What's the Matter with Antimatter in the Atom Smasher?

[Buster's Uncle]

What's the Matter with Antimatter in the Atom Smasher?
By Clara Moskowitz, LiveScience Senior Writer  | LiveScience.com – 20 hrs ago...

The LHCb team stands in front of their experiment, the LHCb detecor, at the Large Hadron Collider in Geneva.

 
Matter and antimatter particles are behaving differently inside a giant atom smasher in Switzerland, physicists announced today (April 24). The discovery could help solve the riddle of why the universe is made of matter and not its strange sibling, antimatter.

All matter particles are thought to have antimatter counterparts with the same mass but opposite charge and spin. When the universe sprang into being 13.8 billion years ago with the Big Bang, it probably had similar amounts of matter and antimatter. Most of this antimatter is thought to have been destroyed in collisions with matter (when the two meet, they annihilate each other), and all that's left over in the universe today is a small overabundance of matter.

To understand why matter dominated over antimatter, physicists look for any differences in how the two behave that might explain the discrepancy. These differences are called charge-parity violation (CP violation), and that's just what scientists have found inside the Large Hadron Collider (LHC) in Geneva. [Whoa! The Coolest Little Particles in Nature]

Inside the 17-mile-long (27 kilometers) underground ring of the machine, protons speed up and smash into each other, creating a shower of daughter particles. One experiment at the collider called LHCb (it stands for "LHC beauty") studies these daughter particles for signs of CP violation that might help elucidate the nature of antimatter.

After analyzing about 70 trillion proton-proton collisions, LHCb found that a particle called the B_s meson was created slightly more often in its matter form than in its antimatter counterpart. B_s (pronounced ("B-sub-S") mesons are made of bottom quarks and strange anti-quarks, whereas antimatter B_s mesons have an antimatter bottom quark and a matter strange quark ("bottom" and "strange" are two flavors of quarks, and anti-quarks are the antimatter partner particles of normal matter quarks).

"The thing about antimatter is it behaves almost identically to normal matter," said Tara Shears, a physicist at England's University of Liverpool, who works on the LHCb experiment. "But the devil is in the details, and it's this very tiny difference that we're trying to measure."

B_s mesons are rare, and 70 trillion collisions inside the Large Hadron Collider created only about a thousand of these elusive particles. Yet these were enough to demonstrate a significant abundance of matter B_s mesons compared with antimatter B_s mesons.

"We expected it to be there, but we've never been able to make a measurement of it before because these particles so rare," Shears told LiveScience.

The B_sparticle is only the fourth subatomic particle known to exhibit such a matter-antimatter asymmetry.

CP violation was first discovered in neutral particles called kaons at the Brookhaven National Laboratory in Long Island in the 1960s. It took 40 more years for researchers in the United States and Japan to find the next example of this asymmetry in the B0 meson. After that, the LHCb experiment and others found evidence for CP violation in the B+ meson.

Yet these instances of CP violation aren't enough to explain the prevalence of matter over antimatter in the universe.

"We still have a lot to do to understand the real nature of antimatter," Shears said. "We know we don't understand the whole story. We've just filled in a little bit more information — a block in our jigsaw puzzle if you like."

The researchers hope to make more progress when the LHC starts up again in 2015, at a much higher energy, after its current hiatus.

The LHCb discovery is detailed in a paper submitted to the journal Physical Review Letters.

http://news.yahoo.com/whats-matter-antimatter-atom-smasher-185127144.html

[Unorthodox]

All matter particles are thought to have antimatter counterparts with the same mass but opposite charge and spin.




...but are they entangled? 


 B_s (pronounced ("B-sub-S")

Or just BS.   

[Buster's Uncle]

As a comic book fan, I hear a lotta BS when ignorant people talk about antimatter.

[Buster's Uncle]

Why does anything exist? Scientists find a bit of the answer
By Ben Hirschler | Reuters – Wed, Apr 24, 2013...

The LHC (Large Hadron Collider) tunnel is pictured during a visit at the Organization for Nuclear Research (CERN) in Meyrin, near Geneva April 10, 2013. REUTERS/Denis Balibouse

LONDON (Reuters) - Scientists probing the nature of antimatter have found a bit more evidence to explain why the universe is not an empty husk, although not enough to account for the billions of galaxies strewn across the cosmos.

Physicists believe that equal amounts of matter and antimatter were created in the Big Bang at the birth of the universe 13.8 billion years ago. Within one second, however, the antimatter had all but disappeared.

That vanishing act - leaving us in a universe with a surplus of matter forming the stars, the Earth and all known life - must be due to a subtle difference between matter and antimatter.

Researchers said on Wednesday they had found tiny variations in the way a type of particle decayed into matter and antimatter during collisions in the Large Hadron Collider (LHC), the giant particle-smasher buried 100 meters (330 feet) underground at the foot of the Jura mountains outside Geneva.

The latest findings are the first to show that a particle known as a Bs meson has a slight preference for decaying into matter and are consistent with earlier experiments on other particles. Unfortunately, the differences are still far too small to explain the great abundance of matter around us.

"The difference that we see in the behavior of antimatter and matter only adds up to about a galaxy's worth, not half a universe," Tara Shears of the University of Liverpool, one of the physicists working on the experiment, said in an interview.

The results, which have been submitted for publication in the journal Physical Review Letters, fit with the three-decade old Standard Model, which aims to describe everything known about how fundamental particles behave.

"Everything seems to add up, it is just that it doesn't come to anything near the amount of difference we need to explain the evolution of the universe," Shears said.

The CERN scientists made their new discovery after analyzing data from 70 trillion collisions between protons in one of four main experiments at the LHC.

They still have another particle to study in this experiment, but they are also ready to cast their net wider to explain the puzzling predominance of matter over antimatter.

"By studying these ... effects, we are looking for the missing pieces of the puzzle," said Pierluigi Campana, another scientist on the collaboration.

Matter and antimatter are almost identical, with the same mass but opposite electrical charges. They can form separate parts of some elementary particles but if they are mixed together both are destroyed instantaneously.

The first observation that particles can decay unevenly into matter and antimatter won two scientists at Brookhaven Laboratory in New York a Nobel Prize in 1980.

After discovering a long-sought elementary particle called the Higgs boson last summer, the giant collider run by CERN, the European Organisation for Nuclear Research, is currently being upgraded to nearly double its power by 2015.

Scientists hope the extra power will open up an entirely new realm of physics to help explain the antimatter conundrum, as well as other mysteries such as dark matter, the unseen stuff that helps to glue galaxies together.

http://news.yahoo.com/why-does-anything-exist-scientists-bit-answer-151042708.html