Coming up on April 30

Thanks for the link Rad. I find it interesting that the LHCb result published in January is in line with the standard model and they too use measurements of the Z boson to show that their W boson mass is not biased. I'm not so concerned that the CDF guys changed their 2012 estimate because that is common if you find systematic errors that you can correct (and their 1-sigma error bars for CDFI are pretty big). Rather, their chi-square plots kind of suck. It looks to me like they are reporting error statistics that technically, mathematically may be correct but are overly optimistic when compared with reality. The LHCb paper has similarly sucky chi-square statistics, so everybody is guilty of playing this statistics game. If we look at the 5-sigma range for the CDFII result and the standard model, they are within spitting distance of each other, so the standard model seems safe even if the CDFII result stands the test of time. My question is how robust is the standard model estimate for the W boson mass? Certainly some assumptions have gone into the calculation and if those assumptions are changed or broadened, then the mass range might shift closer to the CDFII number. Having said that, in the W mass section of the PDG2020 paper (https://pdg.lbl.gov/2021/reviews/rpp2020-rev-w-mass.pdf), figure 53.1 shows so many results landing in the same mass range with small-ish error bars (including the original 2012 CDFI) that something feels fishy about the CDFII result. This issue here isn't with the authors or their work -- they are diligently following their data where it leads. Rather, the hype machine has gotten a hold of the result and is overselling the implications. I predict that, at some point, particle physicists will figure out why the result is so different and fix the analysis to bring it inline with the standard model and this discovery will quietly disappear as many before it have (as Sabine so eloquently stated in an earlier SWTG video).

Super psyched to hear Sabine’s take on this too! For anyone who wants to first get the result from the horse’s mouth, the CDF collaboration presented at the April APS meeting - https://youtu.be/wSAHM2Ehark The money question was at 48:48, essentially asking them to explain why their mass was so different from all the other measurements. IMO the plot in the paper was misleading wrt to CDF I. That was not the original number they published in 2012. In the talk they disclose that they had revised the prior answer on the basis of the new calibration…hmm.

Rad Antonov

I've become lazy with following up physics and technology things because of the videos; they're a great resource. I wish more of my life could be narrated by a funny-as-fuck German.