Abstract The NA48/2 experiment at CERN reports the first observation of the K ± → π 0 π 0 μ ± ν decay based on a sample of 2437 candidates with 15% background contamination collected in 2003–2004. ...The decay branching ratio in the kinematic region of the squared dilepton mass above 0.03 GeV2/c 4 is measured to be (0.65 ± 0.03) × 10 −6. The extrapolation to the full kinematic space, using a specific model, is found to be (3.45 ± 0.16) × 10 −6, in agreement with chiral perturbation theory predictions.
Status of the PADME experiment Spagnolo, Stefania
Journal of physics. Conference series,
12/2018, Letnik:
1137, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Among the theoretical models addressing the dark matter problem, the category based on a secluded sector is attracting increasing interest. The PADME experiment, at the Laboratori Nazionali di ...Frascati of INFN, is designed to be sensitive to the production of a low mass gauge boson A′ of a new U(1) symmetry holding for dark sector particles and weakly coupled to the Standard Model photon. The DAΦNE Beam-Test Facility at LNF will provide a high intensity, mono-energetic positron beam impinging on a low Z target. The PADME detector will measure with high precision the momentum of the photon, produced along with the A′ boson in e+e− → A′+γ annihilation in the target, thus allowing to measure the A′ mass as the missing mass in the final state. This technique, particularly useful in case of invisible decays of the A′ boson, will be exploited for the first time in a fixed target experiment. Simulation studies predict a sensitivity on the interaction strength (ϵ2 parameter) down to 10−6, in the mass region 1 MeV < MA′ < 23.7 MeV. In this work the physics potential, the experimental strategy and the status of readiness of the experiment will be reviewed.
Recent QCD results from the NA48/2 experiment Anzivino, Giuseppina; Anzivino, G.; Arcidiacono, R. ...
Nuclear and particle physics proceedings,
07/2018, Letnik:
300-302
Journal Article
Recenzirano
The NA48/2 experiment collected data in 2003 and 2004 with the main purpose to study direct CP violation in charged kaons decaying in three pions. Thanks to the huge statistics collected, other ...studies are also possible. In this paper two recent results, in the framework of QCD studies, are reported: the measurement of the K± → π0e±ν Form Factors and the first observation of the rare decay K± → π±π0e+e−.
The NA62 experiment at CERN collected a large sample of charged kaon decays in ight with a minimum bias trigger in 2007. Upper limits on the rate of the charged kaon decay into a muon and a heavy ...neutral lepton (HNL) obtained from this data are reported for a range of HNL masses. The NA62 experiment has collected further data in 2015 with a completely new and improved detector. New limits on heavy neutrinos from kaon decays into electron and HNL will be presented.
The PADME collaboration aims to search for signals of a light dark photon
A′
using the beam of the LNF LINAC. The experiment, approved by INFN at the end of 2015, foresees to detect
A′
, produced in ...the annihilation of positrons on a thin fixed target, by searching for missing mass signals. The detector construction is ongoing and should be completed within the end of 2017 in order to allow the collection of about 10
13
positrons on target which are necessary to get a 10
−3
sensitivity on the mixing parameter
ε
up to a dark photon mass of 23.7 MeV/
c
2
.
The NA62 experiment at CERN collected a large sample of charged kaon decays with a highly efficient trigger for decays into electrons in 2007. The kaon beam represents a source of tagged neutral pion ...decays in vacuum. A measurement of the electromagnetic transition form factor slope of the neutral pion in the time-like region from ∼1 million fully reconstructed π0 Dalitz decay is presented. The limits on dark photon production in π0 decays from the earlier kaon experiment at CERN, NA48/2, are also reported.
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