Question

4. (a) Name the four known forces in nature. For each force state the kind of particles the force acts upon, what the approximate range of the force is, and what the field quanta are that mediate the force (4 marks) Briefly explain what is meant by anti-particles and why they are relevant in particle physics (b) (2 marks) Determine whether each of the following decays is allowed. If a decay is allowed determine the interaction involved. If it is not allowed. state which conservation la (c) w(s) is/are violated. p+p - (4 marks)

Answer 1

4.A There is four type of forces is nature

1. Gravitational force

2. Electro - Magnetic Force

3. Strong Force

4. Weak Force

charg

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Weak Interaclionc ponsible foun decay Stura andsa patiel m S lo sec lo- ec Muns into electrnns lo Sec ec. 0 0 in Weah iteractian nev o. 38S 91.1836 土e uo

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Ans 4b.

Cİİ Tr Particle Physics, every t an associated ype of particle has antiparticlehthe Same ss 6 charaes ot electron ρ0sHaớn. Some wHcles , such as Photon are eiwn anti-particle For each pairs of antiparticle partnes, one s atnes, one IS ignted as normal matte Cthe ind of mattev inkbrachd wtth is made of) and the USU othen as anttr Porticle- Antibartidle Paim Can amihi late each other prodc Photons

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Ans 4c

Conserved Consev ed Conseve d No. Le Pton0 o E.m. Reaction is Posi ble by sIntoct Cajon- Not Conserved No Conseved Con served Not Conserved No4 \ん Consevved Reaction is not allowd as chavge, baruyon ma ts not consewd lepton no.. T, awds

TC 兀 et Ve Chan (onserved Conseved Conseved Conseve Reaction is allowed but by Weak Intcractior 4- t- Chang : E Com served Con served (on seved Conserved Sa- Reacton s Possible by sheng T is ossible