Download presentation
Presentation is loading. Please wait.
1
A novel approach to include pp Coulomb force into the 3N Faddeev calculations H. Witała, R. Skibiński, J. Golak Jagiellonian University W. Gloeckle Ruhr Universitaet Bochum
2
Possible method to include pp Coulomb force in 3N calculations: - screening - in nature Coulomb force is always screened - screening allows to use standard methods developed for finite range forces - to get final predictions follow numerically the limit to the unscreened situation Big problem when working with partial waves: - looking for the screening limit requires to increase the screening radius. The number of partial waves required to reproduce the screened pp Coulomb t-matrix increases drastically with the screening radius. This leads to the explosion of the number of partial waves in the 3N system. - solution: treatment of the screened pure Coulomb part without relying on partial wave decomposition – 3-dimensional LS Keep the pp Coulomb force in the proper coordinate
5
Faddeev equation: - free 3N propagator - initial state: deuteron and momentum state of the proton Standard momentum space basis: - nuclear V N and the pp screened Coulomb V c R interaction is acting (in t=1 states) - only V c R is acting in the pp subsystem
6
Projecting Faddeev equation on the states and : The term A direct calculation of its isospin part shows that it vanishes.
7
Insertinginto Eq. for one gets: - it is coupled set of integral equations in the space of the states | > only - it incorporates the contributions of the pp Coulomb force from all waves up to infinity The leading termand the kernel term must be calculated with the 3-dimensional pp screened Coulomb t-matrix Details of formulation: see nucl-th 0903.1522, 0906.3226
8
The t-matrix t N+c R is generated by the interactions V N +V c R. For | > and | ’> states with t=1 its matrix element is a linear combination of the t pp+c R and t np : For t=0:
9
The amplitudesprovide transition amplitude for elastic scattering: and for breakup: with Namely:
10
The screening limit The screening limit of is governed by For pd elastic scattering amplitude one needsfor off-shell p,q values: The breakup amplitude requiresfor on-shell p,q values: off-shell t-matrices half-shell t-matrices - do not acquire a phase factor - acquire an infinitely oscilating phase factor
11
For exponential screening: phase - Euler number - the Sommerfeld parameter
19
Procedure to follow: 1) Solve Faddeev equations for off-shell elastic scattering amplitude 2) Using them determine on-shell breakup amplitude Notice: in linear combinations use renormalized pp+c half-shell t-matrices
20
Results: -simple dynamical model: NN interaction taken as CD Bonn active only in states 1 S 0 and 3 S 1 - 3 D 1 - exponential screening with n=1
29
Summary and conclusions: novel approach to include the pp Coulomb force into the momentum space 3N Faddeev calculations it is based on a standard formulation for finite range forces it relies on a screening of the long-range Coulomb interaction we apply directly the 3-dimensional pp screened Coulomb t-matrix we treat the pp Coulomb force in its proper coordinate for a simple dynamical model feasibility of the approach was demontrated physical pd elastic scattering amplitude has a well defined limit and does not require renormalization to get breakup amplitude on-shell 3N amplitudes are required and renormalized pp half-shell screened t-matrices must be used
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.