...universality of charged-current weak interactions. We select events that have one fully reconstructed B meson and a charged lepton candidate from 189 fb − 1 of electron-positron collision data collected with the Belle II detector. We find R ( X τ / ℓ ) = 0.228 ± 0.016 ( stat ) ± 0.036 ( syst ) , in agreement with standard-model expectations. This is the first direct measurement of R ( X τ / ℓ ) . Published by the American Physical Society 2024