Today, we live in a universe apparently made entirely of matter, yet at the big bang matter and antimatter would have existed in equal quantities. Nature seems to have a slight preference for matter, which allows our universe and everything in it to exist. One way of investigating nature’s preference for matter is to compare hydrogen atoms with their antimatter counterparts, and that’s what makes today’s result important.
“We can keep the antihydrogen atoms trapped for 1000 seconds,” explained ALPHA spokesperson Jeffrey Hangst of Aarhus University. “This is long enough to begin to study them - even with the small number that we can catch so far.”
In the paper published today, some 300 trapped antiatoms are reported to have been studied. The trapping of antiatoms will allow antihydrogen to be mapped precisely using laser or microwave spectroscopy so that it can be compared to the hydrogen atom, which is among the best-known systems in physics. Any difference should become apparent under careful scrutiny. Trapping antiatoms could also provide a complementary approach to measuring the influence of gravity on antimatter, which will soon be investigated with antihydrogen by the AEgIS experiment.
Another important consequence of trapping antihydrogen for long periods is that the antiatoms have time to relax into their ground state, which will allow ALPHA to conduct the precision measurements necessary to investigate a symmetry known as CPT. Symmetries in physics describe how processes look under certain transformations. C, for example, involves swapping the electric charges of the particles involved in the process. P is like looking in the mirror, while T involves reversing the arrow of time.
Individually, each of these symmetries is broken – processes do not always look the same. CPT, however, says that a particle moving forward through time in our universe should be indistinguishable from an antiparticle moving backwards through time in a mirror universe, and it is thought to be perfectly respected by nature. CPT symmetry requires that hydrogen and antihydrogen have identical spectra.
“Any hint of CPT symmetry breaking would require a serious rethink of our understanding of nature,” said Hangst. “But half of the universe has gone missing, so some kind of rethink is apparently on the agenda. ”
The next step for ALPHA is to start performing measurements on trapped antihydrogen, and this is due to get underway later this year. The first step is to illuminate the trapped anti-atoms with microwaves, to determine if they absorb exactly the same frequencies (or energies) as their matter cousins.
“If you hit the trapped antihydrogen atoms with just the right microwave frequency, they will escape from the trap, and we can detect the annihilation – even for just a single atom,” explained Hangst. “This would provide the first ever look inside the structure of antihydrogen – element number 1 on the anti-periodic table.”Contacts:
Follow CERN at:www.cern.ch
India, Israel, Japan, the Russian Federation, the United States of America, Turkey, the European Commission and UNESCO have Observer status.
 ALPHA is one of several AD experiments investigating antimatter at CERN. ATRAP has pioneered trapping techniques, and is also investigating antihydrogen. ASACUSA has made measurements of unprecedented precision of the antiproton’s mass, so far not revealing any divergence from that of the proton. ASACUSA is also developing complementary techniques for studying antihydrogen. AEgIS studies how antiprotons fall under gravity, and ACE investigates the potential use of antiprotons for cancer therapy.
James Gillies | Newswise Science News
Physicists discover that lithium oxide on tokamak walls can improve plasma performance
22.05.2017 | DOE/Princeton Plasma Physics Laboratory
Experts explain origins of topographic relief on Earth, Mars and Titan
22.05.2017 | City College of New York
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.
In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...
Dental plaque and the viscous brown slime in drainpipes are two familiar examples of bacterial biofilms. Removing such bacterial depositions from surfaces is...
For the first time, scientists have succeeded in studying the strength of hydrogen bonds in a single molecule using an atomic force microscope. Researchers from the University of Basel’s Swiss Nanoscience Institute network have reported the results in the journal Science Advances.
Hydrogen is the most common element in the universe and is an integral part of almost all organic compounds. Molecules and sections of macromolecules are...
22.05.2017 | Event News
17.05.2017 | Event News
16.05.2017 | Event News
22.05.2017 | Materials Sciences
22.05.2017 | Life Sciences
22.05.2017 | Physics and Astronomy