Quarks and Leptons
Quarks and Leptons
CONTENTS
1. INTRODUCTION ................................................................ 3
2. HISTORY OF THE UNIVERSE........................................... 4
3. QUANTUM PARTICLES .................................................... 8
3.1. Quarks....................................................................8
3.1.1. Up and Down Quarks............................. 9
3.1.2. The Strange Quark.................................10
3.1.3. The Charm Quark...................................11
3.1.4. The Top Quark .......................................11
3.1.5. The Bottom Quark..................................12
3.1.6. Color Force ............................................12
3.2. Leptons ................................................................13
3.2.1. Electrones and Positrons......................14
3.2.2. Muon........................................................15
3.2.3. Tau...........................................................15
3.2.4. Neutrinos................................................16
4. CONCLUSION....................................................................18
5. BIBLIOGRAPHY.................................................................19
INTRODUCTION
What do we know about the small particles of matters? A lot of people will say that the smallest particle in the space is “Atom”, but is it true? No. The modern quantum particle theory says that there are smaller particles called quarks, leptons, photons and gravitons. Quarks are the particles, which forms protons and neutrons in the atom. They are the smallest particles known which forms nucleus of atoms. There are six quarks and two of them makes protons and neutrons.
Leptons are the negative charged particles. There are three leptons and three neutrino of these three leptons. The most common lepton is electron and its neutrino, electron neutrino.
Before having details about these two particles, we must know a little about the big bang and the beginning of universe.
2. HISTORY OF THE UNIVERSE
Formation of the modern universe was occured step by step and I am going to present it by subscripts. First of all we don’t know anything about how the big bang occured but we can make some predictions about how it was occured after the big bang. The most popular theory is below.
10-43 seconds after the Big Bang
Quantum Gravity
Electromagnetic force, weak and strong nuclear forces are staying as a whole. (Big Union) Universe starts becoming larger from an origin which has endless energy.
t< 10-43s, 1032K (1019GeV, 10-34m) :
gravity ‘freezes’
10 -35 seconds after the Big Bang
Big Union
Swelling stops getting larger continues. Big union is getting broken and the effects of strong nuclear force and electroweak force become visible.
t= 10-35s, 1027K (1016GeV, 10-32 m) :
Universe’s length multiplied in every 10-32s and swelling stops at the end of 10-32th second. Now the length of the universe is 1018m at that time the strong nuclear force becomes separated. There becomes a ratio of 1,000,000\999.999 between matter and anti-matter but the temperature is too high for them to union so they stay in a plasma of quark-gluon.
10-10 seconds after the Big Bang
Electroweak Period
Electromagnetic force and weak nuclear force are separated from each other.
t= 10-10s, 1015K (100 GeV, 10-18 m) : Universe is getting larger. Temperature...