Light Sterile Neutrinos in Particle Physics: Experimental Status

Most of the neutrino oscillation results can be explained by the three-neutrino paradigm. However several anomalies in short baseline oscillation data could be interpreted by invoking a hypothetical fourth neutrino, separated from the three standard neutrinos by a squared mass difference of more than 0.1 eV$^2$. This new neutrino, often called sterile, would not feel standard model interactions but mix with the others. Such a scenario calling for new physics beyond the standard model has to be either ruled out or confirmed with new data. After a brief review of the anomalous oscillation results we discuss the world-wide experimental proposal aiming to clarify the situation.Comment: 14 pages, 2 figures. To appear in the proceedings of the 13th International Conference on Topics in Astroparticle and Underground Physics, TAUP 2013 (F. Avignone & W. Haxton, editors, Physics Procedia, Elsevier) ; Minor revisions in version

Archéologie et paysages dans la plaine rhénane septentrionale

La zone dite du Ried-nord est une portion de la plaine alluviale du Rhin qui s’étend entre la forêt de Haguenau à l’ouest et la Forêt-Noire à l’est. Le paysage actuel est encore marqué par la présence de vastes bras fossiles du fleuve qui parcourent l’ensemble de l’espace alluvial, soit une quinzaine de kilomètres de largeur en moyenne. Plusieurs recoupements de ces puissants bras soulignent l’importance des mouvements latéraux du fleuve qui ont balayé cet espace avant l’endiguement du Rhin au courant du XIXe siècle. Comment les Hommes des sociétés passées se sont-ils accommodés de ce paysage particulier ? à partir de plusieurs sources croisées, une histoire sur plusieurs millénaires des relations entre les Hommes et le fleuve se dessine. L’évolution de l’occupation du sol du Ried-nord est affectée par la nature particulière des déplacements latéraux du Rhin et des risques de crues violentes. Ces deux éléments vont être déterminants pour comprendre le mode de colonisation de cet espace rhénan en plus de sa microtopographie constituée de quelques secteurs légèrement surélevés qui constitueront les espaces privilégiés à l’installation des premières occupations humaines, saisonnières et pérennes.The so called north Ried zone is part of the alluvial Rhine valley stretching between the Haguenau forest, in the west, to the Black Forest in the east. The present landscape is still marked by the existence of vast fossil tributaries flowing across the whole alluvial space, actually about 15 km in width on average. The merging of several of these powerful tributaries underlines the importance of this river, slanting across this huge space before the building of dams in the 19th century. How did our ancestors cope with this very peculiar sort of landscape? Several cross-references provide a thousands of years old history of how man related to the river. The occupation of the Ried territory was gradually affected by the Rhine moving slantwise and by the risk of serious flooding. These two factors were to be essential for the understanding of how this Rhine territory was being colonised and how the microtopography of a few slightly elevated spots were to become privileged settling places for the first human activities, whether seasonal or long term.Das sogenannte Gebiet des Nord-Rieds ist ein Teil der Schwemmland-Ebene des Rheins. Es erstreckt sich vom Hagenauer Forst im Westen bis zum Schwarzwald im Osten. Die heutige Landschaft ist immer noch geprägt durch Alt-Rhein Arme, die das ganze Schwemmland durchziehen auf einer Breite von etwa 15 Kilometer. Zahlreiche Überschneidungen dieser mächtigen Arme unterstreichen die Gewalt der seitlichen Bewegungen des Flusses, die diesen Raum vor der Eindämmung im Laufe des 19. Jahrhunderts, geprägt haben. Wie haben sich die Menschen, der verschiedenen früheren Gesellschaften, dieser besonderen Landschaft angepasst? Ausgehend von sich überschneidenden unterschiedlichen Quellen, zeichnet sich eine mehrere Tausendjahre dauernde Geschichte ab der Beziehung zwischen Mensch und Fluss. Der Wandel in der Bodennutzung im Bereich des Nord-Rieds wird maßgeblich beeinflusst durch die Besonderheit der seitlichen Bewegungen des Flusses und der Gefahr von heftigem Hochwasser. Diese beiden Gegebenheiten sind entscheidend für das Verständnis der Besiedlungsgeschichte in diesem Raum. Zusätzlich muss noch die Mikrotopographie mit einbezogen werden, die einige leicht erhöhte Bereiche aufweist, welche für die ersten menschlichen Siedlungen genutzt wurden, sei es saisonal oder auf Dauer

A proposed search for a fourth neutrino with a PBq antineutrino source

Several observed anomalies in neutrino oscillation data can be explained by a hypothetical fourth neutrino separated from the three standard neutrinos by a squared mass difference of a few eV^2. We show that this hypothesis can be tested with a PBq (ten kilocurie scale) 144Ce or 106Ru antineutrino beta-source deployed at the center of a large low background liquid scintillator detector. In particular, the compact size of such a source could yield an energy-dependent oscillating pattern in event spatial distribution that would unabiguously determine neutrino mass differences and mixing angles.Comment: 4 pages ; 1 table ; 4 figures - Add energy spectrum shape only analysis + referee comments/suggestion

A volumetric energy based high cycle multiaxial fatigue citerion

A reliable design of industrial parts against high-cycle multiaxial fatigue requires a fatigue criterion capable of predicting both the stress gradient and the load-type effects. These effects are very important in the transfer of fatigue data from specimen to component. By using the concept of volume influencing fatigue crack initiation proposed by Palin-Luc and Lasserre with an energy based approach, a new criterion is presented. Based on the strain-work density given to the material, this proposal is usable whatever the constant amplitude loading is: in and out-of-phase combined loadings, with or without mean stress. Its predictions are compared both with a total of 38 experiments on four materials (a mild steel, two high strength steels and a spheroidal graphite cast iron) and with the predictions of local criteria (Crossland, Dang Van, Papadopoulos and Morel). The comparison shows that the predictions of the volumetric proposal are very good and less scattered than those of the local approaches, especially for loadings with mean stresses or under non-proportional loadings

A volumetric energy based high cycle multiaxial fatigue citerion

A reliable design of industrial parts against high-cycle multiaxial fatigue requires a fatigue criterion capable of predicting both the stress gradient and the load-type effects. These effects are very important in the transfer of fatigue data from specimen to component. By using the concept of volume influencing fatigue crack initiation proposed by Palin-Luc and Lasserre with an energy based approach, a new criterion is presented. Based on the strain-work density given to the material, this proposal is usable whatever the constant amplitude loading is: in and out-of-phase combined loadings, with or without mean stress. Its predictions are compared both with a total of 38 experiments on four materials (a mild steel, two high strength steels and a spheroidal graphite cast iron) and with the predictions of local criteria (Crossland, Dang Van, Papadopoulos and Morel). The comparison shows that the predictions of the volumetric proposal are very good and less scattered than those of the local approaches, especially for loadings with mean stresses or under non-proportional loadings

A comprehensive revision of the summation method for the prediction of reactor antineutrino fluxes and spectra

The summation method for the calculation of reactor $\bar{\nu}_e$ fluxes and spectra is methodically revised and improved. For the first time, a complete uncertainty budget accounting for all known effects likely to impact these calculations is proposed. Uncertainties of a few percents at low energies and ranging up to 20% at high energies are obtained on the calculation of a typical reactor $\bar{\nu}_e$ spectrum. Although huge improvements have been achieved over the past decade, the quality and incompleteness of the present day evaluated nuclear decay data still limit the accuracy of the calculations and therefore dominate by far these uncertainties. Pushing the $\beta$-decay modeling of the thousands of branches making a reactor $\bar{\nu}_e$ spectrum to a high level of details comparatively brings modest changes. In particular, including nuclear structure calculations in the evaluation of the non-unique forbidden transitions gives a smaller impact than anticipated in past studies. Finally, this new modeling is challenged against state-of-the-art predictions and measurements. While a good agreement is observed with the most recent Inverse Beta Decay measurements of reactor $\bar{\nu}_e$ fluxes and spectra, it is unable to properly describe the reference aggregate $\beta$ spectra measured at the Institut Laue-Langevin High-Flux reactor in the 80s. This result adds to recent suspicions $\beta$ the reliability of these data and preferentially points toward a misprediction of the $^{235}$U $\bar{\nu}_e$ spectrum.Comment: 34 pages, 16 figures. Submitted to PR

Reactor Neutrinos

We review the status and the results of reactor neutrino experiments, that toe the cutting edge of neutrino research. Short baseline experiments have provided the measurement of the reactor neutrino spectrum, and are still searching for important phenomena such as the neutrino magnetic moment. They could open the door to the measurement of coherent neutrino scattering in a near future. Middle and long baseline oscillation experiments at Chooz and KamLAND have played a relevant role in neutrino oscillation physics in the last years. It is now widely accepted that a new middle baseline disappearance reactor neutrino experiment with multiple detectors could provide a clean measurement of the last undetermined neutrino mixing angle theta13. We conclude by opening on possible use of neutrinos for Society: NonProliferation of Nuclear materials and Geophysics