No Arabic abstract
The uncertainty in the initial neutrino flux is the main limitation for a precise determination of the absolute neutrino cross section. The ERC funded ENUBET project (2016-2021) is studying a facility based on a narrow band beam to produce an intense source of electron neutrinos with a ten-fold improvement in accuracy. Since March 2019 ENUBET is also a Neutrino Platform experiment at CERN: NP06/ENUBET. A key element of the project is the instrumentation of the decay tunnel to monitor large angle positrons produced together with $ u_e$ in the three body decays of kaons ($K_{e3}$) and to discriminate them from neutral and charged pions. The need for an efficient and high purity e/$pi$ separation over a length of several meters, and the requirements for fast response and radiation hardness imposed by the harsh beam environment, suggested the implementation of a longitudinally segmented Fe/scintillator calorimeter with a readout based on WLS fibers and SiPM detectors. An extensive experimental program through several test beam campaigns at the CERN-PS T9 beam line has been pursued on calorimeter prototypes, both with a shashlik and a lateral readout configuration. The latter, in which fibers collect the light from the side of the scintillator tiles, allows to place the light sensors away from the core of the calorimeter, thus reducing possible irradiation damages with respect to the shashlik design. This contribution will present the achievements of the prototyping activities carried out, together with irradiation tests made on the Silicon Photo-Multipliers. The results achieved so far pin down the technology of choice for the construction of the 3 m long demonstrator that will take data in 2021.
The narrow band beam of ENUBET is the first implementation of the monitored neutrino beam technique proposed in 2015. ENUBET has been designed to monitor lepton production in the decay tunnel of neutrino beams and to provide a 1% measurement of the neutrino flux at source. In particular, the three body semi-leptonic decay of kaons monitored by large angle positron production offers a fully controlled $ u_{e}$ source at the GeV scale for a new generation of short baseline experiments. In this contribution the performances of the positron tagger prototypes tested at CERN beamlines in 2016-2018 are presented.
The challenges of precision neutrino physics require measurements of absolute neutrino cross sections at the GeV scale with exquisite (1%) precision. This precision is presently limited by the uncertainties on neutrino flux at the source; their reduction by one order of magnitude can be achieved monitoring the positron production in the decay tunnel originating from the $K_{e3}$ decays of charged kaons in a sign and momentum selected narrow band beam. This novel technique enables the measurement of the most relevant cross sections for CP violation ($ u_e$ and $overline{ u}_e$) with a precision of 1% and requires a special instrumented beam-line. Such non-conventional beam-line will be developed in the framework of the ENUBET Horizon-2020 Consolidator Grant, recently approved by the European Research Council. The project, the first experimental results on ultra-compact calorimeters that can be embedded in the instrumented decay tunnel and the advances on the simulation of the beamline are presented. We also discuss the detector and accelerator activities that are planned in 2016-2021.
This report summarises the conclusions from the detector group of the International Scoping Study of a future Neutrino Factory and Super-Beam neutrino facility. The baseline detector options for each possible neutrino beam are defined as follows: 1. A very massive (Megaton) water Cherenkov detector is the baseline option for a sub-GeV Beta Beam and Super Beam facility. 2. There are a number of possibilities for either a Beta Beam or Super Beam (SB) medium energy facility between 1-5 GeV. These include a totally active scintillating detector (TASD), a liquid argon TPC or a water Cherenkov detector. 3. A 100 kton magnetized iron neutrino detector (MIND) is the baseline to detect the wrong sign muon final states (golden channel) at a high energy (20-50 GeV) neutrino factory from muon decay. A 10 kton hybrid neutrino magnetic emulsion cloud chamber detector for wrong sign tau detection (silver channel) is a possible complement to MIND, if one needs to resolve degeneracies that appear in the $delta$-$theta_{13}$ parameter space.
The ENUBET ERC project (2016-2021) is studying a facility based on a narrow band beam capable of constraining the neutrino fluxes normalization through the monitoring of the associated charged leptons in an instrumented decay tunnel. A key element of the project is the design and optimization of the hadronic beamline. In this proceeding we present progress on the studies of the proton extraction schemes. We also show a realistic implementation and simulation of the beamline.
In this note, we address the beam performance (particle content, rates) with emphasis on the momentum determination and particle identification methods for the new H2-VLE (Very Low Energy) beam line that will serve the double phase ProtoDUNE experiment (also known as WA105), in the framework of the CENF project. The proposed instrumentation is configured to achieve an optimal pi/K/proton separation over the full spectrum of provided beam energies, from 0.4 GeV up to 12 GeV, as well as precise momentum measurement to a percent level, if required by the experiment. This note focuses on the H2-VLE beam line for the Double Phase ProtoDUNE experiment, however the same approach can be implemented for the H4-VLE beam, since the design of the two beam lines is very similar.