Normal Hierarchy Research Articles

SU(3)C×SU(3)L×U(1)X model from SU(6)

We propose the $SU(3)_C\times SU(3)_L\times U(1)_X$ model arising from $SU(6)$ breaking. One family of the Standard Model (SM) fermions arises from two $\bar{6}$ representations and one $15$ representation of $SU(6)$ gauge symmetry. To break the $SU(3)_C\times SU(3)_L\times U(1)_X$ gauge symmetry down to the SM, we introduce three $SU(3)_L$ triplet Higgs fields, where two of them come from the $\bar{6}$ representation while the other one from the $15$ representation. We study the gauge boson masses and Higgs boson mass in detail, and find that the vacuum expectation value (VEV) of the Higgs field for $SU(3)_L\times U(1)_X$ gauge symmetry breaking is around 10 TeV. The neutrino masses and mixing can be generated via the littlest inverse seesaw mechanism. In particular, we have normal hierarchy for neutrino masses and the lightest active neutrino is massless. Also, we consider constraints from the charged lepton flavor changing decays as well. Furthermore, introducing two $SU(3)_L$ adjoint fermions, one $SU(3)_C$ adjoint scalar, and one $SU(3)_L$ triplet scalar, we can achieve gauge coupling unification within 1\%. These extra particles can provide a dark matter candidate as well.

Updated results on neutrino mass and mass hierarchy from cosmology with Planck 2018 likelihoods

In this work we update the bounds on ∑ mν from latest publicly available cosmological data and likelihoods using Bayesian analysis, while explicitly considering particular neutrino mass hierarchies. In the minimal ΛCDM + ∑ mν model with most recent CMB data from Planck 2018 TT,TE,EE, lowE, and lensing; and BAO data from BOSS DR12, MGS, and 6dFGS, we find that at 95% C.L. the bounds are: ∑ mν<0.12 eV (degenerate), ∑ mν<0.15 eV (normal), ∑ mν<0.17 eV (inverted). The bounds vary across the different mass orderings due to different priors on ∑ mν. Also, we find that the normal hierarchy is very mildly preferred relative to the inverted, using both minimum χ2 values and Bayesian Evidence ratios. In this paper we also provide bounds on ∑ mν considering different hierarchies in various extended cosmological models: ΛCDM + ∑ mν+r, wCDM+∑ mν, w0 wa CDM+∑ mν, w0 wa CDM+∑ mν with w(z)⩾ −1, Λ CDM + ∑ mν + Ωk, and Λ CDM + ∑ mν + ALens. We do not find any strong evidence of normal hierarchy over inverted hierarchy in the extended models either.

U(1)B−3Lα extended scotogenic models and single-zero textures of neutrino mass matrices

In this paper, we propose a scotogenic model of neutrino masses with flavor-dependent $U(1)_{B-3L_\alpha}(\alpha=e, \mu, \tau)$ gauge symmetry, in which neutrinos are generated at one-loop level and a fermion dark matter is naturally accommodated. In this model, three one-zero-texture structures of neutrino mass matrix, denoted as patterns A, B and C, are successfully realized by appropriate charge assignment for inert fermions and scalar fields. For each predicted textures, a detailed numerical analysis is carried out to find the allowed regions of neutrino mixing and masses. We find three scenarios (A for normal mass hierarchy, and B and C for inverted mass hierarchy) favored by the latest data of neutrino oscillation experiments and Planck 2018 limit on the sum of neutrino masses. Other phenomenologies such as lepton flavor violation, dark matter and collider signatures are also discussed.

Interplay between exact μ − τ reflection symmetries, four-zero texture and universal texture

In this letter, we consider exact μ−τ reflection symmetries for quarks and leptons. Fermion mass matrices are assumed to be four-zero textures for charged fermions f=u,d,e and a symmetric matrix for neutrinos νL. By a bi-maximal transformation, all the mass matrices lead to μ−τ reflection symmetric forms, which separately satisfy Tumu,ν⁎Tu=mu,ν and Tdmd,e⁎Td=md,e.Reconciliation between the μ−τ reflection symmetries and observed sin⁡θ13 predicts δCP≃sin−1⁡[memμc13s23s13]≃203∘. Moreover, imposition of universal texture (mf)11=0 for f=u,d,ν,e predicts the normal hierarchy with the lightest neutrino mass |m1|=6.26 or 2.54 meV.

Forecast for weighing neutrinos in cosmology with SKA

We investigate what role the SKA neutral hydrogen (HI) intensity mapping (IM) and galaxy sky surveys will play in weighing neutrinos in cosmology. We use the simulated data of the baryon acoustic oscillation (BAO) measurements from the HI surveys based on SKA1 (IM) and SKA2 (galaxy) to do the analysis. For the current observations, we use the Planck 2015 cosmic microwave background (CMB) anisotropies observation, the optical BAO measurements, the type Ia supernovae (SN) observation (Pantheon compilation), and the latest H0 measurement. We consider three mass ordering cases for massive neutrinos, i.e., the normal hierarchy (NH), inverted hierarchy (IH), and degenerate hierarchy (DH) cases. It is found that the SKA observation can significantly improve the constraints on Ωm and H0. Compared to the current observation, the SKA1 data can improve the constraints on Ωm by about 33%, and on H0 by about 36%; the SKA2 data can improve the constraints on Ωm by about 58%, and on H0 by about 66%. It is also found that the SKA observation can only slightly improve the constraints on ∑mv. Compared to the current observation, the SKA1 data can improve the constraints on ∑mv by about 4%, 3%, and 10%, for the NH, IH, and DH cases, respectively; the SKA2 data can improve the constraints on ∑mv by about 7%, 7%, and 16%, for the NH, IH, and DH cases, respectively.

B − L extension of the standard model with Q6 symmetry

We propose a renormalizable B−L Standard Model (SM) extension based on Q6 symmetry which accommodates fermion mass and mixing parameters. Both normal and inverted neutrino mass orderings, the smallness of the active neutrino masses are generated through type I seesaw mechanism. The obtained physical parameters are well consistent with the global fit of neutrino oscillation [1] while the quark masses are in good agreement with the recent experimental data [2]. The model also predicts effective neutrino mass parameters of 〈mee〉=3.23×10−3 eV, mβ=8.92×10−3 eV for normal hierarchy (NH) and 〈mee〉=mβ=4.96×10−2 eV for inverted hierarchy (IH) which are all well consistent with the recent experiments.

Fermion mass and mixing in the extension of the standard model with D4 symmetry

We propose a renormalizable B − L standard model extension based on D4 symmetry which accommodates fermion mass and mixing parameters with CP violation. Both normal and inverted neutrino mass ordering as well as the smallness of the active neutrino masses are generated through a type I seesaw mechanism. The obtained physical parameters are well consistent with the global fit of neutrino oscillation in Esteban et al (2019 J. High Energy Phys. JHEP01(2019)106) while the quark masses are in good agreement with the recent experimental data (Tanabashi et al (Particle Data Group) 2018 Phys. Rev. D 98 030001 and 2019 update). The model also predicts an effective neutrino mass parameter of for normal hierarchy and for inverted hierarchy which are all consistent with the recent experimental limits on neutrinoless double beta decay.

Target neutrino mass precision for determining the neutrino hierarchy

Recent works combining neutrino oscillation and cosmological data to determine the neutrino hierarchy found a range of odds in favour of the normal hierarchy. These results arise from differing approaches to incorporating prior knowledge about neutrinos. We develop a hierarchy-agnostic prior and show that the hierarchy cannot be conclusively determined with current data. The determination of the hierarchy is limited by the neutrino mass scale $\Sigma_{\nu}$ measurement. We obtain a target precision of $\sigma(\Sigma_{\nu}) = 0.014$ eV, necessary for conclusively establishing the normal hierarchy with future data.

Detectability of collective neutrino oscillation signatures in the supernova explosion of a 8.8 M⊙ star

In order to investigate the impact of collective neutrino oscillations (CNO) on the neutrino signal from a nearby supernova, we perform 3-flavor neutrino oscillation simulations employing the multiangle effect. The background hydrodynamic model is based on the neutrino hydrodynamic simulation of a 8.8 \Msun progenitor star. We find that CNO commences after some 100 ms post bounce. Before this, CNO is suppressed by matter-induced decoherence. In the inverted mass hierarchy, the spectrum of $\bar{\nu}_e$ becomes softer after the onset of CNO. To evaluate the detectability of this modification, we define a hardness ratio between the number of high energy neutrino events and low energy neutrino events adopting a fixed critical energy. We show that Hyper-Kamiokande (HK) can distinguish the effect of CNO for supernova distances out to $\sim 10$ kpc. On the other hand, for the normal mass hierarchy, the spectrum of $\nu_e$ becomes softer after the onset of CNO, and we show that DUNE can distinguish this feature for supernova distances out to $\sim 10$ kpc. More work is necessary to optimize the best value of critical energy for maximum sensitivity. We also show that if the spectrum of $\bar{\nu}_e$ in HK becomes softer due to CNO, the spectrum of $\nu_e$ in DUNE becomes harder, and vice versa. This synergistic observations in $\bar{\nu}_e$ and $\nu_e$, by HK and DUNE respectively, will be an intriguing opportunity to test the occurrence of CNO.

String landscape and fermion masses

Besides the string scale, string theory has no parameter except some quantized flux values; and the string theory Landscape is generated by scanning over discrete values of all the flux parameters present. We propose that a typical (normalized) probability distribution $P({\cal Q})$ of a physical quantity $\cal Q$ (with nonnegative dimension) tends to peak (diverge) at ${\cal Q}=0$ as a signature of string theory. In the Racetrack K\"ahler uplift model, where $P(\Lambda)$ of the cosmological constant $\Lambda$ peaks sharply at $\Lambda=0$, the electroweak scale (not the electroweak model) naturally emerges when the median $\Lambda$ is matched to the observed value. We check the robustness of this scenario. In a bottom-up approach, we find that the observed quark and charged lepton masses are consistent with the same probabilistic philosophy, with distribution $P(m)$ that diverges at $m=0$, with the same (or almost the same) degree of divergence. This suggests that the Standard Model has an underlying string theory description, and yields relations among the fermion masses, albeit in a probabilistic approach (very different from the usual sense). Along this line of reasoning, the normal hierarchy of neutrino masses is clearly preferred over the inverted hierarchy, and the sum of the neutrino masses is predicted to be $\sum m_{\nu} \simeq 0.0592$ eV, with an upper bound $\sum m_{\nu} <0.066$ eV. This illustrates a novel way string theory can be applied to particle physics phenomenology.

Neutrino Process in Core-collapse Supernovae with Neutrino Self-interaction and MSW Effects

Abstract We calculate the abundances of 7Li, 11B, 92Nb, 98Tc, 138La, and 180Ta produced by neutrino (ν)-induced reactions in a core-collapse supernova explosion. We consider the modification by ν self-interaction (ν-SI) near the neutrinosphere and the Mikheyev–Smirnov–Wolfenstein (MSW) effect in the outer layers based on time-dependent neutrino energy spectra. Abundances of 7Li and the heavy isotopes 92Nb, 98Tc, and 138La are reduced by a factor of 1.5–2.0 by the ν-SI. In contrast, 11B is relatively insensitive to the ν-SI. We find that the abundance ratio of heavy to light nuclei, 138La/11B, is sensitive to the neutrino mass hierarchy, and the normal mass hierarchy is more likely to be consistent with the solar meteoritic abundances.

Abstract BL1: Deciphering stem and progenitor cells to understand breast cancer

Abstract Breast cancer is a highly heterogeneous disease at the molecular and pathological levels. To understand heterogeneity and potential ‘cells of origin’ of breast cancer, it is important to dissect the normal mammary epithelial differentiation hierarchy as well as the cellular composition of breast tumors. Discrete populations of mouse and human mammary epithelial cells have been isolated on the basis of cell surface marker expression, yielding three primary populations including a stem cell-enriched population and two luminal populations. Their responsiveness to female steroid hormones was investigated, revealing the importance of paracrine regulation of ER/PR– stem/progenitor cells by ER/PR+ luminal ‘hormone sensor’ cells. RANKL was found to be a key paracrine effector of progesterone signaling, underscoring the central role that female hormones play in normal mammary gland homeostasis and cancer. Consistent with this observation, a RANK+ luminal progenitor cell was found to be the likely target cell that gives rise to breast cancer in BRCA1 mutation carriers. Pre-clinical studies further indicate that it may be possible to target this ‘culprit’ cell with the RANKL inhibitor denosumab. This finding is now being tested in a randomized phase III prevention study, ‘BRCA-P’. In further studies, a quiescent stem cell that remains hormone responsive has been identified. Lineage tracing, combined with high resolution 3D imaging (visualizing large regions of intact tissue), was carried out to track stem and progenitor cells in situ. These studies have revealed the presence of long-lived stem cells that replenish mammary epithelium, while unipotent progenitors appear to play an essential role in sustaining the independent lineages on a day-to-day basis. In order to generate a comprehensive single cell expression resource and explore molecular heterogeneity in the mouse mammary gland, single cell profiling at key developmental stages was performed. This has revealed novel intermediates and unexpected changes in the transcriptional landscape that could inform a role for distinct cell types during mammary oncogenesis. To gain insight into cancer heterogeneity and clonal dynamics at cellular resolution, 3D imaging was combined with lineage tracing to track specific cells during cancer development. Through the application of a novel pipeline, the epithelial-to-mesenchymal transition (EMT) was found to be a frequent event, thus highlighting the inherent plasticity of mammary tumors. These findings are currently being extended to human tumors to further understand inter- and intra-tumoral heterogeneity. In parallel, our group has established a bank of patient-derived xenograft (PDX) and patient derived organoid (PDO) models to facilitate the transfer of laboratory findings to the clinic. These serve as useful pre-clinical models to test promising agents. Initial efforts have focused on BH3 mimetics, a new class of drug that targets the BCL-2 family of pro-survival proteins. This work is leading to early phase clinical trials, currently focused on patients with metastatic ER+ breast cancer. Citation Format: JE Visvader, GJ Lindeman. Deciphering stem and progenitor cells to understand breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr BL1.

Towards determining the neutrino mass hierarchy: weak lensing and galaxy clustering forecasts with baryons and intrinsic alignments

ABSTRACT The capacity of Stage IV lensing surveys to measure the neutrino mass sum and differentiate between the normal and inverted mass hierarchies depends on the impact of nuisance parameters describing small-scale baryonic astrophysics and intrinsic alignments. For a Euclid-like survey, we perform the first combined weak lensing and galaxy clustering Fisher analysis with baryons, intrinsic alignments, and massive neutrinos for both hierarchies. We use a matter power spectrum generated from a halo model that captures the impact of baryonic feedback and adiabatic contraction. For weak lensing, we find that baryons cause severe degradation to forecasts of the neutrino mass sum, Σ, approximately doubling σΣ. We show that including galaxy clustering constraints from Euclid and BOSS, and cosmic microwave background (CMB) Planck priors, can reduce this degradation to σΣ to 9 per cent and 16 per cent for the normal and inverted hierarchies, respectively. The combined forecasts, $\sigma _{\Sigma _{\rm {NH}}}=0.034\, \rm {eV}$ and $\sigma _{\Sigma _{\rm {IH}}}=0.034\, \rm {eV}$, preclude a meaningful distinction of the hierarchies but could be improved upon with future CMB priors on ns and information from neutrinoless double beta decay to achieve a 2σ distinction. The effect of intrinsic alignments on forecasts is shown to be minimal, with σΣ even experiencing mild improvements due to information from the intrinsic alignment signal. We find that while adiabatic contraction and intrinsic alignments will require careful calibration to prevent significant biasing of Σ, there is less risk presented by feedback from energetic events like AGN and supernovae.

The laser Isotope separation (LIS) methods for the enrichment of 48Ca.

Neutrino-less double beta decay measurement is a powerful tool to test the Majorana nature of neutrinos. Among the potential double beta decay nuclei, 48Ca has the largest Q value (4.3 MeV), we can expect the least background measurement. On the other hand, a smallness of natural abundance of 48Ca (~0.2%) requires an enrichment to increase the sensitivity to reach interesting regions (Inverted Hierarchy and Normal Hierarchy). We have been studying the laser isotope separation (LIS) methods for the enrichment of 48Ca, where a narrow band diode laser is used to excite the specific isotope in the calcium vapor beam. For the separation, two methods (deflection and ionization) are employed. In the deflection method, the 48Ca atoms are deflected by momentum transfers from laser photons by multiple absorption and emission. In the ionization method, an additional dye laser is used to ionize the excited 48Ca. In this paper, we will report the current status and future prospects of two methods of LIS for the enrichment of 48Ca.

New A4 lepton flavor model from S4 modular symmetry

We study a flavor model with A4 symmetry which originates from S4 modular group. In S4 symmetry, Z2 subgroup can be anomalous, and then S4 can be violated to A4. Starting with a S4 symmetric Lagrangian at the tree level, the Lagrangian at the quantum level has only A4 symmetry when Z2 in S4 is anomalous. We obtain modular forms of two singlets and a triplet representations of A4 by decomposing S4 modular forms into A4 representations. We propose a new A4 flavor model of leptons by using those A4 modular forms. We succeed in constructing a viable neutrino mass matrix through the Weinberg operator for both normal hierarchy (NH) and inverted hierarchy (IH) of neutrino masses. Our predictions of the CP violating Dirac phase δCP and the mixing sin2θ23 depend on the sum of neutrino masses for NH.

Exposure-background duality in the searches of neutrinoless double beta decay

Tremendous efforts are required to scale the summit of observing neutrinoless double beta decay ($0 \nu \beta \beta$). This article quantitatively explores the interplay between exposure (target mass X data taking time) and background levels in $0 \nu \beta \beta$ experiments. In particular, background reduction can substantially alleviate the necessity of unrealistic large exposure as the normal mass hierarchy (NH) is probed. The non-degenerate (ND)-NH can be covered with an exposure of O(100) ton-year, which is only an order of magnitude larger than those planned for next generation projects - provided that the background could be reduced by 0($10^{-6}$) relative to the current best levels. It follows that background suppression will be playing increasingly important and investment-effective, if not determining, roles in future $0 \nu \beta \beta$ experiments with sensitivity goals of approaching and covering ND-NH.

Probing non-standard neutrino interactions with supernova neutrinos at Hyper-K

Non-standard neutrino self interactions (NSSI) could be stronger than Fermi interactions. We investigate the ability to constrain these four-neutrino interactions by their effect on the flux of neutrinos originating from a galactic supernova. In the dense medium of a core collapse supernova, these new self interactions can have a significant impact on neutrino oscillations, leading to changes at the flavor evolution and spectra level. We use simulations of the neutrino flux from a 13 solar mass, core collapse supernova at 10 kpc away, and numerically propagate these neutrinos through the stellar medium taking into account vacuum/MSW oscillations, SM ν − ν scattering as well as ν − ν interactions that arise from NSSI. We pass the resulting neutrino flux to a simulation of the future Hyper-Kamiokande detector to see what constraints on NSSI parameters are possible when the next galactic supernova becomes visible. We find that these constraints depend strongly on the neutrino mass hierarchy and if the NSSI is flavor-violating or preserving. Sensitivity to NSSI in the normal hierarchy (NH) at Hyper-K is limited by the experiment’s ability to efficiently detect νe, but deviations from no NSSI could be seen if the NSSI is particularly strong. In the inverted hierarchy (IH) scenario, Hyper-K can significantly improve constraints on flavor-violating NSSI down to mathcal{O} (10−1)GF.

Latest oscillation results from T2K

T2K is a long-baseline neutrino oscillation experiment built to measure νμ disappearance and νe appearance using the J-PARC neutrino beam and the Super-Kamiokande detector. Presented here are the first results in the search for CP violation in neutrino oscillations with a combined analysis of appearance and disappearance channels using data from both neutrino- and antineutrino-mode beams. The data included in this analysis comprises 7.48×1020 protons on target in neutrino mode, giving 37 electron-like and 135 muon-like events at the far detector, and 7.47 × 1020 protons on target in antineutrino mode, giving 4 electron-like and 66 muon-like events. Including a constraint on sin2(2θ13) from reactor measurements, the 90% confidence interval for δCP spans the range [-2.95, -0.44] for the normal mass hierarchy.

Phenomenology of keV scale sterile neutrino dark matter with S4 flavor symmetry

We study the possibility of simultaneously addressing neutrino phenomenology and the dark matter in the framework of inverse seesaw. The model is the extension of the standard model by the addition of two right handed neutrinos and three sterile fermions which leads to a light sterile state with the mass in the keV range along with three light active neutrino states. The lightest sterile neutrino can account for a feasible dark matter (DM) candidate. We present a S4 flavor symmetric model which is further augmented by Z4 × Z3 symmetry to constrain the Yukawa Lagrangian. The structures of the mass matrices involved in inverse seesaw within the S4 framework naturally give rise to correct neutrino mass matrix with non-zero reactor mixing angle θ13. In this framework, we conduct a detailed numerical analysis both for normal hierarchy as well as inverted hierarchy to obtain dark matter mass and DM-active mixing which are the key factors for considering sterile neutrino as a viable dark matter candidate. We constrain the parameter space of the model from the latest cosmological bounds on the mass of the dark matter and DM-active mixing.

A Hierarchical Integration of Normal and Abnormal Personality Dimensions: Structure and Predictive Validity in a Heterogeneous Sample of Psychiatric Outpatients.

Hierarchical, quantitative models of psychopathology focus primarily on higher-order constructs, whereas less is known about the structure and content comprising lower-order dimensions of psychopathology. Here, we address this gap in the literature by using targeted factor analysis to integrate the 25 maladaptive facet-level traits of the Personality Inventory for Diagnostic and Statistical Manual of Mental Disorder-Fifth edition and the 10 aspect-level traits of the normal personality hierarchy within a sample of 198 psychiatric outpatients. A 10-factor solution replicated previous work, with each of the 10 aspects primarily characterizing only one factor. In addition, the 10 factors differentially predicted a range of diagnoses, including alcohol use disorder, major depression, panic disorder, social anxiety, and borderline and avoidant personality disorders. Our results suggest that research on the development, causes, and structure of lower-order traits within the normal personality hierarchy may serve as an important guide to research on the causes and structure of maladaptive personality.