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1. First Measurement of ${\nu }_e$ and ${\overline{\nu }}_e$ Charged-Current Single Charged-Pion Production Differential Cross Sections on Argon Using the MicroBooNE Detector

   https://doi.org/10.1103/sfrz-c8m9  

   Abratenko, P; Andrade_Aldana, D; Arellano, L; Asaadi, J; Ashkenazi, A; Balasubramanian, S; Baller, B; Barnard, A; Barr, G; Barrow, D; et al (August 2025, Physical Review Letters)

   Understanding electron neutrino interactions is crucial for measurements of neutrino oscillations and searches for new physics in neutrino experiments. We present the first measurement of the flux-averaged ${\nu }_e+{\overline{\nu }}_e$charged-current single charged-pion production cross section on argon using the MicroBooNE detector and data from the NuMI neutrino beam. The total cross section is measured to be $[0.93\pm 0.13(\mathrm{stat})\pm 0.27(\mathrm{syst}\left)\right]\times {10}^{-39}{\mathrm{cm}}^2/\mathrm{nucleon}$at a mean ${\nu }_e+{\overline{\nu }}_e$energy of 730 MeV. Differential cross sections are also reported in electron energy, electron and pion angles, and electron-pion opening angle. 

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2. Solar neutrinos and ${\nu }_2$ visible decays to ${\nu }_1$

   https://doi.org/10.1103/PhysRevD.109.013003  

   de_Gouvêa, André; Weill, Jean; Sen, Manibrata (January 2024, Physical Review D)

   Experimental bounds on the neutrino lifetime depend on the nature of the neutrinos and the details of the potentially new physics responsible for neutrino decay. In the case where the decays involve active neutrinos in the final state, the neutrino masses also qualitatively impact how these manifest themselves experimentally. In order to further understand the impact of nonzero neutrino masses, we explore how observations of solar neutrinos constrain a very simple toy model. We assume that neutrinos are Dirac fermions and there is a new massless scalar that couples to neutrinos such that a heavy neutrino— ${\nu }_2$with mass $m_2$—can decay into a lighter neutrino— ${\nu }_1$with mass $m_1$—and a massless scalar. We find that the constraints on the new physics coupling depend, sometimes significantly, on the ratio of the daughter-to-parent neutrino masses and that, for large-enough values of the new physics coupling, the “dark side” of the solar neutrino parameter space— ${\sin }^2{\theta }_{12}\sim 0.7$—provides a reasonable fit to solar neutrino data, if only ${}^8\mathrm{B}$or ${}^7\mathrm{Be}$neutrino data alone are considered, but no allowed region is found in the combined analysis. Our results generalize to other neutrino-decay scenarios, including those that mediate ${\nu }_2\to {\nu }_1{\overline{\nu }}_3{\nu }_3$when the neutrino mass ordering is inverted mass and $m_2>m_1\gg m_3$, the mass of ${\nu }_3$. Published by the American Physical Society2024 

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3. Measurement of ${\mathrm{\Omega }}_{\mathrm{c}}^0$ baryon production and branching-fraction ratio $\mathrm{BR}({\mathrm{\Omega }}_{\mathrm{c}}^0\to {\mathrm{\Omega }}^{-}{\mathrm{e}}^{+}{\nu }_{\mathrm{e}})/\mathrm{BR}({\mathrm{\Omega }}_{\mathrm{c}}^0\to {\mathrm{\Omega }}^{-}{\pi }^{+})$ in $pp$ collisions at $\sqrt{s}=13\mathrm{TeV}$

   https://doi.org/10.1103/PhysRevD.110.032014  

   Acharya, S; Adamová, D; Agarwal, A; Aglieri_Rinella, G; Aglietta, L; Agnello, M; Agrawal, N; Ahammed, Z; Ahmad, S; Ahn, S U; et al (August 2024, Physical Review D)

   The inclusive production of the charm-strange baryon ${\mathrm{\Omega }}_{\mathrm{c}}^0$is measured for the first time via its semileptonic decay into ${\mathrm{\Omega }}^{-}{\mathrm{e}}^{+}{\nu }_{\mathrm{e}}$at midrapidity ( $\left|y\right|<0.8$) in proton-proton (pp) collisions at the center-of-mass energy $\sqrt{s}=13\mathrm{TeV}$with the ALICE detector at the LHC. The transverse momentum ( $p_{\mathrm{T}}$) differential cross section multiplied by the branching ratio is presented in the interval $2<p_{\mathrm{T}}<12\mathrm{GeV}/c$. The branching-fraction ratio $\mathrm{BR}({\mathrm{\Omega }}_{\mathrm{c}}^0\to {\mathrm{\Omega }}^{-}{\mathrm{e}}^{+}{\nu }_{\mathrm{e}})/\mathrm{BR}({\mathrm{\Omega }}_{\mathrm{c}}^0\to {\mathrm{\Omega }}^{-}{\pi }^{+})$is measured to be $1.12\pm 0.22$(stat) $\pm 0.27$(syst). Comparisons with other experimental measurements, as well as with theoretical calculations, are presented. © 2024 CERN, for the ALICE Collaboration2024CERN 

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4. Search for $h_b\left(2P\right)\to \gamma {\chi }_{bJ}\left(1P\right)$ at $\sqrt{s}=10.860\mathrm{GeV}$

   https://doi.org/10.1103/PhysRevD.111.L011102  

   Boschetti, A; Mussa, R; Tamponi, U; Adachi, I; Aihara, H; Asner, D M; Aushev, T; Ayad, R; Banerjee, Sw; Belous, K; et al (January 2025, Physical Review D)

   In the bottomonium sector, the hindered magnetic dipole transitions between P-wave states $h_b\left(2P\right)\to {\chi }_{bJ}\left(1P\right)\gamma$, $J=0$, 1, 2, are expected to be severely suppressed according to the relativized quark model, due to the spin flip of the $b$quark. Nevertheless, a recent model following the coupled-channel approach predicts the corresponding branching fractions to be enhanced by orders of magnitude. In this Letter, we report the first search for such transitions. We find no significant signals and set upper limits at 90% confidence level on the corresponding branching fractions: $\mathcal{B}\left[h_b\right(2P)\to \gamma {\chi }_{b0}(1P\left)\right]<2.7\times {10}^{-1}$, $\mathcal{B}\left[h_b\right(2P)\to \gamma {\chi }_{b1}(1P\left)\right]<5.4\times {10}^{-3}$and $\mathcal{B}\left[h_b\right(2P)\to \gamma {\chi }_{b2}(1P\left)\right]<1.3\times {10}^{-2}$. These values help to constrain the parameters of the coupled-channel models. The results are obtained using a $121.4{\mathrm{fb}}^{-1}$data sample taken around $\sqrt{s}=10.860\mathrm{GeV}$with the Belle detector at the KEKB asymmetric-energy $e^{+}{e}^{-}$collider. Published by the American Physical Society2025 

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5. Measurement of Angular Coefficients of $\overline{B}\to D^{*}\ell {\overline{\nu }}_{\ell }$ : Implications for $\left|V_{cb}\right|$ and Tests of Lepton Flavor Universality

   https://doi.org/10.1103/PhysRevLett.133.131801  

   Prim, M T; Bernlochner, F; Metzner, F; Aihara, H; Asner, D M; Aushev, T; Ayad, R; Babu, V; Banerjee, Sw; Behera, P; et al (September 2024, Physical Review Letters)

   We measure the complete set of angular coefficients $J_i$for exclusive $\overline{B}\to D^{*}\ell {\overline{\nu }}_{\ell }$decays ( $\ell =e$, $\mu$). Our analysis uses the full $711{\mathrm{fb}}^{-1}$Belle dataset with hadronic tag-side reconstruction. The results allow us to extract the form factors describing the $\overline{B}\to D^{*}$transition and the Cabibbo-Kobayashi-Maskawa matrix element $\left|V_{\mathrm{cb}}\right|$. Using recent lattice QCD calculations for the hadronic form factors, we find $\left|V_{\mathrm{cb}}\right|=(40.7\pm 0.7)\times {10}^{-3}$using the Boyd-Grinstein-Lebed parametrization, compatible with determinations from inclusive semileptonic decays. We search for lepton flavor universality violation as a function of the hadronic recoil parameter $w$and investigate the differences of the electron and muon angular distributions. We find no deviation from standard model expectations. Published by the American Physical Society2024 

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