Mesure des sections efficaces vμ-CC0π différentielles sur H2O et CH et le rapport des sections efficaces H2O /CH avec le détecteur hors-axe WAGASCI

Differential measurement of the vμ-CC0π cross section on H2O and CH and the H2O /CH cross-section ratio using the off-axis WAGASCI detector

• Auteur / Autrice : Olivier Volcy
• Direction : Thomas Mueller
• Type : Thèse de doctorat
• Discipline(s) : Physique des particules
• Date : Soutenance le 02/12/2019
• Etablissement(s) : Université Paris-Saclay (ComUE)
• Ecole(s) doctorale(s) : École doctorale Particules, hadrons, énergie et noyau : instrumentation, imagerie, cosmos et simulation (Orsay, Essonne ; 2015-....)
• Partenaire(s) de recherche : établissement opérateur d'inscription : École polytechnique (Palaiseau, Essonne ; 1795-....)
• Partenaire(s) de recherche : Laboratoire : Laboratoire Leprince-Ringuet (Palaiseau ; 1936-....)
• Jury : Président / Présidente : Yves Sirois
• Jury : Examinateurs / Examinatrices : Thomas Mueller, Alessandra Tonazzo, David Lhuillier, Frédéric Yermia, Jaime Dawson
• Jury : Rapporteurs / Rapporteuses : Alessandra Tonazzo, David Lhuillier

Mots clés

Mots clés contrôlés

Neutrinos -- Interactions

Physique des hautes énergies

Mots clés libres

Section efficace

Neutrino

Wagasci

T2k

Violation CP

Unfolding

Cross section

Neutrino

Wagasci

T2k

CP-violation

Unfolding

Résumé

[Pas de résumé fourni en français]

Several experiments takes to the task of measuring the parameters of the standard modelrelated to the neutrinos. For instance, the JUNO experiment in China has for aim to decideon the mass hierarchy of the three states responsible of the propagation of the neutrinos.The ”Tokai To Kamioka” (T2K) experiment is the first of many experiments that wasable to perform the first measurement on the angle of the PMNS matrix, the matrix respon-sible for the neutrino oscillation. Other experiments such as Double Chooz and Daya Bayhave also performed similar measurement on the PMNS matrix angles. The future Hyper-Kamiokandeexperiment has its sight set on the measurement of the CP factor in the PMNSmatrix, which rules for the matter/antimatter asymetry.As all the beam based oscillation experiments, The T2K measurements depend on aset of detectors near the beam production site and on a detector far away, namely Super-Kamiokande. Detecting the neutrino fluxes at the near location and at the further locationneeds a knowledge on the neutrino cross-sections with the target materials of the different de-tectors. However the near and far detectors are very different in nature. The target materialfor Super-Kamiokande is water while the one for the majority of the current near detectorsis plastic. Moreover, while we have a 4π acceptance for Super Kamiokande, we merely coverthe forward angular region with the near detectors. Because of our limited precision on thedifferent cross-sections coupled with the different materials used in the whole experiment, wehave irreductible uncertainties on the measurement of the angles.In order to improve these numbers, we must either have a better precision on the cross-section measurement with similar angular region, or we must have a measurement on theratio of the cross-sections on the two materials used in the respective detectors.The WAGASCI experiment has for goal to improve the measurements on the cross-sectionof water and plastic as well as perform a measurement on the ratio of both these cross-sections.The WAGASCI detector in its final configuration will allow the measurement of high angletracks thanks to the presence of a grid and of Side Muon Range Detectors. The detectorhas water targets as well as plastic targets, which allows to measure the ratio of the twocross-sections with the same flux. The flux being the main source of systematics errors, thatallows to improve the precision of our measurement compared to a situation where we wouldtake some data with only a water target and then only with a plastic target (this setup hasbeen used previously).In this thesis, we will go over the construction of one of the detector modules : the watermodule. We will also discuss its calibration. Finally we will expand on the analysis de-velopped to treat the data collected by the detector as well as the cross-section extractionand the systematic error estimations. The configuration used here is not the final one, wecannot yet work with high-angle events because we the side-MRD were not yet present atthe time when the data was taken. Furthermore the muon detector used could not stophigh-momentum muons because of a limited depth. However this will be enough to conducta comprehensive analysis with sufficient statistics.