A quark () is a type of elementary particle and a fundamental constituent of matter. Quarks combine to form composite particles called hadrons, the most stable of which are protons and neutrons, the components of atomic nuclei. All commonly observable matter is composed of up quarks, down quarks and electrons. Owing to a phenomenon known as color confinement, quarks are never found in isolation; they can be found only within hadrons, which include baryons (such as protons and neutrons) and mesons, or in quark–gluon plasmas. For this reason, much of what is known about quarks has been drawn from observations of hadrons.
Quarks have various intrinsic properties, including electric charge, mass, color charge, and spin. They are the only elementary particles in the Standard Model of particle physics to experience all four fundamental interactions, also known as fundamental forces (electromagnetism, gravitation, strong interaction, and weak interaction), as well as the only known particles whose electric charges are not integer multiples of the elementary charge.
There are six types, known as flavors, of quarks: up, down, charm, strange, top, and bottom. Up and down quarks have the lowest masses of all quarks. The heavier quarks rapidly change into up and down quarks through a process of particle decay: the transformation from a higher mass state to a lower mass state. Because of this, up and down quarks are generally stable and the most common in the universe, whereas strange, charm, bottom, and top quarks can only be produced in high energy collisions (such as those involving cosmic rays and in particle accelerators). For every quark flavor there is a corresponding type of antiparticle, known as an antiquark, that differs from the quark only in that some of its properties (such as the electric charge) have equal magnitude but opposite sign.
The quark model was independently proposed by physicists Murray Gell-Mann and George Zweig in 1964. Quarks were introduced as parts of an ordering scheme for hadrons, and there was little evidence for their physical existence until deep inelastic scattering experiments at the Stanford Linear Accelerator Center in 1968. Accelerator experiments have provided evidence for all six flavors. The top quark, first observed at Fermilab in 1995, was the last to be discovered.
I red the book halliday resnick I come to know
protons and other such elementry particles are composed of further subparticles called quarks
also that these quarks decide rather its proton or antiproton
as if the arrangement of quarks are like 2up quarks up and 1down quark down then...
We say on-shell and off-shell mass of quarks. 1) What is the difference on-shell and off-shell mass of quarks. 2) At lab. center of mass frame for lepton particles p2= -m2. Can we apply this equation for quarks.
Thank you!
Since Colour Force is Strong Interaction, is there a equation to calculate Strong Interaction or express it mathematically? The closest I came to is the Coupling Constant but it doesn't provide a equation for Colour Force.
I was also looking at the Gluon Field Strength Tensor, is this related...
I read recently, that by separating two quarks, once a high enough energy has been introduced, new quark pairs will form. This sounds to me like a meson, being turned into two mesons. I don't know how clear I am on this, but I was wondering... Is the same true for Baryons. If we magically...
Hi people, I've read some articles about the calculation of mass spectrum. But I'm not clear with this concept. Can we calculate theoretically the mass of quarks. If yes, how? because we never see an isolate quark. Off curse experimentally we can. And my second question is about the mass of...
Ok so I want to preface my question with the fact that I'm not trying to present a crackpot theory, I obviously have a flaw in my logic I just need a little correcting.
So I was reading about gluons and read that they had to have a mass to allow the strong force to have a limiting range. So...
electromagnetism -- interaction between the electron and the quarks
Which theory explains the electromagnetic interaction between the electron and the quarks within a hydrogen atom ? Is it QED or should I look at Standard Model ?
similar to the rough picture of how BHs radiate if I put a proton next to a BH can one of the quarks be absorbed into the BH and the other two escape?
I don't really understand confinement very well but does the confinement picture change next to BH horizon?
As a result of some precise experimental data, we now know that the mass of the quark is not naively 1/3 the mass of the proton. The most recent estimates for the mass of the quark is:
Masses of the current quarks:
= 2 - 8 MeV/c2 = 1.0 - 1.6 GeV/c2 = 168 - 192 GeV/c2...
Centuries ago, Greek philosophers (such as Democritus) postulated that atoms were the fundamental building blocks of matter. Then, in the 1900s Rutherford along with others discovered that atoms consisted of electrons surrounding a nucleus made up of protons and neutrons. With the technological...
In the traditional Standard Model, Why right handed quarks can have mass And there can't be any right handed neutrino? Wikipedia says that it damages renormalizability, but why does that not happen with the corresponding quarks?
In other words, why did you invent the see saw mechanism for...
This might sound like a totally dumb question but anyway:
QCD lagrangian in the limit of mu=md has flavor SU(2) symmetry with respect these two quarks. And we say that these quarks' wave functions are eigenstates of I and Iz. The question is why?
Thanks.
Quark Model of the Neutron According to the quark model of fundamental particles, neutrons-the neutral particles in an atom's nucleus-are composed of three quarks. Two of these quarks are "down" quarks, each with a charge of ; the third quark is an "up" quark, with a charge of . This gives the...
This comes form the wiki article on quarks:
Does that mean that when two Quarks come as close to each other as the Planck distance 10-33m then gravity must be taken account if one is to understand their movement?
I know vaguely that the Planck energy is the point at which a black hole...
I have not yet studied experimental physics!But I would like to know how can we measure the mass of quark,because we can not to have separate quark for color confinement.In quarkonium,by resonance we know the excited state of quarkonium,but how can we know which state they lie(e.g 2^{3}S).
A usual lore from chiral perturbation theory is that the mass of the pion is proportional to the sum of the up and down masses, and then it is going to be zero when such masses are zero.
Now, for the proton, I notice the following remark from Chris Quigg
Why is it different of the pion?
Feynman diagrams from "Quarks and Leptons" Halzen and Martin?
The following scan is from Quarks and Leptons: An Introductory Course in Modern Particle Physics, Francis Halzen (Author), Alan D. Martin (Author), page 9. Can I take anything from the topological difference between figure (b) and...
Hey guys,
Do the quarks determine the element? If I have a atom that has let's say 5 neutrons and 5 protons, and then all of a sudden one of the quarks changes from a down quark to a up quark, this will then change the ratio/amount of protons and neutrons thus changing the element?
What...
Im aware of quark antiquark annihilation in a proton and have heard one opinon but want another. Do all the quarks get annihilated and just the number remain 3 remain constant in the proton or are the 2 up and 1 down quark the specific quarks that exist in the middle of the storm and they never...
Homework Statement
Which of these particles don't follow Pauli exclusion principle and thus have a symmetric wave function?
a) Bosons
b) Fermions
c) Quarks
d) All particles follow Pauli exclusion principle
Homework Equations
None.
The Attempt at a Solution
I think that...
Hi
I have been looking into particle physics and i came across this question but i can not find the answer,
the quetsion is as follows:
the xi particle decays into the following
\Xi -> \wedge + \Pi^{-}
dds -> sud + \overline{u}d
the quark numbers are conserved but the...
Okay, so I've just begun to have a grasp on the concepts of quantum chromodynamics. And what amazes me is that quarks never actually exist on their own as a single particle because of the strong interaction between them. I've read that when you try to pull apart a pair of quarks that is bonded...
Need Help Deciding: "From xrays to quarks" or "the unconscious quantum"
so I never would have expected myself to wind up here for most of my existence, but I recently had an epiphany on my life. I held out for awhile to see if it was just a fad my brain had gone into, but i become more and more...
You often see written that quarks cannot exist by themselves and only exist in mesons (2-quark combos) or baryons (3-quark combos). Yet you also see the top quark referred to as existing by itself. Which is right?
Here is a quote from Susskind's the Cosmic Landscape:
I'm having a very difficult time wrapping my head around this. I'm pessimistic that it can be explained how gluon's hold quarks together because in order to explain x you need to break x down into parts and as of yet we do not know of...
Can someone give me the names of all the particles that the standard model refers too
remember the first 18...
6 quarks (up- down,top-botoom,nice-paradox) x 3 colors = 18
and i also remeber the mpozons (photon,gluion,higgs,w and z ) :confused:
thank you
____________________
antonis...
Please help me understand. It seems to me that the fractional charge of a quark suggests that this is actually the smallest (most fundamental) unit of charge, and that an electron has a combined unit charge.
I have calculated that the strong repulsive force between two down quarks is 25.3N.
A book that I am reading said that the force of attraction between two quarks is 'equivalent to the weight of a ten tonne truck’, whose force is equals to 98000N. How can I compare the values of these two forces...
Do any 1/2 spin baryons exist that are made of three identical (flavored) quarks? I know the Δ-, Δ++ and Ω- have 3/2 spin. If the 1/2 spin versions of these particles can't exist, then why not?
I know that things moving closer to the speed of light will decay at slower rates, but does this include the decay of third generation quarks into second and then first generation quarks? If a third generation quark is created and in an area of the universe where things are moving extremely...
Hi,
Does anyone out there know the rules for mesons when it comes to the particle/antiparticle combinations? Is it simply like an up and anti-up quark that makes up a meson or is it like up and anti-down or down and anti-up? Or can it even be other combinations of the six quarks?
Also I have...
I heard that it had something to do with acceleration in a huge accelerator in fermi-lab but where they can collide going at speeds close to the speed of light , but how does this collision help. Or is this not the way they used?
this passage is from Paul Davies' the Last Three Minutes:
I have a very difficult time believing and understanding this. Why would two quarks being in close proximity create a black hole? A nucleus is only 3 orders of magnitude larger than a quark which i like mount everest compared to a...
Imagine a quark, which has x mass. The quark gives off a graviton, which has y energy. My question is, before the graviton "snaps" back, would the quark lose mass equivalent to y energy?
That is,
xnew = xold - y
Where
xold is the mass of the quark,
xnew is the mass of the quark after...
I have been learning some stuff off of youtube, but I did not get a full enough understanding of how quarks have colors, and anti-quarks have anti-colors and how the gluons have to be colors and anti-colors and how it all works. Some of it doesn't make any sense.
The first question is about a...
when want to illustrate messon and bayyons , we put u,d,s together;
but when talk about family we put u,d together and c,s together.
why? I am really confused!
Is it possible to flip flop a down quark to an up quark? I saw another thread on here but it didn't really provide a good answer that I was looking for. Thank you.
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...