While scientists have become increasingly convinced that the Standard Model of particle physics is incomplete, it’s still unclear exactly how the Standard Model needs to be extended. Experiments have shown that the Standard Model cannot explain certain top quark observations, but a variety of extensions of the Standard Model have been proposed to explain them, and it’s unclear which extension is correct. In a new paper published in Physical Review Letters, physicists Benjamín Grinstein and Christopher W. Murphy at the University of California, San Diego, have explained how upcoming data on the bottom quark can be used to distinguish between competing new physics explanations of unexpected top quark data.
“There has been much excitement the last couple of years precipitated by reports by the two experimental collaborations working at the Tevatron (at Fermilab, outside Chicago) that a much larger-than-expected top-quark forward-backward asymmetry is seen,” Grinstein told Phys.org. “Several models have been proposed to explain this unexpected result. Our paper suggests a way to distinguish among the various models that have been proposed, since these models give very different bottom-quark forward-backward asymmetries. When a sufficiently precise measurement of the bottom-quark forward-backward asymmetry is performed, we will be able to narrow down significantly the new physics that the Tevatron experiments seem to have uncovered.
“But perhaps more importantly, observations of the bottom-quark forward-backward asymmetry in disagreement with expectations from the Standard Model, when put together with the top-quark forward-backward asymmetry, would demonstrate fairly conclusively that there is new physics in the form of new particles and interactions not included in the Standard Model, and would point the way toward its direct experimental confirmation. So, as you can see, this would go to the heart of the question in particle physics.”
Read more at: Phys.org