Friday, March 19, 2021

Muon g-2 Experiment To Report Results On April 7, 2021

The most anticipated physics experiment result since the announcement of the discovery of the Higgs boson in 2012 will be made on April 7, 2021 at 9 AM Mountain Daylight Time. A Zoom link to the announcement will be available soon.

Previous unofficial announcements had pointed towards a December 2020 release, then to a February 2021 release and then to a late March 2021 release date.

The first results from the Muon g-2 experiment at Fermilab will be unveiled and discussed in a special seminar to be held Wednesday, April 7, 2021, at 10:00 AM US Central Time. 
The Muon g-2 experiment searches for telltale signs of new particles and forces by examining the muon’s interaction with a surrounding magnetic field. By precisely determining the magnetic moment of the muon and comparing with similarly exact theoretical predictions, the experiment is sensitive to new physics lurking in the subatomic quantum fluctuations surrounding the muon. A previous experiment performed two decades ago at Brookhaven National Laboratory revealed an intriguing hint of such physics. The highly anticipated result from Fermilab pushes the precision of the experiment into uncharted territory in the quest to confirm or refute that finding. 
The experimental result will be presented by Chris Polly, Fermilab physicist and co-spokesperson for the Muon g-2 scientific collaboration, following a summary of the current theoretical status given by Aida El-Khadra, a UIUC theoretical physicist and co-chair of the Muon g-2 Theory Initiative.
Seminar agenda:
10:00 – 10:05 Introduction 
10:05 – 10:20 Theory overview — Aida El-Khadra, UIUC theoretical physicist
10:20 – 11:00 Muon g-2 results — Chris Polly, Fermilab experimental physicist 
11:00 – 11:20 Question & Answer

From here.

As I explained in a previous post:

The biggest one that is that there will be two new muon g-2 measurements, the last of which was fifteen years ago and the next of which will be announced early this year. The new measurement (and the new theoretical prediction) will be much more accurate than the last, in which the measurement which differed by about three sigma (about 2 parts per million) from the theoretically expected value. The calculation of muon g-2 is sensitive in a global way to almost all aspects of Standard Model physics and can be calculated and measured with extreme precision. The closer that the experimentally measured value of muon g-2 is, the less room there is for new physics beyond the Standard Model. On the other hand, big differences would be strong evidence that scientists are missing something in the Standard Model.

See also here where I explained that:

One of the most important discrepancies between theory and experiment in the Standard Model is the muon g-2 anomaly, a roughly 3 sigma tension. The last precision measurement of muon g-2 was done by the E821 Muon g-2 Experiment at Brookhaven National Laboratory which finished collecting data in 2001 and issued its final report analyzing that data in 2006.

Two more experiments are underway to make a new more precise measurement. The first to produce results will be the E989 Muon g-2 Experiment at Fermilab which is projected to obtain ∼20 times more data and a ∼3-fold reduction of systematic errors compared to E821. The relative error in the new measurement of muon g-2 at E989 will be about 150 parts per billion and will make the experimental error smaller than the uncertainty in theoretical prediction.

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