It’s confirmed: Protons and antiprotons are well-matched. The two kinds of subatomic particles mirror one another within the ratios of their electrical cost to mass, a brand new extraordinarily exact experiment verifies.
Antiprotons are the antimatter counterpart of protons. Every kind of matter particle has such an alter ego, with comparable properties however reverse electrical cost. But antimatter is an enigma: Scientists nonetheless don’t perceive why matter is widespread within the universe whereas antimatter is uncommon (SN: 11/25/19). To examine the origins of this asymmetry, scientists preserve checking, to ever higher precision, for variations between matter and antimatter particles, which may trace at how matter got here to dominate the cosmos.
The Baryon Antibaryon Symmetry Experiment, or BASE, on the European particle physics laboratory CERN, close to Geneva, measures the oscillations of a single antiproton confined inside an electromagnetic entice. These oscillations, which reveal the charge-to-mass ratio of the antiproton, are in contrast with these of a trapped hydrogen ion, comprising a proton and two electrons, which give the proton charge-to-mass ratio.
After greater than 24,000 of those oscillation comparisons, BASE researchers discovered that the 2 charge-to-mass ratios mirror each other with a precision of 1.6 billionths of a %, the crew studies January 5 in Nature. That’s greater than 4 instances as exact because the earlier measurement (SN: 8/12/15).
The end result additionally exams physicists’ understanding of gravity’s impact on antimatter, says Stefan Ulmer, a spokesperson of BASE and physicist at RIKEN in Wako, Japan. The Earth’s gravitational surroundings adjustments because the planet orbits the solar, so if gravity affected protons and antiprotons in another way, that impact would have surfaced through the 12 months and a half over which the information have been taken. “We have shown that antimatter and matter interact with gravity … in an exactly identical way,” to inside an uncertainty of three %, Ulmer says.
