quarks and leptons

Question 1

what is a muon?

Answer 1

a heavy electron (symbol μ). a negatively charged particle with a rest mass over 200 times the rest mass of the electron

Question 2

what is a pion?

Answer 2

a pion or π meson is a particle which can be positively or negatively charged or it can be neutral. it has a rest mass that is greater than that of a man but less than that of a proton.

Question 3

what is a kaon?

Answer 3

a kaon or K meson is a particle which can be positively charged, negatively charged or neutral, it has a rest was that is greater than that of a pion but still less than a proton.

Question 4

how are kaons produced?

Answer 4

like pions kaons are produced in twos through strong interaction, when protons travelling at high speeds crash into nuclei and they each travel far beyond the nucleus in which they originate before they decay. however the decay of kaons was longer and included the pions as a product. kaons must decay via the weak interaction. this and other factors lead to kaons being called strange particles.

Question 5

what are the decay modes of the particles?

Answer 5

a kaon can decay into pions, a muon and an antineutrino, or an antimony and a neutrino.
a charged pion can decay into a muon and an antineutrino, ir an antimony and a neutrino, a π0 meson decays into high energy photons
a muon decays into an electron and an antineutrino. an antimony decays into a positron and a neutrino.

decay always obeys the conservation rules for energy, charge and momentum.

Question 6

how do all of these particles and antiparticles fit on with each other and with pros neutrons and electrons?

Answer 6

they are created through high energy interactions and, apart from neutrinos, they decay into other particles and antiparticles

Question 7

what type of interaction do pions and kaons go through ?

Answer 7

strong and electromagnetic

Question 8

what type of interaction do muons go through

Answer 8

weak and electromagnetic.

Question 9

what are hadrons?

Answer 9

hadrons are particles and antiparticles that interact through the strong interaction

Question 10

what are leptons?

Answer 10

leptons are particles that do not interact through the strong interaction.

Question 11

how do hadrons tend to decay?

Answer 11

through the weak interaction however proton does not tend to do this as it is stable.

Question 12

what happens when charged particles collide with other particles?

Answer 12

• the total energy of the particles and antiparticles before the collision = their rest energy + their kinetic energy
• the total energy of the new particles and antiparticles after the collision = their res energy + their kinetic energy

Question 13

wheat is the conservation of energy?

Answer 13

the rest energy of the products = the total energy before - the kinetic energy of the products.

Question 14

what are the two groups that hadrons can be split onto?

Answer 14

baryons and mesons

Question 15

what is a baryon?

Answer 15

baryons are protons and all other hadrons (including neutrons) that decay into protons, either directly or indirectly.

Question 16

what is a meson?

Answer 16

mesons are hadrons that do not include protons in their decay products

Question 17

what are the lepton rules?

Answer 17

in a reaction between a lepton and a hadron a neutrino or an antineutrino can change into or form a corresponding charged lepton (Ve + n –> p + e-)

in muon decay, the muon changes into a muon neutrino. in addition an electron is created to conserve charge and a corresponding anti neutrino is produced to conserve the lepton number

the lepton number is conserved in any change.

Question 18

what strange particles all decay through weak interaction

Answer 18

those that decay into pions - kaons
the others such as the sigma particle - have a rest mass that is always greater than that of a portion and also they decay either in sequence or directly into protons and pions
strange particles are created in twos

Question 19

what are the three different types of quarks?

Answer 19

up, down and strange quarks.

Question 20

which particle contain quarks?

Answer 20

mesons and baryons as they a fundamental particles.

Question 21

what are the quark formation in baryons?

Answer 21

baryons consist of 3 quarks where as anti baryons consist of 3 antiquarks

Question 22

what is the formation of quarks in mesons?

Answer 22

mesons consist of a quark antiquark pair.

Question 23

what are the conservation rules?

Answer 23

conservation of energy and the conservation of charge apply to all charges in science
conservation rules used only for particle and antiparticle interactions and decays are essentially particle counting rules
conservation of lepton numbers
conservation of strangeness