7th Grade ELA Article Analysis Week of August 29-Sept. 2 New scientific discovery could rewrite the rules of physics By Los Angeles Times

A tiny, invisible force could change our basic understanding of the universe — if it really exists. Physicists at the University of California, Irvine, say they have found evidence for a fifth fundamental force of nature. They claim this new force is carried by a particle that until now has gone totally unnoticed.

The team's scientific paper describes a boson, or subatomic particle, that may force scientists to rewrite the standard model of particle physics. The standard model is a theory that explains how the universe works. It describes the fundamental subatomic particles that make up all matter. It also explains the interactions of matter, or how matter responds to other matter.

There are four known forces that govern, or control, how matter interacts. These forces are gravitation, electromagnetism, and the strong and weak nuclear forces.

Gravitation, or gravity, is the force that pulls matter together. It works over huge distances and sculpts the universe at the enormous scale of galaxies. The strong and weak nuclear forces guide the tiny connections between subatomic particles, while electromagnetism governs the relationship of electric currents and magnetic fields. Scientists have long believed that these four forces govern the bonds between all the matter in the universe.

New Particle Could Affect Standard Physics Model

The UC Irvine researchers say they have found a fifth force, which is transmitted by a particle they are calling “boson X.” The newly discovered force is a sort of mirror image of electromagnetism. Whereas electromagnetism acts on electrons and protons and ignores neutrons, this fifth force works between electrons and neutrons and ignores protons. Electrons and protons are subatomic particles that have equal but opposite electrical charges. Neutrons have no electrical charge.

If the fifth force is real, "it needs to be studied in gory detail,” said physicist David McKeen, who was not involved in the study.

In two published papers, the UC Irvine scientists have suggested how boson X can be added into the standard model of particle physics. Scientists are eager to see revisions in the standard model, which has long been viewed as unsatisfactory because it fails to describe everything in the universe. In fact, it can barely describe a tiny fraction of the universe.

Questions Still Remain About Dark Matter

For example, it cannot explain the existence of dark matter. This mysterious and invisible form of matter can only be detected through its gravitational effects. Dark matter does not interact at all with normal matter, yet it can sculpt galaxy clusters with its massive gravitational influence.

The standard model also does not explain why dark energy, a force that counteracts the effects of gravity, is causing the universe to expand at an increasingly faster rate.

Dark matter makes up nearly 27 percent of the universe’s mass. Dark energy makes up more than 68 percent of the universe's energy. By contrast, normal matter, which can be described pretty accurately by the standard model, makes up less than 5 percent of the universe.

Physicist Timothy Tait, a co-author of the new study, said his team's discovery could help scientists create a model that more accurately describes the universe. It could also help answer some puzzling questions about dark matter.

For example, scientists do not yet know the degree to which dark matter interacts with itself or what might make it interact. The new force-carrying boson could provide some answers.

More Research Needed On Boson X Particle

The force that boson X carries could turn out to be the "dark force” that makes dark matter interact with itself, Tait said.

McKeen was more cautious, however. He stressed that much more work needs to be done before scientists can draw any major conclusions about whether the fifth force exists, and what role it has in explaining mysterious phenomena like dark matter.

“It’s not obvious that it helps us with any of these other outstanding problems,” he said. “It could have a connection, but it’s not obvious to me. But I think it needs to be studied, and then people will understand whether there is or not.”