Angular correlation of the two gamma rays produced in the thermal neutron capture on gadolinium-155 and gadolinium-157

The ANNRI-Gd collaboration studied in detail the single $\gamma$-ray spectrum produced from the thermal neutron capture on $^{155}$Gd and $^{157}$Gd in our previous publications. Gadolinium targets were exposed to a neutron beam provided by the Japan Spallation Neutron Source (JSNS) in J-PARC, Japan. In the present analysis, one new additional coaxial germanium crystal was used in the analysis in combination with the fourteen germanium crystals in the cluster detectors to study the angular correlation of the two $\gamma$ rays emitted in the same neutron capture. We present for the first time angular correlation functions for two $\gamma$ rays produced during the electromagnetic cascade transitions in the (n, $\gamma$) reactions on $^{\rm 155}$Gd and $^{\rm 157}$Gd. As expected, we observe the mild angular correlations for the strong, but rare transitions from the resonance state to the two energy levels of known spin-parities. Contrariwise, we observe negligibly small angular correlations for arbitrary pairs of two $\gamma$ rays produced in the majority of cascade transitions from the resonance state to the dense continuum states.Comment: 21 pages, 13 figure

Gamma Ray Spectra from Thermal Neutron Capture on Gadolinium-155 and Natural Gadolinium

Abstract Natural gadolinium is widely used for its excellent thermal neutron capture cross section, because of its two major isotopes: $^{\rm 155}$Gd and $^{\rm 157}$Gd. We measured the $\gamma$-ray spectra produced from the thermal neutron capture on targets comprising a natural gadolinium film and enriched $^{\rm 155}$Gd (in Gd$_{2}$O$_{3}$ powder) in the energy range from 0.11 MeV to 8.0 MeV, using the ANNRI germanium spectrometer at MLF, J-PARC. The freshly analyzed data of the $^{\rm 155}$Gd($n, \gamma$) reaction are used to improve our previously developed model (ANNRI-Gd model) for the $^{\rm 157}$Gd($n, \gamma$) reaction [K. Hagiwara et al. [ANNRI-Gd Collaboration], Prog. Theor. Exp. Phys. 2019, 023D01 (2019)], and its performance confirmed with the independent data from the $^{\rm nat}$Gd($n, \gamma$) reaction. This article completes the development of an efficient Monte Carlo model required to simulate and analyze particle interactions involving the thermal neutron captures on gadolinium in any relevant future experiments

Epstein-Barr Virus-Induced Gene 3 (EBI3): A Novel Diagnosis Marker in Burkitt Lymphoma and Diffuse Large B-Cell Lymphoma

The distinction between Burkitt lymphoma (BL) and diffuse large B-cell lymphoma (DLBCL), two types of mature aggressive B-cell lymphomas that require distinct treatments, can be difficult because of forms showing features intermediate between DLBCL and BL (here called BL/DLBCL). They can be discriminated by the presence of c-myc translocations characteristic of BL. However, these are not exclusive of BL and when present in DLBCL are associated with lower survival. In this study, we show that Epstein-Barr virus-induced gene 3 (EBI3) is differentially expressed among BL and DLBCL. Analysis of gene expression data from 502 cases of aggressive mature B-cell lymphomas available on Gene Expression Omnibus and immunohistochemical analysis of 184 cases of BL, BL/DLBCL or DLBCL, showed that EBI3 was not expressed in EBV-positive or -negative BL cases, whereas it was expressed by over 30% of tumoral cells in nearly 80% of DLBCL cases, independently of their subtypes. In addition, we show that c-myc overexpression represses EBI3 expression, and that DLBCL or BL/DLBCL cases with c-myc translocations have lower expression of EBI3. Thus, EBI3 immunohistochemistry could be useful to discriminate BL from DLBCL, and to identify cases of BL/DLBCL or DLBCL with potential c-myc translocations

Neutrino Physics with JUNO

The Jiangmen Underground Neutrino Observatory (JUNO), a 20 kton multi-purposeunderground liquid scintillator detector, was proposed with the determinationof the neutrino mass hierarchy as a primary physics goal. It is also capable ofobserving neutrinos from terrestrial and extra-terrestrial sources, includingsupernova burst neutrinos, diffuse supernova neutrino background, geoneutrinos,atmospheric neutrinos, solar neutrinos, as well as exotic searches such asnucleon decays, dark matter, sterile neutrinos, etc. We present the physicsmotivations and the anticipated performance of the JUNO detector for variousproposed measurements. By detecting reactor antineutrinos from two power plantsat 53-km distance, JUNO will determine the neutrino mass hierarchy at a 3-4sigma significance with six years of running. The measurement of antineutrinospectrum will also lead to the precise determination of three out of the sixoscillation parameters to an accuracy of better than 1\%. Neutrino burst from atypical core-collapse supernova at 10 kpc would lead to ~5000inverse-beta-decay events and ~2000 all-flavor neutrino-proton elasticscattering events in JUNO. Detection of DSNB would provide valuable informationon the cosmic star-formation rate and the average core-collapsed neutrinoenergy spectrum. Geo-neutrinos can be detected in JUNO with a rate of ~400events per year, significantly improving the statistics of existing geoneutrinosamples. The JUNO detector is sensitive to several exotic searches, e.g. protondecay via the $p\to K^++\bar\nu$ decay channel. The JUNO detector will providea unique facility to address many outstanding crucial questions in particle andastrophysics. It holds the great potential for further advancing our quest tounderstanding the fundamental properties of neutrinos, one of the buildingblocks of our Universe

Charmonia and open charm production in heavy ion collisions

The production of heavy flavours in heavy ion collisions has been of great interest since the prediction of Matsui and Satz regarding quarkonium suppression in the quark gluon plasma due to color screening mechanisms. The NA50 collaboration has produced the first charmonia measurements in heavy ion collisions which show evidence for strong and anomalous suppressions in central Pb-Pb collisions. For the suppression of bound state quark-antiquark pairs to be a plasma signature, the production of these quarks inside the cold nucleus should first be well known. Differences in the relative yield of heavy flavour between nucleon-nucleon an nucleon-nucleus collisions probes cold nuclear matter effects such as the modifications of the gluon distribution functions or parton energy loss. The gluon-gluon fusion represents the dominant mechanism for the production of quarkonia studied by the heavy ion experiments. The purpose of this presentation is to highlight the latest results from the CERN-SPS and Fermilab fixed target experiments and the first results from the heavy ion collider RHIC

ETUDE DU MECANISME DE SUPPRESSION ANORMALE DU MESON J/PSI DANS LES COLLISIONS PB-PB

CETTE THESE A POUR OBJET L'ANALYSE DE DONNEES ACCUMULEES PENDANT LES MOIS D'OCTOBRE ET NOVEMBRE 1998 PAR L'EXPERIENCE NA50, SITUEE DANS LA ZONE NORD DU CERN. IL S'AGIT DE COLLISIONS DE NOYAUX DE PLOMB, REALISEES PAR L'ENVOI D'UN FAISCEAU DE 158 GEV /NUCLEON CREE DANS LE SUPER PROTON SYNCHROTON (SPS), SUR UNE CIBLE DE 3 MM D'EPAISSEUR. LA FINALITE DE CETTE EXPERIENCE EST DE METTRE EN EVIDENCE LE DECONFINEMENT DES QUARKS DANS CES COLLISIONS. CETTE PHASE DE LA MATIERE, JAMAIS OBSERVEE JUSQU'ICI, A ETE PREDITE PAR DES CALCULS NUMERIQUES DE QCD SUR RESEAU. ELLE DOIT SE TRADUIRE PAR UN NET AMOINDRISSEMENT DE LA PRODUCTION DU MESON J/PSI. CE PHENOMENE, APPELE SUPPRESSION DU J/PSI EST PROVOQUE PAR UNE PROPRIETE FONDAMENTALE DU MILIEU DECONFINE, L'ECRANTAGE DE L'INTERACTION FORTE. LE J/PSI EST DETECTE DANS NA50 PAR SA DESINTEGRATION EN PAIRES DE MUONS. LA SPECIFICITE DES DONNEES DE 1998 PAR RAPPORT AUX PRECEDENTES (1995 ET 1996), A ETE D'UTILISER UNE CIBLE TRES FINE POUR DIMINUER LES REINTERACTIONS, QUI BIAISAIENT LES COLLISIONS LES PLUS CENTRALES AUPARAVANT. L'ANALYSE DE LA PRODUCTION DU J/PSI EST REALISEE DANS CETTE THESE EN FONCTION DE 2 PARAMETRES : L'ENERGIE TRANSVERSE ET CELLE DES FRAGMENTS SPECTATEURS. DEUX METHODES SONT PROPOSEES POUR Y PARVENIR. L'UNE, CLASSIQUE, RAPPORTE LA SECTION EFFICACE DU J/PSI A CELLE DU PROCESSUS DE REFERENCE DRELL-YAN, EN LES TIRANT TOUS DEUX D'UN AJUSTEMENT DU SPECTRE DE MASSE DES MUONS. L'AUTRE REALISE LE MEME RAPPORT, MAIS DETERMINE LE DRELL-YAN A PARTIR DE MODELES THEORIQUES RELIANT PARAMETRE D'IMPACT DE LA COLLISION ET ENERGIES EMISES, AFIN DE DIMINUER LES ERREURS STATISTIQUES. LES RESULTATS OBTENUS POUR LA SUPPRESSION DU J/PSI, CUMULES AVEC CEUX DE 1996, MONTRENT 2 BRUSQUES CHANGEMENTS DE REGIME EN FONCTION DES ENERGIES MESUREES, QUI SONT SEMBLABLES A UN PROCESSUS D'ECRANTAGE SUCCESSIF DES RESONANCES CHARMEES. CECI PLAIDE DONC EN FAVEUR DE L'OBTENTION AU CERN, DANS LES COLLISIONS CENTRALES PB-PB, D'UN MILIEU DE QUARKS DECONFINES.PARIS7-Bibliothèque centrale (751132105) / SudocPARIS-BIUSJ-Physique recherche (751052113) / SudocSudocFranceF

Constitutions et droit pénal

Hottelier Michel, Gonin Luc. Suisse. In: Annuaire international de justice constitutionnelle, 26-2010, 2011. Constitutions et droit pénal - Hiérarchie(s) et droits fondamentaux. pp. 355-380

Contribution à la caractérisation du faisceau de neutrinos de l expérience T2K avec le détecteur proche INGRID (Oscillations de neutrinos)

L'expérience T2K, construite au Japon, est une expérience d'oscillations de neutrinos à base longue. Dans cette expérience, les paramètres décrivant ce phénomène quantique, et plus particulièrement l'angle de mélange theta13, sont mesurés en utilisant un faisceau de neutrinos muoniques produit par un accélérateur de particules. Dans cette thèse, des résultats obtenus à partir des données prises pendant la première année de fonctionnement de l'expérience sont présentés. Après avoir présenté la théorie de l'oscillation quantique des neutrinos, et l'expérience en elle-même, nous nous concentrons sur le détecteur proche sur axe de T2K, INGRID. Nous présentons les études de calibration de ce détecteur, qui ont permis de montrer qu'il fonctionnait correctement, et de façon stable dans le temps. Nous présentons ensuite les mesures réalisées sur le faisceau de neutrinos, pour déterminer sa direction et sa forme dans le plan transverse. Le second objet de cette thèse est un nouveau détecteur, le Module Proton, qui fut la première modification ajoutée au détecteur INGRID. Ce nouveau module a vocation à étudier plus précisément les interactions quasi élastiques se produisant sur l'axe du faisceau. Nous présentons les motivations physiques ainsi que les études de conception qui ont mené à sa construction. Dans la dernière partie de cette thèse, nous présentons les premiers résultats obtenus à partir de données prises par ce module, qui donnent une idée des possibilités offertes par ce nouveau détecteur pour étudier le faisceau de neutrinos de l'expérience T2Khe T2K experiment built in Japan is a long baseline neutrino oscillation experiment. It uses a neutrino beam produced by a particle accelerator to measure the parameters describing this phenomenum, and in particular the yet unknown mixing angle theta13. This thesis presents some of the results obtained from the first years of data taking of the T2K experiment. After presenting the theory of neutrino oscillations and the experiment, we will focus on the on-axis near detector of T2K, the INGRID detector. We will present the studies done for calibration of this detector after its construction, to demonstrate that it is working well and stably in time. We will then present the measurements done to characterize the muonic neutrino beam, in particular to measure its direction as well as its shape in the transverse plane. The second main topic of this thesis is a new detector, added as a first upgrade to the INGRID detector, the Proton Module, which will be used to study more in details the interactions occuring on the axis of the beam. We will review the motivations and studies that led to its design and construction. In the last part, we will present the results obtained with the first data taken by this modulePALAISEAU-Polytechnique (914772301) / SudocSudocFranceF