Hanging from a balloon high above Antarctica, a particle detector has actually found something that basic physics is at a loss to discuss.
2 uncommon signals seen by the detector, called the Antarctic Impulsive Short-term Antenna, or ANITA, cannot be credited to any recognized particles, a group of physicists at Penn State reports online September 25 at arXiv.org. The outcome mean the possibility of brand-new particles beyond those cataloged in the basic design, the theory that explains the different primary particles that comprise matter.
Like the old male in the Pixar motion picture Up, ANITA drifts on a helium balloon, at an elevation of 37 kilometers for about a month at a time. It looks for the signals of high-energy particles from area, consisting of light-weight, ghostly particles called neutrinos. Those neutrinos can communicate within Antarctica’s ice, producing radio waves that are gotten by ANITA’s antennas.
The 2 confusing signals seem from very energetic neutrinos shooting skyward from within the Earth. A neutrino showing up from below isn’t really naturally unexpected: Low-energy neutrinos communicate with matter so weakly that they can zip through the whole world. However high-energy neutrinos cannot go through as much product as lower-energy neutrinos can. So although high-energy neutrinos can skim the edges of the world, they will not endure a pass directly through.
The high angle of the particles’ courses recommends that the neutrinos took a trip through numerous countless kilometers of Earth– excessive for a high-energy neutrino to make it out the opposite. That’s inning accordance with computer system simulations in the brand-new research study, by scientists who are not members of the ANITA partnership. ANITA scientists have actually been trying to find a method to discuss the signals with neutrinos, states Derek Fox, a coauthor of the research study. However inning accordance with Fox and coworkers’ simulations, “those efforts should stop working.”
A high-energy particle might make such a long trek through the Earth just if it were much more reticent to communicate with matter than neutrinos are. A theoretical heavy particle called a stau, proposed in a theory called supersymmetry( SN: 10/ 1/16, p. 12), might fit the costs, Fox and coworkers state. After being developed on the other side of the world by a high-energy neutrino knocking into the Earth, a stau might make it through unharmed prior to decomposing into lighter particles that would ultimately lead to the signals identified by ANITA.
However do not cancel your subscription in the basic design fan club right now. “It’s still possible that there is an extremely ordinary factor that we are seeing these occasions in ANITA,” states ANITA physicist Stephanie Wissel of Cal Poly in San Luis Obispo, Calif. Other spacefaring particles called cosmic rays, which drizzle below above, produce comparable signatures in ANITA. A fundamental misconception of the physics behind cosmic rays’ signatures might discuss the observations, Wissel states.
Supporting their claim, Fox and coworkers likewise recognize 3 occasions in another Antarctic neutrino detector, called IceCube, that they state have some likewise confusing homes. However the leader of that experiment, physicist Francis Halzen of the University of Wisconsin– Madison, isn’t really encouraged. “These occasions are naturally worth taking note of,” he states, however he does not see any proof that they need a brand-new description.
Exactly what’s required is more information, physicists state. The ANITA group prepares to send out the detector up for another Antarctic balloon flight, states ANITA physicist Amy Connolly of Ohio State University in Columbus. “My view is that we ought to keep searching for an ordinary description for these occasions.”
The basic design has actually been verified time and once again, so physicists are loathe to desert it without frustrating proof. “The case that ANITA is seeing something unusual is strong,” states astrophysicist John Beacom, likewise of Ohio State. However “I constantly wager for the basic design.”
Still, these occasions have such severe energies that they are reaching into worlds not available at particle colliders like the Big Hadron Collider near Geneva, Beacom states. “There’s a lot we simply have no idea about how physics operates at these high energies.”