Research Article | Open Access
Constraining the Effective Mass of Majorana Neutrino with Sterile Neutrino Mass for Inverted Ordering Spectrum
Inspired by the experimental anomalies in neutrino physics and recent oscillation data from short baseline and another neutrino experiment, the realization of one extra neutrino flavor seems to be favoring. This extra flavor may change the observable, , of current data taking and next-generation -decay experiments aim to probe and possibly look at the Inverted Ordering region (eV) of parameter space. This observation would allow establishing physics beyond the standard model and phenomena like lepton number violation and Majorana nature of neutrino. The range of this observable () is not very well defined for both the ordering of mass spectrum (Normal Ordering and Inverted Ordering). Several attempts have been made for defining exactly the range for three active neutrino states. For contrasting this range, I have worked with an extra mass state, , and its effect on the observable with various combinations of CP violation Majorana phases by taking into account the updated data on the neutrino oscillation parameters for IO case. Based on the Monte Carlo technique, a parameter region is obtained using the fourth Majorana-Dirac phase of sterile parameters that lead to an effective mass below 0.01 eV or .05 eV for inverted mass ordering case which is planned to be observed in the near future experiment.
In the near future, the positive observation of the neutrino-less double beta decay process would be clear evidence for the lepton number violation and the confirmation of the Majorana nature of neutrinos . In addition to the phenomena discussed earlier, it can also address some of the yet unresolved issues in the neutrino physics and physics beyond the standard model, such as the origin of the tiny neutrino masses, the absolute neutrino mass scale, and the mass ordering and the dark matter physics; see [2–5] for more detail. In general, three active neutrinos are considered in the standard neutrino oscillation picture with mass-squared differences of orders and . From tritium beta decay experiments and cosmological observations, the absolute mass scale of neutrino is also constrained to be below 1 eV. Considering the three neutrino formalisms we have various successful achievements in atmospheric neutrino physics, solar neutrino physics, accelerator, and reactor neutrino experiments but there are experimental anomalies that cannot be explained within the standard three-neutrino framework. Mainly the issue of LSND , MiniBooNE, the Gallium neutrino anomaly [9, 10], and the reactor antineutrino anomaly  are yet not understood clearly. It is frequently interpreted as a hint towards the existence of one or two sterile neutrino states with masses at the eV scale. Such neutrinos are called “sterile” since they cannot participate in the weak interactions due to the collider constraints and point towards the nonstandard neutrino physics. The presence of sterile neutrinos would significantly change the observables in neutrino experiments, specifically the oscillation probabilities in short-baseline experiments and the effective mass in neutrino-less double beta decay [12–14]. Current data taking reactor and solar and gallium experiments support the sterile neutrino oscillations phenomena and recent analysis and discussion can be found in [15, 16]. Constantly growing current and future experiments for verifying the short-baseline neutrino oscillation anomalies and perhaps revealing sterile neutrinos are STEREO , DANSS , NEOS , PROSPECT , Neutrino-4 , BEST , and SOLID .
In the oscillation experiment, total lepton number is conserved while in the neutrinoless double beta decay experiment total lepton number changes by two units. So, some of the fundamental questions like lepton number violation and Majorana nature of neutrino cannot be answered through the neutrino oscillation experiments but can be answered through the neutrino-less double beta decay (0) experiment. Therefore, the most promising process which can be unambiguous Majorana nature of neutrinos is neutrino-less double beta decay and the search for this phenomena has a long history . Current running experiments like KamLAND-Zen, CUORE, CUORE-0, Cuoricino, and GERDA-II are trying to find out the lower bounds on the of this decay for several nucleus samples. Recent lower bound obtained by the KamLAND-Zen collaboration for sample (xenon-136) is yr , GERDA-II collaboration obtaining the lower bound for sample (germanium-76) is yr , and CUORE, CUORE-0 and Cuoricino experiments collectively obtaining the lower bound for sample (tellurium-130) is yr.
The -decay rate is proportional to the effective Majorana mass in the three-Majorana neutrino picture. The range of this effective Majorana mass is not very well understood but, based on the present neutrino oscillation data, it is bounded from below eV in the case of three neutrinos mass spectrum with Inverted Ordering . While for the Normal Ordering configuration of the mass spectrum the lower bound is eV  and it can be extremely small depending on the values of the Dirac, Majorana phases, and the smallest neutrino mass. In the article  the possible range of is determined by varying the Majorana and CPV phases to show the dependency of on the phases. Then a condition is established using the full range of Majorana and Dirac CPV phases and also for some particular Majorana and Dirac CPV phases with NO (Normal Ordering) spectrum, under which in the 3-neutrino mixing exceeds the milli-electron-volt value. In this article, a similar approach is followed to define the possible range of by considering one extra neutrino states (3+1). Neutrino double beta decay experiments are trying to cover the range of from the top and the current reachable upper limit reported by KamLAND-Zen collaboration is . This upper limit is obtained by the KamLAND-Zen collaboration using the lower limit on the half-life of the Xenon-136 sample and they have considered the uncertainties in the NMEs (Nuclear Matrix Elements) in their analysis of the relevant process.
New-generation experiments plan to look the Inverted Ordering region of parameter space and possibly work for the eV energy range. Various running experiments are considered [30, 31] for upgradation and new experiments are also proposed to achieve this goal. Some of those experiments are MAJORANA, LEGEND, CANDLES, AMoRE, PandaX-III, SuperNEMO and DCBA, ZICOS , MOON , COBRA , SNO+, NEXT, and nEXO. If these planned experiments did not find positive response in this energy range (), then next generation experiment will be very interesting for sterile neutrino which will correspond to eV or more below in the -decay experiment.
The introduction of a sterile neutrino at the eV mass scale can change the prediction for the possible range of values in the neutrinoless double-beta decay [12, 32–36]. In the present article, I have determined a sterile parameter region using Monte Carlo technique under which the effective Majorana mass is pushed below a certain value (.01 eV or .05 eV) in the case of 3+1 neutrino mixing with Inverted Ordering mass spectrum. For completeness Normal Ordering scenario of the spectrum with three active and one sterile neutrino is also discussed with the recent global data. Considering the latest global data and various possible CP violation Majorana phases possible ranges of observables in -decay, tritium beta decay experiments and cosmological observations are also discussed.
2. The Effective Mass in 3 and 3+1 Neutrino States
In this section, I will discuss the general formalism of neutrino parameters and evaluate the contributions to the effective mass relevant for neutrino-less double beta decay. First I outline the formalism of three active neutrinos’ mixing and then mixing in the presence of one extra sterile states (3+1). I have worked with the 3+1 scenario when the sterile neutrino is heavier than the active neutrino with Normal Ordering and Inverted Ordering scheme. Another alternative scheme is 1+3; here new nonstandard massive neutrinos is lighter than the three standard massive neutrinos. The 1+3 schemes are disfavored by the cosmological upper bound on the neutrino masses that is smaller than 1 eV, and by the upper bound on the effective neutrino mass in neutrinoless double- decay if neutrinos are Majorana particles, detail discussion can be found in [37, 38]. Hence I will not discuss this scheme further; other possible schemes (3+2/2+3 or 1+3+1) are also available in the literature but not discussed here; more detailed information can be found in .
2.1. Three Active Neutrinos’ Mixing
For three active neutrino states configuration of the effective Majorana mass is defined as
with the partial contribution of the massive Majorana neutrino with mass and U being the leptonic mixing matrix and known as Pontecorvo-Maki-Nakagawa-Sakata (PMNS) matrix, which exactly defined the mixing of the electron neutrino with the three massive neutrinos. The first row of this mixing matrix is the one relevant for -decay, and in standard parameterization it is defined  as
where and , where are the mixing angles, and and are the Dirac and Majorana phases , respectively, and these are the complex phases and the possible range of these parameters are . The values of these phases are not known and all possible values of must take into account all the possible range of these phases. The results for the neutrino squared-mass differences are expressed in terms of the solar and atmospheric squared mass differences, which are defined aswhere . Given this assignment of the squared mass differences, it is currently unknown if the ordering of the neutrino masses is normal, i.e., , or inverted, i.e., . I also defined in the NO(IO). In terms of the lightest neutrino mass, CPV phases, neutrino mixing angles, and neutrino mass-squared differences, the effective Majorana mass readswhere we have defined . Effective mass for both cases, and , can be written in the form
It is then clear that the effective Majorana mass is the length of the vector sum of three vectors in the complex plane for three neutrino mixing case. And their relative orientations are determined by the CPV phase factors and that can push the range of significantly up and down with Normal or Inverted ordering of the neutrino mass spectrum. Tables 1 and 2 show the best fit, 1, 2, and 3 ranges of the three neutrino oscillation parameters used for this analysis with NO and IO of the mass spectrum obtained from the recently updated global data .
Generally, the observation of the absolute values of neutrino masses is done through the measurements of the effective electron neutrino mass in the -experiment and it is expressed as
and the sum of the neutrino masses in cosmological experiments, which is defined as
Therefore, it is helpful to estimate the allowed regions in the and planes, as shown in Figure 3.
2.2. Four-Neutrino Mixing Case
In this section, I consider the case of 3+1 mixing in which there is a new massive neutrino at the eV scale which is mainly sterile. This 3+1 scheme mixing is motivated by the explanation of the reactor, Gallium and LSND anomalies, which requires the existence of a new squared-mass difference , recent analysis using global data can be found in . By accommodating one sterile neutrino in three neutrino mixing mechanism, the effective Majorana mass in 0 is expressed as and this expression can be written asThis extra flavor contribution comes with an extra complex phase factor that must be varied between 0 and 2 for full physics analysis as and to estimate the all possible value of . However, for both orderings (NO and IO), remains the same and defined as
where one can neglect the contributions of and , which are much smaller than . If three active neutrinos are lighter than the sterile neutrino ones, the expression for can be expressed aswhere is the standard expression for three active neutrinos as defined by (5) and (6). Table 3 shows the best-fit, 2, and the 3 range of the oscillation parameter for fourth sterile states used in this work for this analysis. The right panel of Figures 1 and 2 shows the allowed range of as a function of the lightest mass for NO and IO case, respectively, using data from  for 3+1 case and  for 3 active neutrinos’ state.
3. Normal Ordering Configuration
The aim of this work is to constrain the range for IO spectrum only but for completeness; I will start my analysis with the normal ordering of the mass spectrum, discussed in this section; then in the following sections I will discuss the inverted ordering of mass spectrum in detail. The length of the vector, that determines with the phase factor can be obtained from (11) and (12), and the vectors as a function of lightest neutrino mass with NO are , , , and . The lengths of the three partial mass contribution to in (6) are shown in the left panel of Figure 1 as functions of lightest neutrino mass; for 3 variations of oscillation parameters is provided in the Table 1. One can see that contribution of is dominant for .01 eV while is dominant for .001 eV and cannot be cancelled by the smaller contribution of and for any values of the relative phase differences as shown in the right panel of Figure 1. In the other region cancellation is possible mainly between the values .001 and .1 eV. Result for effective Majorana mass, , as a function of is shown in the right panel of Figure 1 with three active neutrinos’ state and one extra flavour state. The minimum and maximum values of the allowed bands for are obtained from the relative phase and the coefficients.
4. Inverted Ordering Configuration
For 3+1 neutrino states with Inverted Ordering, the length of the vectors that determines with the phase factor can be obtained from (6), (11), and (12). These vectors as a function of the lightest neutrino mass are , , , and . The lengths are shown in the left panel of Figure 2 as functions of for 3 variations of oscillation parameters as given in Tables 2 and 3. Right panel shows the value of effective Majorana mass as a function of lightest neutrino mass in the 3 and 3+1 neutrino case as defined by (6) and (13), respectively. One can see that is always dominant to, because is smaller than and . Therefore, there can not be a complete cancellation of three mass contribution to for three active neutrinos with Inverted Ordering, as shown in the right panel of Figure 3. So one can obtain the lower and upper bounds of for three active neutrino states with Inverted Ordering. Here, maximum and minimum values of the allowed bands for are obtained from the relative phase factor and the coefficients of the oscillations parameters as given in Table 2. From the right panel of Figure 2, one can obtain the lower and upper bounds of the in the case of three active neutrino with Inverted Ordering mass spectrum,The next generation and current data-taking neutrinoless double-beta decay experiments will try to explore the range of between the limits in (14) and testing the Majorana nature of neutrinos in the case of an Inverted Ordering. This range is estimated by measurements of the half-life of the nucleus samples, so the available major source of uncertainty in the measurements is uncertainty in NME. And second uncertainty is the accurate determination of the oscillation parameters which are directly dependent on . So these systematic uncertainties must be taken into account to accurately determine the range of and this is the major aim of the next generation neutrino experiments.
While for the sterile neutrino case there can be a total cancellation between the partial contributions and for .06 eV as shown in the right panel of Figure 2. Comparing 3 and 3+1 mixing as shown in the right panel of Figure 2, one can see that the predictions of effective Majorana mass are completely different in the 3 and 3+1 cases if there is an Inverted Ordering [12, 32–36, 40, 41]. This difference in the effective Majorana mass comes mainly from the phase factors, , , and . The various possible ranges of for the particular choice of the phase cases are shown in the Appendix.
Since strongly depends on the phases , , and and this phase combination determines the maximum and minimum of with coefficients of oscillation parameters. These phase combinations can significantly change the range of the , region of plane, and region of plane as shown in Figure 2 (right panel and Figure 5) and Figure 3 (right and left panel), respectively. Here I consider the phase combination which gives the maximum and minimum possible range of as shown in the right panel of Figure 2 and its dependency on the fourth sterile phase parameter only for estimating the lower bound. For understanding these phase dependencies on , a Monte Carlo code is developed, which is based on root package. In the code, all parameters are varied in the full range to get the maxima and minima of . Then to find the particular parameter region, in my case ( versus ), as shown in Figure 4, that range causes below a certain values to be estimated. I have varied the full range of , i.e., , and lightest neutrino mass in the range of 1.00-0.0001 eV and then find a region between and that can push the effective mass below the certain values (.01 eV or .05 eV) shown in Figure 4. If this parameter lies within the red dotted region, the effective Majorana mass will be less than .01 eV, similarly, if this parameter lies within the blue dotted region, will be .05 as shown in Figure 4. If the scenario 3+1 mixing with Inverted Ordering of mass spectrum exists and goes below 0.01 eV or 0.05 eV and observed in the near future; then sterile parameter must lie within the region shown in Figure 4.
For completeness, left and right panel of Figure 3 show the correlation between and the measurable quantities and for all the possible combination of phases that will be observed in beta decay experiment [43–45] and cosmological and astrophysical data [46, 47], respectively. Figure 3 shows the 90% C.L. upper limit band for from the results of the KamLAND-Zen experiment  taking into account the uncertainties of the nuclear matrix element calculations. In addition, in Figure 3, left panel also shows the 90% C.L. sensitivity on of the KATRIN experiment  and right panel shows the 90% C.L. upper limit interval on of the Planck collaboration . By considering the 3 ranges for the mass-squared differences, this last bound gives 0.05 eV in the NO case as shown in the right panel of Figure 1 and 0.04 eV in the IO case , which is shown in the right panel of Figure 2.
5. Result and Discussion
Current data taking and next-generation -decay experiments aiming to look and possibly cover the Inverted Ordering range eV is obtained for three-neutrino case. For contrasting this range in four-neutrino case by considering recent global-fit data on the neutrino mixing angles and the neutrino mass-squared differences, I have determined the parameter space under which the effective Majorana mass in the Inverted Ordering case goes down to .05 eV and .01 eV as shown in Figure 4. For obtaining this parameter space I have considered the full range of fourth Dirac-Majorana phase while keeping other phase fixed and varying the lightest neutrino mass in the range of 1.00 eV - 1 eV.
Finally one can conclude now by saying that if we obtained the below the range discussed then it will be very interesting for sterile neutrino physics. And the parameter range obtained in this analysis will be useful for the development of models and experiments in eV range to explore the sterile neutrino physics. Several oscillation types of experiment are planned mainly to investigate the LSND/MiniBooNE anomaly, particularly the Short-Baseline Neutrino program at Fermilab, which will use three detectors: Short-Baseline Near Detector , MicroBooNE , and ICARUS.
IO Case with Other Phases
See Figure 5.
The data used to support the findings of this study are included within the article.
Conflicts of Interest
The author declares that they have no conflicts of interest.
This work is partially supported by the Department of Physics, Lucknow University, Lucknow, India. Financially it is supported by Government of India, DST Project no. SR/MF/PS02/2013, Department of Physics, Lucknow University. I thank Professor Werner Rodejohann for useful discussion and suggestions and Dr. Jyotsna Singh for providing various kinds of support in the department.
- J. Schechter and J. W. F. Valle, “Neutrinoless double-β decay in su(2) x u(1) theories,” Physical Review D, vol. 25, no. 11, Article ID 2951, 1982.
- W. Rodejohann, “Neutrino-less double beta decay and particle physics,” International Journal of Modern Physics E, vol. 20, no. 9, pp. 1833–1930, 2011.
- S. Gariazzo, C. Giunti et al., “Light sterile neutrinos,” Journal of Physics G: Nuclear and Particle Physics, vol. 43, no. 3, 2016.
- J. D. Vergados, H. Ejiri, and F. Šimkovic, “Theory of neutrinoless double-beta decay,” Reports on Progress in Physics, vol. 75, no. 10, Article ID 106301, 2012.
- F. F. Deppisch, M. Hirsch, and H. Pas, “Neutrinoless double beta decay and physics beyond the standard model,” Journal of Physics G: Nuclear and Particle Physics, vol. 39, no. 12, Article ID 124007, 2012.
- F. Capozzi, E. Lisi, A. Marrone, and A. Palazzo, “Current unknowns in the three neutrino framework,” Progress in Particle and Nuclear Physics, vol. 102, pp. 48–72, 2018.
- A. Aguilar, (LSND Collaboration) et al., “Evidence for neutrino oscillations from the observation of electron anti-neutrinos in a muon anti-neutrino beam,” Physical Review D, vol. 64, Article ID 112007, 2001.
- A. A. Aguilar-Arevalo, “Improved Search for Oscillations in the MiniBooNE Experiment,” Phys.Rev.Lett 110, article no. 161801, 2013.
- M. Laveder, “Unbound neutrino roadmaps,” Nuclear Physics B Proceeding and Supplements, vol. 168, pp. 344–346, 2007.
- C. Giunti and M. Laveder, “Short-baseline active-sterile neutrino oscillations?” Modern Physics Letters A, vol. 22, no. 33, pp. 2499–2509, 2007.
- G. Mention, Physical Review D: Particles, Fields, Gravitation and Cosmology, Article ID 073006, 0730.
- J. Barry, W. Rodejohann, and H. Zhang, “Light sterile neutrinos: models and phenomenology,” Journal of High Energy Physics, vol. 2011, no. 7, article 091, 2011.
- W. Rodejohann, “Neutrinoless double beta decay and neutrino physics,” Journal of Physics G: Nuclear and Particle Physics, vol. 2012, 12, no. 39, 2012.
- C. Giunti and E. M. Zavanin, “Predictions for neutrinoless double-beta decay in the 3+1 sterile neutrino scenario,” Journal of High Energy Physics, vol. 171, 2015.
- M. Dentler, Á. Hernández-Cabezudo, J. Kopp et al., “Updated global analysis of neutrino oscillations in the presence of eV-scale sterile neutrinos,” Journal of High Energy Physics, vol. 2018, no. 8, 2018.
- C. Giunti and T. Lasserre, “eV-scale Sterile Neutrinos,” 2019.
- H. Almazn, STEREO-Collaboration et al., “Sterile neutrino constraints from the STEREO experiment with 66 days of reactor-on data,” Physical Review Letters, vol. 121, Article ID 161801, 2018.
- M. Danilov and DANSS-Collaboration, “Recent results of the DANSS experiment,” arXiv:1811.07354 [hep-ex], 2018, https://arxiv.org/ct?url=https%3A%2F%2Fdx.doi.org%2F10.1393%2Fncc%2Fi2018-18162-0&v=9b3c596b.
- Y. J. Ko et al., “NEOS-Collaboration, Sterile neutrino search at the neos experiment,” Physical Review Letters, vol. 118, Article ID 121802, 2017.
- J. Ashenfelter, (PROSPECT Collaboration) et al., “First search for short-baseline neutrino oscillations at HFIR with PROSPECT,” Physical Review Letters, vol. 121, Article ID 251802, 2018.
- A. Serebrov et al., “The first observation of effect of oscillation in neutrino-4 experiment on search for sterile neutrino,” JETP Letters, pp. 1–9, 2018.
- V. N. Gavrin, B. T. Cleveland, V. V. Gorbachev et al., “Search for sterile neutrinos in gallium experiments with artificial neutrino sources,” Physics of Particles and Nuclei, vol. 48, no. 6, pp. 967–969, 2017.
- Y. Abreu et al., “Optimisation of the scintillation light collection and uniformity for the SoLid experiment,” JINST 13:P09005, 2018.
- A. S. Barabash, “Experiment double beta decay: Historical review of 75 years of research,” Physics of Atomic Nuclei, vol. 74, no. 4, pp. 603–613, 2011.
- A. Gando et al., “Search for majorana neutrinos near the inverted mass hierarchy region with KamLAND-Zen,” Physical Review Letters, vol. 117, article no. 082503, no. 10, Article ID 109903, 2016.
- C. Alduino et al., “First Results from CUORE: A Search for Lepton Number Violation via 0νββ Decay of 130Te,” Physical Review Letters, vol. 120, article no. 132501, 2018.
- S. Pascoli and S. T. Petcov, “The SNO solar neutrino data, neutrinoless double beta-decay and neutrino mass spectrum,” Physics Letters B, vol. 544, no. 3-4, pp. 239–250, 2002.
- C. Patrignani and (Particle Data Group), “Review of particle physics,” Chinese Physics C, vol. 40, no. 10, Article ID 100001, 2016.
- J. Penedo and S. Petcov, “The 10−3 eV frontier in neutrinoless double beta decay,” Physics Letters B, vol. 786, pp. 410–417, 2018.
- J. D. Vergados, H. Ejiri, and F. Šimkovic, “Neutrinoless double beta decay and neutrino mass,” International Journal of Modern Physics E, vol. 25, no. 11, p. 1630007, 2016.
- S. DellOro, S. Marcocci, M. Viel, and F. Vissani, “Neutrinoless double beta decay: 2015 review,” Advances in High Energy Physics, vol. 2016, Article ID 2162659, 37 pages, 2016.
- C. Giunti, M. Laveder, Y. F. Li, Q. Y. Liu, and H. W. Long, “Update of short-baseline electron neutrino and antineutrino disappearance,” Physical Review D: Particles, Fields, Gravitation and Cosmology, vol. 86, Article ID 113014, 2012.
- S. Goswami and W. Rodejohann, “Constraining mass spectra with sterile neutrinos from neutrinoless double beta decay, tritium beta decay, and cosmology,” Physical Review D: Particles, Fields, Gravitation and Cosmology, vol. 73, Article ID 113003, 2006.
- S. Goswami and W. Rodejohann, “MiniBooNE results and neutrino schemes with 2 sterile neutrinos: Possible mass orderings and observables related to neutrino masses,” Journal of High Energy Physics, vol. 2007, no. 10, 2007.
- I. Girardi, A. Meroni, and S. T. Petcov, “Neutrinoless double beta decay in the presence of light sterile neutrinos,” Journal of High Energy Physics, vol. 2013, article 146, 2013.
- C. Giunti, “Light sterile neutrinos: Status and perspectives,” Nuclear Physics B, vol. 908, pp. 336–353, 2015.
- S. Dell’Oro, S. Marcocci, M. Viel, and F. Vissani, “Neutrinoless Double Beta Decay: 2015 Review,” Advances in High Energy Physics, vol. 2016, Article ID 2162659, 37 pages, 2016.
- M. Gerbino and M. Lattanzi, “Status of neutrino properties and future prospects—cosmological and astrophysical constraints,” Frontiers of Physics, vol. 5, no. 70, 2018.
- S. M. Bilenky, J. Hosek, and S. T. Petcov, “On the oscillations of neutrinos with dirac and majorana masses,” Physics Letters B, vol. 94, no. 4, pp. 495–498, 1980.
- S. M. Bilenky, S. Pascoli, and S. Petcov, “Majorana neutrinos, neutrino mass spectrum, CP violation, and neutrinoless double β decay. II. Mixing of four neutrinos,” Physical Review D: Particles, Fields, Gravitation and Cosmology, vol. 64, Article ID 113003, 2001.
- S. Ge, W. Rodejohann, and K. Zuber, “Half-life expectations for neutrinoless double beta decay in standard and nonstandard scenarios,” Physical Review D: Particles, Fields, Gravitation and Cosmology, vol. 96, no. 5, 2017.
- “Rene Brun and Fons Rademakers, ROOT-An Object Oriented Data Analysis Framework,” in Proceedings of the AIHENP’96 Workshop, vol. 389 of Nucl. Inst. and Meth. in Phys. Res. A, pp. 81–86, Lausanne, Switzerland, 1997, http://root.cern.ch/.
- V. N. Aseev, A. I. Belesev, and A. I. Berlev, “An upper limit on electron antineutrino mass from Troitsk experiment,” Physical Review D: Particles, Fields, Gravitation and Cosmology, vol. 84, Article ID 112003, 2011.
- Ch. Kraus, B. Bornschein, and L. Bornschein, “Final results from phase II of the Mainz neutrino mass searchin tritium β decay,” The European Physical Journal C, vol. 40, no. 4, pp. 447–468, 2005.
- K. Eitel, “Direct neutrino mass experiments,” Nuclear Physics B—Proceedings Supplements, vol. 197, 143, 2005.
- N. Aghanim, “Planck intermediate results. XLVI. Reduction of large-scale systematic effects in HFI polarization maps and estimation of the reionization optical depth,” Astronomy and Astrophysics (A&A), vol. 596, 2016.
- S. Koksbang and S. Hannestad, “Constraining dynamical neutrino mass generation with cosmological data,” Journal of Cosmology and Astroparticle Physics, vol. 2017, 2017.
- S. Mertens and KATRIN Collaboration, “Status of the KATRIN experiment and prospects to search for keV-mass sterile neutrinos in tritium β-decay,” Physics Procedia, vol. 61, pp. 267–273, 2015.
- R. Acciarri, C. Adams, R. An et al., A Proposal for a Three Detector Short-Baseline Neutrino Oscillation Program in the Fermilab Booster Neutrino Beam, 2015.
- MicroBooNE collaboration, R. Acciarri, C. Adams, R. An, A. Aparicio et al., Design and Construction of the MicroBooNE Detector, 2017, JINST 12, P02017.
- M. Antonello et al., “Experimental search for the LSND anomaly with the ICARUS LArTPC detector in the CNGS beam,” 2012, ICARUS Collaboration.
Copyright © 2019 Jaydip Singh. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The publication of this article was funded by SCOAP3.