Scrutable

The W boson is heavier than expected , apparently.

Just for information because the Guardian didn't give the numbers, they measured it at 80,433.5 MeV/c² instead of 80,379 MeV/c².

I’m looking forward to all the amateur physicists who will step forward with their own theories about this.

It's not clear to me how tightly constrained the W mass was, given how many free parameters there are in the Standard Model, or how hard they fudged it to make it seem the currently accepted value was "predicted".

nekomatic wrote: ↑

Fri Apr 08, 2022 7:05 am

The W boson is heavier than expected , apparently.

The BBC sensibly reminds us that 2 other experiments, though less "accurate", excluded a discrepancy of this size.

After the faster-than-light neutrinos, and various other things that quickly went away once brought into the limelight, you think they'd hang back a bit on the "we've found new physics". Or maybe they tried to make a sober report and the excitement got added in by others.

We know there a gaps (like the 70% matter that's Dark), and the discrepancy between the measurements of the Rate of Expansion of the universe, so we're definitely looking at 'new physics' being needed; whether this 'old physics' is a hint of where there's an overlap is what's significant.

But as dyqik says, did we really know the 'expected' value to 1 7 parts in 10,000?

Gfamily wrote: ↑

Fri Apr 08, 2022 10:01 am

We know there a gaps (like the 70% matter that's Dark), and the discrepancy between the measurements of the Rate of Expansion of the universe, so we're definitely looking at 'new physics' being needed; whether this 'old physics' is a hint of where there's an overlap is what's significant.

But as dyqik says, did we really know the 'expected' value to 1 7 parts in 10,000?

I'm not up on standard model calculations, but I expect that we did know that. Although all of the standard model isn't all as precise as QED, I'll remind you that QED makes predictions for certain quantities to better than 1 part in 100,000,000,000,000.

But I'd look for experimental discrepancies before looking for new physics. Different particle accelerators work in different ways, and the detectors on them aren't built the same way, and run different (but overlapping) code, different (but overlapping) calibrations, etc.

IvanV wrote: ↑

Fri Apr 08, 2022 9:39 am

nekomatic wrote: ↑

Fri Apr 08, 2022 7:05 am

The W boson is heavier than expected , apparently.

The BBC sensibly reminds us that 2 other experiments, though less "accurate", excluded a discrepancy of this size.

After the faster-than-light neutrinos, and various other things that quickly went away once brought into the limelight, you think they'd hang back a bit on the "we've found new physics". Or maybe they tried to make a sober report and the excitement got added in by others.

I've not looked at this yet, but I expect the report is similar to the faster than light neutrinos one in tone, which was "we've found this in a large chunk of data, we've tried checking everything we on the experiment can think of, so maybe it's new, or maybe one of you clever buggers can think of something we missed".

dyqik wrote: ↑

Fri Apr 08, 2022 11:39 am

I'll remind you that QED makes predictions for certain quantities to better than 1 part in 100,000,000,000,000.

If anyone's interested in a PopSci explanation of how this level of prediction can be made, I suggest reading Nicholas Mee's book "Higgs Force: The Symmetry-Breaking Force that Makes the World an Interesting Place" which mainly looks at the ways that our modern view of physics is based on how symmetries are created and broken, but which also describes how QED allows those predictions to be made.

It also includes details of the Higgs Field/Force.

A review
https://popsciencebooks.blogspot.com/20 ... e.html?m=1