scholarly journals An alternative method of determining the neutrino mass ordering in reactor neutrino experiments

2017 ◽  
Vol 772 ◽  
pp. 179-183 ◽  
Author(s):  
S.M. Bilenky ◽  
F. Capozzi ◽  
S.T. Petcov
Keyword(s):  
Neutrino Mass ◽  
Alternative Method ◽  
Reactor Neutrino ◽  
Neutrino Experiments

scholarly journals PHYSICS POTENTIAL OF A 2540 km BASELINE SUPERBEAM EXPERIMENT

2011 ◽  
Vol 26 (27) ◽  
pp. 2051-2063 ◽  
Author(s):  
ANIKET JOGLEKAR ◽  
SUPRABH PRAKASH ◽  
SUSHANT K. RAUT ◽  
S. UMA SANKAR
Keyword(s):  
Neutrino Mass ◽  
Neutrino Beam ◽  
Mass Hierarchy ◽  
Medium Energy ◽  
Neutrino Mass Hierarchy ◽  
Physics Potential ◽  
Reactor Neutrino ◽  
Numi Beam ◽  
Neutrino Experiments ◽  
Scintillator Detector

We study the physics potential of a neutrino superbeam experiment with a 2540 km baseline. We assume a neutrino beam similar to the NuMI beam in medium energy configuration. We consider a 100 kton totally active scintillator detector at a 7 mr off-axis location. We find that such a configuration has outstanding hierarchy discriminating capability. In conjunction with the data from the present reactor neutrino experiments, it can determine the neutrino mass hierarchy at 3σ level in less than 5 years, if sin22θ13≥0.01, running in the neutrino mode alone. As a stand alone experiment, with a five-year neutrino run and a five-year anti-neutrino run, it can determine nonzero θ13 at 3σ level if sin22θ13≥7×10-3 and hierarchy at 3σ level if sin22θ13≥8×10-3. This data can also distinguish δ CP = π/2 from the CP conserving values of 0 and π, for sin22θ13≥0.02.

scholarly journals Constraining visible neutrino decay at KamLAND and JUNO

2020 ◽  
Vol 80 (10) ◽  
Author(s):  
Yago P. Porto-Silva ◽  
Suprabh Prakash ◽  
O. L. G. Peres ◽  
Hiroshi Nunokawa ◽  
Hisakazu Minakata
Keyword(s):  
Neutrino Mass ◽  
Massive Neutrino ◽  
Normal Ordering ◽  
Different Types ◽  
Reactor Neutrino ◽  
Neutrino Experiments ◽  
Pseudo Scalar ◽  
Neutrino Decay

AbstractWe study visible neutrino decay at the reactor neutrino experiments KamLAND and, JUNO. Assuming the Majoron model of neutrino decay, we obtain constraints on the couplings between Majoron and neutrino as well as on the lifetime/mass of the most massive neutrino state i.e., $$\tau _{3} / m_{3}$$ τ 3 / m 3 or $$\tau _{2} / m_{2}$$ τ 2 / m 2 , respectively, for the normal or the inverted mass orderings. We obtain the constraints on the lifetime $$\tau _{2} / m_{2} \ge 1.4 \times 10^{-9}~{\mathrm{s/eV}}$$ τ 2 / m 2 ≥ 1.4 × 10 - 9 s / eV in the inverted mass ordering for both KamLAND and JUNO at 90% CL. In the normal ordering in which the bound can be obtained for JUNO only, the constraint is milder than the inverted ordering case, $$\tau _{3} / m_{3} \ge 1.0 \times 10^{-10}$$ τ 3 / m 3 ≥ 1.0 × 10 - 10  s/eV at 90% CL. We find that the dependence of lightest neutrino mass ($$=m_{{{\mathrm{lightest}}}}$$ = m lightest ), $$m_1 (m_3)$$ m 1 ( m 3 ) for the normal (inverted) mass ordering, on the constraints for the different types of couplings (scalar or pseudo-scalar) is rather strong, but the $$m_{{{\mathrm{lightest}}}}$$ m lightest dependence on the lifetime/mass bound is only modest.

scholarly journals TEXTURE ZEROS FOR DIRAC NEUTRINOS AND CURRENT EXPERIMENTAL TESTS

2013 ◽  
Vol 28 (12) ◽  
pp. 1350040 ◽  
Author(s):  
XUE-WEN LIU ◽  
SHUN ZHOU
Keyword(s):  
Neutrino Mass ◽  
Mass Matrix ◽  
Experimental Tests ◽  
Neutrino Mixing ◽  
Mixing Angle ◽  
Dirac Particles ◽  
Texture Zero ◽  
Reactor Neutrino ◽  
The Stability ◽  
Neutrino Experiments

The Daya Bay and RENO reactor neutrino experiments have revealed that the smallest neutrino mixing angle is in fact relatively large, i.e. θ13 ≈9°. Motivated by this exciting progress, we perform a systematic study of the neutrino mass matrix Mν with one or two texture zeros, in the assumption that neutrinos are Dirac particles. Among 15 possible patterns with two texture zeros, only three turn out to be favored by current neutrino oscillation data at the 3σ level. Although all the six patterns with one texture zero are compatible with the experimental data at the 3σ level, the parameter space of each pattern is strictly constrained. Phenomenological implications of Mν on the leptonic CP violation and neutrino mass spectrum are explored, and the stability of texture zeros against the radiative corrections is also discussed.

scholarly journals Non-standard interactions in SMEFT confronted with terrestrial neutrino experiments

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Yong Du ◽  
Hao-Lin Li ◽  
Jian Tang ◽  
Sampsa Vihonen ◽  
Jiang-Hao Yu
Keyword(s):  
Neutrino Oscillation ◽  
New Physics ◽  
Effective Field ◽  
Scalar Leptoquark ◽  
Double Chooz ◽  
The Standard Model ◽  
Reactor Neutrino ◽  
Model Independent ◽  
Neutrino Experiments ◽  
Individual Dimension

Abstract The Standard Model Effective Field Theory (SMEFT) provides a systematic and model-independent framework to study neutrino non-standard interactions (NSIs). We study the constraining power of the on-going neutrino oscillation experiments T2K, NOνA, Daya Bay, Double Chooz and RENO in the SMEFT framework. A full consideration of matching is provided between different effective field theories and the renormalization group running at different scales, filling the gap between the low-energy neutrino oscillation experiments and SMEFT at the UV scale. We first illustrate our method with a top- down approach in a simplified scalar leptoquark model, showing more stringent constraints from the neutrino oscillation experiments compared to collider studies. We then provide a bottom-up study on individual dimension-6 SMEFT operators and find NSIs in neutrino experiments already sensitive to new physics at ∼20 TeV when the Wilson coefficients are fixed at unity. We also investigate the correlation among multiple operators at the UV scale and find it could change the constraints on SMEFT operators by several orders of magnitude compared with when only one operator is considered. Furthermore, we find that accelerator and reactor neutrino experiments are sensitive to different SMEFT operators, which highlights the complementarity of the two experiment types.

Majorana phases and neutrino–antineutrino oscillations

2014 ◽  
Vol 29 (21) ◽  
pp. 1444003 ◽  
Author(s):  
Zhi-Zhong Xing
Keyword(s):  
Neutrino Mass ◽  
Mass Hierarchy ◽  
Neutrino Mass Hierarchy ◽  
Special Cases ◽  
The Future ◽  
Massive Neutrinos ◽  
Neutrino Experiments ◽  
Majorana Phases

If massive neutrinos are the Majorana particles, how to pin down the Majorana CP-violating phases will eventually become an unavoidable question relevant to the future neutrino experiments. I argue that a study of neutrino–antineutrino oscillations will greatly help in this regard, although the issue remains purely academic at present. In this talk I first derive the probabilities and CP-violating asymmetries of neutrino–antineutrino oscillations in the three-flavor framework, and then illustrate their properties in two special cases: the normal neutrino mass hierarchy with m1 = 0 and the inverted neutrino mass hierarchy with m3 = 0. I demonstrate the significant contributions of the Majorana phases to the CP-violating asymmetries, even in the absence of the Dirac phase.

scholarly journals Statistical interpretation of sterile neutrino oscillation searches at reactors

2021 ◽  
Vol 81 (1) ◽  
Author(s):  
Pilar Coloma ◽  
Patrick Huber ◽  
Thomas Schwetz
Keyword(s):  
Neutrino Oscillation ◽  
Sterile Neutrino ◽  
Statistical Significance ◽  
Statistical Interpretation ◽  
Actual Distribution ◽  
Mixing Angle ◽  
Log Likelihood ◽  
Reactor Neutrino ◽  
Neutrino Experiments ◽  
Experimental Effort

AbstractA considerable experimental effort is currently under way to test the persistent hints for oscillations due to an eV-scale sterile neutrino in the data of various reactor neutrino experiments. The assessment of the statistical significance of these hints is usually based on Wilks’ theorem, whereby the assumption is made that the log-likelihood is $$\chi ^2$$ χ 2 -distributed. However, it is well known that the preconditions for the validity of Wilks’ theorem are not fulfilled for neutrino oscillation experiments. In this work we derive a simple asymptotic form of the actual distribution of the log-likelihood based on reinterpreting the problem as fitting white Gaussian noise. From this formalism we show that, even in the absence of a sterile neutrino, the expectation value for the maximum likelihood estimate of the mixing angle remains non-zero with attendant large values of the log-likelihood. Our analytical results are then confirmed by numerical simulations of a toy reactor experiment. Finally, we apply this framework to the data of the Neutrino-4 experiment and show that the null hypothesis of no-oscillation is rejected at the 2.6 $$\sigma $$ σ level, compared to 3.2 $$\sigma $$ σ obtained under the assumption that Wilks’ theorem applies.

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