Quarks

• The three most common flavours of quarks are:?up, down?and?strange
• The majority of hadrons are made up of different combinations of these quarks

The three main quarks that make up most hadrons

• Each quark has a charge, baryon number and strangeness
• These will be provided on the data sheet

Quarks Table provided on the datasheet

• The charge of a hadron is determined by the sum of the charges of its quarks
• For example, a proton is made up of two up quarks and a down quark. Adding up their charges gives the charge of a proton:

• Equivalently, the baryon number and strangeness of a hadron is determined by the sum of the baryon numbers and strangeness of its quarks

Anti-quarks

• The equivalent antiparticle of the quark is the anti-quark

The three main anti-quarks that make up most hadrons

• These are identical to quarks except with opposite relative charges, baryons numbers and strangeness

Anti-quarks Table

• Quarks have a?baryon number of +1/3
• Anti-quarks having a?baryon number of –1/3
• Strange quarks have?a strangeness of –1
• Anti-strange quarks have?a strangeness of +1
  • This is unique to the strange quark

   

Baryons

• Protons and neutrons are?not?fundamental particles
  • They are each made up of three quarks

   

• Protons?are made up of?two up?quarks and a?down?quark
• Neutrons?are made up of?two down?quarks and an?up?quark

Protons and neutrons are made up of three quarks

Mesons

• Pions and kaons are made up of a quark and anti-quark pair
• Pions?are either:
  • π+?made up of an?up?quark and an?anti-down?quark
  • π–?made up on an?anti-up?quark and a?down?quark
  • π0?made up of an?up?quark and?anti-up?quark?or?down?quark and?anti-down?quark

   

Pions consist of up and down quarks, and their respective antiparticles, depending on their sign

• Kaons?are either:
  • K+?made up of an?up?quark and an?anti-strange?quark
  • K–?made up on an?anti-up?quark and a?strange?quark
  • K0?made up of an?down?quark and?anti-strange?quark?or?anti-down?quark and?strange?quark

   

Kaons consist of up, down and strange quarks, and their respective antiparticles, depending on their sign

Step 1: Calculate the number of protons

The number of protons is from the proton number = 26 protons

Step 2: Calculate the number of neutrons

Number of neutrons = nucleon number – proton number

Number of neutrons = 56 - 26 = 30 neutrons

Step 3: Up quarks in a proton

Protons are made up of uud quarks = 2 up quarks

Step 4: Up quarks in a neutron

Neutrons are made up of udd quarks = 1 up quark

Step 5: Total number of up quarks

26 protons × 2 up quarks = 52 up quarks

30 neutrons × 1 up quark = 30 up quarks

Total number of up quarks = 52 + 30 = 82 up quarks