108 research outputs found

    Nearly Bi-Maximal Neutrino Mixing, Muon g-2 Anomaly and Lepton-Flavor-Violating Processes

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    We interpret the newly observed muon g-2 anomaly in the framework of a leptonic Higgs doublet model with nearly degenerate neutrino masses and nearly bi-maximal neutrino mixing. Useful constraints are obtained on the rates of lepton-flavor-violating rare decays τμγ\tau \to \mu \gamma, μeγ\mu \to e \gamma and τeγ\tau \to e \gamma as well as the μ\mu-ee conversion ratio RμeR_{\mu e}. We find that Γ(μeγ)\Gamma (\mu \to e \gamma), Γ(τeγ)\Gamma (\tau \to e \gamma) and RμeR_{\mu e} depend crucially on possible non-zero but samll values of the neutrino mixing matrix element Ve3V_{e3}, and they are also sensitive to the Dirac-type CP-violating phase. In particular, we show that Γ(τμγ)/mτ5\Gamma (\tau \to \mu \gamma)/m^5_\tau, Γ(μeγ)/mμ5\Gamma (\mu \to e \gamma)/m^5_\mu and Γ(τeγ)/mτ5\Gamma (\tau \to e \gamma)/m^5_\tau are approximately in the ratio 1:2Ve32:2Ve321: 2|V_{e3}|^2: 2|V_{e3}|^2 if Ve3|V_{e3}| is much larger than O(102){\cal O}(10^{-2}), and in the ratio 2(Δmatm2)2:(Δmsun2)2:(Δmsun2)22 (\Delta m^2_{\rm atm})^2: (\Delta m^2_{\rm sun})^2:(\Delta m^2_{\rm sun})^2 if Ve3|V_{e3}| is much lower than O(103){\cal O}(10^{-3}), where Δmatm2\Delta m^2_{\rm atm} and Δmsun2\Delta m^2_{\rm sun} are the corresponding mass-squared differences of atmospheric and solar neutrino oscillations.Comment: LaTex 6 pages (2 PS figures). Phys. Rev. D (in printing

    Public mental health problems during COVID-19 pandemic: a large-scale meta-analysis of the evidence

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    The coronavirus disease 2019 (COVID-19) pandemic has exposed humans to the highest physical and mental risks. Thus, it is becoming a priority to probe the mental health problems experienced during the pandemic in different populations. We performed a meta-analysis to clarify the prevalence of postpandemic mental health problems. Seventy-one published papers (n = 146,139) from China, the United States, Japan, India, and Turkey were eligible to be included in the data pool. These papers reported results for Chinese, Japanese, Italian, American, Turkish, Indian, Spanish, Greek, and Singaporean populations. The results demonstrated a total prevalence of anxiety symptoms of 32.60% (95% confidence interval (CI): 29.10-36.30) during the COVID-19 pandemic. For depression, a prevalence of 27.60% (95% CI: 24.00-31.60) was found. Further, insomnia was found to have a prevalence of 30.30% (95% CI: 24.60-36.60). Of the total study population, 16.70% (95% CI: 8.90-29.20) experienced post-traumatic stress disorder (PTSD) symptoms during the COVID-19 pandemic. Subgroup analysis revealed the highest prevalence of anxiety (63.90%) and depression (55.40%) in confirmed and suspected patients compared with other cohorts. Notably, the prevalence of each symptom in other countries was higher than that in China. Finally, the prevalence of each mental problem differed depending on the measurement tools used. In conclusion, this study revealed the prevalence of mental problems during the COVID-19 pandemic by using a fairly large-scale sample and further clarified that the heterogeneous results for these mental health problems may be due to the nonstandardized use of psychometric tools.Action Contro

    Weak Phase γ\gamma and Strong Phase δ\delta from CP Averaged BππB\to \pi\pi and πK\pi K Decays

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    Assuming SU(3) symmetry for the strong phases in the four decay modes B\rarrow \pi^-\pi^+, \pi^0 \pi^+, \pi^- K^+, \pi^- \bar{K}^0 and ignoring the relative small electroweak penguin effects in those decays, the weak phase γ\gamma and the strong phase δ\delta can be determined in a model independent way by the CP-averaged branching ratios of the four decay modes. It appears that the current experimental data for BππB\to \pi\pi and πK\pi K decays prefer a negative value of cosγcosδ\cos\gamma\cos\delta. By combining with the other constraints from VubV_{ub}, Bd,s0Bˉd,s0B^{0}_{d,s}-\bar{B}^{0}_{d,s} mixings and indirect CP-violating parameter ϵK\epsilon_K within the standard model, two favorable solutions for the phases γ\gamma and δ\delta are found to lie in the region: 35^{\circ}\alt\gamma\alt 62^{\circ} and 106^{\circ}\alt \delta \alt 180^{\circ} or 86^{\circ}\alt\gamma\alt 151^{\circ} and 0^{\circ}\alt\delta\alt 75^{\circ} within 1σ\sigma standard deviation. It is noted that if allowing the standard deviation of the data to be more than 1σ\sigma, the two solutions could approach to one solution with a much larger region for the phases γ\gamma and δ\delta. Direct CP asymme try aϵ(πK+)a_{\epsilon''}^{(\pi^- K^+)} in B\rarrow \pi^-K^+ decay can be as large as the present experimental upper bound. Direct CP asymmetry aϵ(π+π)a_{\epsilon''}^{(\pi^+\pi^-)} in B\rarrow \pi^-\pi^+ decay can reach up to about 40% at 1σ\sigma level.Comment: 14 Pages, ReVTeX, 5 figures, one figure (Fig.3) is correcte

    Partial Wave Analysis of J/ψγ(K+Kπ+π)J/\psi \to \gamma (K^+K^-\pi^+\pi^-)

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    BES data on J/ψγ(K+Kπ+π)J/\psi \to \gamma (K^+K^-\pi^+\pi^-) are presented. The KKˉK^*\bar K^* contribution peaks strongly near threshold. It is fitted with a broad 0+0^{-+} resonance with mass M=1800±100M = 1800 \pm 100 MeV, width Γ=500±200\Gamma = 500 \pm 200 MeV. A broad 2++2^{++} resonance peaking at 2020 MeV is also required with width 500\sim 500 MeV. There is further evidence for a 2+2^{-+} component peaking at 2.55 GeV. The non-KKˉK^*\bar K^* contribution is close to phase space; it peaks at 2.6 GeV and is very different from KKˉK^{*}\bar{K^{*}}.Comment: 15 pages, 6 figures, 1 table, Submitted to PL

    Protons in near earth orbit

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    The proton spectrum in the kinetic energy range 0.1 to 200 GeV was measured by the Alpha Magnetic Spectrometer (AMS) during space shuttle flight STS-91 at an altitude of 380 km. Above the geomagnetic cutoff the observed spectrum is parameterized by a power law. Below the geomagnetic cutoff a substantial second spectrum was observed concentrated at equatorial latitudes with a flux ~ 70 m^-2 sec^-1 sr^-1. Most of these second spectrum protons follow a complicated trajectory and originate from a restricted geographic region.Comment: 19 pages, Latex, 7 .eps figure

    Search for the Lepton Flavor Violation Processes J/ψJ/\psi \to μτ\mu\tau and eτe\tau

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    The lepton flavor violation processes J/ψμτJ/\psi \to \mu\tau and eτe\tau are searched for using a sample of 5.8×107\times 10^7 J/ψJ/\psi events collected with the BESII detector. Zero and one candidate events, consistent with the estimated background, are observed in J/ψμτ,τeνˉeντJ/\psi \to \mu\tau, \tau\to e\bar\nu_e\nu_{\tau} and J/ψeτ,τμνˉμντJ/\psi\to e\tau, \tau\to\mu\bar\nu_{\mu}\nu_{\tau} decays, respectively. Upper limits on the branching ratios are determined to be Br(J/ψμτ)<2.0×106Br(J/\psi\to\mu\tau)<2.0 \times 10^{-6} and Br(J/ψeτ)<8.3×106Br(J/\psi \to e\tau) < 8.3 \times10^{-6} at the 90% confidence level (C.L.).Comment: 9 pages, 2 figure

    Comparative cellular analysis of motor cortex in human, marmoset and mouse

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    The primary motor cortex (M1) is essential for voluntary fine-motor control and is functionally conserved across mammals(1). Here, using high-throughput transcriptomic and epigenomic profiling of more than 450,000 single nuclei in humans, marmoset monkeys and mice, we demonstrate a broadly conserved cellular makeup of this region, with similarities that mirror evolutionary distance and are consistent between the transcriptome and epigenome. The core conserved molecular identities of neuronal and non-neuronal cell types allow us to generate a cross-species consensus classification of cell types, and to infer conserved properties of cell types across species. Despite the overall conservation, however, many species-dependent specializations are apparent, including differences in cell-type proportions, gene expression, DNA methylation and chromatin state. Few cell-type marker genes are conserved across species, revealing a short list of candidate genes and regulatory mechanisms that are responsible for conserved features of homologous cell types, such as the GABAergic chandelier cells. This consensus transcriptomic classification allows us to use patch-seq (a combination of whole-cell patch-clamp recordings, RNA sequencing and morphological characterization) to identify corticospinal Betz cells from layer 5 in non-human primates and humans, and to characterize their highly specialized physiology and anatomy. These findings highlight the robust molecular underpinnings of cell-type diversity in M1 across mammals, and point to the genes and regulatory pathways responsible for the functional identity of cell types and their species-specific adaptations.Cardiovascular Aspects of Radiolog
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