Difference between revisions of "Quark"

Revision as of 17:52, 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 (u) - 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 (d) - 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 (s) - With a charge of \(-\frac{1}{3}\)e which decays quickly via the weak interaction into a down-quark.
Top-quark (t) - With a charge of \(+\frac{2}{3}\)e which decays quickly via the weak interaction.
Bottom-quark (b) - With a charge of \(-\frac{1}{3}\)e which decays quickly via the weak interaction.
Charm-quark (c) - With a charge of \(+\frac{2}{3}\)e which decays quickly via the weak interaction.

Conserved Quantities

Properties of the **quarks**.
Quark	Charge/e	Strangeness	Baryon Number	Lepton Number
Up-quark	\(Q=+\frac{2}{3}\)	\(S=0\)	\(B=+\frac{1}{3}\)	\(L=0\)
Down-quark	\(Q=-\frac{1}{3}\)	\(S=0\)	\(B=+\frac{1}{3}\)	\(L=0\)
Strange-quark	\(Q=-\frac{1}{3}\)	\(S=-1\)	\(B=+\frac{1}{3}\)	\(L=0\)
Top-quark	\(Q=+\frac{2}{3}\)	\(S=0\)	\(B=+\frac{1}{3}\)	\(L=0\)
Bottom-quark	\(Q=-\frac{1}{3}\)	\(S=0\)	\(B=+\frac{1}{3}\)	\(L=0\)
Charm-quark	\(Q=+\frac{2}{3}\)	\(S=0\)	\(B=+\frac{1}{3}\)	\(L=0\)

Properties of the antiquarks
Antiquark	Charge/e	Strangeness	Baryon Number	Lepton Number
Antiup-quark	\(Q=-\frac{2}{3}\)	\(S=0\)	\(B=-\frac{1}{3}\)	\(L=0\)
Antidown-quark	\(Q=+\frac{1}{3}\)	\(S=0\)	\(B=-\frac{1}{3}\)	\(L=0\)
Antistrange-quark	\(Q=+\frac{1}{3}\)	\(S=+1\)	\(B=-\frac{1}{3}\)	\(L=0\)
Antitop-quark	\(Q=-\frac{2}{3}\)	\(S=0\)	\(B=-\frac{1}{3}\)	\(L=0\)
Antibottom-quark	\(Q=+\frac{1}{3}\)	\(S=0\)	\(B=-\frac{1}{3}\)	\(L=0\)
Anticharm-quark	\(Q=-\frac{2}{3}\)	\(S=0\)	\(B=-\frac{1}{3}\)	\(L=0\)

@@ Line 25: / Line 25: @@
 | style="height:20px; width:120px; text-align:center;"|
 [[Up-quark]]
-| style="height:20px; width:120px; text-align:center;"|<math>q=+\frac{2}{3}</math>
+| style="height:20px; width:120px; text-align:center;"|<math>Q=+\frac{2}{3}</math>
 | style="height:20px; width:120px; text-align:center;"|<math>S=0</math>
 | style="height:20px; width:120px; text-align:center;"|<math>B=+\frac{1}{3}</math>
@@ Line 32: / Line 32: @@
 | style="height:20px; width:120px; text-align:center;"|
 [[Down-quark]]
-| style="height:20px; width:120px; text-align:center;"|<math>q=-\frac{1}{3}</math>
+| style="height:20px; width:120px; text-align:center;"|<math>Q=-\frac{1}{3}</math>
 | style="height:20px; width:120px; text-align:center;"|<math>S=0</math>
 | style="height:20px; width:120px; text-align:center;"|<math>B=+\frac{1}{3}</math>
@@ Line 39: / Line 39: @@
 | style="height:20px; width:120px; text-align:center;"|
 [[Strange-quark]]
-| style="height:20px; width:120px; text-align:center;"|<math>q=-\frac{1}{3}</math>
+| style="height:20px; width:120px; text-align:center;"|<math>Q=-\frac{1}{3}</math>
 | style="height:20px; width:120px; text-align:center;"|<math>S=-1</math>
 | style="height:20px; width:120px; text-align:center;"|<math>B=+\frac{1}{3}</math>
@@ Line 46: / Line 46: @@
 | style="height:20px; width:120px; text-align:center;"|
 [[Top-quark]]
-| style="height:20px; width:120px; text-align:center;"|<math>q=+\frac{2}{3}</math>
+| style="height:20px; width:120px; text-align:center;"|<math>Q=+\frac{2}{3}</math>
 | style="height:20px; width:120px; text-align:center;"|<math>S=0</math>
 | style="height:20px; width:120px; text-align:center;"|<math>B=+\frac{1}{3}</math>
@@ Line 53: / Line 53: @@
 | style="height:20px; width:120px; text-align:center;"|
 [[Bottom-quark]]
-| style="height:20px; width:120px; text-align:center;"|<math>q=-\frac{1}{3}</math>
+| style="height:20px; width:120px; text-align:center;"|<math>Q=-\frac{1}{3}</math>
 | style="height:20px; width:120px; text-align:center;"|<math>S=0</math>
 | style="height:20px; width:120px; text-align:center;"|<math>B=+\frac{1}{3}</math>
@@ Line 60: / Line 60: @@
 | style="height:20px; width:120px; text-align:center;"|
 [[Charm-quark]]
-| style="height:20px; width:120px; text-align:center;"|<math>q=+\frac{2}{3}</math>
+| style="height:20px; width:120px; text-align:center;"|<math>Q=+\frac{2}{3}</math>
 | style="height:20px; width:120px; text-align:center;"|<math>S=0</math>
 | style="height:20px; width:120px; text-align:center;"|<math>B=+\frac{1}{3}</math>
@@ Line 76: / Line 76: @@
 | style="height:20px; width:120px; text-align:center;"|
 [[Antiup-quark]]
-| style="height:20px; width:120px; text-align:center;"|<math>q=-\frac{2}{3}</math>
+| style="height:20px; width:120px; text-align:center;"|<math>Q=-\frac{2}{3}</math>
 | style="height:20px; width:120px; text-align:center;"|<math>S=0</math>
 | style="height:20px; width:120px; text-align:center;"|<math>B=-\frac{1}{3}</math>
@@ Line 83: / Line 83: @@
 | style="height:20px; width:120px; text-align:center;"|
 [[Antidown-quark]]
-| style="height:20px; width:120px; text-align:center;"|<math>q=+\frac{1}{3}</math>
+| style="height:20px; width:120px; text-align:center;"|<math>Q=+\frac{1}{3}</math>
 | style="height:20px; width:120px; text-align:center;"|<math>S=0</math>
 | style="height:20px; width:120px; text-align:center;"|<math>B=-\frac{1}{3}</math>
@@ Line 90: / Line 90: @@
 | style="height:20px; width:120px; text-align:center;"|
 [[Antistrange-quark]]
-| style="height:20px; width:120px; text-align:center;"|<math>q=+\frac{1}{3}</math>
+| style="height:20px; width:120px; text-align:center;"|<math>Q=+\frac{1}{3}</math>
 | style="height:20px; width:120px; text-align:center;"|<math>S=+1</math>
 | style="height:20px; width:120px; text-align:center;"|<math>B=-\frac{1}{3}</math>
@@ Line 97: / Line 97: @@
 | style="height:20px; width:120px; text-align:center;"|
 [[Antitop-quark]]
-| style="height:20px; width:120px; text-align:center;"|<math>q=-\frac{2}{3}</math>
+| style="height:20px; width:120px; text-align:center;"|<math>Q=-\frac{2}{3}</math>
 | style="height:20px; width:120px; text-align:center;"|<math>S=0</math>
 | style="height:20px; width:120px; text-align:center;"|<math>B=-\frac{1}{3}</math>
@@ Line 104: / Line 104: @@
 | style="height:20px; width:120px; text-align:center;"|
 [[Antibottom-quark]]
-| style="height:20px; width:120px; text-align:center;"|<math>q=+\frac{1}{3}</math>
+| style="height:20px; width:120px; text-align:center;"|<math>Q=+\frac{1}{3}</math>
 | style="height:20px; width:120px; text-align:center;"|<math>S=0</math>
 | style="height:20px; width:120px; text-align:center;"|<math>B=-\frac{1}{3}</math>
@@ Line 111: / Line 111: @@
 | style="height:20px; width:120px; text-align:center;"|
 [[Anticharm-quark]]
-| style="height:20px; width:120px; text-align:center;"|<math>q=-\frac{2}{3}</math>
+| style="height:20px; width:120px; text-align:center;"|<math>Q=-\frac{2}{3}</math>
 | style="height:20px; width:120px; text-align:center;"|<math>S=0</math>
 | style="height:20px; width:120px; text-align:center;"|<math>B=-\frac{1}{3}</math>
 | style="height:20px; width:120px; text-align:center;"|<math>L=0</math>
 |}