New finding of particle physics may help to explain the absence of antimatter

November 13, 2018

In the Standard Model of particle physics, there is almost no difference between matter and antimatter. But there is an abundance of evidence that our observable universe is made up only of matter - if there was any antimatter, it would annihilate with nearby matter to produce very high intensity gamma radiation, which has not been observed. Therefore, figuring out how we ended up with an abundance of only matter is one of the biggest open questions in particle physics.

Because of this and other gaps in the Standard Model, physicists are considering theories which add a few extra particles in ways that will help to solve the problem. One of these models is called the Two Higgs Doublet Model, which, despite the name, actually adds four extra particles. This model can be made to agree with all particle physics observations made so far, including ones from the Large Hadron Collider at CERN, but it was unclear whether it could also solve the problem of the matter-antimatter imbalance. The research group, led by a University of Helsinki team, set out to tackle the problem from a different angle. Their findings have now been published in a paper in the Physical Review Letters.

About ten picoseconds after the Big Bang - right about the time the Higgs boson was turning on - the universe was a hot plasma of particles.

"The technique of dimensional reduction lets us replace the theory which describes this hot plasma with a simpler quantum theory with a set of rules that all the particles must follow", explains Dr. David Weir, the corresponding author of the article.

"It turns out that the heavier, slower-moving particles don't matter very much when these new rules are imposed, so we end up with a much less complicated theory."

This theory can then be studied with computer simulations, which provide a clear picture of what happened. In particular, they can tell us how violently out of equilibrium the universe was when the Higgs boson turned on. This is important for determining whether there was scope for producing the matter-antimatter asymmetry at this time in the history of the universe using the Two Higgs Doublet Model.

"Our results showed that it is indeed possible to explain the absence of antimatter and remain in agreement with existing observations", Dr. Weir remarks. Importantly, by making use of dimensional reduction, the new approach was completely independent of any previous work in this model.

If the Higgs boson turned on in such a violent way, it would have left echoes. As the bubbles of the new phase of the universe nucleated, much like clouds, and expanded until the universe was like an overcast sky, the collisions between the bubbles would have produced lots of gravitational waves. Researchers at the University of Helsinki and elsewhere are now gearing up to look for these gravitational waves at missions such as the European LISA project.
-end-
Further information: University Researcher David Weir, phone: +358 40 6545364, david.weir@helsinki.fi">david.weir@helsinki.fi

Jens Andersen, Tyler Gorda, Andreas Helset, Lauri Niemi, Tuomas Tenkanen, Anders Tranberg, Aleksi Vuorinen and David Weir, "Nonperturbative analysis of the Electroweak phase transition in the Two Higgs Doublet Model", Phys. Rev. Lett. 121, 191802 (2018).

University of Helsinki

Related Big Bang Articles from Brightsurf:

Do big tadpoles turn into big frogs? It's complicated, study finds
University of Arizona researchers studied the evolution of the body sizes of frogs and their tadpoles.

A 'bang' in LIGO and Virgo detectors signals most massive gravitational-wave source yet
Researchers have detected a signal from what may be the most massive black hole merger yet observed in gravitational waves.

Analysis: Health sector, big pharma spent big on lobbying for COVID-19 funding
To date, Congress has authorized roughly $3 trillion in COVID-19 relief assistance -- the largest relief package in history.

Unequal neutron-star mergers create unique "bang" in simulations
In a series of simulations, an international team of researchers determined that some neutron star collisions not only produce gravitational waves, but also electromagnetic radiation that should be detectable on Earth.

Supermassive black holes shortly after the Big Bang: How to seed them
They are billions of times larger than our Sun: how is it possible that supermassive black holes were already present when the Universe was 'just' 800 million years old?

Big data could yield big discoveries in archaeology, Brown scholar says
Parker VanValkenburgh, an assistant professor of anthropology, curated a journal issue that explores the opportunities and challenges big data could bring to the field of archaeology.

APS tip sheet: modeling the matter after big bang expansion
Matter's fragmentation after the big bang.

Giving cryptocurrency users more bang for their buck
A new cryptocurrency-routing scheme co-invented by MIT researchers can boost the efficiency -- and, ultimately, profits -- of certain networks designed to speed up notoriously slow blockchain transactions.

The core of massive dying galaxies already formed 1.5 billion years after the Big Bang
The most distant dying galaxy discovered so far, more massive than our Milky Way -- with more than a trillion stars -- has revealed that the 'cores' of these systems had formed already 1.5 billion years after the Big Bang, about 1 billion years earlier than previous measurements revealed.

The 'cores' of massive galaxies had already formed 1.5 billion years after the big bang
A distant galaxy more massive than our Milky Way -- with more than a trillion stars - has revealed that the 'cores' of massive galaxies in the Universe had formed already 1.5 billion years after the Big Bang, about 1 billion years earlier than previous measurements revealed.

Read More: Big Bang News and Big Bang Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.