Nuclear effects in electron- and neutrino-nucleus scattering within a relativistic quantum mechanical framework

We study the impact of the description of the knockout nucleon wave function on electron- and neutrino-induced quasielastic and single-pion production cross sections. We work in a fully relativistic and quantum mechanical framework, where the relativistic mean-field model is used to describe the target nucleus. The focus is on Pauli blocking and the distortion of the final nucleon, these two nuclear effects are separated and analyzed in detail. We find that a proper quantum mechanical treatment of these effects is crucial to provide the correct magnitude and shape of the inclusive cross section. Also, this seems to be key to predict the right ratio of muon- to electron-neutrino cross sections at very forward scattering angles.Comment: 14 pages, 14 figure

AA-dependence of quasielastic charged-current neutrino-nucleus cross sections

Background: 12C has been and is still widely used in neutrino-nucleus scattering and oscillation experiments. More recently, 40Ar has emerged as an important nuclear target for current and future experiments. Liquid argon time projection chambers (LArTPCs) possess various advantages in measuring electroweak neutrino-nucleus cross sections. Concurrent theoretical research is an evident necessity. Purpose: 40Ar is larger than 12C, and one expects nuclear effects to play a bigger role in reactions. We present inclusive differential and total cross section results for charged-current neutrino scattering on 40Ar and perform a comparison with 12C, 16O and 56Fe targets, to find out about the A-dependent behavior of model predictions. Method: Our model starts off with a Hartree-Fock description of the nucleus, with the nucleons interacting through a mean field generated by an effective Skyrme force. Long-range correlations are introduced by means of a continuum random phase approximation (CRPA) approach. Further methods to improve the accuracy of model predictions are also incorporated in the calculations. Results: We present calculations for 12C, 16O, 40Ar and 56Fe, showcasing differential cross sections over a broad range of kinematic values in the quasielastic regime. We furthermore show flux-folded results for 40Ar and we discuss the differences between nuclear responses. Conclusions: At low incoming energies and forward scattering we identify an enhancement in the 40Ar cross section compared to 12C, as well as in the high $\omega$ (low $T_\mu$ ) region across the entire studied $E_\nu$ range. The contribution to the folded cross section of the reaction strength at values of $\omega$ lower than 50 MeV for forward scattering is sizeable.Comment: 9 pages, 8 figures ; complete revision of calculations with updated discussion of results, Fig. 4 replaced, updated reference list, minor typographical correction

CRPA calculations for neutrino-nucleus scattering : from very low energies to the quasielastic peak

International audienceWe present continuum random phase approximation calculations (CRPA) for neutrino-induced quasielastic scattering off atomic nuclei. The validity of our formalism is checked by a careful confrontation of its results with semi-inclusive double-differential electron scattering data. We pay special attention to excitations in the giant resonance region. The CRPA is well-suited for the description of interactions in this energy range. We aim at providing a uniform description of one-nucleon knockout processes over the whole energy range from threshold to the quasielastic peak. Our calculations point to the fact that low-energy and giant-resonance excitations provide a non-negligible contribution to the interaction strength, especially at forward lepton-scattering angles

Influence of short-range correlations in neutrino-nucleus scattering

Background: Nuclear short-range correlations (SRCs) are corrections to mean-field wave functions connected with the short-distance behavior of the nucleon-nucleon interaction. These SRCs provide corrections to lepton- nucleus cross sections as computed in the impulse approximation (IA). Purpose: We want to investigate the influence of SRCs on the one-nucleon (1N) and two-nucleon (2N) knockout channel for muon-neutrino induced processes on a $^{12}$C target at energies relevant for contemporary measurements. Method: The model adopted in this work, corrects the impulse approximation for SRCs by shifting the com- plexity induced by the SRCs from the wave functions to the operators. Due to the local character of the SRCs, it is argued that the expansion of these operators can be truncated at a low order. Results: The model is compared with electron-scattering data, and two-particle two-hole responses are presented for neutrino scattering. The contributions from the vector and axial-vector parts of the nuclear current as well as the central, tensor and spin-isospin part of the SRCs are studied. Conclusions: Nuclear SRCs affect the 1N knockout channel and give rise to 2N knockout. The exclusive neutrino-induced 2N knockout cross section of SRC pairs is shown and the 2N knockout contribution to the QE signal is calculated. The strength occurs as a broad background which extends into the dip region.Comment: 16 pages, 10 figures. Version published in Physical Review

Desarrollo de un sistema de detección de caídas basado en acelerómetros

Este proyecto tiene como finalidad el desarrollo de un sistema de detección de caídas para personas de edad avanzada basado en el uso de acelerómetros. El 30 % de los mayores se cae una vez al año y estas caídas causan el 70 % de los accidentes mortales en el colectivo de personas mayores de 75 años. Por esta razón, se pretende realizar un sistema fiable y que ofrezca una respuesta de emergencia efectiva, así como un sistema poco intrusivo y fácil de usar. Inicialmente, se realizó un análisis de los sistemas de este tipo propuestos o existentes en el mercado, con el objetivo de detectar las carencias de los mismos, así como identificar los requisitos a implementar en el sistema. La monitorización de las actividades y caídas tanto en el Virtual Living Lab AIDE como en el despliegue real del sistema permitió diseñar el algoritmo de detección. Este algoritmo se integra en un sistema compuesto por un dispositivo detector portable desarrollado sobre el microordenador Beaglebone Green. El dispositivo, poseedor de la autonomía y conectividad requeridos, está pensado para ser llevado sujeto a la cintura. Como parte de la respuesta de emergencia, se crearon dos aplicaciones Android. Una de ellas ideada para usuarios que vivan solos y la otra para los que estén acompañados de una persona encargada de su cuidado. El sistema persigue favorecer la autonomía de una persona que cuida a otra, pero también la de la persona cuidada. Mediante la monitorización no intrusiva, se consigue que la persona cuidada se sienta menos dependiente y tenga menos miedo, pues, si se cae, el sistema avisará a quien tenga que hacerlo. En el diseño de este sistema ha sido relevante contemplar ciertos aspectos particulares sobre el tipo de usuario final al que iba dirigido, que era, principalmente, personas mayores. Esto ha condicionado el aspecto de la interfaz y el diseño físico del aparato. Sobre todo, ha condicionado la interacción, siendo el objetivo requerir el menor número de acciones posible. El sistema se probó con los tipos de caída más frecuentes que son las frontales, traseras y laterales, lográndose un índice de acierto aproximado del 90’78 %, constituyendo un primer resultado prometedor. Aparte de mejorar el ratio de aciertos, se pueden llegar a alcanzar otros hitos como un diseño más ergonómico o el refinamiento del algoritmo de detección de caídas. Se espera que este proyecto contribuya de manera notable al ámbito de la detección automática de caídas, ya sea mediante la publicación del sistema o por la recopilación de información

Electron versus muon neutrino induced cross sections in charged current quasi-elastic processes

Differences between $\nu_e$ and $\nu_{\mu}$ quasielastic cross sections are essential in neutrino oscillation analyses and CP violation searches for experiments such as DUNE and T2HK. The ratio of these is however poorly known experimentally and for certain kinematic regions theoretical models give contradictory answers. We use two independent mean-field based models to investigate this ratio using $^{40}$Ar and $^{12}$C targets. We demonstrate that a proper treatment of the final nucleon's wave function confirms the dominance of $\nu_{\mu}$ over $\nu_e$ induced cross sections at forward lepton scattering.Comment: Updated Fig. 2, minor changes to text, accepted for publication in Phys. Rev. Letter

Assessing the theory-data tension in neutrino-induced charged pion production: the effect of final-state nucleon distortion

Pion production on nuclei constitutes a significant part of the total cross section in experiments involving few-GeV neutrinos. Combined analyses of data on deuterium and heavier nuclei points to tensions between the bubble chamber data and the data of the MINER$\nu$A experiment, which are often ascribed to unspecified nuclear effects. To understand the origin of these tensions, a microscopic quantum mechanical framework is needed to compute nuclear matrix elements. We use the local approximation to the relativistic distorted wave impulse approximation (RDWIA) to assess the role of final-state nucleon distortion. To perform this comparison under conditions relevant to neutrino experiments, we compute cross sections for the MINER$\nu$A and T2K charged pion production datasets. The inclusion of nucleon distortion leads to a reduction of the cross section up to 10\%, but to no significant change in shape of the flux-averaged cross sections. Results with and without distortion compare favorably to experimental data, with the exception of the low-$Q^2$ MINER$\nu$A $\pi^+$ data. We point out that hydrogen target data from BEBC is also overpredicted at low-$Q^2$, and that the discrepancy is similar in shape and magnitude to what is found in comparison to MINER$\nu$A data. Including nucleon distortion alone cannot explain the overprediction of low-$Q^2$ cross sections measured by MINER$\nu$A. The similar overprediction of BEBC data on hydrogen means that it is impossible to ascribe this discrepancy solely to a nuclear effect. Axial couplings and their $Q^2$ dependence should ideally be derived from more precise data on hydrogen and deuterium

Lypsyrobottitilojen lomituskäytännöt

Robottilypsy tuo uudenlaisia näkökohtia lypsyrobottitilojen lomituskäytäntöihin. Fyysisesti raskaan lypsytyön jäädessä pois voidaan keskittyä seuraamaan eläinten terveyttä ja hyvinvointia, jolloin eläinten hoitajan ammattitaitoa tarvitaan. Pohjoissavolaisilta paikallisyksiköiltä puuttuu yhtenäiset toimintaohjeet robottitilojen hälytyksien vastaanotosta ja niiden kuittaamisesta. Työssä tehtiin lomituskäytäntöjä selvittävä kysely, joka lähetettiin robottitilojen lomituksia järjestäville paikallisyksiköille, lypsyrobottitiloille sekä lypsyrobottitiloilla työskenteleville lomittajille. Vastaukset kerättiin verkkosalkkuun luodun kyselyn avulla. Kysely lähetettiin yhdeksälle paikallisyksikölle, 48 robottitilalle ja 84 lomittajalle. Kyselyn vastausprosentiksi saatiin paikallisyksiköiden osalta 100, robottitilojen 37,5 ja lomittajien osalta 34,5. Robottitilojen lomitusten kuumin puheenaihe tällä hetkellä on se, kuka hoitaa päivystykset ja hälytysten vastaanottamisen. Yleinen käytäntö hälytysten vastaanotossa on, kahden lomaan oikeutetun tilalla molempien ollessa lomalla tilan ulkopuolella, että lomittaja/lomittajat hoitaa automaattisesti päivystyksen. Sama asia toistuu yhden lomaan oikeutetun yrittäjän tilalla. Tutkimuksessa oli myös sellaisia tiloja jotka eivät tarvinneet päivystystä lainkaan. Keskimäärin näitä tiloja on 4,4 tilaa / paikallisyksikkö. Lypsytyön jäädessä pois se ei tarkoita automaattisesti työmenekin vähenemistä. Kyselyyn vastanneista tiloista 17 % työmenekki koettiin lypsyrobotin asentamisen jälkeen lisääntyneeksi jonkin verran. Tähän syynä oli karjamäärän lisääntyminen. Vastanneista tiloista 56 % oli asentanut robotin uuteen pihattoon. Tutkimuksen mukaan keskimääräinen lomittajan työaika robottitiloilla on 8,11 tuntia. Keskimäärin lypsylehmiä tiloilla on 66,39 kappaletta, hiehoja 43,33 kappaletta ja vasikoita 25,56. Kyselyyn vastanneista lomittajista 86 % mielestä robottitiloilla lomittaminen on mennyt parempaan suuntaan. Tämä johtuu töiden fyysisestä keventymisestä. Työn muuttumista huonompaan suuntaan arvioi 10% lomittajista. Lomittajat kertoivat syyksi työajan pidentymisen ja henkisen paineen kasvamisen. Jatkotutkimusta tälle työlle voisi olla, yhtenäisten oimintaohjeiden laatiminen lypsyrobottitilojen lomituksille.Robot milking systems bring new aspects for farm relief ractices at dairy farms. When hard physical work is no more needed, an animal care taker can focus more on observing nimals’ health and welfare, so more professional skills are also needed. The local unit in Northern Savo does not have a coherent operational model for receiving and signing for alarms from robot milking farms. In this Thesis we made an inquiry to find out the relief practices at robot milking dairy farms. We sent the inquiry to the local unit organizing farm relief services in Northern Savo, to robot milking farms and farm relief workers working at the farms. The results were collected in Verkkosalkku. We sent questionnaires to nine local units, 48 robot milking farms and 84 farm relief workers. The response per cent we got from local unit was 100 %, the farms 37,5 % and from farm relief workers 34,5 % At the moment the biggest problem is who will take care of duties and receiving the alarms from the robot milking farms. The common practice is that when both persons entitled for holiday are absent from the farm at the same time, the farm relief worker will automatically take care of the duty. This applies also for a single farm entrepreneur. In our research there were also farms which had no need for duty at all. On average there were this kind of farms about 4,4 farm per a local unit area. When milking work goes out it does not mean that working time decreases. The farms who answered to the inquiry, 50% of them say that working hours stay same and 17% farmers say that working hours increased to some extent. The reason for this is that the number of animals increased. 56% of the farmers who answered to the inquiry had installed the robot in a new loose stall stable. In ours research relief worker’s working time is average 8,11 hours. The average amount of dairy cattle at a farm are 66,39, heifers are 43,33 and calves 25,56. About the farm relief workers who answered the inquiry 86% say that work is going better at the robot milking farms. This is because there is less physical work. 10% of the farm relief workers said that working got worse. The reason for this is longer working hours and more mental pressure. As a follow-up research for this Thesis a common operational model for farm relief work practices at robot milking farms could be made

The Robot@Home2 dataset: A new release with improved usability tools

Released in 2017, Robot@Home is a dataset captured by a mobile robot during indoor navigation sessions in apartments. This paper presents Robot@Home2, an enhanced version of the Robot@Home dataset, aimed at improving usability and functionality for developing and testing mobile robotics and computer vision algorithms. Robot@Home2 consists of three main components. Firstly, a relational database that states the contextual information and data links, compatible with Standard Query Language. Secondly,a Python package for managing the database, including downloading, querying, and interfacing functions. Finally, learning resources in the form of Jupyter notebooks, runnable locally or on the Google Colab platform, enabling users to explore the dataset without local installations. These freely available tools are expected to enhance the ease of exploiting the Robot@Home dataset and accelerate research in computer vision and robotics.Partial funding for open access charges: Universidad de Málaga / CBU