Oscilace neutrin

Institute of Particle and Nuclear PhysicsÚstav částicové a jaderné fyzikyFaculty of Mathematics and PhysicsMatematicko-fyzikální fakult

Non-standard antineutrino interactions at Daya Bay

We study the prospects of pinning down the effects of non-standard antineutrino interactions in the source and in the detector at the Daya Bay neutrino facility. It is well known that if the non-standard interactions in the detection process are of the same type as those in the production, their net effect can be subsumed into a mere shift in the measured value of the leptonic mixing angle theta_13. Relaxing this assumption, the ratio of the antineutrino spectra measured by the Daya Bay far and near detectors is distorted in a characteristic way, and good fits based on the standard oscillation hypothesis are no longer viable. We show that, under certain conditions, three years of Daya Bay running can be sufficient to provide a clear hint of non-standard neutrino physics.Comment: 31 pages, 12 figures; a brief discussion of systematics added in v2, published versio

Synergies and Prospects for Early Resolution of the Neutrino Mass Ordering

The measurement of neutrino Mass Ordering (MO) is a fundamental element for the understanding of leptonic flavour sector of the Standard Model of Particle Physics. Its determination relies on the precise measurement of $\Delta m^2_{31}$ and $\Delta m^2_{32}$ using either neutrino vacuum oscillations, such as the ones studied by medium baseline reactor experiments, or matter effect modified oscillations such as those manifesting in long-baseline neutrino beams (LB$\nu$B) or atmospheric neutrino experiments. Despite existing MO indication today, a fully resolved MO measurement ($\geq$5$\sigma$) is most likely to await for the next generation of neutrino experiments: JUNO, whose stand-alone sensitivity is $\sim$3$\sigma$, or LB$\nu$B experiments (DUNE and Hyper-Kamiokande). Upcoming atmospheric neutrino experiments are also expected to provide precious information. In this work, we study the possible context for the earliest full MO resolution. A firm resolution is possible even before 2028, exploiting mainly vacuum oscillation, upon the combination of JUNO and the current generation of LB$\nu$B experiments (NOvA and T2K). This opportunity is possible thanks to a powerful synergy boosting the overall sensitivity where the sub-percent precision of $\Delta m^2_{32}$ by LB$\nu$B experiments is found to be the leading order term for the MO earliest discovery. We also found that the comparison between matter and vacuum driven oscillation results enables unique discovery potential for physics beyond the Standard Model.Comment: Entitled in arXiv:2008.11280v1 as "Earliest Resolution to the Neutrino Mass Ordering?

Real-time Monitoring for the Next Core-Collapse Supernova in JUNO

Core-collapse supernova (CCSN) is one of the most energetic astrophysical events in the Universe. The early and prompt detection of neutrinos before (pre-SN) and during the SN burst is a unique opportunity to realize the multi-messenger observation of the CCSN events. In this work, we describe the monitoring concept and present the sensitivity of the system to the pre-SN and SN neutrinos at the Jiangmen Underground Neutrino Observatory (JUNO), which is a 20 kton liquid scintillator detector under construction in South China. The real-time monitoring system is designed with both the prompt monitors on the electronic board and online monitors at the data acquisition stage, in order to ensure both the alert speed and alert coverage of progenitor stars. By assuming a false alert rate of 1 per year, this monitoring system can be sensitive to the pre-SN neutrinos up to the distance of about 1.6 (0.9) kpc and SN neutrinos up to about 370 (360) kpc for a progenitor mass of 30$M_{\odot}$ for the case of normal (inverted) mass ordering. The pointing ability of the CCSN is evaluated by using the accumulated event anisotropy of the inverse beta decay interactions from pre-SN or SN neutrinos, which, along with the early alert, can play important roles for the followup multi-messenger observations of the next Galactic or nearby extragalactic CCSN.Comment: 24 pages, 9 figure

Detailed Investigation of Electron Antineutrino Oscillations in the Daya Bay Experiment

Observed disappearance of reactor antineutrinos in the short baseline in Daya Bay can be explained by the phenomenon of neutrino flavour oscillations. The analysis in standard three- neutrino framework provides the best measurement of mixing angle of θ13 and the value of effective mass squared difference ∆m2 ee with comparable precision with other experiments. The unprecedented precision of Daya Bay motivates us to extend our search beyond standard three-neutrino oscillation scheme. It this thesis, we have explored two scenarios of possible physics Beyond Standard Model (BSM). We have tested the fundamental symmetry of the nature by searching for the Lorentz Invariance violation effect within the framework of the Standard-Model Extension (SME). Such an effect could be observed as a deviation from three- neutrino oscillation prediction in the oscillated antineutrino spectrum. Since we have not observed any significant deviation, we have been able to set the limits on the SME parameters. Some of the limits were measured for the first time while some turned out not to be competitive with the measurement of other experiments. We have also performed search for Non-standard Interactions (NSIs) in the Daya Bay. Being forbidden in the Standard Model, these interactions are predicted by BSM theories for which..

Podrobné zkoumání oscilací elektronových antineutrin v experimentu Daya Bay

Observed disappearance of reactor antineutrinos in the short baseline in Daya Bay can be explained by the phenomenon of neutrino flavour oscillations. The analysis in standard three- neutrino framework provides the best measurement of mixing angle of θ13 and the value of effective mass squared difference ∆m2 ee with comparable precision with other experiments. The unprecedented precision of Daya Bay motivates us to extend our search beyond standard three-neutrino oscillation scheme. It this thesis, we have explored two scenarios of possible physics Beyond Standard Model (BSM). We have tested the fundamental symmetry of the nature by searching for the Lorentz Invariance violation effect within the framework of the Standard-Model Extension (SME). Such an effect could be observed as a deviation from three- neutrino oscillation prediction in the oscillated antineutrino spectrum. Since we have not observed any significant deviation, we have been able to set the limits on the SME parameters. Some of the limits were measured for the first time while some turned out not to be competitive with the measurement of other experiments. We have also performed search for Non-standard Interactions (NSIs) in the Daya Bay. Being forbidden in the Standard Model, these interactions are predicted by BSM theories for which...Pozorovaný deficit reaktorových elektronových antineutrin na krátkých vzdálenostech v experimentu Daya Bay může být vysvětlen pomocí jevu oscilací neutrin. Měření, za předpokladu existence tří vůní neutrin, nám poskytuje nejpřesnější hodnotu směšovacího úhlu θ13 a hodnotu efektivního rozdílu kvadrátu hmotností m2 ee s přesností srovnatelnou s ostatními experimenty. Přesnost, s jakou měří experiment Daya Bay tyto parametry, nás motivuje k rozšíření našeho zkoumání za hranice standardních oscilací se třemi vůněmi neutrin. V této práci jsme zkoumali dva možné scénáře fyziky za Standardním Modelem (SM). Jako první jsme testovali platnost symetrie lorentzovské invariance pomocí hledání jejího narušení v rámci modelu Standard-Model Extension (SME). Narušení by bylo pozorováno jako odchylka od předpovědi standardních oscilací v zoscilovaném energetickém spektru antineutrin. Naše analýza poskytla limity na parametry SME, jelikož nebyla pozorována žádná výrazná odchylka od standardních oscilací. Některé z těchto limitů byly naměřeny vůbec poprvé. Za druhé jsme zkoumali možné efekty nestandardních interakcí (NI) v oscilacích v experimentu Daya Bay. Takové interakce jsou zakázané ve SM, ale mohou být dovolené v teoriích za SM, pro které je SM nízkoenergetická limita. Nestandardní interakce by se projevily v procesu...Ústav částicové a jaderné fyzikyInstitute of Particle and Nuclear PhysicsFaculty of Mathematics and PhysicsMatematicko-fyzikální fakult

Podrobné zkoumání oscilací elektronových antineutrin v experimentu Daya Bay

Pozorovaný deficit reaktorových elektronových antineutrin na krátkých vzdálenostech v experimentu Daya Bay může být vysvětlen pomocí jevu oscilací neutrin. Měření, za předpokladu existence tří vůní neutrin, nám poskytuje nejpřesnější hodnotu směšovacího úhlu θ13 a hodnotu efektivního rozdílu kvadrátu hmotností m2 ee s přesností srovnatelnou s ostatními experimenty. Přesnost, s jakou měří experiment Daya Bay tyto parametry, nás motivuje k rozšíření našeho zkoumání za hranice standardních oscilací se třemi vůněmi neutrin. V této práci jsme zkoumali dva možné scénáře fyziky za Standardním Modelem (SM). Jako první jsme testovali platnost symetrie lorentzovské invariance pomocí hledání jejího narušení v rámci modelu Standard-Model Extension (SME). Narušení by bylo pozorováno jako odchylka od předpovědi standardních oscilací v zoscilovaném energetickém spektru antineutrin. Naše analýza poskytla limity na parametry SME, jelikož nebyla pozorována žádná výrazná odchylka od standardních oscilací. Některé z těchto limitů byly naměřeny vůbec poprvé. Za druhé jsme zkoumali možné efekty nestandardních interakcí (NI) v oscilacích v experimentu Daya Bay. Takové interakce jsou zakázané ve SM, ale mohou být dovolené v teoriích za SM, pro které je SM nízkoenergetická limita. Nestandardní interakce by se projevily v procesu...Observed disappearance of reactor antineutrinos in the short baseline in Daya Bay can be explained by the phenomenon of neutrino flavour oscillations. The analysis in standard three- neutrino framework provides the best measurement of mixing angle of θ13 and the value of effective mass squared difference ∆m2 ee with comparable precision with other experiments. The unprecedented precision of Daya Bay motivates us to extend our search beyond standard three-neutrino oscillation scheme. It this thesis, we have explored two scenarios of possible physics Beyond Standard Model (BSM). We have tested the fundamental symmetry of the nature by searching for the Lorentz Invariance violation effect within the framework of the Standard-Model Extension (SME). Such an effect could be observed as a deviation from three- neutrino oscillation prediction in the oscillated antineutrino spectrum. Since we have not observed any significant deviation, we have been able to set the limits on the SME parameters. Some of the limits were measured for the first time while some turned out not to be competitive with the measurement of other experiments. We have also performed search for Non-standard Interactions (NSIs) in the Daya Bay. Being forbidden in the Standard Model, these interactions are predicted by BSM theories for which...Ústav částicové a jaderné fyzikyInstitute of Particle and Nuclear PhysicsFaculty of Mathematics and PhysicsMatematicko-fyzikální fakult

Možnosti určení hierarchie hmot neutrin

Ústav částicové a jaderné fyzikyInstitute of Particle and Nuclear PhysicsFaculty of Mathematics and PhysicsMatematicko-fyzikální fakult