Prospects for K+→π+ννˉK^+ \to \pi^+ \nu \bar{ \nu } at CERN in NA62

The NA62 experiment will begin taking data in 2015. Its primary purpose is a 10% measurement of the branching ratio of the ultrarare kaon decay $K^+ \to \pi^+ \nu \bar{ \nu }$, using the decay in flight of kaons in an unseparated beam with momentum 75 GeV/c.The detector and analysis technique are described here.Comment: 8 pages for proceedings of 50 Years of CP

Physics beyond the standard model with kaons at NA62

The NA62 experiment at CERN Super Proton Synchrotron was designed to measure BR(K+ \u2192 \u3c0+\u3bdv\u304) with an in-fight technique, never used before for this measurement. This decay is characterised by a very precise prediction in the Standard Model. Its branching ratio, which is expected to be less than 10-10, is one of the best candidates to indicate indirect effects of new physics beyond SM at the highest mass scales. NA62 result on K+ \u2192 \u3c0+\u3bdv\u304 from the full 2016 data set is described. Also a search for an invisible dark photon A\u2032 has been performed, exploiting the efficient photon-veto capability and high resolution tracking of the NA62. The signal stems from the chain K+ \u2192 \u3c0+\u3c00 followed by \u3c00 \u2192 A\u2032\u3b3. No significant statistical excess has been identified. Upper limits on the dark photon coupling to the ordinary photon as a function of the dark photon mass have been set, improving on the previous limits over the mass range 60 - 110 MeV/c2

Externalities and the nucleolus

In most economic applications, externalities prevail: the worth of a coalition depends on how the other players are organized. We show that there is a unique natural way of extending the nucleolus from (coalitional) games without externalities to games with externalities. This is in contrast to the Shapley value and the core for which many different extensions have been proposed

Search for heavy neutral lepton production in K+ decays

A search for heavy neutral lepton production in K+ decays using a data sample collected with a minimum bias trigger by the NA62 experiment at CERN in 2015 is reported. Upper limits at the 10(-7)to 10(-6) level are established on the elements of the extended neutrino mixing matrix vertical bar U-e4 vertical bar(2)and vertical bar U-mu 4 vertical bar(2)for heavy neutral lepton mass in the ranges 170-448MeV c(2) and 250-373MeV/c(2), respectively. This improves on the previous limits from HNL production searches over the whole mass range considered for vertical bar U-e4 vertical bar(2), and above 300MeV/c(2) for vertical bar U-mu 4 vertical bar(2)

NA62 and NA48/2 results on search for Heavy Neutral Leptons

In this paper we present new results on upper limits for the search of Heavy Neutral Leptons (HNL) with data collected by NA48/2 (2003-2004), NA62-RK (2007) and NA62 (2015) CERN experiments. The data collected with different trigger configuration allow to search for both long and short living heavy neutrinos in the mass range below the kaon mass. In addition the status of the search for K+ → π+vv with the NA62 detector will be briefly presented

Forbidden Kaon and Pion Decays in NA62

NA62, an experiment at the CERN SPS to measure the branching ratio for the decay K+ -> pi+ nu nu-bar with ~10% precision, will observe ~10^13 K+ decays in its fiducial volume, and will thus also be able to carry out a rich program to search for forbidden K+ and pi0 decays, including in particular K+ decays that violate the conservation of lepton flavor and/or number. NA62's potential performance in searches for a number of forbidden K+ and pi0 decays is discussed, with initial sensitivity estimates

The NA62 Experiment at CERN: Status of the Construction

The NA62 collaboration is building a new experiment tailored to measure the ultra-rare kaon decay K+ →π +νν. The first physics run is planned in autumn 2014. This paper presents the detectors of the new experiment and reports on the status of construction as well as first results from the Technical Run in November 2012

Searches for rare and forbidden kaon decays at the NA62 experiment at CERN

The NA62 experiment at the CERN SPS aims at measuring the branching ratio (BR) of the rare K+ \u2192 \u3c0+vv\u304 decay, with a precision of 3c 10%. This goal will be achieved after two years of data taking by collecting 3c 1013 K+ decays in the fiducial volume. The K+ \u2192 \u3c0+vv\u304 is a "golden mode" in flavor physics because of the precise theoretical prediction. Thanks to the unprecedent kaon flux, it will also be possible to search for many other forbidden processes, including leptor flavor violation modes, sterile neutrinos, supersymmetric particles. The expected NA62 performances will wallow the exclusion limits for several decay modes to be improved. The experiment will start collecting data in late 2014. \ua9 Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence