Jorge Luis Borges: L’origine prima di arte e scienza

Search for K+ decays to a muon and invisible particles

The NA62 experiment at CERN reports searches for $K^+\to\mu^+N$ and $K^+\to\mu^+\nu X$ decays, where $N$ and $X$ are massive invisible particles, using the 2016-2018 data set. The $N$ particle is assumed to be a heavy neutral lepton, and the results are expressed as upper limits of ${\cal O}(10^{-8})$ of the neutrino mixing parameter $|U_{\mu4}|^2$ for $N$ masses in the range 200-384 MeV/$c^2$ and lifetime exceeding 50 ns. The $X$ particle is considered a scalar or vector hidden sector mediator decaying to an invisible final state, and upper limits of the decay branching fraction for $X$ masses in the range 10-370 MeV/$c^2$ are reported for the first time, ranging from ${\cal O}(10^{-5})$ t…

PRELIMINARY OBSERVATIONS OF THE BEHAVIOUR IN TWO CAPTIVE CHIMPANZEES (PAN TROGLODYTES) AT BIOPARCO (CARINI, PALERMO)

The beam and detector of the NA62 experiment at CERN

NA62 is a fixed-target experiment at the CERN SPS dedicated to measurements of rare kaon decays. Such measurements, like the branching fraction of the $K^{+} \rightarrow \pi^{+} \nu \bar\nu$ decay, have the potential to bring significant insights into new physics processes when comparison is made with precise theoretical predictions. For this purpose, innovative techniques have been developed, in particular, in the domain of low-mass tracking devices. Detector construction spanned several years from 2009 to 2014. The collaboration started detector commissioning in 2014 and will collect data until the end of 2018. The beam line and detector components are described together with their early …

Jorge Luis Borges: Il linguaggio e la cifra.

Kaon physics at the CERN-SPS

The NA48/2 and NA62 collaborations report on recent results, current status, and prospects of kaon physics at the CERN-SPS. The NA62 collaborations aims to measure the decay [Formula: see text] with an uncertainty of 10% or better. The NA62 detector and preliminary results from a pilot run in 2014 are presented. In addition, recent results of the NA48/2 collaboration are reported. A search for Dark Photons has been performed in [Formula: see text] decays via the kaon decays [Formula: see text] and [Formula: see text]. No dark photon signal was observed and new upper limits on the mixing parameter [Formula: see text] and the dark photon mass were computed. We also report the first observati…

Cortázar: Posiciones e Intersticios

Pensamiento intersticial, viaje del lector a través de un texto que implosiona en sí mismo, en un incesante proceso de deconstrucción, la literatura de Cortázar logra generar regiones misteriosas del imaginario, lugares protegidos y prolíficos en los que se realiza el milagro de una intuición, de una chispa de la que surge, a partir de la reelaboración de la tradición, la identidad de un nuevo recorrido, de un aventuroso viaje de descubrimientos. Se trata de una prorrumpente y revolucionaria recodificación del discurso literario, de un centro propulsivo con mil posibles ramificaciones y de la creación de un nuevo methodos de lectura, en el sentido de un ‘recorrido’ o ‘viaje’ (odos) ‘a travé…

Editoria di interesse ispanico in Sicilia nei secoli XVI e XVII

Banca dati su catalogo on-line prodotto della ricerca PRIN 2008. La banca dati contiene circa 200 schede bibliografiche di esemplari del XVI e del XVII secolo di interesse ispanico pubblicate in Sicilia.