f2(1810) as a triangle singularity

Abstract

We perform calculations showing that a source producing K * K * in J = 2 and L = 0 gives rise to a triangle singularity at 1810 MeV with a width of about 200 MeV from the mechanism K * → πK and then KK * merging into the a1(1260) resonance. We suggest that this is the origin of the present f2(1810) resonance and propose to look at the πa1(1260) mode in several reactions to clarify the issue.PACS numbers:

Polarization transfer in hyperon decays and its effect in relativistic nuclear collisions

“…The evidence of global polarization of Λ hyperons in relativistic nuclear collisions [1] is having a remarkable impact in this field. Indeed, the global polarization turns out to be in a very good quantitative agreement with the combined predictions of thermodynamics and hydrodynamics [2][3][4][5]. These predictions are based on the assumption that local thermodynamic equilibrium is achieved at some early stage of the process (Quark Gluon Plasma -QGPformation) and maintained until hadronization, where the fluid basically breaks up into a kinetic hadronic system.…”

Role of a triangle singularity in the πN(1535) contribution to γp→pπ0η

“…Adding to this list of reinterpretation of some accepted resonances is the case of the f 2 (1810), also explained in Ref. [30] as the production of the f 2 (1650) followed by the decay into K * K * , K * → πK, KK * → a 1 (1260). In some cases the singularity helps to explain enhancements in cross sections not attributed to any resonance.…”

Anomalous enhancement of the isospin-violating Λ(1405) production by a triangle singularity in Λc→

“…Other than the "a 1 ð1420Þ" the interpretation of the "f 1 ð1420Þ" and "f 2 ð1810Þ" in the PDG [19] as a peak of the triangle singularity was proposed in Refs. [20,21], respectively. Furthermore, possible manifestations of the TS in the heavy sector were investigated in Refs.…”