Decay-times of pions and kaons formed by laser-induced nuclear processes in ultra-dense hydrogen H(0)

Laser-induced nuclear reactions in ultra-dense hydrogen H(0) (see review in Physica Scripta 2019) create mesons (kaons, pions) with up to 100 MeV thus velocity 0.55 c for the kaons. The pion decay-time is determined to be 25.92 ± 0.04 ns (standard fit error) in agreement with the tabulated results from the Particle Data Group. The same general behaviour is found with either deuterium or normal hydrogen forming the ultra-dense phase H(0) on the laser target. Many mesons decay close to the target and generate muons with relativistic energies at current densities of 1–10 mA cm -2 per laser pulse of < 0.4 J energy as measured at 1–2 m distances. This corresponds to 10 13 muons and a similar number of initially created mesons per laser pulse. The large number of mesons created proves that they are formed from the baryons in H(0). Here the decay-times of the initially formed kaons and pions are measured accurately. Their kinetic energies are determined from their dilated decay-times. A baryon annihilation process agrees with the observed particle types and their energies (Holmlid, Int. J. Hydrogen Energy 2021, Holmlid and Olafsson High Energy Density Physics 2021). It gives creation of a pair of kaons and of two pairs of pions from a pair of baryon-antibaryon with accurate energy.