How Does an E Baryon Decay into a D Baryon and a Photon?

[Inara]

An E baryon, traveling with an energy of 2 GeV, decays electromagnetically into a D baryon and a photon.

Sketch how this decay might appear in the general case
(i) in the lab frame
E D
A. Essentially I assume you will have ----> <
photon
(with the photon and D coming off that with a 90 degree angle between them.

(ii) in the rest frame of the E baryon.

A.
Photon D
------> E <------ The photon approaching each other with equal and opposite momentum.

What conditions are necessary for D to have maximum energy.

A. D must have equal and opposite momenta to the photon.

 

[OlderDan]

I can't find any references for D baryons and E baryons. Do you have rest masses for these? I'm not seeing why there has to be a 90° angle in the lab frame. In the rest frame of the E Baryon the D baryon and the photon must have 180° angle between them.