The NA62 experiment collected a large sample of charged kaon decays in 2007 with a highly efficient trigger for decays into electrons. A measurement of the π0 electromagnetic transition form factor ...slope parameter from 1.11×106 fully reconstructed K±→π±πD0, πD0→e+e−γ events is reported. The measured value a=(3.68±0.57)×10−2 is in good agreement with theoretical expectations and previous measurements, and represents the most precise experimental determination of the slope in the time-like momentum transfer region.
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−.
A sample of 1.69×107 fully reconstructed π0→γe+e− decay candidates collected by the NA48/2 experiment at CERN in 2003–2004 is analyzed to search for the dark photon (A′) production in the π0→γA′ ...decay followed by the prompt A′→e+e− decay. No signal is observed, and an exclusion region in the plane of the dark photon mass mA′ and mixing parameter ε2 is established. The obtained upper limits on ε2 are more stringent than the previous limits in the mass range 9 MeV/c2<mA′<70 MeV/c2. The NA48/2 sensitivity to the dark photon production in the K±→π±A′ decay is also evaluated.
The NA48 experiment at CERN has performed a new measurement of direct CP violation, based on data taken in 1997 by simultaneously collecting
K
L
and
K
S
decays into
π
0
π
0 and
π
+
π
−. The result ...for the CP violating parameter
Re
(ε
′/ε)
is (18.5±4.5(stat)±5.8(syst))×10
−4.
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.
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 π 0 Dalitz decay is presented. The limits on dark photon production in π 0 decays from the earlier kaon experiment at CERN, NA48/2, are also reported.
A study of the dynamics of the rare decay K±→π±γγ has been performed on a sample of 232 decay candidates, with an estimated background of 17.4±1.1 events, collected by the NA62 experiment at CERN in ...2007. The results are combined with those from a measurement conducted by the NA48/2 Collaboration at CERN. The combined model-independent branching ratio in the kinematic range z=(mγγ/mK)2>0.2 is BMI(z>0.2)=(0.965±0.063)×10−6, and the combined branching ratio in the full kinematic range assuming a Chiral Perturbation Theory description is B(Kπγγ)=(1.003±0.056)×10−6. A detailed comparison of the results with the previous measurements is performed.
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