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1. Anomalies in hadronic $B$ decays: An update

   https://doi.org/10.1103/5jp1-7cfw  

   Bhattacharya, Bhubanjyoti; Bouchard, Marianne; Hudy, Luke; Jean, Alexandre; London, David; MacKenzie, Christopher (September 2025, Physical Review D)

   Recently, $B\to PP$ decays ( $B=\{B^0,B^{+},B_s^0\}$ , $P=\{\pi ,K\}$ ) were analyzed under the assumption of flavor SU(3) symmetry ( ${\mathrm{SU}\left(3\right)}_F$ ). Although the individual fits to $\mathrm{\Delta }S=0$ or $\mathrm{\Delta }S=1$ decays are good, it was found that the combined fit is very poor: there is a $3.6\sigma$ disagreement with the ${\mathrm{SU}\left(3\right)}_F$ limit of the standard model ( ${\mathrm{SM}}_{{\mathrm{SU}\left(3\right)}_F}$ ). One can remove this discrepancy by adding ${\mathrm{SU}\left(3\right)}_F$ -breaking effects, but 1000% ${\mathrm{SU}\left(3\right)}_F$ breaking is required. In this paper, we extend this analysis to include decays in which there is an $\eta$ and/or ${\eta }^{\prime }$ meson in the final state. We now find that the combined fit exhibits a $4.1\sigma$ discrepancy with the ${\mathrm{SM}}_{{\mathrm{SU}\left(3\right)}_F}$ , and 1000% ${\mathrm{SU}\left(3\right)}_F$ -breaking effects are still required to explain the data. These results are rigorous, group-theoretically—no theoretical assumptions have been made. But when one adds some theoretical input motivated by QCD factorization, the discrepancy with the ${\mathrm{SM}}_{{\mathrm{SU}\left(3\right)}_F}$ grows to $4.9\sigma$ . 

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2. Anomalies in Hadronic $B$ Decays

   https://doi.org/10.1103/PhysRevLett.133.211802  

   Berthiaume, Raphaël; Bhattacharya, Bhubanjyoti; Boumris, Rida; Jean, Alexandre; Kumbhakar, Suman; London, David (November 2024, Physical Review Letters)

   In this Letter, we perform fits to $B\to PP$ decays, where $B=\{B^0,B^{+},B_s^0\}$ and the pseudoscalar $P=\{\pi ,K\}$ , under the assumption of flavor SU(3) symmetry [ ${\mathrm{SU}\left(3\right)}_F$ ]. Although the fits to $\mathrm{\Delta }S=0$ or $\mathrm{\Delta }S=1$ decays individually are good, the combined fit is very poor: there is a $3.6\sigma$ disagreement with the ${\mathrm{SU}\left(3\right)}_F$ limit of the standard model ( ${\mathrm{SM}}_{{\mathrm{SU}\left(3\right)}_{\mathrm{F}}}$ ). One can remove this discrepancy by adding ${\mathrm{SU}\left(3\right)}_F$ -breaking effects, but 1000% ${\mathrm{SU}\left(3\right)}_F$ breaking is required. The above results are rigorous, group theoretically—no dynamical assumptions have been made. When one adds an assumption motivated by QCD factorization, the discrepancy with the ${\mathrm{SM}}_{{\mathrm{SU}\left(3\right)}_{\mathrm{F}}}$ grows to $4.4\sigma$ . Published by the American Physical Society2024 

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3. Exact results in softly broken supersymmetric chiral gauge theories with flavor

   https://doi.org/10.1103/wvb3-gybj  

   Leedom, Jacob M; Murayama, Hitoshi; Singh, Gup; Suter, Bethany; Wong, Jason (July 2025, Physical Review D)

   We present exact results in softly broken supersymmetric $\mathrm{SU}\left(N_C\right)$ chiral gauge theories with charged fermions in one antisymmetric, $N_F$ fundamental, and $N_C+N_F-4$ antifundamental representations. We achieve this by considering the supersymmetric version of these theories and utilizing anomaly mediated supersymmetry breaking at a scale $m\ll \mathrm{\Lambda }$ to generate a vacuum. The connection to nonsupersymmetric theories is then conjectured in the limit $m\to \infty$ . For odd $N_C$ , we determine the massless fermions and unbroken global symmetries in the infrared. For even $N_C$ , we find global symmetries are nonanomalous and no massless fermions. In all cases, the symmetry breaking patterns differ from what the tumbling hypothesis would suggest. 

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4. Search for charged-lepton flavor violation in the production and decay of top quarks using trilepton final states in proton-proton collisions at $\sqrt{s}=13\mathrm{TeV}$

   https://doi.org/10.1103/PhysRevD.111.012009  

   Hayrapetyan, A; Tumasyan, A; Adam, W; Andrejkovic, J W; Bergauer, T; Chatterjee, S; Damanakis, K; Dragicevic, M; Escalante_Del_Valle, A; Hussain, P S; et al (January 2025, Physical Review D)

   A search is performed for charged-lepton flavor violating processes in top quark ( $t$ ) production and decay. The data were collected by the CMS experiment from proton-proton collisions at a center-of-mass energy of 13 TeV and correspond to an integrated luminosity of $138{\mathrm{fb}}^{-1}$ . The selected events are required to contain one opposite-sign electron-muon pair, a third charged lepton (electron or muon), and at least one jet of which no more than one is associated with a bottom quark. Boosted decision trees are used to distinguish signal from background, exploiting differences in the kinematics of the final states particles. The data are consistent with the standard model expectation. Upper limits at 95% confidence level are placed in the context of effective field theory on the Wilson coefficients, which range between $0.024–0.424{\mathrm{TeV}}^{-2}$ depending on the flavor of the associated light quark and the Lorentz structure of the interaction. These limits are converted to upper limits on branching fractions involving up (charm) quarks, $t\to e\mu u$ ( $t\to e\mu c$ ), of $0.032\left(0.498\right)\times {10}^{-6}$ , $0.022\left(0.369\right)\times {10}^{-6}$ , and $0.012\left(0.216\right)\times {10}^{-6}$ for tensorlike, vectorlike, and scalarlike interactions, respectively. 

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5. Parton physics from a heavy-quark operator product expansion: Lattice QCD calculation of the fourth moment of the pion distribution amplitude

   https://doi.org/10.1103/xs4z-nblq  

   Detmold, William; Grebe, Anthony V; Kanamori, Issaku; Lin, C-J David; Perry, Robert J; Zhao, Yong (January 2026, Physical Review D)

   The pion light-cone distribution amplitude (LCDA) is an essential nonperturbative input for a range of high-energy exclusive processes in quantum chromodynamics. Building on our previous work, the continuum limit of the fourth Mellin moment of the pion LCDA is determined in quenched QCD using quark masses which correspond to a pion mass of $m_{\pi }=550\mathrm{MeV}$ . This calculation finds $⟨{\xi }^2⟩=0.202\left(8\right)\left(9\right)$ and $⟨{\xi }^4⟩=0.039\left(28\right)\left(11\right)$ where the first error indicates the combined statistical and systematic uncertainty from the analysis and the second indicates the uncertainty from working with Wilson coefficients computed to next-to-leading order. These results are presented in the $\overline{\mathrm{MS}}$ scheme at a renormalization scale of $\mu =2\mathrm{GeV}$ . 

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