Quarks Definition and 253 Threads

I have searched the Internet and I have not found a simple layman's explanation other than this. We observe their decay products of quarks and that is what the mass is reconstructed from. Is this correct? If so I would like to have that confirmed. I am just looking for a simple direct...

so, I was told that only Up and Down are stable Quarks in the nucleus, and the others are only explained by observations in particular decay.

Everything in the universe that has a beginning seems to also have an end. Stars, galaxies, molecules, atoms. But what about elementary particles? In case of heat death would it become a uniform quark soup?

Do we actually know for sure that quarks and leptons are as small as it gets, the complete fundamental particles? If so, how?

In many-body theory for electronic structure, fermions experience a force resulting from Pauli Exclusion. So by extension, would quarks and other subatomic fermions experience this force? If so, what is the "high energy" physics side of the story to forces arising from exchange rules? Is it a...

I am wondering if anyone has determined by experiment or calculation at what rate or even better what frequency the quarks move around at inside a neutron and proton? Do neutrons or protons vibrate at a specific frequency.

Homework Statement I am given the following interaction, $$\pi^-+p\rightarrow \pi^++\pi^-+n,$$ and asked to draw the Feynman (quark flow diagram). Homework Equations None; just baryon number conservation, quark flavor conservation, etc. The Attempt at a Solution First, as baryon number and...

Is this some sort of issue with color or another quantity that needs to be conserved?

Hi everyone, I have the following question When a positive pion interacts with a proton, a kaon can be produced, along with another strange particle, as shown in this equation \pi^++\textrm{P}\longrightarrow \textrm{K}^++\textrm{X} Circle the type of interaction shown...

To what extent are Feynman's parton model and Gell-man's quark model similar?

Quarks in a Mole If I have one mole of hydrogen, I only have Up and Down Quarks, right? If I have one mole of Plutonium, I should have all the Quarks, right? Where on the Periodic Chart do all the Quarks start showing up?

Hello! Could anybody help me? My wondering seems so trivial, but I can't skip it. They say that since u and d quarks are much lighter than QCD scale(~200MeV), in reality we can consider the QCD Lagrangian has an approximate global chiral symmetry with respect to these two flavors. At first, it...

The pole masses of the heavy quarks (c, b and t) are relatively well defined in QCD (i.e. the solution of m²(p²) = p² extrapolated using the beta function and the available data from other values of µ usually obtained based upon model dependent decompositions of hadron masses that include these...

When protons, due to their electric charge, interact with photons are the quarks somehow also involved in this same electric interaction? After all, the quarks do have fractional electric charges. Thanks in advance.

Hi, guys. This is actually a question about quantum mechanics, but since the context in which it appeared is particle physics, I'll post it here. On Thompson's book (page 227, equation (9.32)), we have $$T_+ |d\bar{u}\rangle = |u\bar{u}\rangle - |d\bar{d}\rangle$$ But I thought...

Hello, guys. I have not understood what it means when one writes ##\pi^+=u\bar{d}##, for example. I though it simply meant that the ##\pi^+## meson was composed of one up-quark and one anti-down-quark. However, that doesn't explain what writing ##\pi^0=\frac{1}{\sqrt{2}}(d\bar{d}-u\bar{u})##...

So I'm wonder How does the annihilation occur? Does the quarks pair up like magnets for matter and antimatter? Do matter and antimatter have the same quarks?

Hi. I'm wondering if anyone has any info on "quark seeding" like: Is it possible to dope the crystal lattice of a solid material by replacing electrons with quarks ?

Homework Statement This is not a homework question, I'm asking it here to avoid being shot down elsewhere. Are quarks tightly bound to each nucleon? Is the nucleus just a bunch of anonymous quarks held together by the strong nuclear force, or is each proton and neutron separate? When...

A kaon is a type of quark right? Is a way of thinking about it similar to the way a cell becomes specialized: a Kaon would be like a specialized quark?

i can't seem to get a handle on this...help :)

I know that quarks can never exist in isolation, and also group up so that they have a net neutral colour charge. But I am wondering at the start of the universe, or under very, very extreme conditions (such as the start of the universe) would quarks have been able to exist by themselves. I have...

So during a particle physics lecture, the lecturer used Heisenberg's uncertainty principle to set a lower limit on the KE of the quarks bound in a proton (given the mass,size of proton and the mass of u/d quarks), which is of the order of 100 MeV, while the mass of quarks is about several...

Hello, everybody. I have a question that is really confusing me: how can they find charm, strange, top, and bottom quarks? They are in the 2nd and 3rd generations, so they are more unstable than the first generation up and down quarks, and unlike them, they are not found in protons or neutrons...

Quarks join up with other quarks to form composite particles like protons and neutrons, but in the center of something like a nucleus, how do they know which quarks are in THEIR proton or neutron? When all the quarks are together and it becomes a "soup" of quarks, why doesn't it form things like...

Because of the enormous mass of top quarks, they decay before hadronizing. But this doesn't explain why the top quarks are only quarks can be observed as bare quarks. If you look into any unhadronized quark in the time interval in the order of 10^-25 seconds, you must be able to observe it as a...

Homework Statement Two quarks of the same mass m, interact via the confining potential V=kr -Use the Bohr model to find V,R,E of the bound system -Determine the angular frequency of the emitted radiation by transition from n => w (??) -For mc^2 = 2 Gev and K = .5GeV per ?? what are the values...

So, I have a question, and maybe we don't have an answer, or maybe it's a simple answer. I was thinking, and if we have a pentaquark, I'm pretty sure we have to have a quark-antiquark pair (of any color-anticolor) and 3 quarks (one of each color). If, per say, the quark and antiquark were...

I've been trying to find a source for this somewhere, but I always end up with different sources explaining what holds protons and neutrons together in the nucleus of an atom. I know that the gluons hold them together, but I'm not sure exactly how they do this, and what type of transfers occur...

I know that all the quark names have a meaning and that the strange quark was named "strange quark" because it had strange properties.What are those strange properties the strange quark possess?

I am a junior in high school and after I spent some time studying quarks and antiquarks, I continue to raise more questions about their relationship to other fundamental quantities. I tried searching the internet for answers but the posts I've been reading only raised more questions for me. Are...

I read some time ago there are many more as 3 quarks in proton but lot of publications mention only 3 quarks! Where is the truth?

Please be esy on me for asking what seems a very silly question but i have only just started reading about this sort of thing very recently. I can only learn by asking so please bear with me. thanks My question is, how do we know when we have found a new particle, for example when physicists...

Is there a simple explanation for why up & down quarks have different charge?

Hi there, so my question is as follows. I understand that only the weak interaction can change the flavour of a quark, but why? Idea 1: It's due to the change in flavour also meaning a change in mass, thus a massive exchange particle is needed (gravity is negligible so forget the massive...

I need to write a conclusion for a presentation I'm doing on "Seeing the infinitely small" (translation from french), which is basically about microscopes and the LHC, how to observe the different levels of small and all that... What can I write to answer, "why are we trying to observe the...

Are quarks really considered fundamental particles that cannot be divided further? If an up quark can transmute to a down quark and release a W+ boson which decays to a positron and a neutrino (for example) - doesn't this mean that there is substructure to a quark? What exactly is it that makes...

If susy really exist in nature, why does it not exist between leptons or quarks and gauge bosons such as photons, weak currents or gluons in the standard model?

I was reading my book and it states that the lack of anti-symmetry in the total wave function of the Δ++ particle led to the introduction of the missing degree of freedom, or color. It states that free particles are colorless so they must be in color singlet states. From there, it just lists the...

I have seen in many places, for example here, the statement that the proton consists of valence quarks and sea quarks. I am somewhat confused as to where this picture comes from. The sea quarks are virtual quark-antiquark pairs. I have encountered virtual particles only in the context of...

Hello all, I'm trying to answer a question about a meson and a proton interacting to form a neutron and an unknown meson- to be determined. The equation is : (Anti up and strange) + (uud) --> udd + (xy) I arrived at strange and anti down OR anti strange and down. Are both possibilities...

Homework Statement (a) Find energy of incoming beam that creates highest cross section (b) What are the differences in the two reactions, using quark diagrams? (c) What would the peaks of the two reactions be like? Homework EquationsThe Attempt at a Solution Part(a) [/B] Cross section is...

Hi. I was reading an introductory book about particle physics and I visited the PDG for an exercise. I found this... http://pdg.lbl.gov/2014/tables/rpp2014-tab-mesons-strange.pdf On page 9, the data of K1(1270) is given. How do I figure out it's quark content? If I look at the data for K*(892)...

I have done large amounts of research and could not find any books, sites or forums of how the strange matter in strange stars is formed. I know that the process of the formation of the strange star carries out mostly like the collapse into neutron stars and quark stars but how do these strange...

If I toss a single, composite particle toward a gravitational singularity, would the quarks inside it be tidally rip apart from their confinement with enough energy to create another pair of quarks? And if so, how many times can that process happen before space gets small enough so that...

Dirac gave an argument once upon a time showing that quantization of angular momentum together with the presumed existence of a magnetic monopole implies quantization of charge. If there is, anywhere in the universe, a magnetic monopole of magnetic charge Q_m, then the only possible values for...

In a recent online lecture it was said there is now known releationship between the masses of quarks. My online search seemed to back this up. My comparison suggests: [SIZE="3"]Mcharm ≈ Mtop * fine Mup ≈ Mcharm * fine / 4 Mstrange ≈ Mbottom * fine * 3 Mdown ≈ Mstrange * fine * 7...

Hi Based on what I know (it might be wrong) properties of nuclei are calculated based on the different (simplified) models of the p and n "particles" (shells, droplets etc). I have 2 questions: 1. To what extent can we assume that n and p are "elementary" particles bound by residual strong...

I am looking at the structure of protons, and in my script, when they define the Parton Distribution Functions of all parton species they say that the integral over PDFs of all parton species yields a total momentum fraction of: \sum_i \int_{0}^{1} f_{i}(x) x dx =1 where i denots the...

well, what are they? do they exist?