Are quarks real?

[derek w]

How do we know that quarks are real?If they cannot be isolated.

 

Why could it not be that gluons go through a cycle of re-configuring,which creates an apparition of quarks and colour charges?

[Bill Angel]

Here is one article on how physicists know that quarks are real:

 

http://www.physics.ox.ac.uk/documents/PUS/dis/DIS.htm

[ajb]

You might be interested in glueballs, which are bound states of gluons.

 

Anyway, as Bill Angel has pointed to, deep inelastic scattering experiments provide evidence of quarks.

[derek w]

Thanks,nice links.

[chandragupta]

1351842728[/url]' post='711320']

Here is one article on how physicists know that quarks are real:

 

http://www.physics.o...PUS/dis/DIS.htm

 

Thank you. You have introduced me to a beautiful site. It gave me a great insight into the workings of this amazing quantum world.

[chandragupta]

How far the energy level of electrons can be increased so as to enable them to help us 'see' the inside structure of nucleus ? The article you mentioned, states that high energy content of electrons tends to rupture or break down ( my word, not of the article writer) the possible quarks into hadrons ,thus issue becomes that of interpretation. So there is no way to directly 'see' quarks even with the help of high energy electron beam except in an indirect way via interpretation of the breakdown products i.e. hadrons, of quarks. Your thoughts?

[swansont]

There are very few direct observations of anything, once you enter the realm of modern physics. Almost everything is a matter of properly interpreting what your instrumentation tells you, which puts a premium on having a good experimental setup.

[chandragupta]

1351844003[/url]' post='711321']

You might be interested in glueballs, which are bound states of gluons.

 

Anyway, as Bill Angel has pointed to, deep inelastic scattering experiments provide evidence of quarks.

 

You mentioned 'glueballs', bound states of gluons, in the context of existence or otherwise of quarks. Would you be kind to indicate how these glueballs relate to interaction represented in Richard Feynman's 'Feynman diagram' where a quark & antiquark are shown to annihilate each other to give rise to a photon & a gluon? Do these gluons then bound together to form these glueballs ?

[ajb]

I am not sure what can be understood about glueballs in perturbation theory; so I am not sure how to answer your question. My understanding is that lattice field theory is needed, rather than perturbation theory.

[chandragupta]

1351884003[/url]' post='711377']

I am not sure what can be understood about glueballs in perturbation theory; so I am not sure how to answer your question. My understanding is that lattice field theory is needed, rather than perturbation theory.

 

My understanding of PERTURBATION THEORY is that it relates to classical world of mega structures such as stars where this theory tries to explain as to how the initiation of the process of birth of a baby star takes place inside the primordial cloud of hydrogen. In this theory it is conceived that when two such cloud formations bump into each other , they cause a 'squeeze' in this hydrogen cloud (these clouds can be 100 light years across) which increases the density inside the cloud & thus BIRTH OF GRAVITY & consequent initiation of BABY STAR FORMATION takes place. Therefore like you I would find difficult to relate this concept of PERTURBATION THEORY to the world of quanta. Can I request you to explain the LATTICE FIELD THEORY which you have mentioned?

[ajb]

My understanding of PERTURBATION THEORY

 

In quantum field theory perturbation theory is about approximating the theory with the vacuum configuration and then considering small fluctuations about this. This is where Feynman diagrams "live" and is the correct place to discuss "exchange particles" like the gluon.

 

From what I understand, you cannot say much about glueballs in that framework. This is not that surprising as the path integral approach, which is the standard way of dealing with particle physics, is best suited to scattering experiments rather than calculating properties of bound states.

 

 

Can I request you to explain the LATTICE FIELD THEORY which you have mentioned?

 

The basic idea is to put a quantum field theory on a lattice and deal with finite sums rather than infinite integrals. You can read a little more here.

[chandragupta]

Thanks. Your posting re. Perturbation theory in the realm of quanta has been very helpful. I conceive that in this theory the unimaginably vast regions of space time which remain unoccupied by galaxies & giant primordial hydrogen clouds are accepted as being not TRUELY ABSOLUTE VACUUM regions. Instead they are conceived as being filled with unseen & unmeasurable oceans of energy where quanta of all kinds are being formed & are being immediately annihilated so as to maintain the EQUILIBRIUM between the aforesaid ocean of unseen energy on one hand & the world of quanta on the other. In this 'DANCE' between ocean of unseen energy & the formation of world of quanta , minutest of minute perturbations in the ocean of energy are the initiators .Richard Feynman's Diagrams are a very beautiful way to express this 'DANCE' between unseen ocean of energy & quanta. Your thoughts ?

[ajb]

Richard Feynman's Diagrams are a very beautiful way to express this 'DANCE' between unseen ocean of energy & quanta. Your thoughts ?

 

Feynman diagrams are graphical notion for terms in a series expansion.

[chandragupta]

1352039082[/url]' post='711558']

Feynman diagrams are graphical notion for terms in a series expansion.

 

Thank you. I would also be deeply interested to know your view re. my concept of PERTURBATION THEORY as applied to the world of quanta . This concept was attached as the main theme prior to the matter of Richard Feynman's diagram.

[ajb]

This concept was attached as the main theme prior to the matter of Richard Feynman's diagram.

 

Perturbation theory is much older can be used in classical mechanics. The idea is to study small deviations from configurations that you know how to handle.

[chandragupta]

1352104401[/url]' post='711645']

Perturbation theory is much older can be used in classical mechanics. The idea is to study small deviations from configurations that you know how to handle.

 

Thanks.