Data collected from experiments conducted over one decade ago may lead scientists to finally reconfigure one of science’s most important scientific principles: the Standard Model of particle physics.
Inside the BaBar experiment at the SLAC National Accelerator Laboratory, researchers say experimental data shows a certain particle decay happening at a pace far exceeding that predicted by the Standard Model.
The data from BaBar, a high-energy physics experiment based at the U.S. Department of Energy’s (DOE) SLAC National Accelerator Laboratory, show that a particular type of particle decay called “B to D-star-tau-nu” happens more often than the Standard Model predicts.
“The excess over the Standard Model prediction is exciting,” said BaBar spokesperson Michael Roney of the University of Victoria in Canada. “But before we can claim an actual discovery, other experiments have to replicate it and rule out the possibility this isn’t just an unlikely statistical fluctuation.”
“If the excess decays shown are confirmed, it will be exciting to figure out what is causing it,” said BaBar physics coordinator Abner Soffer, associate professor at Tel Aviv University. “We hope our results will stimulate theoretical discussion about just what the data are telling us about new physics.”
While the data is far from new, the latest experimental results are a longtime coming. The BaBar experiment observed particle collisions from 1999 to 2008, but the large amount of data collected during the time has left physicists to analyze the data piece by piece.
While the BaBar findings are more sensitive than previous studies of these decays, they are not statistically significant enough to claim they present a clear break from the Standard Model.
Researchers continue to apply BaBar data to a variety of questions in particle physics. The data collected by the experiment remains one of the most important data collections in the field of physics, and it is seen as invaluable for researchers.
The data, for instance, has raised more questions about Higgs bosons, which arise from the mechanism thought to give fundamental particles their mass. Higgs bosons are predicted to interact more strongly with heavier particles – such as the B mesons, D mesons and tau leptons in the BaBar study – than with lighter ones, but the Higgs posited by the Standard Model can’t be involved in this decay.
The team noted that an upcoming experiment could lead to confirmation of their findings, setting the stage for further research into the odd findings, possibly upending the Standard Model itself. If the Belle experiment at the Japanese high-energy physics laboratory KEK replicates the finding, “the combined significance could be compelling enough to suggest how we can finally move beyond the Standard Model,” said researchers.
Researchers from the team presented their findings at the 10th annual Flavor Physics and Charge-Parity Violation Conference in Hefei, China, and detailed them in a paper submitted to the journal Physical Review Letters.