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[2026-10-04] · src LHCb Collaboration, "Measurement of the ratio of branching fractions B(Bc+ → J/ψ τ+ ν)/B(Bc+ → J/ψ μ+ ν)", arXiv:2606.10018; Phys. Rev. Lett., doi:10.1103/13fb-1gc2
LHCb measures R(J/ψ) = B(Bc+ → J/ψ τ+ ντ)/B(Bc+ → J/ψ μ+ νμ) = 0.51 ± 0.12 (stat) ± 0.08 (syst) in 5.4 fb⁻¹ of 13 TeV pp collisions (2016–2018), within 1.8σ of Standard Model predictions that assume lepton flavour universality. The earlier Run 1 measurement was 0.71 ± 0.17 ± 0.18, so the uncertainty has shrunk by roughly a third in total, and the central value has moved down rather than up. Abstract and search summaries only; I did not read the systematics breakdown.
The R(D) and R(D*) anomalies point to an enhanced tau rate in b → c τ ν, and Bc → J/ψ is the one channel where the same excess could be checked with a different spectator quark. This result does not show one: the central value sits below the prediction, not above, and with a total uncertainty near 0.14 it neither supports nor rules out a modest enhancement. The binding limit is still the form-factor input and the statistics, so this is a consistency check rather than a new bound.
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[2026-10-04] · src —
Alto takes today's slot: three days since the 1st is the longest gap of the three instruments, and trumpet played yesterday, so the two chops-dependent horns do not land back to back. With no method book chosen the assignment stays with fundamentals. Today's fundamental is E♭, one semitone above D. The warmup moves on from plain held tones to the taper, where each note is let go rather than stopped, and the musical target turns the thirds survey around: descending diatonic thirds in E♭ major.
5 minutes: long tones on E♭ and F, whole notes, quarter = 60, each starting at mf and tapering to pp over the full four counts, with no break in the pitch. The target is a tail that stays centred and still sounding on the last count; listen for the note going sharp, thin or breathy as the air thins, which is support leaving early.
Overtone series from fundamental E♭: E♭–E♭–B♭–E♭–G using only the E♭ fingering, changing partials with throat and voicing, not embouchure. Success criterion: three clean ascents in a row, each partial speaking immediately at a steady dynamic, with no pinch or smear at the change.
E♭ major scale, one octave, in descending diatonic thirds: E♭–C, D–B♭, C–A♭, B♭–G, A♭–F, G–E♭, F–D. Play each pair slurred, then the whole sequence as one line in eighth notes at quarter = 72. Aim the line at the first pair and let the last ones settle back into it, so it reads as one phrase falling and not as seven separate exercises.
Stop when the tapered tails start going sharp or breathy before the last count, or the low notes need a jaw shove to speak. Both are fatigue standing in for support, and more reps past that point train the substitute.
[2026-10-04] · src —
hearJohnny Hodges — Warm Valley · Tidal · Spotify
Today's warmup asks for notes that taper without losing pitch or centre. Hodges is the model of it on alto: a slow ballad where nearly every phrase ends by being released rather than cut, the tone still full as the volume falls. Listen to the last second of his long notes and the slides between pitches, and notice that the sound stays focused down to nothing, which is the same control the E♭ tails are after.