Recent content by dukwon

Like some kind of expensive Rube Goldberg machine, this was ultimately caused by a tree falling over some 50 km away. Here's an official write-up (albeit no mention of the tree): https://home.cern/news/news/accelerators/accelerator-report-quench-lhc-inner-triplet-magnet-causes-small-leak-major...

It's the day of the media event! Here's the YouTube live stream link (starts 16:00 CERN time) ... and we start the day off with 7 magnet quenches (6 dipoles and a quadrupole) First estimate for recovery of the cryogenic conditions is 15:00. The plan was to have beams in "adjust" by 13:00. We...

First collisions with 6.8 TeV per beam (for van der Meer scans). First "stable beams" at this energy are still 5 weeks away

New beam-energy world record this morning with the first ramp of pilot beams to 6.8 TeV

I have to admit I have not been paying much attention to Belle II operations. It seems the 50 /ab milestone has slipped by 6 years from 2025 to 2031: https://www-superkekb.kek.jp/Luminosity_projection.html What happened? Surely that can't all be due to COVID?

... the deuteron? Why? Why not strongly?

The author must be distinguishing between baryons and antibaryons. Indeed strange antibaryons have positive strangeness.

The ≈ is used because the ω has a tiny bit of ss̅ The ω and ϕ arise from mixing of two SU(3) wave functions: $$\phi = \psi_8 \cos\theta - \psi_1 \sin\theta$$ $$\omega = \psi_8 \sin\theta + \psi_1 \cos\theta$$ where $$\psi_8 = \frac{1}{\sqrt{6}}(u\overline{u} - d\overline{d} - 2s\overline{s})$$...

We produce MC for physics analysis after the data has been taken and we know what the conditions were. There is some Run 3 MC (at 14 TeV) but it's for detector upgrade studies, not physics analysis. Our 2017 MC productions are only just starting now

Ion run is over. LS2 started about 2 hours ago.

I've never seen acceptance be taken from data (how do you count particles that you don't detect?) but if that's what you do, then yeah its statistical uncertainty should enter into the statistical uncertainty of the result.

Say your acceptance is calculated from MC; the statistical uncertainty is just due to the sample size. If you take branching fractions (please don't just say "branching", it's confusing) from an external measurement, then the statistical uncertainty is due to the size of the dataset used in...

The statistical uncertainty on your result should only depend on the size of the data sample with which you made the measurement. If you get acceptance from MC and a branching fraction from some other analysis then their uncertainties contribute only to the systematic uncertainties. If you can...

Roger Barlow isn't an expert?

I like this interpretation; it sounds rather noble. The analysis had 2 people working on it, and it wasn't the primary project for either of them. It went into review in 2015 and it kind of petered out until some renewed effort earlier this year. It wasn't a conscious decision. The...