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The NA62 Collaboration

Publications and source records attributed to The NA62 Collaboration.

5 recordsLinked to original sources

arXiv2024

Development of a new CEDAR for kaon identification at the NA62 experiment at CERN

The NA62 experiment at CERN utilises a differential Cherenkov counter with achromatic ring focus (CEDAR) for tagging kaons within an unseparated monochromatic beam of charged hadrons. The CEDAR-H detector was developed to minimise the amount of material in the path of the beam by using hydrogen gas as the radiator medium. The detector was shown to satisfy the kaon tagging requirements in a test-beam before installation and commissioning at the experiment. The CEDAR-H performance was measured using NA62 data collected in 2023.

hep-ex↗

arXiv2024

Measurement of the $K^+\toπ^+γγ$ decay

A sample of 3984 candidates of the $K^+\toπ^+γγ$ decay, with an estimated background of $291\pm14$ events, was collected by the NA62 experiment at CERN during 2017-2018. In order to describe the observed di-photon mass spectrum, the next-to-leading order contribution in chiral perturbation theory was found to be necessary. The decay branching ratio in the full kinematic range is measured to be $(9.61\pm0.17)\times10^{-7}$. The first search for production and prompt decay of an axion-like particle with gluon coupling in the process $K^+\toπ^+a$, $a\toγγ$ is also reported.

hep-ex↗

arXiv2023

A study of the $K^+ \to π^0 e^+ νγ$ decay

A sample of $1.3 \times 10^5$ $K^+ \to π^0 e^+ νγ$ candidates with less than 1% background was collected by the NA62 experiment at the CERN SPS in 2017-2018. Branching fraction measurements are obtained at percent relative precision in three restricted kinematic regions, improving on existing results by a factor larger than two. An asymmetry, possibly related to T-violation, is investigated with no evidence observed within the achieved precision.

hep-ex↗

arXiv2023

Performance of the NA62 trigger system

The NA62 experiment at CERN targets the measurement of the ultra-rare $K^{+} \to π^{+}ν\barν$ decay, and carries out a broad physics programme that includes probes for symmetry violations and searches for exotic particles. Data were collected in 2016-2018 using a multi-level trigger system, which is described highlighting performance studies based on 2018 data.

hep-ex↗

arXiv2017

Search for Heavy Neutrinos in $K^+ \rightarrow μ^+ ν_μ$ Decays

The NA62 experiment recorded a large sample of $K^+ \rightarrow μ^+ ν_μ$ decays in 2007. A peak search has been performed in the reconstructed missing mass spectrum. In the absence of a signal, limits in the range $2 \times 10^{-6}$ to $10^{-5}$ have been set on the squared mixing matrix element $|U_{\mu4} |^2$ between muon and heavy neutrino states, for heavy neutrino masses in the range 300-375 MeV/$c^2$. The result extends the range of masses for which upper limits have been set on the value of $|U_{\mu4} |^2$ in previous production search experiments.

hep-ex↗