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Searches for Heavy Neutral Leptons at ShiP and LHCb

Applicant Bay Aurelio
Number 172614
Funding scheme Project funding
Research institution Laboratoire de physique des hautes énergies 2 EPFL - SB - IPEP - LPHE2
Institution of higher education EPF Lausanne - EPFL
Main discipline Particle Physics
Start/End 01.10.2017 - 30.09.2019
Approved amount 209'068.00
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Keywords (4)

SHiP Collaboration; Heavy Neutral Leptons; LHCb Collaboration; New Physics

Lay Summary (French)

Lead
Grâce aux expériences du LHC au CERN, les scientifiques ont été en mesure de confirmer l’ensemble des prédictions du Modèle standard, en particulier l’existence d’un boson de Higgs. Toutefois plusieurs lacunes sont présentes dans le Modèle standard, tout spécialement l'absence d’explication pour la matière noire et l’énergie noire (qui constituent respectivement 25 % et 70 % de l’Univers), la masse des neutrinos, et l'absence d'antimatière.La nouvelle physique, c’est-à-dire les particules et les phénomènes qui expliqueraient ces lacunes, est activement recherchée dans des régions encore inexplorées. Dans ce contexte, l'expérience SHiP cherche des particules difficiles à détecter: celle qui interagissent très peu avec la matière et qui ont un long temps de vie. Ces particules sont de bons candidats pour la matière noire. De plus, si leur présence est confirmée, il serait alors possible d'expliquer la masse des neutrinos et l'asymétrie matière-antimatière de l'Univers.
Lay summary

Le détecteur SHiP, de 120 m de long sur 20 m de large, sera accueilli dans un hall souterrain au CERN et alimenté par une ligne d’extraction de l'accélérateur de protons SPS. Les particules connues (du Modèle standard), produites lorsque les protons du SPS frapperont la cible de SHiP, seront en grande partie absorbées dans une portion filtre du détecteur. Les nouvelles particules, par contre, poursuivraient leur route pour se désintégrer dans une région spécialement équipée du détecteur, devenant ainsi détectables.

Ce subside du FNRS permet de financer le salaire d'un postdoc qui participera au design et a la phase de recherche et développement de l'expérience SHiP.

La capacité de supprimer efficacement le bruit de fond des particules ordinaires (du Modele standard) est vital pour réussir à détecter les particules de la nouvelle physique. Un des éléments du filtre est destiné à la suppression des muons qui sont des particules chargées très pénétrantes. L'idée est d'utiliser un électroaimant produisant un champ magnétique avec une topologie particulière, dans le but de défléchir la trajectoire des muons vers l'extérieur du détecteur. Le postdoc participera donc au design et à la simulation de l'électroaimant, qui pourrait être du type supraconducteur.

Après le filtre à muons, SHiP prévoit un détecteur qui permettra d'étudier les particules légères, comme le neutrino tau. Ce neutrino est le moins connu et l'anti-neutrino tau est la seule particule prévue par le Modèle standard qui n'a pas encore été observée. Ce sous-système de SHiP contient un détecteur basé sur la technologie des fibres scintillantes (SciFi). La lumière produite par le passage des particules chargées est transportée par les fibres jusqu’à des photo-détecteurs à semi-conducteur (SiPM). Le groupe de l'EPFL a déjà développé cette technologie dans le cadre de l'expérience LHCb. La deuxième partie de ce projet FNRS est consacré à adapter la technologie SciFi et SiPM à SHiP.
 

Direct link to Lay Summary Last update: 03.01.2018

Lay Summary (English)

Lead
Thanks to the experiments at the LHC of CERN, scientists were able to confirm all the predictions of the Standard Model of particles, in particular the existence of a Higgs boson. However, several gaps are present in the Standard Model, especially the lack of explanation for dark matter and dark energy (which constitute 25% and 70% of the Universe, respectively), the mass of the neutrinos, the absence of antimatter in the Universe.The New Physics, that is to say the particles and the phenomena which would explain these gaps, is actively sought for in unexplored regions.In this context, the SHiP experiment looks for particles difficult to detect because they interact very little with matter and have a long time of life. These particles are good candidates for dark matter. Moreover, if their presence is confirmed, one would be able to explain the mass of the neutrinos and the asymmetry matter-antimatter in the Universe.
Lay summary

The SHiP detector would be housed in an underground hall at CERN, 120 m long by 20 m wide, and powered by an SPS proton accelerator extraction line. The known particles (of the Standard Model), produced when the SPS protons hit the SHiP target, will be largely absorbed in a filter portion of the detector. The new particles, instead, would continue on their way to disintegrate in a particular area of the detector, thus becoming detectable.

This subsidy from the SNSF allows to finance the salary of a postdoc who will participate in the design and research & development phase of the SHiP experiment.

The ability to remove the background from ordinary (Standard Model) particles is vital to successfully detect the particles associated to New Physics. One of the elements of the filter is intended for the suppression of the muons, very penetrating charged particles and difficult to stop. The idea is to use an electromagnet to produce a magnetic field having a particular topology, in order to deflect the trajectory of the muons towards the outside of the detector. The postdoc will therefore participate in the design and simulation of the electromagnet, which could be of superconducting type.

After the muon filter, SHiP provides a detector that will study light particles, such as the tau neutrino. This neutrino is the least known and the tau anti-neutrino is the only particle predicted by the Standard Model that has not yet been observed. For the construction of this subsystem, SHiP foresees a detector based on scintillating fiber technology (SciFi). The light produced by the passage of a charged particle is conveyed by the fibers to semiconductor photodetectors (SiPM). The EPFL group has already developed this technology as part of the LHCb experiment. The second part of this SNSF project is devoted to adapting the SciFi and SiPM technology to SHiP.

Direct link to Lay Summary Last update: 03.01.2018

Responsible applicant and co-applicants

Employees

Project partner

Publications

Publication
Sensitivity of the SHiP experiment to Heavy Neutral Leptons
Ahdida C., Albanese R., Alexandrov A., Anokhina A., Aoki S., Arduini G., Atkin E., Azorskiy N., Baaltasar Dos Santos F., Back J. J., Bagulya A., Baranov A., Bardou F., Barker G. J., Battistin M., Bauche J., Bay A., Bayliss V., Bencivenni G., Berdnikov Y. A., Berdnikov A. Y., Berezkina I., Bertani M., Betancourt C., et al. (2019), Sensitivity of the SHiP experiment to Heavy Neutral Leptons, in Journal of High Energy Physics, 2019(4), 77-77.
The experimental facility for the Search for Hidden Particles at the CERN SPS
Ahdida C., Albanese R., Alexandrov A., Anokhina A., Aoki S., Arduini G., Atkin E., Azorskiy N., Back J.J., Bagulya A., Santos F. Baaltasar Dos, Baranov A., Bardou F., Barker G.J., Battistin M., Bauche J., Bay A., Bayliss V., Bencivenni G., Berdnikov A.Y., Berdnikov Y.A., Berezkina I., Bertani M., Betancourt C., et al. (2019), The experimental facility for the Search for Hidden Particles at the CERN SPS, in Journal of Instrumentation, 14(03), P03025-P03025.

Collaboration

Group / person Country
Types of collaboration
SHiP (CERN experiment) Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
Seminar Individual talk The SHiP experiment 21.10.2019 UC Santa Barbara, United States of America Redi Federico Leo;
Joint Annual Meeting of SPS and OPG Talk given at a conference Dark sectors searches at high-intensity colliders 26.08.2019 Zuerich, Switzerland Redi Federico Leo;
Dark Matter @ LHC 2019 Poster Dark Matter and Dark Sector with the SHiP experiment at CERN 13.08.2019 U Washington, United States of America Redi Federico Leo;
Weak Interactions and Neutrinos 2019 Talk given at a conference The SHiP experiment 03.06.2019 Bari, Italy Redi Federico Leo;
Prospective Technological, Methodical and Material Solutions for New Physical Effects Searches, MISiS, Moscow Talk given at a conference Lecture on SHiP 01.10.2018 Moscow, Russia Redi Federico Leo;
SPS annual meeting 2018 Talk given at a conference The proposed SHiP experiment 28.08.2018 EPFL Lausanne, Switzerland Rodrigues Cavalcante Ana Barbara;


Communication with the public

Communication Title Media Place Year
Talks/events/exhibitions epfl portes ouvertes Western Switzerland 2019
Other activities International master classes Western Switzerland 2018

Associated projects

Number Title Start Funding scheme
166915 FLARE 2016: Operation and upgrade of the LHCb experiment 01.04.2016 FLARE
166208 High Precision CP Violation Physics at LHCb 01.04.2016 Project funding

Abstract

The Search for Hidden Particles (SHiP) experiment is a new general-purpose fixed target facility at the Super Proton Synchrotron at CERN to search for hidden particles, as predicted by a large number of models, providing an explanation for dark matter, neutrino oscillations, and the origin of the baryon asymmetry in the Universe.The experiment is aimed at searching for very weakly interacting long-lived particles including Heavy Neutral Leptons (right-handed partners of neutrinos), light supersymmetric particles, dark photons, etc.The objective of the present project is to contribute to the R&D effort for SHiP, in view of the preapration of a Comprehensive Design Report.In parallel, we propose to use the data collected by the LHCb detector during Run 2, to search for HNL in beauty hadron decays for which we will consider a novel inclusive approach.We ask SNSF to support the project through one postdoc salary over a three year period.
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