- #1
binbagsss
- 1,265
- 11
The question is for which of the ##1P## meson states - ##1^{1}P_{1}, 1^{3}P_{0},1^{3}P_{1}, 1^{3}P_{2} ## ##D_{s}## states decaying to a ##1S## state is the decay: ##D_{s}**^{+} -> D_{s}^{+}\pi^{0} ## possible?
Solution
So the strong interaction conserves parity. Parity of meson is given by ## (-1)^{l+1} ##, for the ##1s## states, ##l=0## and so ##p=1##.
The solution than states as both the decay products have zero spin the total angular momentum of the decaying particle must be equal to the orbitial angular momentum of ##D_{s}^{+}\pi^{0}## system.
So I agree with this last comment, but I have no idea why both decay products have ##0## spin?
I know that a meson is a quark and its antiquark, and so the spin adds to either ##1## or ##0##. But how do we know which it is?
The solution then uses parity of the ##D_{s}^{+}\pi^{0}## system is ##P = (−1)^{l} × −1 × −1 ## *2.
Im confused where this comes from - so I know that the parity of a meson in it's lowest states - i.e- ##l=0## is ##-1##. And I know that for a system of particles ##P=(-1)^{l}##, but, I've never seen how to consider the parity of two particles decayed. Is this how you 'add' the parities ?
And so how exactly should you think of the system of decay products. So a particle has an intrinsic parity. Is this a particle or a quark? I.e is ##P=(-1)^{l}## coming from thinking of a system of quarks or a system of the two particles ##D_{s}^{+}\pi^{0}##?
(From which the solution follows from the fact that we require ##P=1##, again I'm okay with this once I understand expression *2.)
Thanks, your help is really appreciated !
Solution
So the strong interaction conserves parity. Parity of meson is given by ## (-1)^{l+1} ##, for the ##1s## states, ##l=0## and so ##p=1##.
The solution than states as both the decay products have zero spin the total angular momentum of the decaying particle must be equal to the orbitial angular momentum of ##D_{s}^{+}\pi^{0}## system.
So I agree with this last comment, but I have no idea why both decay products have ##0## spin?
I know that a meson is a quark and its antiquark, and so the spin adds to either ##1## or ##0##. But how do we know which it is?
The solution then uses parity of the ##D_{s}^{+}\pi^{0}## system is ##P = (−1)^{l} × −1 × −1 ## *2.
Im confused where this comes from - so I know that the parity of a meson in it's lowest states - i.e- ##l=0## is ##-1##. And I know that for a system of particles ##P=(-1)^{l}##, but, I've never seen how to consider the parity of two particles decayed. Is this how you 'add' the parities ?
And so how exactly should you think of the system of decay products. So a particle has an intrinsic parity. Is this a particle or a quark? I.e is ##P=(-1)^{l}## coming from thinking of a system of quarks or a system of the two particles ##D_{s}^{+}\pi^{0}##?
(From which the solution follows from the fact that we require ##P=1##, again I'm okay with this once I understand expression *2.)
Thanks, your help is really appreciated !