Trial hints at a new twist in physics

Experiment may point to new form of matter or energy

Nov. 9 — An experiment that involved smashing together certain subatomic particles at great speeds produced an unexpected result, prompting physicists yesterday to announce that they might be on the verge of finding a new form of matter or energy

DISCREPANCIES BETWEEN experimental and theoretical results have previously led to the discovery of new particles or forces. While this discrepancy could be a fluke, the scientists who conducted the experiment said the odds were it represented something meaningful. If some hidden matter or energy did cause the discrepancy, it may help scientists find their way to the ultimate quest of physics — a unified theory that explains how all the particles and forces in the universe interact with each other.

http://www.msnbc.com/news/655262.asp

“It could be a very big deal,” said Kevin McFarland, an assistant professor in the Department of Physics and Astronomy at the University of Rochester in New York who helped conduct the research. “It would be very exciting if we find another force.”

The scientists, who are associated with the Department of Energy’s Fermi National Accelerator Laboratory near Chicago, are conducting follow-up experiments with a high-energy particle accelerator to verify and explain the result.

FOCUS ON NEUTRINOS

The experiment involved a type of subatomic particle called a neutrino. This particle is a cousin of the electron, which is well-known from high school textbooks as one of the constituents of atoms. Unlike electrons, which are negatively charged, neutrinos have no charge. Because they are also very light compared with other subatomic particles, they behave in a ghostly way — wandering through the universe at the speed of light without interacting very much with other particles.

“If you lie out in the sun, there are a hundred trillion neutrinos passing through your body at any time,” said McFarland.

In the experiment, researchers fired neutrinos at a target and calculated how often the particles slammed into the nucleus of an atom. Because neutrinos are “invisible” to scientists’ detectors, the physicists measured how often the collisions produced another type of particle, called a muon. “It’s like you’re firing a gun into an apple,” said McFarland. “The bullet goes in and you get a spray of apple out the back.”

Since neutrinos are so small, most of the time they passed through the nucleus without affecting it. The frequency of collisions told scientists about the electromagnetic forces that affect how neutrinos behave — the so-called weak forces. The scientists found slightly fewer interactions with one of the weak forces than had been predicted by the Standard Model, physicists’ current description of fundamental forces and particles. Since the model is very precise, scientists concluded that the difference was significant.

“This measurement differs from what we expect by three units,” said Michael Shaevitz, professor of physics at Columbia University and another investigator. “On a statistical basis, that would be a 1 in 400 probability of happening as a result of chance. It would be way out there on the tail of the probability curve.”

Peter Meyers, a professor of physics at Princeton University who was not part of the research team, said the finding is the “sort of crack” that “has been sought for many, many years.”

Meyers cautioned that he couldn’t say whether the new finding amounted to a significant discrepancy because he hadn’t seen the actual data. But he added that “the Standard Model started falling into place in the ’70s. People figured it wouldn’t be the last word, but it’s been 20-30 years without finding discrepancies that have lasted very long.”

McFarland said he thinks “there is a high probability that something is wrong with the theory.”

The research has been submitted for publication in the journal Physical Review Letters. McFarland and Shaevitz’s collaborating scientists were from the University of Cincinnati, Kansas State University, Northwestern University, the University of Oregon and the University of Pittsburgh.

-- Anonymous, November 09, 2001

Answers

I enjoyed this report. Thank you. I'll tell Dr. Mark Frauschi about it.

He will be at our nice meeting place.

Thank you again.

-- Anonymous, November 09, 2001

Physics ain't my deal. Finally got lost somewhere between up, down and strange quarks. Would be neat if what they find is matter and not energy. We got a whole hell of a lot of that theoretically missing and the brain here would digest the idea better. Good find.

-- Anonymous, November 09, 2001

"MATTER" AND "ENERGY" ARE RELATED, SHEEP DIP. TRY E= mc**2 .

-- Anonymous, November 10, 2001

2nd paragraph. "If some hidden matter or energy did cause...."

You read the article right?

-- Anonymous, November 10, 2001

SHEEP DIP: WHAT THE FUCK DOES SCIENCE CARE WHAT A REPORTER PUTS IN THE 2nd Paragraph??

-- Anonymous, November 10, 2001

You're regressing. My granddaughter tells me this stuff cause it's new to her.

You and only you used the word "matter" in the title subject line of this thread. Maybe you could go argue with yourself and save some of that fourth dimension stuff. Better...just listen to their music.

-- Anonymous, November 10, 2001

Left a chew there for ya. Did you spot it or are you dimensionally challenged? Surprised noone else picked it up but then looking back the only people that respond to your posts are me & Peter. Now that HAS to be discouraging. If you'd just lighten up we might even get along. Not going to invite you to lunch again though.

-- Anonymous, November 10, 2001