PT Journal
AU Sakai, S
   Oset, E
   Guo, FK
TI Triangle singularity in the B-> K- pi X-0 (3872) reaction and sensitivity to the X(3872) mass
SO Physical Review D
JI Phys. Rev. D
PY 2020
BP 054030
EP 10pp
VL 101
IS 5
DI 10.1103/PhysRevD.101.054030
LA English
AB We have done a study of the B--> K-pi X-0(3872) reaction by means of a triangle mechanism via the chain of reactions: B--> K-D*(0);(D) over bar*(0); D*(0)-> pi D-0(0); D-0(D) over bar*(0)-> X(3872). We show that this mechanism generates a triangle singularity in the pi X-0(3872) invariant mass for a very narrow window of the X(3872) mass, around the present measured values, and show that the peak positions and the shape of the mass distributions arc sensitive to the X(3872) mass, such that a measurement of the reaction can serve to improve on the present values of this mass. In particular, we point out that the X(3872) mass relative to the D-0(D) over bar*(0) threshold may be extracted from the asymmetry of the pi X-0 line shape.
ER