[Jlab-pwa] Baryon contamination

[Szczepaniak, Adam P]

Dear Carlos 
> I went through your note that seems to agree with our computations (after we take care of notation differences). Just
> two points: I believe we need a normalization coefficient in front of the B's in (6) as in equation (4) of my note?


Correct 

> It is not
> clear to me how the B's (you called B_H, I believe) are written in the reflectivity basis? Perhaps for the pKK case it will good to start 
> using the helicity basis?
> 

This can be done easily, I did not write this part explicitly because I wasn't sure how the nucleon and photon spins are handled in the current PWA^* -- so I wrote it in the helicity basis. 
^* I know that by reflectivity (epsilon) you make a transformation to the transverse polarization in the meson systems, but the question about the nucleons and photons still remains (at least to me. 
Maybe you could  write a short note about this part. This way it will be easy to merge the two. 


> Another practical question is that for equation (4) Will we get the full B as a function of s_D , t_1  theta and phi (GJ)? I suppose the data by SAID
> have to be recalculated in those variables since is in the K-p CM? If we get functions for the  B's as function of the GJ angles (for given s_D and integrated over t_1,
> Iwe will get ready to include them in our PWA code.  In principle we also will need several sets of B's (for K-, for  K+ and K*?) ro it will be good enough to start with only one set?
> 

Yes, the idea is to provide the full B (not just the Kp parts). That is an amplitude which takes on input either 4-vectors or the variables you list above and on output gives the complex value of the full amplitude. 

Cheers
Adam