Design and optimisation of a variable momentum secondary beamline for the NP06/ENUBET project

The precision of the measurement of the cross-section of the electronic and muon neutrino is mainly limited by the knowledge of the initial flux. The current precision is on the order of 5−10%. The ENUBET (Enhanced NeUtrino Beam from kaon Tagging) project proposes a new facility capable of monitoring the neutrino beam produced by a secondary meson beam by tagging the corresponding lepton emitted in the same production decay. This type of study places several restrictions on the secondary beam, that essentially defines the energy spectrum of the neutrinos reaching the far detector. In this Ph.D. thesis work, we present the studies carried out for the design and optimization of a modular momentum beamline (Multi-Momentum Beamline) at the BE-EA-LE section of CERN. The proposed layout is optimized for the transport of $K$$^{+}$ and $\pi$$^{+}$ mesons with momentum centered around 8.5, 6 and 4 GeV/c. Using this beamline, it is possible to monitor the neutrino energy in the area of interest of experiments such as HyperK, T2K, and DUNE through the same configuration of magnets. In addition to modularity, the developed multi-momentum beamline presents remarkable properties such as a very satisfactory neutrino yield, control of the background, and satisfactory beam properties and performance that are all discussed in detail. A special target optimization procedure for maximizing the hadron yield has also been devised. Furthermore, the design is made up of only elements already in use at CERN. The use of pre-existing magnets allows a quantitative as well as qualitative analysis of the performance of the beamline as well as a low cost in the implementation. Finally, a comparison between Monte-Carlo and data for the ENUBINO prototype, tested at CERN’s EAST area is presented

Design and Diagnostics of High-Precision Accelerator Neutrino Beams

Neutrino oscillation physics has entered a new precision era, which poses major challenges to the level of control and diagnostics of the neutrino beams. In this paper, we review the design of high-precision beams, their current limitations, and the latest techniques envisaged to overcome such limits. We put emphasis on “monitored neutrino beams” and advanced diagnostics to determine the flux and flavor of the neutrinos produced at the source at the per-cent level. We also discuss ab-initio measurements of the neutrino energy–i.e., measurements performed without relying on the event reconstruction at the ν detector–to remove any flux induced bias in the determination of the cross sections

Design and Diagnostics of High-Precision Accelerator Neutrino Beams

Neutrino oscillation physics has entered a new precision era, which poses major challenges to the level of control and diagnostics of the neutrino beams. In this paper, we review the design of high-precision beams, their current limitations, and the latest techniques envisaged to overcome such limits. We put emphasis on “monitored neutrino beams” and advanced diagnostics to determine the flux and flavor of the neutrinos produced at the source at the per-cent level. We also discuss ab-initio measurements of the neutrino energy–i.e., measurements performed without relying on the event reconstruction at the ν detector–to remove any flux induced bias in the determination of the cross sections.</jats:p

NuTag: proof-of-concept study for a long-baseline neutrino beam

International audienceThe study of neutrino oscillation at accelerators is limited by systematic uncertainties, in particular on the neutrino flux, cross-section, and energy estimates. These systematic uncertainties could be eliminated by a novel experimental technique: neutrino tagging. This technique relies on a new type of neutrino beamline and its associated instrumentation which would enable the kinematical reconstruction of the neutrinos produced in $\pi^{\pm} \to \mu^{\pm} \nu_\mu$ and $K^{\pm} \to \mu^{\pm} \nu_\mu$ decays. This article presents a proof-of-concept study for such a tagged beamline, aiming to serve a long baseline neutrino experiment exploiting a megaton scale natural water Cherenkov detector. After optimizing the target and the beamline optics to first order, a complete Monte Carlo simulation of the beamline has been performed. The results show that the beamline provides a meson beam compatible with the operation of the spectrometer, and delivers a neutrino flux sufficient to collect neutrino samples with a size comparable with similar experiments and with other un-tagged long-baseline neutrino experimental proposals

The ENUBET Multi Momentum Secondary Beamline Design

The aim of neutrino physics for the next decades is to detect effects due to CP violation, mass hierarchy, and search for effects beyond the Standard Model predictions. Future experiments need precise measurements of the neutrino interaction cross-sections at the ~GeV/c regime, currently limited by the exact knowledge of the initial neutrino flux on a ~10-20% uncertainty level. The ENUBET project is proposing a novel facility, capable of constraining the neutrino flux normalization through the precise monitoring of the Ke3 (K±>e+pi0nu) decay products in an instrumented decay tunnel. ENUBET can also monitor muons from the two body kaon and pion decays (nu flux) and measure the neutrino energy with a 10% precision without relying on the event reconstruction at the neutrino detector. We present here a novel design based on a broad (4-8.5 GeV/c) momentum range secondary beamline, that widen the cross-section energy range that can be explored by ENUBET. In this poster, we discuss the target optimization studies and we show the early results on the new line’s optics and the layout design. We discuss the expected performance of this line and the forthcoming activities

Performance Optimization of a Short-Baseline Neutrino Beamline at CERN

International audienc

NuTag: proof-of-concept study for a long-baseline neutrino beam

International audienceThe study of neutrino oscillation at accelerators is limited by systematic uncertainties, in particular on the neutrino flux, cross-section, and energy estimates. These systematic uncertainties could be eliminated by a novel experimental technique: neutrino tagging. This technique relies on a new type of neutrino beamline and its associated instrumentation which would enable the kinematical reconstruction of the neutrinos produced in $\pi^{\pm} \to \mu^{\pm} \nu_\mu$ and $K^{\pm} \to \mu^{\pm} \nu_\mu$ decays. This article presents a proof-of-concept study for such a tagged beamline, aiming to serve a long baseline neutrino experiment exploiting a megaton scale natural water Cherenkov detector. After optimizing the target and the beamline optics to first order, a complete Monte Carlo simulation of the beamline has been performed. The results show that the beamline provides a meson beam compatible with the operation of the spectrometer, and delivers a neutrino flux sufficient to collect neutrino samples with a size comparable with similar experiments and with other un-tagged long-baseline neutrino experimental proposals

Performance Optimization of a Short-Baseline Neutrino Beamline at CERN

International audienc

M2 Experimental Beamline Optics Studies for Next Generation Muon Beam Experiments at CERN

In the context of the Physics Beyond Colliders Project, various new experiments have been proposed for the M2 beamline at the CERN North Area fixed target experimental facility. The experiments include MUonE, NA64µ, and the successor to the COMPASS experiment, tentatively named AMBER/NA66. The AMBER/NA66 collaboration proposes to build a QCD facility requiring conventional muon and hadron beams for runs up to 2024 in the first phase of the experiment. MUonE aims to measure the hadronic contribution to the vacuum polarization in the context of the (gµ-2) anomaly with a setup longer than 40 m and a 160 GeV/c high intensity, low divergence muon beam. NA64µ is a muon beam program for dark sector physics requiring a 100 - 160 GeV/c muon beam with a 15-25 m long setup. All three experiments request similar beam times up to 2024 with compelling physics programs, which required launching extensive studies for integration, installation, beam optics, and background estimations. The experiments will be presented along with details of the studies performed to check their feasibility and compatibility with an emphasis on the updated optics for these next-generation muon beam experiments

Reflectivity Studies and Production of New Flat Mirrors for the Cherenkov Threshold Detectors at CERN

Cherenkov threshold detectors (XCET) are used for identifying particles in the experimental areas at CERN. These detectors observe Cherenkov light emitted by charged particles travelling inside a pressurized gas vessel. A key component of the XCET detector is the 45-degree flat mirror reflecting the Cherenkov light towards the photomultiplier (PMT). A thorough analysis and optimization was conducted on the design and materials of this mirror, along with the surface coatings and coating techniques. A suitable manufacturing process was selected, and the first mirror prototype was produced, installed, and tested in the East Area at CERN. Experimental data obtained during beam tests is presented to assess the efficiency of the new coating and materials used.Cherenkov threshold detectors (XCET) are used for identifying particles in the experimental areas at CERN. These detectors observe Cherenkov light emitted by charged particles travelling inside a pressurized gas vessel. A key component of the XCET detector is the 45-degree flat mirror reflecting the Cherenkov light towards the photomultiplier (PMT). A thorough analysis and optimization was conducted on the design and materials of this mirror, along with the surface coatings and coating techniques. A suitable manufacturing process was selected, and the first mirror prototype was produced, installed, and tested in the East Area at CERN. Experimental data obtained during beam tests is presented to assess the efficiency of the new coating and materials used