Question

4. The 7 meson has spin-0, a total width T = 1.31 +0.05 keV and two important decay modes: 7 + T° +7° +7° and 9 + A++ +7°. (a) (1 mark) What force dictates the decay of this particle? (b) (3 marks) Deduce the parity of the 7 meson. Show your work. (c) (2 marks) Using your answer from (b), explain why the decays n +7° +7° and n++ + + have never been observed. (d) (3 marks) Use the charge conjugation operation to determine the C-parity of the n meson. (Hint: get the C-parity of the meson first.) Show your work.

Answer 1

ANSWER:

Given that, The n meson has Spin-o, a total width T=1.3110.05 and two important decay modes : n> Tuttit Tio - natt tita a) Given decay processes core, not tht to Diftitis using consevation laws B=> 0 = 0+0+0 , 0= 0+0+0 > Baryon number consegved. ototo as Lepton number conserved. L o= 0+0+0 conserved G => che o =0+0+0 i O = +1 +(-1)+0 , O3 O +0+0 Sterangness conserve S = 0o+0+0 in not conserv EU >0=1+1+1 , 0 = +1+1+1)+ 1 => Frospin , 0 = +1-1+0 =) Ig is conserved. 0-0 +0+0 13 →

I' is not conserved but fg is conserved. in 16 is followed by electromagnetic delay. b) The 1... parity of the meson Parity of Tit, it and to -1, Parity is multiplicative property, whese 'n' is parity of n. > From decay 0 - m - -1% -1%-12-1 ou 1 = = -18-18-1=-1 Fhom parity of na-1 c) zet us assume, can be and na Tit _ + -0 -0 TI + 1 0-> = 3 observed, then, from @ Parity comes -1x -1 = + 1 allo forom @ Parlty comes -1*-1 = +1 but i has parity = -1 only. .: decay © and → can not be observed.

d) using the conjugation operation . To have change = 0 cct (TO) TO :c- parity of T = +1. is a multiplicate Also, Ċ - parity property. s from decoy 0. we get .c- poority of n = (+1)x(+1) X(+1)= +1