It will present a new measurement of the W boson mass to be published soon, no #openscience article yet.
There are already articles appearing, but in this thread, I try to explain why this is important with one (famous) plot
Why? Because the W boson is really important for the standard model, particularly for checking its consistency. I'm really excited!
The standard model, the physics theory that particle physics use is great at predicting things. This plot checks its internal consistency by comparing different ways to determine the mass of two particles: the W boson (connected to the weak interaction) and the top quark
The standard model is great at predicting connections between particles, this plot was made by a theory collaboration called #GFitter, which includes some @desynews colleagues. This plot has two green bands, these are the measured values of the top quark and the W boson
There is a lot more in this plot: the possible values that the standard model predicts/calculates for the W boson and top quark if everything else is perfect. This depends on the value of the mass of the Higgs boson and is represented by the diagonal lines
There also is the blue blob. This are the values that the standard model predicts if all other information in the formula is measured and filled in. The blue blob is following the known value of the Higgs boson mass at 125 GeV, but is wider as there are measurement uncertainties
And finally, the green ellipse. Which is where the green lines intersect.
I'm sure you noticed the blue and green ellipses don't perfectly overlap, and this is what this consistency check is actually looking at: two ways to measure the same thing, and they should be the same!
Measuring the W boson mass or top quark mass more accurately will affect the green ellipse... and can point to inconsistencies with the prediction. Here are some crude scenarios of what could happen (yes I'm totally into low-fi graphics ☺️😇🤓)
So it turns out that the new measurement of the W boson claims that the green ellipse should move up quite a lot. A LOT! so much that the two ellipses would definitely not be consistent, meaning that the standard model prediction is not consistent with the measurement. Exciting!
This is particularly exciting for particle physicists because now we can all do some sciencing and try to figure out if the apparent agreement can be explained by some missing measurement mistake, a miscalculation of one of the two numbers, or truly something new!
Here are some links to articles that cover this result, of various levels of detail:
The particle physics magazine for the general public @symmetrymag (with news from all the labs in the particle physics discipline) has a nice writeup too!
And I am assuming by tomorrow also on more general preprint site @arxiv
If you paid attention (of course you did!) the first figure of this paper should be really really easy to understand (it's the same figure, just with some other things on there, specifically which W boson/top quark combos are consistent with SUSY (green) science.org/doi/10.1126/sc…
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The hype for this experiment is slowly rising, as new results are expected to be presented at a Fermilab colloquium later this week. Now, why is this #gminus2 experiment so interesting and gets even jaded particle physicists like me excited? A thread:
While the standard model is awesome and can predict a huge number of different behaviours of the tiny particles that we are all built from, it is considered an effective theory, meaning physicists eventually expect it to stop working (pic: @symmetrymag )
Effective theories are not necessarily bad - they're great at predicting things, but only within certain limits
A familiar example is the theory of Gravity as developed by Newton, it works really well, but if you go extreme it goes bad and you need Einstein's general relativity
As you probably are aware, the "standard model" physics theory used to describe elementary particles inside atoms is really good at describing things. It is also clear that it is what physicists call an effective theory, meaning it will not work at all energies
Other examples of successful effective theories are for example Newtons gravitational laws and Einstein's general theory of relativity. Both describe gravity, both are correct, but Newtons only works for small objects that do not move very fast.