New particle turns up in Japan

Physicsweb ^ | Nov 14, 2003 | Belle Dumé

[Diddley]

The Belle collaboration at the KEK laboratory in Japan has discovered a new sub-atomic particle which it is calling the "X(3872)". The particle does not fit into any known particle scheme and theorists are speculating that it might be a hitherto unseen type of meson that contains four quarks (arxiv.org/abs/hep-ex/0309032; Phys. Rev. Lett. to be published).

The discovery has been confirmed by the CDF collaboration at Fermilab in the US, where the new particle is being called the "mystery meson". Mesons are particles that contain a quark and an antiquark that are held together by the strong nuclear force.

Since there are six different "flavours" of quark - up, down, strange, charm, bottom and top - it is possible to form a large number of different mesons.

The Belle team measured the decay of B-mesons - mesons that contain a bottom quark - produced in electron-positron collisions at the KEK B-factory in Japan. The team plotted the number of candidate events for B mesons against mass and observed a significant spike in the distribution at 0.775 GeV. This corresponds to a mass of nearly 3872 MeV. The particle decayed almost immediately into other, longer lived particles.

The KEK team says that the mass of this new meson is higher than theoretical predictions. Moreover, the way in which it decays also differs from theory. One possibility is that current models of the strong force need to be modified. Alternatively it could be that X(3872) is the first example of a "molecular state" meson that contains two quarks and two antiquarks.

Until recently particle physicists had only ever detected particles that contain two or three quarks. However, in the past year evidence has emerged for another four-quark particle known as the Ds(2317) and a five-quark particle known as the pentaquark.

Author Belle Dumé is Science Writer at PhysicsWeb

[general_re]

Thanks for the heads up!

Truly, it was nothing, requiring absolutely no effort on my part. ;)

[ThinkPlease]

Great summary of particle physics RA! There's plenty of stuff in there I didn't know about.

[Qwinn]

"News to me, but I hadn't been following that issue. In fact, I thought electricity was a pretty settled deal. Number one sounds the most like what I've heard."

*nod*. I believe this was a recent development that has called into dispute what had been an accepted model. They somehow determined that the electrons going in on one end of the wire were -not- the same ones coming out the other end, which seriously contradicts #1 (I -think- the experiment involved cutting the wire -while- a charge was going through it). And #2 had been discredited long ago. I find it an interesting question.

"It's well documented that mass distorts space."

*nod* Okay, that's what I thought you meant. And yes, I knew the effect was well documented, but I thought what caused that effect was the issue. Maybe I'm just dwelling too much on Einstein's concept of how the universe worked, but my impression is that he held that there was no such thing as "space" as something that could be bent - that all "space" is merely imaginary coordinate points between other objects (mass or energy) as legitimate points of reference. That if there was a big bang, then before it, there was no such thing as definable space because there was only one point of reference. Relativity to the extreme.

I have trouble accepting that. I think there -is- an, I dunno what term to give it, "dimensional construct?" that can be called "space" that can actually be bent and that exists independently of any matter or energy as points of reference. I know it's getting rather metaphysical, but I think this construct can be bent and it is what makes a graviton unnecessary.

I don't want to say that the "objective space" and "graviton" models are mutually exclusive, they're not, but at the same time, if you have one you don't need the other. If gravitons exist, then you don't need an objective space to be bent to distort light, gravitons could act on the photons of light and make light bend. If objective space exists that can be bent, then you don't need a particle to cause the attraction between two objects, the objects slide toward another down this dimensional construct of objective space, like the "web" of space as depicted in those old Discover Magazine commercials. The "web" actually exists, but it is neither matter nor energy as we know it. That's what I think.

Am I making any sense? I suspect there's terminology I could be using that would make me a lot clearer, and I have either forgotten or never aware of what those terms are.

Qwinn

[William Tell]

js1138 said: "The math gets harder but the number of entities goes down."

Hmmm...sometimes.

A theory that supposes that everything is composed of earth, air, fire, and water is actually very simple.

Unfortunately, it has little predictive power. Chemistry made little progress while people were trying to identify "phlogiston" which was released during burning.

When techniques became more refined, it was possible to determine that an object which "burns" can become heavier. We know now that most "burning" is the combining of other elements with oxygen.

Many discoveries in quantum physics were initially predictions made based on expectations created by "holes" in the symmetry of the prevailing theory.

The idea of the "graviton" is appealing because the theory of the mechanisms by which the other forces act requires an exchange particle. It would be very unsymmetric to suppose that gravity is an exception to this "rule".

A negative way to view the future progress of physics is to imagine that new discoveries will all hinge on being able to harness greater and greater particle energies in order to view new phenomenon. The reality is that the discoveries may require this, but that there will be anomalies observed without such experiments whose physics will become clear as future refinements are made to theory.

General Relativity predicted the bending of light rays in a gravitational field and the anomolies observed in the orbit of Mercury. It is the ability to explain such things which solidifies support for the new theories and which dictate that there will be no return to a "simpler" theory which is unable to explain the anomalies.

The necessity to suppose the existence of "dark matter" in the universe to help explain observed anomalies seems oddly similar to "phlogiston" and makes me expect future corrections.

I have similar difficulty with the supposition that the strong force does not follow the inverse-square law. This law reflects the relation between a distance and the area of a sphere which has that distance for a radius. Fairly obvious considerations of conservation support inverse-square reductions in force.

Can anybody offer an "explanation" for what the distance law is for the strong force? Is there a theoretical prediction of what distance law this force should exhibit?

[Preech1]

I was wondering who would post the Godzilla picture...thanks, you made this thread worth all the scientific "Slurpy Brain Freeze" headaches.

[Qwinn]

Good post.

"A theory that supposes that everything is composed of earth, air, fire, and water is actually very simple."

I actually always thought of these as more related to the -states- of matter, earth = solid, air = gas, fire = plasma, water = liquid.

Qwinn

[PatrickHenry]

How about a simple, "Thanks!"???

In Star Trek, when one character hails another (through their lapel-button intercom system), the usual response is "Acknowledged!" Can't get in trouble with that one.

[Alamo-Girl]

LOLOLOL! Thanks for the chuckle!

[Alamo-Girl]

Acknowledged! (Thank you!)

[Lazamataz]

In Star Trek, when one character hails another (through their lapel-button intercom system), the usual response is "Acknowledged!" Can't get in trouble with that one.

Condescending. Furthermore, it contains the word 'knowledge', which, if you direct to people of color, implies you have more knowledge then they do.

Practice a lot of phrenology, racist scum?

[Lazamataz]

Acknowledged!

AG! Tell me you're not a racist too!

[Lazamataz]

Oh no! It's GODZIRRA!

[PatrickHenry]

To avoid non-PC responses to a ping, one could always reply: "Pong!" But that's kinda AOL-ish. However, if "Acknowledged!" was good enough for Kirk and Spock, it's good enough for me.

[Sofa King]

I'm rooting for tamp-on

[William Tell]

Qwinn said: "I actually always thought of these as more related to the -states- of matter, earth = solid, air = gas, fire = plasma, water = liquid. "

We know that now. The ancients were confounded in their attempt to explain "earth" due to the extreme variety of chemical compounds. They could see that some substances could appear to "transmute" from one thing to another. This made the attempt to turn lead into gold seem like something that might be easy if one just knew the secret.

Today we know the secret of turning lead into gold (add a bunch of protons) but we are convinced that it will never be easy, requiring a super-nova for any appreciable quantities.

We know now that "air" is simply a mixture of some of the same elements that make up earth but in gaseous form. The ancients didn't know this. The early chemistry which proved that burning was the result of combining with something in air and that that something, oxygen, was just one constituent of air, was quite a breakthrough.

[Lazamataz]

To avoid non-PC responses to a ping, one could always reply: "Pong!" But that's kinda AOL-ish. However, if "Acknowledged!" was good enough for Kirk and Spock, it's good enough for me.

You mean the James Kirk who routinely violated the Prime Directive? The sexist James Kirk who patronizingly patted female ensigns on the butt and stuck various organs into every green-skinned alien chick he could find? The James Tiberious Kirk who messed up so many timelines that we are no longer sure this is how time should have unfolded?

You want to hitch your star to THAT un-PC jackass????

[mdmathis6]

It was my fault they found it, I forgot to flush before I left Tokyo......

[Qwinn]

Agreed.

"Today we know the secret of turning lead into gold (add a bunch of protons) but we are convinced that it will never be easy, requiring a super-nova for any appreciable quantities."

Actually, to go from lead to gold, you need to remove three protons from each atom (82 to 79). I always found that interesting, that lead and gold -are- pretty close to each other on the periodic table. In between are mercury (80) and thallium (81).

I believe that they had something similar to a periodic table back then where they misplaced those two and thought that they were right next to each other. I think those guys were smarter than they're given credit for - they were off on some important basics, but I think they were overall on the right track. Actually, they definetly were, since our science did stem from theirs :)

Qwinn

[Qwinn]

Hey now!

I'm far more a Picard fan than a Kirk fan, and there's -plenty- I'll slam Kirk for, but...

"The sexist James Kirk who patronizingly patted female ensigns on the butt" - I don't think he ever did that. The kid "Charlie" did in one episode, and he got ripped apart for it.

"Stuck various organs into every green-skinned alien chick he could find?" - HEY! There weren't -any- green-skinned alien chicks on Star Trek, were there? There was one with green hair (Gamesters of Triskelion planet, I think, and yeah, he probably did do her, lol, he definetly wanted to) and there was a blue chick in that insane asylum episode, but I'm pretty sure there wasn't a green skin alien chick! Lol.

Oh, and Kirk never ever said "Beam me up, Scotty" either. =P

*proudly beams his utter geekness for all to see*

Qwinn

[AdmSmith]

Yo may try this link http://www.nobel.se/physics/educational/matter/12.html for a quick tour on quarks and the strong force. The animation will answer your question on the distance law.