This paper explores the effects of changes in matter density profiles on neutrino oscillation probabilities, and whether these could potentially be seen by the future Hyper-Kamiokande long-baseline ...oscillation experiment (T2HK). The analysis is extended to include the possibility of having an additional detector in Korea (T2HKK). In both cases, we find that these effects will be immeasurable, as the magnitudes of the changes in the oscillation probabilities induced in all density profile scenarios considered here remain smaller than the estimated experimental sensitivity to the oscillation probabilities of each experiment, for both appearance and disappearance channels. Therefore, we conclude that using a constant density profile is sufficient for both the T2HK and T2HKK experiments.
Abstract
The next-generation experiment JUNO will determine the solar oscillation parameters - sin
2
θ
12
and
Δ
m
21
2
- with great accuracy, in addition to measuring sin
2
θ
13
,
Δ
m
31
2
and the ...mass ordering. In parallel, the continued study of solar neutrinos at Hyper-Kamiokande will provide complementary measurements in the solar sector. Here we address the expected sensitivity to non-universal and flavour-changing non-standard interactions (NSI) with d-type quarks from the combination of these two future neutrino experiments. We also show the robustness of the measurement of the solar parameters and sin
2
θ
12
and
Δ
m
21
2
in the presence of NSI and comment on the enduring potential viability of the LMA-D solution.
A
bstract
We show that the four high-energy Littlest Seesaw parameters in the flavour basis, namely two real Yukawa couplings plus the two right-handed neutrino masses, can be determined by an ...excellent fit to the seven currently constrained observables of low-energy neutrino data and leptogenesis. Taking into account renormalisation group corrections, we estimate
χ
2
≃ 1.5-2.6 for the three d.o.f., depending on the high-energy scale and the type of non-supersymmetric Littlest Seesaw model. We extract allowed ranges of neutrino parameters from our fit data, including the approximate mu-tau symmetric predictions
θ
23
= 45° ± 1° and
δ
= −90° ± 5°, which, together with a normal mass ordering with
m
1
= 0, will enable Littlest Seesaw models to be tested in future neutrino experiments.
We report the results of a neutrino search in Super-Kamiokande (SK) for coincident signals with the first detected gravitational wave (GW) produced by a binary neutron-star merger, GW170817, which ...was followed by a short gamma-ray burst, GRB170817A, and a kilonova/macronova. We searched for coincident neutrino events in the range from 3.5 MeV to ∼100 PeV, in a time window 500 s around the gravitational wave detection time, as well as during a 14-day period after the detection. No significant neutrino signal was observed for either time window. We calculated 90% confidence level upper limits on the neutrino fluence for GW170817. From the upward-going-muon events in the energy region above 1.6 GeV, the neutrino fluence limit is 16.0 − 0.6 + 0.7 ( 21.3 − 0.8 + 1.1 ) cm−2 for muon neutrinos (muon antineutrinos), with an error range of 5° around the zenith angle of NGC4993, and the energy spectrum is under the assumption of an index of −2. The fluence limit for neutrino energies less than 100 MeV, for which the emission mechanism would be different than for higher-energy neutrinos, is also calculated. It is 6.6 × 107 cm−2 for anti-electron neutrinos under the assumption of a Fermi-Dirac spectrum with average energy of 20 MeV.
The next-generation neutrino experiment JUNO will determine the solar oscillation parameters - \(\sin^2 \theta_{12}\) and \(\Delta m^2_{21}\) - with great accuracy, in addition to measuring ...\(\sin^2\theta_{13}\), \(\Delta m^2_{31}\), and the mass ordering. In parallel, the continued study of solar neutrinos at Hyper-Kamiokande will provide complementary measurements in the solar sector. In this paper, we address the expected sensitivity to non-universal and flavour-changing non-standard interactions (NSI) with \(d\)-type quarks from the combination of these two future neutrino experiments. We also show the robustness of their measurements of the solar parameters \(\sin^2 \theta_{12}\) and \(\Delta m^2_{21}\) in the presence of NSI. We study the impact of the exact experimental configuration of the Hyper-Kamiokande detector, and conclude it is of little relevance in this scenario. Finally, we find that the LMA-D solution is expected to be present if no additional input from non-oscillation experiments is considered.
This paper explores the effects of changes in matter density profiles on neutrino oscillation probabilities, and whether these could potentially be seen by the future Hyper-Kamiokande long-baseline ...oscillation experiment (T2HK). The analysis is extended to include the possibility of having an additional detector in Korea (T2HKK). In both cases, we find that these effects will be immeasurable, as the magnitudes of the changes in the oscillation probabilities induced in all density profile scenarios considered here remain smaller than the estimated experimental sensitivity to the oscillation probabilities of each experiment, for both appearance and disappearance channels. Therefore, we conclude that using a constant density profile is sufficient for both the T2HK and T2HKK experiments.
This project aims to explore the effects that changes in a matter density profile could have on neutrino oscillations, and whether these could potentially be seen by the future Hyper-Kamiokande ...experiment (T2HK). The analysis is extended to include the possibility of having a second detector in Korea (T2HKK).
We show that the four high-energy Littlest Seesaw parameters in the flavour basis,namely two real Yukawa couplings plus the two right-handed neutrino masses, can be determined by an excellent fit to ...the seven currently constrained observables of low-energy neutrino data and leptogenesis. Taking into account renormalisation group corrections, we estimate \(\chi^2 \simeq 1.5-2.6\) for the three d.o.f., depending on the high-energy scale and the type of non supersymmetric Littlest Seesaw model. We extract allowed ranges of neutrino parameters from our fit data, including the approximate mu-tau symmetric predictions \(\theta_{23}=45^o\pm 1^o\) and \(\delta = -90^o \pm 5^o \), which, together with a normal mass ordering with \(m_1=0\), will enable Littlest Seesaw models to be tested in future neutrino experiments.
We present the development of neutron-tagging techniques in Super-Kamiokande IV using a neural network analysis. The detection efficiency of neutron capture on hydrogen is estimated to be 26%, with a ...mis-tag rate of 0.016 per neutrino event. The uncertainty of the tagging efficiency is estimated to be 9.0%. Measurement of the tagging efficiency with data from an Americium-Beryllium calibration agrees with this value within 10%. The tagging procedure was performed on 3,244.4 days of SK-IV atmospheric neutrino data, identifying 18,091 neutrons in 26,473 neutrino events. The fitted neutron capture lifetime was measured as 218 \pm 9 \mu s.
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