Quarks Definition and 258 Threads

For leptons we have charged leptons electron, muon, tau and uncharged leptons electron neutrino, muon nutrino, tau neutrino. For quarks we have charged quarks pairs down, up and strange, charm and truth, beauty. But we have no neutral quarks. Why? The force carrying particle for the charged...

Atoms, and therefore matter, is made of protons and neutrons, which are in turn made up of quarks, up and down flavors, is it not possible that other matter may be made up of different quarks, so as to make different atoms, that would be very different to those we already know of and also...

Hi, I was told by a physics tutor that if you do the following you will result in pi with a complementary between the heaviest quarks and leptons in forms of spin 0 and 1. So I copied what she was saying: ((Top Quark mass/Tau mass)/(Charm Quark mass/Muon mass)) / ((Charm Quark mass/Muon...

Hi everybody :) A lagrangian of the u and d quarks where they don't have a mass, shares chiral SU(2) and U(1) symmetries. In the vacuum, we write <0| \bar{Q} Q | 0 > = \eta where Q is the douplet of u and d quarks. In such a way we break chiral symmetries. The current associated with...

Please teach me this: It seem to me that lepton manifests broken symmetry SU(2) with couple electron and neutrino(electron is a state with mass,neutrino is a state with nearly zero mass).Similarly for 2 other families of lepton,we have a state with mass and a state with nearly zero mass.But I...

is it true that they spin the direction you think of, whether it was clockwise or counter clockwise, it will follow your mind.. is that true?

Are quarks that made up a proton or neutron naturally entangled at all times? If not. When do they lose entanglement or reestablish entanglement? If they are always entangled. How about between two protons/neutrons or more. Are they all entangled?

I'm reading The Lightness of Being by Frank Wilczek. The strong force falls off rapidly with distance. And yet when we attempt to separate two quarks the force increases enormously. I assumed the strong force acted between hadrons (= groups of quarks) and between quarks but this...

Hello everyone. I'm not a physicist however have been doing some research on the concepts behind dark energy and string theory and it has presented me with a question: Is it possible that dark matter could be the components of quarks that haven't pulled together to form the quarks. We can't...

So, I was brushing my teeth and started thinking about pi and how it is irrational. One thing led to another and I remembered Atom, by Asimov (which I haven't yet finished). Now, assuming pi is irrational, if we have a wheel with a radius of 1/2 (units don't really matter), and unroll it so that...

In the early universe the quarks where moving freely. So I am wondering how did the quarks enter the protons and neutrons shell/wall after the temperature where ok for it to happen? Or, how did the protons and neutrons encapsulate the quarks?

As we know that a proton and a neutron is comes from an interaction of three quarks that inside of it.:rolleyes: I think about 1. "Can we separated them from a proton or a neutron?" 2. "What will be happen if we can do that?" 3. "Is it will result a big explosion like nuclear fusion/fission?"

The quarks in neutrons have opposide charges and therefore they should attract, but why don't they just fall into each other. Is it the Heisenberg principle or degeneracy pressure?

Hi everyone, I'm new to PhysicsForums. I don't really know if what I have to offer is anything new to anyone or if it is simply meaningless numerological garbage, but it just looked too beautiful for me to ignore, and if this is common knowledge, then I humbly apologize. I did a search on this...

Martin Rees in his book Just Six Numbers says that in the early universe there 1 billion antiquarks and a billion and one quarks. Is that really known? How is known what the ratio of antiquarks to quarks was?

Hello. One basic question. What properites that quarks have which their "compound" forms [protons/neutrons] don't have and vice-versa? That is, a proton may have some property or characteristic and the quarks might not be having that. So something which is NOT available at the components...

Hello. > Is there any electromagnetic force of repulsion between two quarks? > And, hypothetically speaking [as independent quarks are not observable], could there be EMF of attraction between an electron and an independent quark? Actually, both the questions boil down to the following -...

Please teach me this: I wonder whether there exist only quarks(6 quarks) and leptons being really elementary particles. Or there are many another types of particles? Thank you in advance.

My understanding of colour so far is that if we had, say, a baryon with quark content uuu, we would need to invoke a new quantum number that would allow each quark not to be in the same quantum state to avoid violating the Pauli principle. Now apparently this new quantum number is called colour...

Quarks transform in the fundamental representation under SU(3), gluons in the adjoint represention under SU(3), leaving the theory (QCD) invariant. But how can I find out how quarks transform under SO(3)? I know how to decompose a Lorentz tensor under SO(3), like a four-vector or EM field...

Why is it that the binding energy creates mass in the case of quarks but depletes mass in the case of protons and neutrons? Am i mistaken?

I don't know much about quarks but if a proton is uud and a neutron is udd, is the (mass of a neutron)-(mass of proton)=mass of a down quark?

I was searching for a "upness" over the internet and found nothing but what hints of up and down quarks having quantum number conservation is this isospin thing, which I haven't learnt. May I ask if there is an "upness" or "downness"? i.e number of up quarks - number of antiup quarks for...

hi, how do you calculate the classical radius of nucleons or quarks? do you include only the electrostatic potential energy or also some nuclear potential energy?. i have read many times that the classical radius of nucleons is lower than the classical radius of the electron, is it right...

The ATLAS experiment has recently sent two papers for publication. Both look for evidence of quark substructure, in two different ways. http://arxiv.org/abs/1008.2461" , submitted to Physical Review Letters, looks for an excited quark, and does not see any evidence of one. Based on that...

Hi guys, If I have a \Sigma triplet of baryons, how do I calculate the EM and gravitational binding energy of these baryons? (assuming there is 1fm of distance between quarks and that each quark has 1/3 the mass of the \Sigma), I guess I have to use the EM and Gravitational Potential...

Forces between 2 down quarks...could someone please help me : ) Hi I am going slightly insane with this question I have! "A neutron contains two down quarks at a separation of approximately 10^−15 m. Calculate the strength in Newtons of the electrical force between two down quarks at a...

Since everything is made of quarks and electrons, why use the word "life"? Everything is just physics including "life" so why not present it that way? It's all interacting particles, some interactions are just more complex than others. Why categorize things as living or non-living? What does it...

I understand that they 'jitter'. Do they spin around one another or have some sort of 'orbit' in respect to each another? Is it chaotic? Do they actually touch one another?

Up quarks are half the mass of bottom quarks, while Charm quarks are ten times heavier than strange quarks, and top quarks are 40 times heavier than bottom. Why do the relative masses of the particles change? I had always that that they were just higher energy versions of the same...

I recently noticed that the density of an electron, assuming it is a particle, was e21 gm cm3. This is e7 x more than a neutron star 2 x e14. I then looked up quarks. The up quark is the most dense (mass = 9 x e-27 gms, radius .5 x e-17 cm) with a density e5 x the electron or 1.7 x e25. Thus, a...

Problems with fundamental particles and quarks :( Hi, I have no idea where to post this so I hope its ok... I'm studying A level physics. We have a topic on fundamental particles. Yea couple of questions... 1. Whats the difference between a (insert lepton here)-neutrino, and its...

Im trying to understand parity in the Standard Model. Ive read that quarks have positive parity. However I thought that the reason electrons have negative parity is because of the a symmetry of their wave functions, and this is what defines them as fermions. Quarks are fermions as well as I...

1) In non-mathmatical terms, please correct my description of vitual particles... a) virtual particles are real but too small to be observed directly. i.e. their dimensions are within Plank's values and subject to Heisenberg's uncertainty principles. b) virtual particles are real...

I have not had any luck in finding out how much is known about the actual positions of quarks in protons and neutrons. I am confused by the brief snippets of information I have managed to find. First by the fact that an electron is fired at a nucleon and that its path can reveal the prescence...

Hi I'm referring to the book Quarks and Leptons (Halzen, Martin). On pages 79-82 nonrelativistic perturbation theory is investigated (i.e. by using the Schroedinger equation, which is first order in time). On Page 85, however, the transition amplitude (T_fi) is used that has been derived on...

Hello; What is colour? Is it like the charge between quarks? I can't conceptually understand it, probably because of the wording. Thanks.

In e+e- annihilation, are the jets that are produced quarks and gluons, or hadrons? What is the basic idea behind a QCD calculation for such a process? For example, do I take the two initial states to be e+e-, and the two final states to be q+q- (quark and antiquark), but also add the...

in string theory is it that each quark of an atom has one string or is it made up of millions? i know this is a kinda silly question

I know that particle accelerators have created and observed top quarks. Also, that they have measured their mass. However, I do not find if we have detected their size (or even attempted to detect their diameter, it would be hard to because they decay so quickly). I find it interesting that a...

I am aware that there is strong evidence for the presence of quarks inside of protons and neutrons through the analysis of deep inelastic scattering experiments. The questions I have specifically relate to the data which supports the composition of the neutron versus the proton, how we have...

Homework Statement The ∑+ particle is a baryon with strangeness -1. How many quarks does the ∑+ particle contain?Homework Equations How many of the quarks are strange? The Attempt at a Solution I know it contains 3 quarks, 2 ups and 1 strange quark but I'm not sure how to work this out, for...

If you model the quarks as massless, there should be no flavor mixing, because flavor mixing is achieved through the CKM matrix, which is a mass matrix. However, if quarks are massless, there ought to be an axial flavor symmetry, but there isn't. So to reconcile this, we must spontaneously...

Having discovered up, down, strange, charm and bottom quarks, why did scientists undertake similar experiments using higher and higher energies?

Does anybody know how quarks are formed? and why they always in fraction numbers like 1/3, 2/3. Since charge are always quantized. does this mean quarks are not quantized.?.

Hi, I am currently a student, still grasping some basic concepts of quantum mechanics. I've been reading some books, and the model on quarks intrigue me. There's something I'll like to clarify though. Mass Up Quark - 1.5 to 3.3 MeV/c2 Down Quark - 3.5 to 6.0 MeV/c2 Electron - 0.511...

What kind of limitations are there for trying to split up the quarks from their binding formation?

Homework Statement Describe the use of quarks in chemistry. Homework Equations N/A (I think?) The Attempt at a Solution I've tried searching, and can find plenty of information on what the quark is, but I can't find a thing on how it is used. I searched google, google scholars...

Homework Statement What are jets, and how do they provide evidence for quarks. Homework Equations The Attempt at a Solution High energy collisions between hadron can cause quarks within hadrons to fly apart from each other at high energies. Before being observed as quarks, these...

1-electron scattering 2-collider data 3- ? is there anything else which supports the quark model or is it just those 2. from what I've read so far its just those 2 but could be incorrect so correct me if my primative understandings off THANKS