Lambda decay, momentum of the pion and proton

[Cocoleia]

You should be able to deduce this from 4-momentum conservation.

I think I understand the concept of 4 momentum, but I am unsure about if I will have to be using sin/cos or some type of geometry to find the angles. I understand the conservation of momentum so then, only the x component will change and it will be the cos of the angle ?

But my problem is there are two particles decaying, the pion and the proton so they would potentially both have different angles & momentum except I only focus on the pion right now

 

[Orodruin]

I think I understand the concept of 4 momentum, but I am unsure about if I will have to be using sin/cos or some type of geometry to find the angles. I understand the conservation of momentum so then, only the x component will change and it will be the cos of the angle ?

4-momentum conservation is just energy and momentum conservation wrapped up into one and a more convenient way of constructing invariant quantities.

I suggest you write down the general momentum and energy conservation equations assuming that the pion has some unknown total momentum at some angle $\theta$ to the initial direction.

 

[Cocoleia]

4-momentum conservation is just energy and momentum conservation wrapped up into one and a more convenient way of constructing invariant quantities.

I suggest you write down the general momentum and energy conservation equations assuming that the pion has some unknown total momentum at some angle $\theta$ to the initial direction.

In this case I would assume the the energy conservation is simply Ea=Eb+Ec

However for momentum if I separate into the three components,

but then I am ignoring the proton and if I add in that
Pa=Pb+Pc I'm not sure how to combine the angle to this

 

[Cocoleia]

4-momentum conservation is just energy and momentum conservation wrapped up into one and a more convenient way of constructing invariant quantities.

I suggest you write down the general momentum and energy conservation equations assuming that the pion has some unknown total momentum at some angle $\theta$ to the initial direction.

Alternatively

http://www.dzre.com/alex/P442/lectures/lec_04.pdf

I see all their formulas for angles and such but I just can't relate it my head