Study of the possible role of triangle singularities in ${B^ - }, o {D^{*0}}{pi ^ - }{pi ^0}eta $ and ${B^ - }, o {D^{*0}}{pi ^ - }{pi ^ + }{pi ^ - }$

摘要

Studying the effects of triangle singularities in hadronic processes is of the utmost importance since they can originate peaks that may wrongfully be associated with resonances. In this work, the role of the triangle mechanism in the decays ${B^ - }, o {D^{*0}}{pi ^ - }{pi ^0}eta $ and ${B^ - }, o {D^{*0}}{pi ^ - }{pi ^ + }{pi ^ - }$ is explored. Here, the singularity appears when B~(-) decays into ${D^*}{K^{*0}}{K^ - }$ , K ~(*0)decays into K ~(+)through pion emission, and K ~(-) K ~(+)fuse together forming either the a _(0)(980) or f _(0)(980) which then decays into π ~(0) η or π~(+)π ~(–), respectively. As a result, the K ~(*) K ~(+) K ~(-)loop generates a peak in the invariant mass of π ~(-) a _(0)or π ~(-) f _(0)around 1420 MeV. The branching ratios that come from this peak are $Br({B^ - } o {D^{*0}}{pi ^ - }{a_0};,{a_0} o {pi ^0}eta ) = (1.66 pm 0.45) imes {10^{ - 6}}$ and $Br({B^ - } o {D^{*0}}{pi ^ - }{f_0};,{f_0} o {pi ^ + }{pi ^ - }) = (2.82 pm 0.75) imes {10^{ - 6}}$ , which are well within the measurable range. Thus, this work makes interesting predictions about an effect of a triangle singularity in an experiment that is feasible in present experimental facilities.