Analysis of the data recorded by the Mont Blanc neutrino detector and by the Maryland and Rome gravitational-wave detectors during SN1987A

Summary The data recorded by the gravitational wave and the neutrino detectors mentioned in the title have been analysed over a period of several days that includes the Mont Blanc 5ν burst occurrence time. A correlation is found during a period of about two hours roughly centred on the 5ν burst, independently between Maryland and Mont Blanc and Rome and Mont Blanc. The probability that these two correlations be due to chance is of the order of between 10⁻⁶ and 10⁻⁵. It is found that this effect is mainly due to a dozen of large Maryland and Rome events distributed during the above two-hour period.

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Riassunto I dati registrati con le antenne gravitazionali ed i rivelatori di neutrini indicati nel titolo sono stati analizzati in un periodo di vari giorni, includendo il tempo di occorrenza dell'evento di 5 neutrini rivelato al Monte Bianco. è stata trovata una correlazione durante circa due ore centrata al tempo dei 5ν, indipendentemente Maryland/Monte Bianco e Roma/Monte Bianco. La probabilità che queste due correlazioni siano dovute al caso è dell'ordine di 10⁻⁶÷10⁻⁵. è stato trovato che questo effetto è dovuto essenzialmente ad una dozzina di segnali registrati a Roma e in Maryland durante il sopramenzionato periodo di due ore.

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Резюме Проводится анализ данных, зарегистрированных нейтринным детектором на Мон Блане и детекторами гравитационных волн в Мэриленде и Риме, за период, охватывающий несколько дней, которые включают время появления 5ν вспышки на Мон Блане. Обнаружена корреляция в течение приблизительно двух часов, центр которой приблизительно совпадает со временем 5ν вспышки, независимо в данных Мэриленд и Мон Блан и в данных Рим и Мон Блан. Вероятность того, что эти две корреляции являются случайными, имеет порядок величины 10⁻⁶÷10⁻⁵. Обнаружено, чтот эффект обусловлен в основном дюжиной сигналов, зарегистрированных в Риме и Мэриленде в течение периода около двух часов.

     

SN 1987 A: Correlations between the Maryland and Rome gravitational wave detector data and the Mont Blanc and Kamiokande neutrino detector data

Summary The author reports on the analysis of the data obtained with the detectors given in the title in the period 12h of February 22, 1987 to 6h of February 23, 1987, that includes the time of the ν observation with the Mont Blanc detector during SN 1987a. A very significant correlation has been observed among the data of the above detectors in a period of one or two hours which includes the time of the Mont Blanc 5ν observation. The correlation between the g.w. data and the Kamiokande data is found if a time of 7.8s is added to the Kamioka recorded time; this is very close to the time difference, 6.2s, between the IMB and Kamioka large ν bursts observed at ≈7h 35 min. To speed up publication, the proofs were not sent to the authors and were supervised by the Scientific Committee.     

Updated limits on the electron neutrino mass and large angle oscillations from SN1987A

We supplement Maximum Likelihood methods with a Monte-Carlo simulation to re-investigate the SN1987A neutrino burst detection by the IMB and Kamiokande experiments. The detector simulations include background in the the latter and “dead-time” in the former. We consider simple neutrinosphere cooling models, explored previously in the literature, to explore the case for or against neutrino vacuum mixing and massive neutrinos. In the former case, involving kinematically irrelevant masses, we find that the full range of vacuum mixing angles, 0 ≤ sin² 2θv ≤ 1, is permitted, and the Maximum Likelihood mixing angle is sin² 2θv = 0.45. In the latter case we find that the inclusion of “dead-time” reduces previous m_νe upper bounds by 10%, and supplementing the Maximum Likelihood analysis with a Monte-Carlo goodness-of-fit test results in a further 15% reduction in the m_νe upper limit. Our 95% C.L. upper limit for m_νe is 19.6 eV, while the best fit value is ∼ 0 eV.     

The mass of the electron neutrino: Monte Carlo studies of SN 1987A observations

Monte Carlo simulations of a wide class of possible neutrino emission models are used to assign statistical significance to the limits set on the mass of the electron neutrino by observations of SN 1987A. Using the combined Kamiokande II and IMB data sets, we reject neutrino masses greater than 16 eV at the 5% significance level.     

Is the LMA solar-neutrino solution ruled out by SN1987A data?

The development of new supernova neutrino detectors relies on the expected hard energy spectrum of the ν_μ and ν_τ emitted in the supernova. We show that SN1987A was sensitive to the large mixing angle (LMA) and “just so” solution to the solar neutrino problem. We review the previous analysis of the SN1987A data and propose a new analysis. The results of this analysis strongly disfavor the LMA solution, provided the ν_μ and ν_τ are hard as predicted     

SN1987A; n-stars, s-stars and the observational evidences

Summary We discuss a SN model with s-matter in the core, compatible with the set of experimental results obtained on SN 1987A by ν-detectors and gravitational antennas.