Quarks

Quarks

1. Quarks are fundamental particles

   • Quarks are the building blocks for hadrons (baryons and mesons). Antiparticles of hadrons are made of antiquarks
   • To make protons and neutrons you only need 2 types of quark- the up quark (u) and the down quark (d)
   • An extra one called the strange quark (s) lets you make more particles with a property called strangness
   • Strangness is only conserved some of the time
     • 1. Strangeness like baryon number is a quantum number
     • 2. Strange particles like kaons are created via the strong force but decay via the weak
     • 3. Strangeness is conserved in the strong interaction but not in the weak
     • 4.That means that strange particles are always produced in pairs
       • One has a strangeness of +1 and the other -1 so the overall strangeness in 0

2. Quarks

   • Up. Symbol u. Charge +2/3 . Baryon number +1/3. Strangness 0
   • Down. Symbol d. Charge -1/3. Baryon number +1/3. Strangeness 0.,
   • Strabge. Symbol s. Charge -1/3. Baryon number +1/3. Strangeness -1

3. Antiquarks

   • Anti-up. Symbol u. Charge -2/3. Baryon number -1/3. Strangeness 0
   • Anti- down. Symbol d. Charge +1/3. Baryon number -1/3. Strangeness 0
   • Anti- strange. Symbol s. Charge +1/3. Baryon number -1/3. Strangeness +1