Giving Weight to Antimatter

Antimatter Interferometry for Gravity Measurements

Paul Hamilton, Andrey Zhmoginov, Francis Robicheaux, Joel Fajans, Jonathan S. Wurtele, and Holger Müller

Phys. Rev. Lett. 112, 121102 (2014)

Published March 25, 2014

Does antimatter feel the same gravitational pull as ordinary matter? The standard model of particle physics assumes this is the case, but experimental evidence remains hard to gather: measurements are complicated by the fact that antimatter is rare and annihilates when brought into contact with matter. Still, researchers are eager to test this assumption, since the standard model cannot explain the gravitational behavior of 95% of the Universe’s matter nor the abundance of matter vs antimatter. As reported in Physical Review Letters, experts in antihydrogen and atom interferometry are working together to design an interferometer that could measure the free-fall acceleration of any species of atoms, in particular antihydrogen.

The research team, led by Holger Müller at the University of California, Berkeley, has theorized a scheme in which antihydrogen atoms are cooled by lasers and then moved with light into a vertical interferometer cell. Because of the wave nature of the ultracold atoms, antihydrogens behave as matter waves that travel upwards and downwards within the cell and interfere. By counting the number of atoms that leave the cell, the device measures the phase shift between the two interfering paths and thus gravity. Since antihydrogen atoms cannot be produced in large quantities, the setup employs a special trick: it “recycles” the atoms that do not annihilate, sending them multiple times through the interferometer. The scheme could be integrated into the ALPHA antihydrogen trap at CERN and, with current antihydrogen production rates, it would allow the measurement of the gravitational acceleration of antihydrogen with a precision of 1%. Further improvements could potentially drive the precision up to levels comparable to those attained in experiments on ordinary matter. – Matteo Rini

Comments

This strange mineral grows on dead bodies and turns them blue

If you were to get up close and personal with Ötzi the Iceman – the 5,000-year-old mummy of a tattooed , deep-voiced man who died and was frozen in the Alps – you’d notice that his skin is flecked with tiny bits of blue. At first, it would appear that these oddly bluish crystal formations embedded in his skin are from freezing to death or some other sort of trauma, but it’s actually a mineral called vivianite (or blue ironstone) and it happens to form quite often on corpses left in iron-rich environments. For Ötzi, the patches of vivianite are from him resting near rocks with flecks of iron in them, but other cases are way more severe. According to Chris Drudge at Atlas Obscura , a man named John White was buried in a cast iron coffin back in 1861. During those days, coffins often had a window for grieving family members to peer inside even if the lid was closed during the funeral. Sometime after he was buried, that window broke, allow...

It's Official: Time Crystals Are a New State of Matter, and Now We Can Create Them

Peer-review has spoken. Earlier this year , physicists had put together a blueprint for how to make and measure time crystals - a bizarre state of matter with an atomic structure that repeats not just in space, but in time, allowing them to maintain constant oscillation without energy. Two separate research teams managed to create what looked an awful lot like time crystals back in January, and now both experiments have successfully passed peer-review for the first time, putting the 'impossible' phenomenon squarely in the realm of reality. "We've taken these theoretical ideas that we've been poking around for the last couple of years and actually built it in the laboratory," says one of the researchers , Andrew Potter from Texas University at Austin. "Hopefully, this is just the first example of these, with many more to come." Time crystals are one of the coolest things physics has dished up in recent months, because they point to a...

The Dark Side Of The Love Hormone Oxytocin

New research shows oxytocin isn't the anti-anxiety drug we thought it was. Oxytocin, the feel-good bonding hormone released by physical contact with another person, orgasm and childbirth (potentially encouraging monogamy ), might have a darker side. The love drug also plays an important role in intensifying negative emotional memories and increasing feelings of fear in future stressful situations, according to a new study. Two experiments performed with mice found that the hormone activates a signaling molecule called extracellular-signal-related kinases (ERK), which has been associated with the way the brain forms memories of fear . According to Jelena Radulovic, senior author on the study and a professor at Northwestern University's medical school, ERK stimulates fear pathways in the brain's lateral septum, the region with the highest levels of oxytocin. Mice without oxytocin receptors and mice with even more oxytocin receptors tha...

Aestus Ajith

Search This Blog