scholarly journals Atmospheric Neutrinos

2012 ◽  
Vol 2012 ◽  
pp. 1-24 ◽  
Author(s):  
Takaaki Kajita

Atmospheric neutrinos are produced as decay products in hadronic showers resulting from collisions of cosmic rays with nuclei in the atmosphere. Electron-neutrinos and muon-neutrinos are produced mainly by the decay chain of charged pions to muons to electrons. Atmospheric neutrino experiments observed zenith angle and energy-dependent deficit of muon-neutrino events. It was found that neutrino oscillations between muon-neutrinos and tau-neutrinos explain these data well. This paper discusses atmospheric neutrino experiments and the neutrino oscillation studies with these neutrinos.

2019 ◽  
Vol 206 ◽  
pp. 09009
Author(s):  
Ha Nguyen Thi Kim ◽  
Van Nguyen Thi Hong ◽  
Son Cao Van

Neutrinos are neutral leptons and there exist three types of neutrinos (electron neutrinos νe, muon neutrinos νµ and tau neutrinos ντ). These classifications are referred to as neutrinos’s “flavors”. Oscillations between the different flavors are known as neutrino oscillations, which occurs when neutrinos have mass and non-zero mixing. Neutrino mixing is governed by the PMNS mixing matrix. The PMNS mixing matrix is constructed as the product of three independent rotations. With that, we can describe the numerical parameters of the matrix in a graphical form called the unitary triangle, giving rise to CP violation. We can calculate the four parameters of the mixing matrix to draw the unitary triangle. The area of the triangle is a measure of the amount of CP violation.


2021 ◽  
Vol 10 (3) ◽  
Author(s):  
Jiwon Woo ◽  
Gyuhyeon Lee

Matter-dominant universe cannot be explained with the Standard Model. In order to understand why the current universe mainly consists of matter particles, scientists turned their attention to neutrino oscillations, and conducted research on the properties of the particle and its potential relationship with the matter-antimatter asymmetry observed in the universe. In this research, the probability function of a neutrino oscillation was studied for 2-neutrino case to understand neutrino oscillation in particle accelerator experiments. For a more practical study, the neutrino oscillation probability function was calculated for two neutrino experiments and was used to verify neutrino detector positions and calculated ∆m2 which is mass difference between oscillating two different neutrinos. From this work, it was understood that detectors are located at positions with the highest probability for detecting neutrino oscillations, and it was also confirmed that neutrino were oscillating from muon neutrinos to electron neutrinos in particle accelerator experiments.


2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Shinya Fukasawa ◽  
Osamu Yasuda

The sensitivity of the atmospheric neutrino experiments to the nonstandard flavor-dependent interaction in neutrino propagation is studied under the assumption that only nonvanishing components of the nonstandard matter effect are the electron and tau neutrino componentsϵee, andϵeτ,ϵττand that the tau-tau component satisfies the constraintϵττ=|ϵeτ|2/(1+ϵee)which is suggested from the high energy behavior for atmospheric neutrino data. It is shown that the Super-Kamiokande (SK) data for 4438 days constrains|tanβ|≡|ϵeτ/(1+ϵee)|≲0.8at 2.5σ(98.8%) CL whereas the future Hyper-Kamiokande experiment for the same period of time as SK will constrain as|tanβ|≲0.3at 2.5σCL from the energy rate analysis and the energy spectrum analysis will give even tighter bounds onϵeeand|ϵeτ|.


2002 ◽  
Vol 17 (24) ◽  
pp. 3364-3377 ◽  
Author(s):  
◽  
C. K. JUNG

K2K is a long baseline neutrino oscillation experiment using a neutrino beam produced at the KEK 12 GeV PS, a near detector complex at KEK and a far detector (Super-Kamiokande) in Kamioka, Japan. The experiment was constructed and is being operated by an international consortium of institutions from Japan, Korea, and the US. The experiment started taking data in 1999 and has successfully taken data for about two years. K2K is the first long beseline neutrino oscillation experiment with a baseline of order hundreds of km and is the first accelerator based neutrino oscillation experiment that is sensitive to the Super-Kamiokande allowed region obtained from the atmospheric neutrino oscillation analysis. A total of 44 events have been observed in the far detector during the period of June 1999 to April 2001 corresponding to 3.85 × 1019 protons on target. The observation is consistent with the neutrino oscillation expectations based on the oscillation parameters derived from the atmospheric neutrinos, and the probability that this is a statistical fluctuation of non-oscillation expectation of [Formula: see text] is less than 3%.


Author(s):  
Sandhya Choubey

Neutrino physics has come a long way and made great strides in the past decades. We discuss the prospects of what more can be learned in this field in the forthcoming neutrino oscillation facilities. We will mostly focus on the potential of the long-baseline experiments and the atmospheric neutrino experiments. Sensitivity of these experiments to standard neutrino oscillation parameters will be presented. We will also discuss the prospects of new physics searches at these facilities.


2019 ◽  
Vol 208 ◽  
pp. 07001
Author(s):  
Morihiro Honda

It is well known that the correlation of atmospheric neutrinos and muons are simply correlated in the energy region of 1–10 GeV, and used for the test bench of the hadronic interaction model used for the calculation of the atmospheric neutrino flux. However, the correlation becomes unclear for neutrinos in the energy range below 1 GeV, which is important for the study of mass ordering of neutrino and CP phase of the neutrino mass. We extend the study of the correlation to the lower neutrino energies and find that the atmospheric muon flux observed at high altitude shows a good correlation to the atmospheric neutrino flux, and could be used to calibrate the hadronic interaction model.


1999 ◽  
Vol 14 (12) ◽  
pp. 1953-1974 ◽  
Author(s):  
T. SAKAI ◽  
O. INAGAKI ◽  
T. TESHIMA

We analyze the solar, terrestrial and atmospheric neutrino experiments including SuperKamiokande data using the three-flavor neutrinos framework and obtain the allowed region for parameters [Formula: see text]. In solar neutrino experiments, we obtain the large angle solution [Formula: see text] and small angle solution (3×10-6-1.2×10-5 eV 2, 0.003-0.01) for θ13=0°-20°. From the terrestrial and atmospheric neutrino experiments including the sub-GeV and multi-GeV zenith angle dependence in SuperKamiokande 535 days data, we found that the νμ-ντ mixing is large and the range of [Formula: see text] as 0.02~0.0002  eV 2. There is no significant difference between large θ12 angle solution and small one.


2004 ◽  
Vol 19 (08) ◽  
pp. 1167-1179 ◽  
Author(s):  
A. BELLERIVE

This paper reviews the constraints on the solar neutrino mixing parameters with data collected by the Homestake, SAGE, GALLEX, Kamiokande, SuperKamiokande, and SNO experiments. An emphasis will be given to the global solar neutrino analyses in terms of matter-enhanced oscillation of two active flavors. The results to-date, including both solar model dependent and independent measurements, indicate that electron neutrinos are changing to other active types on route to the Earth from the Sun. The total flux of solar neutrinos is found to be in very good agreement with solar model calculations. Future measurements will focus on greater accuracy for mixing parameters and on better sensitivity to low neutrino energies.


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