Subatomic particles

[dwnielsen]

I would like to create an inventory of all the fundamental particles. I'm getting entirely lost in the forest.

Could you check these facts for me?

There are 40 basic baryons total (20 spin-1/2; 20 spin-3/2).

There are 32 basic mesons total (17 pseudoscalar; 15 vector).

Also, what is the theoretical merit of exotic baryons, exotic mesons, glueballs, tetraquarks, hybrid mesons, etc?

Antiparticles are truly to be considered a completely different particle type from their counterpart, correct? Eg, we recognize that "flew" is just a modification of the word "fly". Is it similar with antiparticles, or must they be considered a totally different form of matter? Does each color of quark constitute a different type of particle, or just a different characteristic of a fundamental particle type?

Thanks for any clarity on this.

[astromark]

Oh.. ! So you are telling me that the pereodic table of elements is not the whole story... and I thought I understood things, bother.
As you are asking of things I have little knowledge of my answer to your question is sadly lacking any substance... I defer to the greater minds to help you. BUT ! I do see some small part of your post that I can speak with some authority on... 'Fly = Flew' only that flew is the past tense for the flying not to be confused with the chimney which might be flue which is not a viral infection flu... I trust to have helped, or not. Generaly I try to stay inside the subject of astronomy and leave particle ecceleratorse to the physicists... mark.

[Jeff Root]

This addresses one of your questions... without necessarily answering it...

Antiparticles are exact mirror images of their ordinary counterparts. When
you know which properties are reversed in general between ordinary particles
and antiparticles, and you know the properties of some new particle you just
found out about, then you can say exactly what the properties of its
counterpart are. The mass is the same, but the electric charge is reversed,
the color charge is reversed, the spin direction is reversed, etc. So in some
ways the particles are identical; in other ways they are exact opposites.
One cannot be changed into the other. They are as alike as the number
three is like the number negative three.

Mark, I hope you recovered from getting your head stuck in that flu.

-- Jeff, in Minneapolis

[trinitree88]

This addresses one of your questions... without necessarily answering it...

Antiparticles are exact mirror images of their ordinary counterparts. When
you know which properties are reversed in general between ordinary particles
and antiparticles, and you know the properties of some new particle you just
found out about, then you can say exactly what the properties of its
counterpart are. The mass is the same, but the electric charge is reversed,
the color charge is reversed, the spin direction is reversed, etc. So in some
ways the particles are identical; in other ways they are exact opposites.
One cannot be changed into the other. They are as alike as the number
three is like the number negative three.

Mark, I hope you recovered from getting your head stuck in that flu.

-- Jeff, in Minneapolis

Jeff. Point of order. There is no color charge on the leptons, so the positron is not anti-color to the electron. The same holds for muons, taus. All the mesons, and baryons, that are composed of quarks, have color charge. There it switches. Color was introduced to explain how a proton or neutron could contain two identical quarks, when Fermi-Dirac statistics required that they be distinct somehow. pete

MarK. It's nice to be fluent in many languages.

[dwnielsen]

This is helping, thanks! What about the neutrino flavors, are they just to be considered sort of "isotopes" of a basic neutrino type? In the Standard-Model Table, they are usually shown distinctly. Is this accurate?

[Celestial Mechanic]

Why not try the Particle Data Group website? Your first stop for high-energy physics information!

[dwnielsen]

Thanks, CM! Looks like there's some really interesting info on that site. It might be a bit technical for me, though. It's introducing even more confusing concepts, like leptoquarks.

This project seems to be an exercise in ontology, just trying to figure out how all these modes of matter play in determining whether something is entirely unique or just a bit different - without knowing the mechanisms of interaction.

But surely the new standard model is, well, standard?

[trinitree88]

This is helping, thanks! What about the neutrino flavors, are they just to be considered sort of "isotopes" of a basic neutrino type? In the Standard-Model Table, they are usually shown distinctly. Is this accurate?

dwnielsen. try this site too. SEE:http://www.ps.uci.edu/~superk/neutrino.html

[korjik]

Six quarks and their antiparticles, three leptons, their antiparticles and their neutrinos.

What exactly are you calling fundamental?

[dwnielsen]

Well, specifically I was wondering if all the standard mesons were accounted for in that quantity of 32.

Is it possible that a better Standard-Model Table would explicitly list the following (and combine the neutrinos)?

[edit: quark]
u u' d d' c c' s s' t t' b b'
lepton
nu e e' mu mu' tau tau'
boson
gamma g Z0 W- W+

[Eta C]

Let me second CM's recommendation of the PDG. Although it is technical, it is the up to date reference on all things related to particle physics. I'd recommend, for a start, the article on the quark model. It explains how quarks and anti-quarks combine to form mesons (quark-anti-quark combinations) and baryons (three quark combinations). If the equations get too mind-boggling look at the figures that show how the various combos are formed (up through those containing charm).

For a less technical description try the Particle Adventure. Its a site put together by Lawrence Berkeley Lab (who also do the PDG) that explains the basics without going into all of the math behind them.

I'll try to come back with a bit more later.

[Cougar]

To simplify, they're all just different vibration/energy modes of strings....

or not.

[dwnielsen]

..mesons (quark-anti-quark combinations)..

According to Wikipedia, some mesons are composed of multiple particle-antiparticle combinations. These are confusing.

[dwnielsen]

The neutrino type seems so different in mass, shouldn't they be an entirely different class than merely a lepton?

[01101001]

Why not try the Particle Data Group website? Your first stop for high-energy physics information!

But my first stop for actually shopping for subatomic particles is The Particle Zoo at CERN.

They accept Paypal, checks, and money orders.

[dwnielsen]

But my first stop for actually shopping for subatomic particles is The Particle Zoo at CERN.

They accept Paypal, checks, and money orders.

Ha ha! The universe at your doorstep: only $115. But still, that's more than I can pay.

[astromark]

Well now, that's 'a maz ing' ... Haveing just visated that web site...http://www.particlezoo.net/ We can stop looking for proof of the Higgs Boson particle... I have seen one with mine own eyes...... Stop wasting those billions of $ on the L H C. We do not need it. It would appear as if members of 'the Order Of Kilopi' are in some way wired wrongly...I am NOT part of that group so am fortunat in that I see things a little differently...
The number of sub atomic particles yet found is not the whole story. That is why so much effort and money are being spent on attempting to clear the muddy waters of dis information. Given time we will learn these unknown things.. we just need to wait a while yet. You can not rush these things...

[Eta C]

According to Wikipedia, some mesons are composed of multiple particle-antiparticle combinations. These are confusing.

Yeah, I can understand the confusion. Basically, that means that the particle in question (such as the pi 0) is a linear superposition of three q-qbar states. It's a little difficult to explain why that's the case in the context of a message board, but it is true.

As to neutrinos, they definitely are leptons. If you check the recommended web sites you'll find that each charged lepton (electron, muon, and tau) has its corresponding neutrino. Until recently all neutrinos were thought to be massless. Recent experiments and observations have shown that they are not. Do a search on "solar neutrino problem" or better yet check out John Bachall's site for a discussion on this. Anyway, one outcome of this is the discovery that neutrinos have mass, although the uncertainty in that mass is great.

The Standard model, in its simplest form, has three basic kinds of fundamental particles, quarks, leptons, and the force-carrying bosons (no relation to the clown). Quarks and leptons come in three generations. Most matter we see consists of the first of these, the up and down quarks and the electron and its neutrino. Protons & neutrons are combinations of up and down and electrons need no explanation. The next generation quarks are the strange and charmed with the muon and its neutrino. Finally, comes the top & bottom quarks with the tau and its neutrino. These higher generations were important in the early universe, but now have to be created in accelerators or in high energy cosmic ray collisions. We know from experiments (search on Z-zero width) that there are only three generations.

The four forces are carried by different bosons. So, electromagnetism is carried by the photon. The weak nuclear force by the Z and W bosons. The strong (or more properly color) force by gluons. Gravity is the odd man out. It has resisted quantizaion so far but the hypothetical graviton would be the force carrier should this theory be worked out. In your OP you mention glueballs. These are an odd prediction of Quantum Chromodynamics, the theory of the color force. Unlike photons, which are electrically neutral, gluons have the "color" charge. Thus, they can bind to each other. QCD should allow particles that have no quarks and consist of nothing but "glue," hence glueball. My Ph.D. dissertation involved a search for a potential glueball in decays of the J/Psi vector meson, so I have a soft spot for it. The problem is that the decay signature of a glueball is not unique, so it's hard to conclusively say that what one sees is, in fact, a glueball and not just a normal meson.

Well, that's probably enough for one post. By the way, did you see the reference to my namesake? The Eta-C is the charm-anticharm pseudoscalar meson. It also played a large part in my research so it seemed to be an appropriate name. It certainly beat calling myself "Glueball."

[dwnielsen]

Mucho mas thanks, Eta. I knew when I saw your userID that I was about to get some helpful info.

I borrowed a book from the library that states,

Some experiments show that the three neutrinos may, in fact, be the same particle switching among different "modes." This is supported by measurements of neutrinos from the Sun, which consistently number only about one-third of what is expected. Mode-switching accounts for the "missing" neutrinos because the detectors measure only electron-neutrinos, and the solar neutrinos would become a random mix of the three modes on the way to Earth. If there were more than three modes, there would be even more missing neutrinos..

Could I ask yet another question?

These are the common 3D skewed-axis representations of baryons, showing the 40 types:
spin-1/2 baryons
spin-3/2 baryons

These are what I've managed to find for the mesons, which show only 25 total:
spin-0 mesons
spin-1 mesons

Wikipedia lists 32 mesons total. Is there a more-complete graph representation out there? (Sorry, I should probably be able to figure this out on my own, but I prefer to know the results are right.)