The research findings appear in the September issue of Physical Review Letters. "Black hole bombs and photon mass bounds" is co-authored by Emanuele Berti, UM assistant professor of physics and astronomy, along with fellow researchers Paolo Pani, Vitor Cardoso, Leonardo Gualtieri and Akihiro Ishibashi.
Illustration by Ana Sousa.
Schematic illustration of the 'black hole bomb' effect. A wave thrown at a black hole can be magnified upon reflection, extracting rotational energy and spinning down the black hole. The mass of the particle acts like a 'wall' for outgoing waves (represented by the enclosing sphere in this figure), so the reflection/amplification process is repeated and causes an instability.
The paper details how the scientists, who work in Portugal, Italy, Japan and the U.S., found a way to use astrophysical observations to test a fundamental aspect of the Standard Model – namely, that photons have no mass – better than anyone before.
"The test works like this: if photons had a mass, they would trigger an instability that would spin down all black holes in the universe," Berti said. "But astronomers tell us that the gigantic, super-massive black holes at galactic centers are spinning, so this instability cannot be too strong.
"The mass of the photon, if it has a mass at all, must be extremely tiny."
"Ultralight photons with nonzero mass would produce a 'black hole bomb': a strong instability that would extract energy from the black hole very quickly," said Pani, the paper's lead author. "The very existence of such particles is constrained by the observation of spinning black holes. With this technique, we have succeeded in constraining the mass of the photon to unprecedented levels: the mass must be one hundred billion of billions times smaller than the present constraint on the neutrino mass, which is about two electron-volts."
The results of this study can be used to investigate the existence of new particles, such as those possibly contributing to the dark matter that is the subject of a search using the Large Hadron Collider at CERN in Geneva. CERN is the site where the breakthrough discovery of the Higgs boson was reported earlier this year.
"That discovery filled one of the most important gaps in our understanding of the standard model of particle physics, because it explains how particles get their mass," Gualtieri said. "However, not all particles have mass. Physics makes progress by testing every nook and cranny of our commonly accepted theories. So, if we believe that a particle has no mass, we'd better test this idea with precise experiments.
"Observations of super-massive black holes may provide new insights which are not accessible in laboratory experiments. This would certainly be exciting. Perhaps these new frontiers in astrophysics will give us a clearer understanding of the microscopic universe."
"Paolo, Vitor, Leonardo and I are all part of an IRSES Network on 'Numerical Relativity and High-Energy Physics' funded by the European Union," Berti said. "Paolo presented a talk on this work at the first meeting of our network that was held in Aveiro, Portugal in July. This network will be used in the next four years to strengthen our collaboration even further."
Pani, who received the Fubini Prize from the Italian National Institute of Nuclear Physics for the best Ph.D. thesis nationwide in 2011, is a post-doctoral researcher at Instituto Superior Técnico in Lisbon, Portugal, supported by a European Marie Curie Fellowship.
"Paolo started working with us when he visited Ole Miss in 2007," Berti said. "We have been working together on this particular project since January 2012, and we have co-authored nine papers so far."
A post-doctorate researcher at UM before returning to his native Portugal, Cardoso is a professor at Instituto Superior Tecnico, where his group is supported by a prestigious European Research Council Starting Grant. Cardoso and Berti have published 37 papers together over the past decade.
"Gualtieri and I were both Ph.D. students under the supervision of Valeria Ferrari in Rome, Italy," Berti said. "We have also been collaborating for more than a decade. Leonardo is now a research professor ('ricercatore') in Rome."
Ishibashi works at the KEK Theory Center and at the Department of Physics of Kinki University in Japan, where physicists at the center are studying in great depth phenomena similar to the one described in the PRL paper.
This study was funded, in part, by National Science Foundation Grant No. PHY-0900735 and by CAREER Grant No. PHY-1055103.To view the team's PRL paper before publication, go to http://arxiv.org/abs/arXiv:1209.0465 or
http://www.newscientist.com/article/mg21528824.100-heavy-photons-are-too-light-to-be-behind-dark-matter.html.For more information about the UM Department of Physics and Astronomy, go to http://www.olemiss.edu/depts/physics_astronomy/.
For more news from the University of Mississippi, visit http://news.olemiss.edu/
Edwin Smith | Newswise Science News
Significantly more productivity in USP lasers
06.12.2016 | Fraunhofer-Institut für Lasertechnik ILT
Shape matters when light meets atom
05.12.2016 | Centre for Quantum Technologies at the National University of Singapore
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
06.12.2016 | Materials Sciences
06.12.2016 | Medical Engineering
06.12.2016 | Power and Electrical Engineering