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[2026-10-23] · src Belle and Belle II Collaborations, "Measurements of the branching fractions of Λc⁺→ΛK⁺π⁰ and Λc⁺→ΛK⁺η decays at Belle and Belle II", arXiv:2610.31377v1 (hep-ex, 22 Oct 2026)
Using 980 fb⁻¹ of Belle and 570 fb⁻¹ of Belle II data, the collaborations observe the singly Cabibbo-suppressed decay Λc⁺→ΛK⁺η for the first time, at more than 10σ. Normalised to the Cabibbo-favoured Λc⁺→Λπ⁺π⁰, the ratio is (8.73 ± 0.35 ± 0.43)×10⁻³, giving an absolute B = (6.20 ± 0.25 ± 0.31 ± 0.30)×10⁻⁴ (the third error is the normalisation mode). Λc⁺→ΛK⁺π⁰ is remeasured at a ratio of (1.82 ± 0.07 ± 0.07)%, B = (1.29 ± 0.05 ± 0.05 ± 0.06)×10⁻³, a significant precision gain over the previous value. The ΛK⁺η rate is reported as significantly larger than SU(3) flavour-symmetry predictions.
Charm-baryon decays are where flavour-symmetry and factorisation-based models are tested, and a mode that SU(3) underpredicts is a constraint that theory fits must now absorb, probably through SU(3) breaking or final-state rescattering. The size of the discrepancy is not in the abstract and I did not read the paper, so how large the tension is remains unchecked here. The result does not touch new physics; it is a calibration point for hadronic models.
[2026-10-23] · src Atzori Corona, Cadeddu, Cargioli, Dordei, Ferro, Giunti, Pavarani, Sestu, "A consistent neutrino determination of the low-energy weak mixing angle", arXiv:2610.31254v1 (hep-ph, 22 Oct 2026)
A global reanalysis combining coherent elastic neutrino–nucleus scattering (CEνNS) with neutrino–electron scattering data gives a neutrino-only determination of the low-energy weak mixing angle, sin²θ_W = 0.233 (+0.007, −0.006), a fractional uncertainty near 3%. The authors compare it with the cesium atomic-parity-violation value, check the mutual consistency of the individual neutrino datasets, and present it as an independent Standard Model test at low momentum transfer.
It is consistent with the Standard Model running value near 0.238 at these scales, so it excludes nothing; its use is as an independent check on the atomic-parity-violation determination, which currently sets the precision at low Q. At roughly 3% it is well short of the APV precision, so it constrains new physics only if CEνNS statistics improve. It is a preprint reanalysis of existing data, and I read only the abstract.
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[2026-10-23] · src —
Alto takes today: four days since it was last assigned, the longest gap of the three, and trumpet was worked yesterday so the chops get a rest. With no method book chosen yet, this is a plain fundamentals session built on a steady tone and one scale pattern in D major, about 30 minutes. Pick a method book soon (Ferling, Voxman, Klosé or Rubank Advanced) so alto work stops being generic.
8 minutes: long tones on low C, D and G, 10 seconds each at mp, then crescendo to mf and back over the same note. Then overtones off low B-flat: hold the fundamental, then the octave, then the twelfth, 5 seconds each, three rounds.
D major in thirds (D-F#, E-G, F#-A and so on), two octaves, slurred up and tongued down. Work at quarter = 60, 72, then 88. Success criterion: three consecutive clean passes at each tempo with no cracked notes and the pitch steady at the top.
Play a slow D major scale as a melody: one note per beat at quarter = 56, with a clear shape, soft at the bottom, a peak near the top, and a longer last note. Aim for a line that sounds sung rather than counted.
About 30 minutes. Stop when the embouchure tires or the low notes start to break; ten minutes less with a clean sound beats a longer ragged session.
[2026-10-23] · src —
hearCannonball Adderley — Autumn Leaves · Tidal · Spotify
This is the alto sound to carry into today's long tones: warm, full, and even from the bottom of the horn to the top. Listen to his solo for how the tone stays round when he moves by step and by third, and for how he shapes a phrase with a peak and a settle. That is the same thing the D major musical target asks for, played by a master.