More Like this

1. Evidence for $B^{+}\to K^{+}\nu \overline{\nu }$ decays

   https://doi.org/10.1103/PhysRevD.109.112006  

   Adachi, I; Adamczyk, K; Aggarwal, L; Ahmed, H; Aihara, H; Akopov, N; Aloisio, A; Anh_Ky, N; Asner, D M; Atmacan, H; et al (June 2024, Physical Review D)

   We search for the rare decay $B^{+}\to K^{+}\nu \overline{\nu }$ in a $362{\mathrm{fb}}^{-1}$ sample of electron-positron collisions at the $\mathrm{\Upsilon }\left(4S\right)$ resonance collected with the Belle II detector at the SuperKEKB collider. We use the inclusive properties of the accompanying $B$ meson in $\mathrm{\Upsilon }\left(4S\right)\to B\overline{B}$ events to suppress background from other decays of the signal $B$ candidate and light-quark pair production. We validate the measurement with an auxiliary analysis based on a conventional hadronic reconstruction of the accompanying $B$ meson. For background suppression, we exploit distinct signal features using machine learning methods tuned with simulated data. The signal-reconstruction efficiency and background suppression are validated through various control channels. The branching fraction is extracted in a maximum likelihood fit. Our inclusive and hadronic analyses yield consistent results for the $B^{+}\to K^{+}\nu \overline{\nu }$ branching fraction of $[2.7\pm 0.5(\mathrm{stat})\pm 0.5(\mathrm{syst}\left)\right]\times {10}^{-5}$ and $\left[{1.1}_{-0.8}^{+0.9}\right(\mathrm{stat}{)}_{-0.5}^{+0.8}\left(\mathrm{syst}\right)]\times {10}^{-5}$ , respectively. Combining the results, we determine the branching fraction of the decay $B^{+}\to K^{+}\nu \overline{\nu }$ to be $[2.3\pm 0.5(\mathrm{stat}{)}_{-0.4}^{+0.5}\left(\mathrm{syst}\right)]\times {10}^{-5}$ , providing the first evidence for this decay at 3.5 standard deviations. The combined result is 2.7 standard deviations above the standard model expectation. Published by the American Physical Society2024 

   more » « less
2. Observation of Transverse $\mathrm{\Lambda }/\overline{\mathrm{\Lambda }}$ Hyperon Polarization in $e^{+}{e}^{-}$ Annihilation at Belle

   https://doi.org/10.1103/PhysRevLett.122.042001  

   Guan, Y.; Vossen, A.; Adachi, I.; Adamczyk, K.; Ahn, J. K.; Aihara, H.; Al Said, S.; Asner, D. M.; Atmacan, H.; Aulchenko, V.; et al (January 2019, Physical Review Letters)
3. Study of $e^{+}{e}^{-}\to {\mathrm{\Sigma }}^0{\overline{\mathrm{\Sigma }}}^0$ and ${\mathrm{\Sigma }}^{+}{\overline{\mathrm{\Sigma }}}^{-}$ by initial state radiation method at Belle

   https://doi.org/10.1103/PhysRevD.107.072008  

   Gong, G.; Li, L. K.; Zhang, Y.; Yan, W.; Adachi, I.; Aihara, H.; Al Said, S.; Asner, D. M.; Atmacan, H.; Aushev, T.; et al (April 2023, Physical Review D)
4. Implications for the $\mathrm{\Delta }{A}_{FB}$ anomaly in ${\overline{B}}^0\to D^{*+}{\ell }^{-}\overline{\nu }$ using a new Monte Carlo event generator

   https://doi.org/10.1103/PhysRevD.107.015011  

   Bhattacharya, Bhubanjyoti; Browder, Thomas E.; Campagna, Quinn; Datta, Alakabha; Dubey, Shawn; Mukherjee, Lopamudra; Sibidanov, Alexei (January 2023, Physical Review D)
5. Beam-Target Helicity Asymmetry for $\overrightarrow{\gamma }\overrightarrow{n}\to {\pi }^{-}p$ in the $N^{*}$ Resonance Region

   https://doi.org/10.1103/PhysRevLett.118.242002  

   Ho, D.; Peng, P.; Bass, C.; Collins, P.; D’Angelo, A.; Deur, A.; Fleming, J.; Hanretty, C.; Kageya, T.; Khandaker, M.; et al (June 2017, Physical Review Letters)