Researchers' best hope of getting to the bottom of particle flavor may lie in a slew of new experiments being proposed to tackle what's called the "intensity frontier." Scientists are hoping that by studying the weird flavor behavior of particles, they might go further toward explaining matter's persistence after the Big Bang. "There have got to be some other new equations that we haven't seen the evidence for yet that also predict different kinds of matter-antimatter asymmetries." "You get a difference with these asymmetries, but it's about a billion times smaller than you need," Peskin said. Researchers have observed some asymmetries in the decay rates of matter and antimatter, but these alone are not sufficient to explain the universe as we see it. Physicists think that differences in the way matter decays compared with antimatter may explain why matter took longer to decay, and therefore survived. Most of the matter and antimatter particles created at the beginning of the universe are thought to have destroyed each other, leaving a small amount of matter left over that became the stars and galaxies we see today. When a particle and its antimatter partner meet, they annihilate each other to become pure energy. "So what happened to all the antimatter? We think this is related to flavor physics." "There's a matter-antimatter asymmetry in the universe, in the sense that the universe is made out of matter and there's no antimatter observed today, but in the Big Bang, matter and antimatter were created in equal amounts," Hewett said. Yet physicists think there should be a lot more antimatter in the universe than there is, and flavor physics may help to explain this "loss" of antimatter. Every particle is thought to have an antimatter partner, with the same mass, but the opposite charge. "They don’t exist really in everyday life."īesides searching for the origin of flavor, physicists studying these topics also hope to learn about related mysteries, such as matter's weird twin, antimatter. "They existed in the very early fractions of a second of the universe and then they decayed away," Hewett told LiveScience, referring to the rare particle flavors. Same goes for leptons: While electrons abound, some of the other flavors, such as muons and taus, are rarely found in nature. Protons and neutrons, in turn, contain just up and down quarks top and bottom, charm and strange quarks are nary to be found. The elements in the periodic table, such as carbon, oxygen and hydrogen, are composed of protons, neutrons and electrons. (Image credit: Karl Tate, LiveScience Infographic Artist)Īnd while particles do come in many flavors, our universe is preferentially made up of just a few. This is only possible if they have mass, albeit a very small mass in the case of the electron neutrino.Here's a breakdown of the Standard Model and the tiny particles it is responsible for. Until recent years it was thought the neutrino was a massless particle but it has since been found that neutrinos can "oscillate" (change) between different types. The up and down quarks form the protons and neutrons that we are familiar with: a proton is a bound state of 2 up quarks and 1 down quark, whilst a neutron is a bound state of 1 up quark and 2 down quarks. The quarks are never seen in isolation but always bound together in pairs or triplets, to form protons, neutrons, and many other particles. Furthermore, leptons are believed to be point-like fundamental particles. All fermionic-based matter is divided into two broad categories: hadrons and leptons.Īll the hadrons are composed of quarks, whereas leptons are material particles not containing quarks.
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