To decipher a long-standing mystery about how long a neutron can survive outside an atomic nucleus, physicists released a testable hypothesis positing the presence of a right-handed version of our left-handed universe. They formulated a mind-bending experiment at the Department of Energy’s Oak Ridge National Laboratory to try to observe a particle that has been theorized yet not detected. If found, the theorized “mirror neutron,” a dark-matter twin to the neutron, could demonstrate a difference between replies from two types of neutron lifetime tests and procure the first observation of dark matter.
“Dark matter remains one of the most important and puzzling questions in science—clear evidence we don’t understand all matter in nature,” announced ORNL’s Leah Broussard, who directed the study published in Physical Review Letters.
“The neutron lifetime is an important parameter in the Standard Model because it is used as an input for calculating the quark mixing matrix, which describes quark decay rates,” announced Gonzalez, who computed the probabilities of neutrons oscillating for the ORNL study. “If the quarks don’t mix as we expect them to, that hints at new physics beyond the Standard Model.”
To calculate the lifetime of a free neutron, scientists adopt two approaches that should appear in the same answer. One hooks neutrons in a magnetic bottle and counts their disappearance. At the same time, the other counts protons occurring in a beam as neutrons decay. It seems that neutrons appear to survive nine seconds longer in a beam than in a bottle.