0000000000014286
AUTHOR
Shuntaro Sakai
Triangle singularity in the B−→K−π0X(3872) reaction and sensitivity to the X(3872) mass
We have done a study of the B−→K−π0X(3872) reaction by means of a triangle mechanism via the chain of reactions: B−→K−D*0D¯*0; D*0→π0D0; D0D¯*0→X(3872). We show that this mechanism generates a triangle singularity in the π0X(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 are 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 D0D¯*0 threshold may be extracted from the asymmetry of the π0X line shape.
The χ decay to ϕK⁎K¯,ϕh1(1380) testing the nature of axial vector meson resonances
Abstract We perform a theoretical study of the χ c J → ϕ K ⁎ K ¯ → ϕ K π K ¯ reaction taking into account the K ⁎ K ¯ final state interaction, which in the chiral unitary approach is responsible, together with its coupled channels, for the formation of the low lying axial vector mesons, in this case the h 1 ( 1380 ) given the selection of quantum numbers. Based on this picture we can easily explain why in the χ c 0 decay the h 1 ( 1380 ) resonance is not produced, and, in the case of χ c 1 and χ c 2 decay, why a dip in the K + π 0 K − mass distribution appears in the 1550-1600 MeV region, that in our picture comes from a destructive interference between the tree level mechanism and the resc…
Triangle singularity in the B−→K−π0X(3872) reaction and sensitivity to the X(3872) mass
We have done a study of the ${B}^{\ensuremath{-}}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{0}X(3872)$ reaction by means of a triangle mechanism via the chain of reactions: ${B}^{\ensuremath{-}}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{D}^{*0}{\overline{D}}^{*0}$; ${D}^{*0}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}{D}^{0}$; ${D}^{0}{\overline{D}}^{*0}\ensuremath{\rightarrow}X(3872)$. We show that this mechanism generates a triangle singularity in the ${\ensuremath{\pi}}^{0}X(3872)$ 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 are sensitiv…