Difference between revisions of "Quark"
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==Key Stage 5== | ==Key Stage 5== | ||
===Meaning=== | ===Meaning=== | ||
− | '''Quarks''' are a type of [[fermion]] and are the constituent parts of [[hadron]]s. | + | '''Quarks''' ('''q''') are a type of [[fermion]] and are the constituent parts of [[hadron]]s. |
===About Quarks=== | ===About Quarks=== |
Revision as of 17:42, 18 July 2019
Key Stage 5
Meaning
Quarks (q) are a type of fermion and are the constituent parts of hadrons.
About Quarks
- Quarks are believed to be fundamental particles but they have never been observed on their own.
- Quarks always exist as part of hadron including a baryon, which is a triplet of quarks or a meson which is a quark-antiquark pair.
- There are 6 types of quark including:
- Up-quark - With a charge of \(+\frac{2}{3}\)e, two of which are found in proton and one of which is found in a neutron.
- Down-quark - With a charge of \(-\frac{1}{3}\)e, two of which are found in a neutron and one of which is found in a proton.
- Strange-quark - With a charge of \(-\frac{1}{3}\)e which decays quickly via the weak interaction into a down-quark.
- Top-quark - With a charge of \(+\frac{2}{3}\)e which decays quickly via the weak interaction.
- Bottom-quark - With a charge of \(-\frac{1}{3}\)e which decays quickly via the weak interaction.
- Charm-quark - With a charge of \(+\frac{2}{3}\)e which decays quickly via the weak interaction.
Conserved Quantities
Quark | Charge/e | Strangeness | Baryon Number | Lepton Number |
\(q=+\frac{2}{3}\) | \(S=0\) | \(b=+\frac{1}{3}\) | \(l=0\) | |
\(q=-\frac{1}{3}\) | \(S=0\) | \(b=+\frac{1}{3}\) | \(l=0\) | |
\(q=-\frac{1}{3}\) | \(S=-1\) | \(b=+\frac{1}{3}\) | \(l=0\) | |
\(q=+\frac{2}{3}\) | \(S=0\) | \(b=+\frac{1}{3}\) | \(l=0\) | |
\(q=-\frac{1}{3}\) | \(S=0\) | \(b=+\frac{1}{3}\) | \(l=0\) | |
\(q=+\frac{2}{3}\) | \(S=0\) | \(b=+\frac{1}{3}\) | \(l=0\) |
Antiquark | Charge/e | Strangeness | Baryon Number | Lepton Number |
\(q=-\frac{2}{3}\) | \(S=0\) | \(b=-\frac{1}{3}\) | \(l=0\) | |
\(q=+\frac{1}{3}\) | \(S=0\) | \(b=-\frac{1}{3}\) | \(l=0\) | |
\(q=+\frac{1}{3}\) | \(S=+1\) | \(b=-\frac{1}{3}\) | \(l=0\) | |
\(q=-\frac{2}{3}\) | \(S=0\) | \(b=-\frac{1}{3}\) | \(l=0\) | |
\(q=+\frac{1}{3}\) | \(S=0\) | \(b=-\frac{1}{3}\) | \(l=0\) | |
\(q=-\frac{2}{3}\) | \(S=0\) | \(b=-\frac{1}{3}\) | \(l=0\) |