Search for K+→π+νν‾ at NA62 Aglieri Rinella, G.; Angelucci, B.; Antonelli, A. ...
Nuclear and particle physics proceedings,
January-March 2017, Volume:
282-284
Journal Article
Peer reviewed
Among the meson decays, K→πνν‾ are the cleanest environment, from the theoretical point of view, where to search for new physics effects. The NA62 Experiment at CERN SPS aims to measure the ...BR(K+→π+νν‾) with a 10% precision by the end of 2018. It has been commissioned with technical runs in 2014 and 2015, and some preliminary results of the detector performances and quality of data are here reported.
The NA62 experiment at CERN collected a large sample of charged kaon decays with a highly efficient trigger for decays into electrons in 2007. The kaon beam represents a source of tagged neutral pion ...decays in vacuum. A measurement of the electromagnetic transition form factor slope of the neutral pion in the time-like region from ∼1 million fully reconstructed π0 Dalitz decay is presented. The limits on dark photon production in π0 decays from the earlier kaon experiment at CERN, NA48/2, are also reported.
We derive the oxygen abundance (O/H), the nitrogen-to-oxygen (N/O) abundance ratio, and their corresponding radial gradients for a sample of 1431 galaxies from MaNGA DR15 survey using two different ...realizations of the strong line method: empirical R calibration and the Bayesian model-based {\sc HII-CHI-mistry} ({\sc HCm}) code. We find that both abundance calculation methods reveal a correlation between the O/H gradient and the stellar mass of a galaxy. This relation is non-linear, with the steepest average gradients in the intermediate mass range and flatter average gradients for high- and low-mass galaxies. The relation between the N/O gradient and the stellar mass is, on average, non-linear with the steepest gradients in the intermediate mass range (\(\log(M/M_\sun) \sim 10\)), flatter gradients for high-mass galaxies, and the flattest gradients for low-mass galaxies. However, the general trend of steepening N/O gradient for higher masses, reported in previous studies, remains evident. We find a dependence between the O/H and N/O gradients and the galaxy mean stellar age traced by the \(D\)(4000) index. For galaxies of lower masses, both gradients are, generally, steeper for intermediate values of \(D\)(4000) and flatter for low and high values of \(D\)(4000). Only the most massive galaxies do not show this correlation. We interpret this behaviour as an evolution of the metallicity gradients with the age of stellar population. Though the galaxies with a positive slope of the \(D\)(4000) radial gradient tend to have a flatter O/H and N/O gradients, as compared to those with a negative \(D\)(4000) gradient.
The ionizing source of Low Ionization Nuclear Emission Regions (LINERs) is uncertain. Because of this, an empirical relation to determine the chemical abundances of these objects has not been ...proposed. In this work, for the first time, we derived two semi-empirical calibrations based on photoionization models to estimate the oxygen abundance of LINERS as a function of the \(N2\) and \(O3N2\) emission-line intensity ratios. These relations were calibrated using oxygen abundance estimations obtained by comparing the observational emission-line ratios of 43 LINER galaxies (taken from the MaNGA survey) and grids of photoionization models built with the {\sc Cloudy} code assuming post-Asymptotic Giant Branch (post-AGB) stars with different temperatures. We found that the oxygen abundance of LINERs in our sample is in the \(\rm 8.48 <~ 12+log(O/H) <~ 8.84\) range, with a mean value of \(\rm 12+\log(O/H)=8.65\). We recommend the use of the \(N2\) index to estimate the oxygen abundances of LINERs, since the calibration with this index presented a much smaller dispersion than the \(O3N2\) index. In addition, the estimated metallicities are in good agreement with those derived by extrapolating the disk oxygen abundance gradients to the centre of the galaxies showing that the assumptions of the models are suitable for LINERs. We also obtained a calibration between the logarithm of the ionization parameter and the OIII/OII emission-line ratio.
Based on 28 359 marriage records for 1990–2000 throughout the Republic of North Ossetia-Alania, endogamy indices were calculated for different categories of the population of the republic: for the ...entire population in each district, for the urban and rural population, for the main ethnic groups. The cartographic analysis showed a reduction of endogamy in the direction of west to east. The obtained values of endogamy positively correlate with the values of random inbreeding. It is shown that the Republic of North Ossetia–Alania is not a population of the highest hierarchical level; the Ossetian people live on the territory of two republics, North and South Ossetia, without losing family ties, despite the presence of borders.
The influence of temperature on the dependences of the DeltaE effect of Fe^sub 75^Si^sub 10^B^sub 15^ metallic amorphous wires, which were subjected to thermomagnetic treatment at temperatures of ...from 370 to 470°C, on the magnetic field has been studied. It was shown that, at all temperatures of thermomagnetic treatment at relatively low heating temperatures, the negative DeltaE effect is observed. The increase in the heating temperature of the wire during measurements of the DeltaE effect at temperatures of 30-330°C leads to a decrease in both the magnitude of negative DeltaE effect and the field of reaching the maximum DeltaE effect magnitude. The dependence of the induced anisotropy field on the heating temperature of the wire has been determined. The obtained results are explained based on the concept of magnetoeleastic interactions between the core of wire and its near-surface area.PUBLICATION ABSTRACT
The influence of temperature on the dependences of the Delta E effect of Fe sub(75)Si sub(10)B sub(15) metallic amorphous wires, which were subjected to thermomagnetic treatment at temperatures of ...from 370 to 470 degree C, on the magnetic field has been studied. It was shown that, at all temperatures of thermomagnetic treatment at relatively low heating temperatures, the negative Delta E effect is observed. The increase in the heating temperature of the wire during measurements of the Delta E effect at temperatures of 30-330 degree C leads to a decrease in both the magnitude of negative Delta E effect and the field of reaching the maximum Delta E effect magnitude. The dependence of the induced anisotropy field on the heating temperature of the wire has been determined. The obtained results are explained based on the concept of magnetoeleastic interactions between the core of wire and its near-surface area.
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