Speaker
Description
In the talk a missing part of the extensively used chiral effective field theories is presented which is necessary for accurate study of the processes involving
bound states.
Contemporary high precision experimental studies of the processes where bound states are involved open the possibility of the accurate study of their characteristic features. To maximise the
accuracy the precision of the corresponding theoretical approaches should match the mentioned experimental precision.
As the theoretical expressions describing these processes contain the moving bound state wave functions it is necessary to express the latters in terms of ones at rest, the task considered in the talk.
Two versions of the Perturbation Theory (PT) are presented which provide this connection between the wave functions, one being
a PT for the Lorentz boost operator, which has the form of the evolution operator between
$x_0=0$ and $Px=0$ hyperplanes (P is the bound state 4-momentum),
another is a PT for the solution of the relativistic bound state Schroedinger equation, relating it to the rest frame. The latter is specifically practical for the "Modern theory of nuclear forces" as it is expressed directly in terms of the nucleon-nucleon (NN)
potentials, developed in great detail for their use in the chiral PT for the few nucleon physics studies.
Currently used in the low energy EFT approximate moving bound state wave functions are reproduced in the lowest order of our PT.