The Big Theoretical Physics Problem At The Center Of The ‘Muon g-2’ Puzzle

“Assuming that the experimental results from the Muon g-2 collaboration hold up — and there’s every reason to believe they will, including the solid agreement with the earlier Brookhaven results — all eyes will turn towards the theorists. We have two different ways of calculating the expected value of the muon’s spin magnetic moment, where one agrees with the experimental values (within the errors) and the other does not.

Will the Lattice QCD groups all converge on the same answer, and demonstrate that not only do they know what they’re doing, but that there’s no anomaly after all? Or will Lattice QCD methods reveal a disagreement with the experimental values, the same way that they presently disagree with the other theoretical method we have that presently disagrees so significantly with the experimental values we have: of using experimental inputs instead of theoretical calculations?

It’s far too early to say, but until we have a resolution to this important theoretical issue, we won’t know what it is that’s broken: the Standard Model, or the way we’re presently calculating the same quantities we’re measuring to unparalleled precisions.”

Princess

-Real name: -

-A.k.a.: Jun The Swan, G-3 Agatha June Jun Kelly Jennar, G-2

-Publisher: Top Cow

-Type: Human

-Afilliations: G-Force

Since I've been given the incredible opportunity to work on this project next summer, I thought I’d dive into what this project exactly is, why it’s so important, and how it has the potential to change everything.

First, what exactly is a muon? A muon is one of the 17 fundamental particles we know of, and can be though of as the “fatter” and shorter-lived cousin of the electron. Standing still, muons have a mean lifetime of about 2.2 microseconds, and decay into an electron, a muon neutrino, and a muon antineutrino.

Back in 2001, the Brookhaven National Laboratory in New York found a strange property of the muon. Like all particles, the muon has a magnetic moment that dictates how it will align itself in a magnetic field. Strangely, Brookhaven found that this magnetic moment disagrees with our predictions by 3.5 standard deviations. This is fascinating, but it’s not quite accurate enough to announce as a “discovery”. And that is where Fermilab comes in.

In 2013, the large 50-foot diameter muon magnetic storage ring from Brookhaven was carefully hauled across the country to Illinois, in an event called “The Big Move” which took 35 days to complete.

With Fermilab’s high-intensity particle beam, this experiment could be done with a much greater accuracy than ever before, at 0.14 parts per million. The magnet was installed and finally turned on once again in 2015, and received its first beam of muons in 2017. It still needs some calibrating and fine-tuning before it can take accurate data, but this 17 year long journey is finally approaching the moment of truth. By 2020, we will know for certain if the magnetic moment of the muon will pave the way for new physics or not.

Inktober Day 11: gay bird man

Pe 20 mai, Vladimir Putin și Xi Jinping au semnat Declarația Comună privind Crearea unei Lumi Multipolare și a unui Nou Tip de Relații Internaționale. Georgiana Arsene Semnificația acestui eveniment este departe de a fi clară pentru toată lumea: mulți îl percep doar ca pe un alt document declarativ, similar cu care multe au fost deja semnate. Cu toate acestea, cheia pentru a înțelege acest…