scholarly journals Tentative sensitivity of future 0νββ-decay experiments to neutrino masses and Majorana CP phases

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Guo-yuan Huang ◽  
Shun Zhou
Keyword(s):  
Neutrino Mass ◽  
Statistical Approach ◽  
Credible Interval ◽  
Neutrino Masses ◽  
Strength Of Evidence ◽  
Statistical Framework ◽  
Massive Neutrinos ◽  
Near Future ◽  
The Bayesian Approach

Abstract In the near future, the neutrinoless double-beta (0νββ) decay experiments will hopefully reach the sensitivity of a few meV to the effective neutrino mass |mββ|. In this paper, we tentatively examine the sensitivity of future 0νββ-decay experiments to neutrino masses and Majorana CP phases by following the Bayesian statistical approach. Provided experimental setups corresponding to the experimental sensitivity of |mββ| ≃ 1 meV, the null observation of 0νββ decays in the case of normal neutrino mass ordering leads to a very competitive bound on the lightest neutrino mass m1. Namely, the 95% credible interval in the Bayesian approach turns out to be 1.6 meV ≲ m1 ≲ 7.3 meV or 0.3 meV ≲ m1 ≲ 5.6 meV when the uniform prior on m1/eV or on log10(m1/eV) is adopted. Moreover, one of two Majorana CP phases is strictly constrained, i.e., 140° ≲ ρ ≲ 220° for both scenarios of prior distributions of m1. In contrast, if a relatively worse experimental sensitivity of |mββ| ≃ 10 meV is assumed, the constraint on the lightest neutrino mass becomes accordingly 0.6 meV ≲ m1 ≲ 26 meV or 0 ≲ m1 ≲ 6.1 meV, while two Majorana CP phases will be essentially unconstrained. In the same statistical framework, the prospects for the determination of neutrino mass ordering and the discrimination between Majorana and Dirac nature of massive neutrinos in the 0νββ-decay experiments are also discussed. Given the experimental sensitivity of |mββ| ≃ 10 meV (or 1 meV), the strength of evidence to exclude the Majorana nature under the null observation of 0νββ decays is found to be inconclusive (or strong), no matter which of two priors on m1 is taken.

scholarly journals GENERALIZED FRIEDBERG-LEE MODEL FOR NEUTRINO MASSES AND LEPTONIC CP VIOLATION FROM μ-τ SYMMETRY BREAKING

2008 ◽  
Vol 23 (21) ◽  
pp. 3384-3387 ◽  
Author(s):  
ZHI-ZHONG XING ◽  
HE ZHANG ◽  
SHUN ZHOU
Keyword(s):  
Cp Violation ◽  
Symmetry Breaking ◽  
Neutrino Mass ◽  
Mass Matrix ◽  
Neutrino Masses ◽  
Neutrino Mixing ◽  
Mass Model ◽  
Lee Model ◽  
Massive Neutrinos ◽  
Free Parameters

Assuming the Majorana nature of massive neutrinos, we generalize the Friedberg-Lee neutrino mass model to include CP violation in the neutrino mass matrix Mν. The most general case with all the free parameters of Mν being complex is discussed. We show that a favorable neutrino mixing pattern (with θ12 ≈ 35.3°, θ23 = 45°, θ13 ≠ 0° and δ = 90°) can naturally be derived from Mν, if it has an approximate or softly-broken μ-τ symmetry. We also point out a different way to obtain the nearly tri-bimaximal neutrino mixing pattern with δ = 0° and non-vanishing Majorana phases.

scholarly journals Including massive neutrinos in thermal Sunyaev Zeldovich power spectrum and cluster counts analyses

2020 ◽  
Vol 497 (2) ◽  
pp. 1332-1347 ◽  
Author(s):  
Boris Bolliet ◽  
Thejs Brinckmann ◽  
Jens Chluba ◽  
Julien Lesgourgues
Keyword(s):  
Power Spectrum ◽  
Neutrino Mass ◽  
Cold Dark Matter ◽  
Transfer Functions ◽  
Mass Function ◽  
Small Scale ◽  
X Ray ◽  
Mass Bias ◽  
Massive Neutrinos

ABSTRACT We consistently include the effect of massive neutrinos in the thermal Sunyaev Zeldovich (SZ) power spectrum and cluster counts analyses, highlighting subtle dependencies on the total neutrino mass and data combination. In particular, we find that using the transfer functions for cold dark matter (CDM) + baryons in the computation of the halo mass function, instead of the transfer functions including neutrino perturbations, as prescribed in recent work, yields an ≈0.25 per cent downward shift of the σ8 constraint from tSZ power spectrum data, with a fiducial neutrino mass Σmν = 0.06 eV. In ΛCDM, with an X-ray mass bias corresponding to the expected hydrostatic mass bias, i.e. (1 − b) ≃ 0.8, our constraints from Planck SZ data are consistent with the latest results from SPT, DES-Y1, and KiDS+VIKING-450. In νΛCDM, our joint analyses of Planck SZ with Planck 2015 primary CMB yield a small improvement on the total neutrino mass bound compared to the Planck 2015 primary CMB constraint, as well as (1 − b) = 0.64 ± 0.04 (68 per cent CL). For forecasts, we find that competitive neutrino mass measurements using cosmic variance limited SZ power spectrum require masking the heaviest clusters and probing the small-scale SZ power spectrum up to ℓmax ≈ 104. Although this is challenging, we find that SZ power spectrum can realistically be used to tightly constrain intracluster medium properties: we forecast a 2 per cent determination of the X-ray mass bias by combining CMB-S4 and our mock SZ power spectrum with ℓmax = 103.

Neutrino Masses and Mixings

2019 ◽  
pp. 313-326
Author(s):  
Michael E. Peskin
Keyword(s):  
Experimental Determination ◽  
Neutrino Mass ◽  
Neutrino Masses ◽  
Neutrino Mixing ◽  
Neutrino Flavor ◽  
Flavor Mixing ◽  
Pmns Matrix ◽  
The Masses ◽  
Neutrino Masses And Mixings

This chapter discusses the search for and eventual discovery of the masses of neutrinos. It explains that observability of neutrino mass depends on neutrino flavor mixing. It introduces the PMNS matrix describing neutrino mixing and describes the experimental determination of the parameters of this matrix.

Statistical approach for describing failures and lifetimes of water mains

1998 ◽  
Vol 38 (6) ◽  
pp. 209-217 ◽  
Author(s):  
Jianhua Lei ◽  
Sveinung Sægrov
Keyword(s):  
Data Base ◽  
Ductile Iron ◽  
Counting Process ◽  
Statistical Approach ◽  
Process Models ◽  
Average Lifetime ◽  
Maintenance Practice ◽  
Water Mains ◽  
Near Future

This paper demonstrates the statistical approach for describing failures and lifetimes of water mains. The statistical approach is based on pipe inventory data and the maintenance data registered in the data base. The approach consists of data pre-processing and statistical analysis. Two classes of statistical models are applied, namely counting process models and lifetime models. With lifetime models, one can estimate the probability which a pipe will fail within a time horizon. With counting process models one can see the deteriorating (or improving) trend in time of a group of “identical” pipes and their rates of occurrence of failure (ROCOF). The case study with the data base from Trondheim municipality (Norway) demonstrates the applicability of the statistical approach and leads to the following results: 1). In the past 20 years, Trondheim municipality has experienced approximately 250 to 300 failures per year. However, the number of failures per year will significantly increase in the near future unless better maintenance practice is implemented now. 2). Unprotected ductile iron pipes have a higher probability of failures than other materials. The average lifetime of unprotected ductile iron pipes is approximately 30 to 40 years shorter than the lifetime of a cast iron pipe. 3). Pipes installed 1963 and 1975 are most likely to fail in the future; 4) The age of a pipe does not play a significant role for the remaining lifetime of the pipe; 5). After 2 to 3 failures, a pipe enters a fast-failure stage (i.e., frequent multiple between failures).

Determination of the Number of Conserved Chromosomal Segments Between Species

Genetics ◽  
2001 ◽  
Vol 157 (3) ◽  
pp. 1387-1395 ◽  
Author(s):  
Sudhir Kumar ◽  
Sudhindra R Gadagkar ◽  
Alan Filipski ◽  
Xun Gu
Keyword(s):  
Statistical Approach ◽  
Common Ancestor ◽  
Chromosomal Rearrangements ◽  
Structural Similarity ◽  
The Other ◽  
Segment Length ◽  
Human Genomes ◽  
Genomic Divergence ◽  
Human And Mouse

AbstractGenomic divergence between species can be quantified in terms of the number of chromosomal rearrangements that have occurred in the respective genomes following their divergence from a common ancestor. These rearrangements disrupt the structural similarity between genomes, with each rearrangement producing additional, albeit shorter, conserved segments. Here we propose a simple statistical approach on the basis of the distribution of the number of markers in contiguous sets of autosomal markers (CSAMs) to estimate the number of conserved segments. CSAM identification requires information on the relative locations of orthologous markers in one genome and only the chromosome number on which each marker resides in the other genome. We propose a simple mathematical model that can account for the effect of the nonuniformity of the breakpoints and markers on the observed distribution of the number of markers in different conserved segments. Computer simulations show that the number of CSAMs increases linearly with the number of chromosomal rearrangements under a variety of conditions. Using the CSAM approach, the estimate of the number of conserved segments between human and mouse genomes is 529 ± 84, with a mean conserved segment length of 2.8 cM. This length is <40% of that currently accepted for human and mouse genomes. This means that the mouse and human genomes have diverged at a rate of ∼1.15 rearrangements per million years. By contrast, mouse and rat are diverging at a rate of only ∼0.74 rearrangements per million years.

Projection of near-future anthropogenic PM2.5 over India using statistical approach

2018 ◽  
Vol 186 ◽  
pp. 178-188 ◽  
Author(s):  
Abhishek Upadhyay ◽  
Sagnik Dey ◽  
Pramila Goyal ◽  
S.K. Dash
Keyword(s):  
Statistical Approach ◽  
Near Future

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.

Proteometabolomic characterization of apical bud maturation in Pinus pinaster

2020 ◽  
Author(s):  
Luis Valledor ◽  
Sara Guerrero ◽  
Lara García-Campa ◽  
Mónica Meijón
Keyword(s):  
Pinus Pinaster ◽  
Ribosomal Proteins ◽  
Potential Role ◽  
Statistical Approach ◽  
Wood Quality ◽  
Growth Patterns ◽  
Future Scenario ◽  
Apical Bud

Abstract Bud maturation is a physiological process which implies a set of morphophysiological changes which lead to the transition of growth patterns from young to mature. This transition defines tree growth and architecture, and in consequence traits such as biomass production and wood quality. In Pinus pinaster, a conifer of great timber value, bud maturation is closely related to polycyclism (multiple growth periods per year). This process causes a lack of apical dominance, and consequently increased branching that reduces its timber quality and value. However, despite its importance, little is known about bud maturation. In this work, proteomics and metabolomics were employed to study apical and basal sections of young and mature buds in P. pinaster. Proteins and metabolites in samples were described and quantified using (n)UPLC-LTQ-Orbitrap. The datasets were analyzed employing an integrative statistical approach, which allowed the determination of the interactions between proteins and metabolites and the different bud sections and ages. Specific dynamics of proteins and metabolites such as HISTONE H3 and H4, RIBOSOMAL PROTEINS L15 and L12, CHAPERONIN TCP1, 14–3-3 protein gamma, gibberellins A1, A3, A8, strigolactones and ABA, involved in epigenetic regulation, proteome remodeling, hormonal signaling and abiotic stress pathways showed their potential role during bud maturation. Candidates and pathways were validated employing interaction databases and targeted transcriptomics. These results increase our understanding of the molecular processes behind bud maturation a key step towards improving timber production and natural pine forests management in a future scenario of climate change. However, further studies are necessary by using different P. pinaster populations that show contrasting wood quality and stress tolerance in order to generalize the results.

In search of an optimum plutonium density measurement fluid

2009 ◽  
Vol 97 (4-5) ◽  
Author(s):  
K. M. Dziewinska ◽  
A. M. Peters ◽  
J. A. La Verne ◽  
P. Martinez ◽  
J. J Dziewinski ◽  
...  
Keyword(s):  
National Laboratory ◽  
Density Measurement ◽  
Chemical Properties ◽  
Decomposition Products ◽  
Los Alamos National Laboratory ◽  
Corrosion Rates ◽  
Physical And Chemical ◽  
Near Future ◽  
Plutonium Metal

AbstractDensity measurements of plutonium metal and its alloys are performed at Los Alamos National Laboratory (LANL) using a technique based on the Archimedes principle. The goal is to find and characterize a fluid for density determination of large objects made of plutonium to replace the currently used monobromobenzene. Physical and chemical properties must be considered while selecting the fluid. Chemical properties of the fluid must ensure low corrosion rates and good resistance to radiological decomposition. The study was carried on to evaluate the corrosion rates of Pu metal cause by FC-43 and the FC-43 decomposition products of radiolysis. The results of these studies proved favourable for this application. The evaluation of the surface reactions between FC-43 and Pu metal will be conducted in the near future.

(GE/m**3). According to this definition one odour unit is the amount of odorants in one cubic meter of air at odour thres­ hold level. The new definition is a real concentration and gives a better form of input parameter for dispersion models. On the basis of guideline VDI 3881 parts 1, 2, and 3 ringtests were carried out with different odorants. The results can be summerized as follows: -The dispersion of results varies and depends on the compo­ sition of the participants and on problems of sampling and preparation of odorous sample. Lower dispersion is obtained when results with obvious errors in application of guide­ lines or with large deviations from mean value are excluded. -Participants of the Netherlands get systematically lower threshold values than the others. The reason has to be investigated. -All findings of the ringtests lead to the conclusion that it is possible to determine odour thresholds which do not differ by more than factor 10. At present another ringtest is in preparation. This test will be carried out in summer 1985. The French collegues will also participate in this test. Experience of all ringtests will be reported in part 4 of guideline VDI 3881. Guideline VDI 3882 deals with the determination of odour intensity and hedonic tone. The members of the working group "odorous substances" assume that odour threshold and odour concentration are insufficient for the characterization of odorous perception. They recommend to judge the odour inten­ sity and the hedonic tone by category estimation. Moreover, it is their opinion that the odour determination with olfacto­ meters is not suitable to assess odour in ambient air. There­ fore they are preparing two guidelines dealing with these problems. Guideline VDI 3883 gives instructions on the regis­ tration of nuisance by interviews with nearby residents of emitting plants or inhabitants of industrial areas. Addition­ ally guideline VDI 3940 describes the determination of odour in ambient air by inspection panels based on the following idea: During constant conditions as to the class of weather, wind speed, and wind direction each local point is charac­ terized by a frequency of odour perception representing the probability to perceive an odour. The situation at a local point will be have to determine the portion of a year with a frequency of odorous perception greater than 5 % in a random test. Both guidelines, VDI 3882 and 3940, should give corres­ ponding results. Guideline VDI 3781 part 5 completes the complex of odour determination and judgement with the calculation of disper­ sion models. The calculation methode and odour determination by panelists should give comparable results. The following summery can be given. Odour measurements with olfactometers is only a small part of the whole field of odour determination in ambient air and the measurement of odour nuisance must be approached in the near future with appropriate urgency.

1986 ◽  
pp. 76-94
Keyword(s):  
Input Parameter ◽  
Ambient Air ◽  
Mean Value ◽  
Hedonic Tone ◽  
Local Point ◽  
Odour Threshold ◽  
Real Concentration ◽  
Category Estimation ◽  
Near Future
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