Quarks Definition and 253 Threads

https://en.wikipedia.org/wiki/James_Bjorken Remembering theoretical physicist James D. “BJ” Bjorken, 90, who played a crucial role in discovering quarks https://www6.slac.stanford.edu/news/2024-08-14-remembering-theoretical-physicist-james-d-bj-bjorken-90-who-played-crucial-role...

The strong nuclear force keeps the protons together. The larger the number of protons, the larger the nucleus, but the weaker the bonds between the protons as the radius of the nucleus increases and more unstable is the element. However, since the strong nuclear force originates from within each...

This question was not my idea. I heard it while watching a YouTube video hosted by a celebrity astrophysicist and a comedian. This astrophysicist answers the physics questions of his Patreon supporters, and one of the supporters asked him about the spaghettification of quarks. I'm paraphrasing...

How much force will it required to pull a quark out of a proton, and how much for to pull a proton out of a atom ?

If we say that a proton has a kinetic energy of ##50## GeV, can we say that each of the three quarks that compose it have roughly a mean energy of ##\approx\frac{50}{3}=17## GeV? If not, what can we say about the energy of each individual quark inside a baryon with a known energy?

Instead of electron transistors why not go smaller particles like quarks?

Mass behaves opposite that of other quantum numbers when combining matter (quarks) and antimatter. Why?

Isospin must be transformable if it is the case. In which case there must be additional Bosons for doing the transformation.

I think there are so far as we can tell particles of mass that are made up of quarks and leptons (electrons and what not). So far as we know those the fundamental particles of matter. Question - how hard have we banged on quarks/leptons to see if we can blow those up into smaller units? I...

I understand how the existence of quarks is inferred from the three particle-emitting cones or jets and by the quarks’ ability to deflect particles passing through the composite particle, but I don’t see how the existence of gluons is conclusively demonstrated by this rather than just being an...

Homework Statement:: I came across the following in an online article. I am unable to understand how these elementary particles cause a force to exist. "Each of the four forces results from the exchange of force-carrier particles.". Above statement is taken from...

Hello everyone, I know that if two of the quarks (e.g. strange & bottom) had coinciding masses, there would be no CP-violation in the standard model. Apparently the reason lies in the parameters of the CKM-matrix, but I don't understand how to show that. Can someone explain?

Would baryons not made with standard Up or Down quarks exhibit smaller radii than neutrons and protons? I'm thinking like for example how muons have much smaller orbitals than electrons, on the lepton side of things.

Hello, from what I understood at the very beginning of the universe, the universe was too dense and too hot to allow matter (atoms) to exist, so at the very beginning, the universe was a kind of soup of quarks (components of protons and neutrons). What I was wondering is how quarks appeared in...

The experimentally measured properties of protons and neutrons are known with exquisite detail. Our data is not quite as extremely precise, but still very good more other baryons and mesons with light quarks (u, d, and s) as valence quarks, such as pions and kaons. Yet, on a percentage basis...

"M. Shupe [Phys. Lett. 86B, 87 (1979)] has proposed that all quarks and leptons are composed of two even more elementary constituents:" (Griffiths) I am redoing the book of elementary particles from Griffths, and this exercise has showed really interesting to me. How is the currently status of...

Can someone please explain the four classes of fundamental particles? (Just the basics) I came here because I never learned any chem or physics in school so please explain like I’m five :)

I would like to ask scientists or anybody: what do you think about qwarks, do you consider them to be the littiest parts of matter or that matter is cyclically or infinitaly smalling, like numbers, or that there are some smaller parts, which have not been observed, but they have an end in their...

Is it possible - perhaps in a different universe with different physical constant and vacuum energy - that atoms can be formed from strange/charm or top/bottom quarks?

The proton and neutron are composed of up and down quarks. What is made up of all the rest quarks?

Most articles said electrons, quarks and gluons are indivisible thus have no compositions unlike the other particles. So, does that means electrons, quarks and gluons are composed of nothing and these elementary particles are indeed 100% void?

I study physics on my own and just ended up Griffiths' book on Quantum Mechanics. Is this level of QM enough to be able to study Halzen and Martin's Quarks and Leptons book on particle physics? I planned on studying it while studying Sakurai QM, but I just wanted to be sure that I could at least...

I have some difficulties interpreting an exercise. It states that the dibaryon H is made of uuddss, with total spin zero, and relative angular momentum 0 as well. It then proceeds to use that the spin of every pair of particles uu, dd, and ss is equal to 1. Why is that the case? It seems obvious...

So various articles and videos suggest that if a piece of strange matter, or a strangelet, were to touch the Earth, the entire Earth would eventually get converted into strange matter too. Now, from what I've read strange quarks have a half-life of ##10^{-10}## s, so I can't see how it would...

Hello! I haven't really seen a feynman diagram with a higgs boson decaying to a top-anti top quark pair. The mass of a top pair is much higher than the Higgs mass on shell, but is there any reason why we can't have a Higgs boson (very) off-shell decay to 2 top quarks. The probability of that...

At high energies, quarks behave like single particles, due to the asymptotic freedom in QCD. Have we observed these free quarks yet in experiment? Does the freedom energy match the theoretical models?

hello, in the model of quarks, each of them is described by a flavor, but the quantum number for the first generation of quarks is the same (the isospin) for the up (1/2) and down (-1/2) quark. For the other generation though it is a distinct number (s,charm,...) for each quark. From what I...

quantum field physics gives us real good understanding different kinds of forces. i got interested in this topic when i was reading a textbook . and i found interesting how for quantum chromodynamics there are eight types of quarks and all have different effects. but in the book it was not...

Hi, I have been taught that quarks don't exist individually on their own, as they has with be with at least another antiquark to form a colorless state. But in the quark-gluon plasma, do we have individual quarks in a color state or do they still, somehow, are in a color-neutral state? Thanks!

If an up quark has 2/3 of positive charge and down quark has 1/3 of negative charge then why don't they add together by their electromagnetic force?

If Quarks and Antiquarks are bound together and don't appear individually why does baryon have 3 quarks but no antiquarks? Again apologies if this is obvious and or novice. Thanks Anthony

Hello! In Modern Particle Physics by Mark Thomson, in the Electroweak Unification chapter, pg. 412 he talks about the branching ration of the W decay to quarks. And for this he includes both the ##W\to q \bar{q'}## and ##W\to q \bar{q'}g## i.e. the state with a gluon and 2 quarks in the final...

I have already known the cross sections can be presented like this. σ（e+e- -> hadrons）∝ Σ eq^2 & σ(e+e- -> μ+μ- ) ∝ e^2, where eq is the charge of a certain quark(u, d, s, c or b) But I don't know the relationship between Nc and eq. (This is my first time to post a thread. I don't know how to...

Summary: If 5 of the quarks can eventually decay into the up (plus other stuff), why are they still considered fundamental? I can't decide if I'm just misinterpreting the word fundamental in this particular usage or if there is something about the non-up quarks that makes them fundamental even...

In this CERN video quarks are represented as spheres. Is this how quarks look like. I thought they were fluctuations in the quantum field.

Hi guys, Merry Christmas to you all! I wanted to know whether a neutral pion can be made up of a strange quark and an anti-strange quark. I know that the kaon is the only strange meson and all variations contain an s quark but wouldn't the strangeness be zero in an s quark/anti-s quark pair as...

If all three quarks in a baryon have the same flavor, they all spin the same direction, causing the baryon to have 3/2 spin. In a proton, do both up-quarks spin in the same direction (with the down-quark spinning opposite)? Or can the two up-quarks spin in opposite directions?

Moderator's note: this thread is a spin-off from https://www.physicsforums.com/threads/self-interference-in-double-slit-experiments.952744/ According to nonperturbative QCD, quarks and gluons don't exist and in nonperturbative QED with two spinors (e.g. proton and electron) hydrogen isn't...

Im carefully studying Deep Inelastic Scattering and I have the doubt if valence quarks are real physical entities or if they are just a way we can think hadrons are built. I understand that inside hadron we have the Parton Distribution Functions that say that there are an infinite number of...

https://phys.org/news/2018-08-long-sought-higgs-boson.html

Are strongly interacting dark matter quarks displaced by visible matter? Chiral Gravitational Waves and Baryon Superfluid Dark Matter We develop a unified model of darkgenesis and baryogenesis involving strongly interacting dark quarks

I have been trying to understand some of the basic differences in the fundamental nature of leptons and quarks. One article on this issue compares leptons and quarks as "oranges vs apples" to which I basically agree except for one aspect. How can the charges of the quarks be 1/3 or 2/3 the...

I understand there are three generations of quarks, which have the same charge but different mass. My question is, in a single generation how many different kinds of quarks are there. For example, in the first generation there are the up quark and down quark, each of which has an antiquark. So...

I've heard that the weak nuclear force is stronger than the electromagnetic force at distances of 10^-18 m. I've also heard that the strong force becomes repulsive at a distance of 0.7 fm. So if two quarks got to a distance of <<10^-18 m which force would win, the strong force or the weak force?

Okay, I've been seeing the following story circulating around various websites. I get the feeling that it's a scam, but I don't want to prejudge it. So I thought I'd ask the various experts about what they think of it...

In the electromagnetic interaction, opposite electric charges q attract each other. In the strong nuclear force, the proton p(uud) is attracted to p(uud) and the neutron n(udd), and n(udd) is attracted to p(uud) and n(udd). Both neutrons and protons have a hypercharge Y=+1, and 3rd...

Can a W Boson convert an up quark into a down quark of the same generation? Where can I find a resource to understand what all the possibilities are for an up quark converting into other quarks of same or other generations?

I am using a program that requires the energy of the up quark and down quark be given in Joules. I tried to find these values on the internet but could not find these values. Can someone please tell me what is the energy of the Up and Down Quark in Joules?

As far as I know there are Mesons (quark-Antiquark pair) and Baryons (three quarks). But are there Hadrons which contain more than 3 Quarks?