Anti-hydrogen origin revealed by collision simulation

January 18, 2016, SciencePOD
"Scientists studying the formation of antihydrogen ultimately hope to explain why there is more matter than antimatter in the universe."

Antihydrogen is a particular kind of atom, made up of the antiparticle of an electron—a positron—and the antiparticle of a proton—an antiproton. Scientists hope that studying the formation of anti hydrogen will ultimately help explain why there is more matter than antimatter in the universe. In a new study published in EPJ D, Igor Bray and colleagues from Curtin University, Perth, Australia, demonstrate that the two different numerical calculation approaches they developed specifically to study collisions are in accordance. As such, their numerical approach could therefore be used to explain antihydrogen formation.

There are several methods of explaining anti-hydrogen creation. These involve calculating what happens when a particular kind of particle, made up of an electron and a positron bound together, called positronium, scatters on a proton or on an antiproton. The trouble is that devising numerical simulations of such collision is particularly difficult due to the presence of two centres for the occurrence: the atomic level with the proton and at the positronium level.

The authors employed two very different calculations —using a method dubbed coherent close-coupling—for both one- and two-centre collisions respectively in positron scattering on hydrogen and helium. Interestingly, they obtained independently convergent results for both approaches. Such convergence matters, as it is a way to ascertain the accuracy of their calculations for anti-hydrogen formation.

They then also compared the estimates of the area in the vicinity of the atom  within which the positronium would need to be to ensure collision. They found excellent agreement with the two methods for . However, their method did not prove quite as good for helium. This indicates that there is further room for improvement in the theory for helium before the approach  can be applied to more complex atoms, such as magnesium and .

Explore further: Physicists find ways to increase antihydrogen production

More information: Igor Bray et al. Internal consistency in the close-coupling approach to positron collisions with atoms, The European Physical Journal D (2016). DOI: 10.1140/epjd/e2015-60591-7

Related Stories

Physicists find ways to increase antihydrogen production

May 20, 2015

(—There are many experiments that physicists would like to perform on antimatter, from studying its properties with spectroscopic measurements to testing how it interacts with gravity. But in order to perform these ...

Revealed: Positronium's behavior in particle billiards

July 6, 2015

Collision physics can be like a game of billiards. Yet in the microscopic world, the outcome of the game is hard to predict. Fire a particle at a group of other particles, and they may scatter, combine or break apart, according ...

The debut of the antihydrogen beam

March 7, 2014

The standard model of particle physics suggests that matter and antimatter are equal and opposite in every way. Yet the observable Universe is made almost entirely of matter—an asymmetry that remains one of the greatest ...

Recommended for you

On the rebound

January 22, 2018

Our bodies have a remarkable ability to heal from broken ankles or dislocated wrists. Now, a new study has shown that some nanoparticles can also "self-heal" after experiencing intense strain, once that strain is removed.

Nanoparticle gel controls twisted light with magnetism

January 22, 2018

"Help me, Obi Wan Kenobi. You're my only hope." For many of those around at the release of Star Wars in 1977, that scene was a first introduction to holograms—a real technology that had been around for roughly 15 years.

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

not rated yet Jan 19, 2016
Quote from a 2013 article concerning antimatter: "No one has ever seen antimatter actually fall in the field of gravity," said co-author Dr Makoto Fujiwara of TRIUMF

Read more at:

Makes one wonder if antimatter possesses antigravitational properties. if so then ships with proper antimatter containment could have 'neutral gravitational buoyancy' and not possess much if any inertia. In that way they could be accelerated to fantastic velocities with small forces, and be capable of ninety or 180 degree course changes literally on a dime with no inertial effects felt. Our universe in such a place would be surrounded by a halo of antimatter, which would be why it is not found at the center where all the 'normal' matter is. That would explain why the universe ever expands, and why we have not found antimatter is far away beyond the dreams of Einstein, trillions of lightyears away.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.