Ро мезондары: қасиеттері мен ыдырауы

Short lived hadronic particle that is an isospin triplet
The rho mesons have a very short lifetime and their decay width is about 145 with the peculiar feature that the decay widths are not described by a Breit–Wigner form. The principal decay route of the rho mesons is to a pair of pions with a branching rate of 99.9%.

After several false starts, the ρ meson and the ω meson were discovered at Lawrence Berkeley Laboratory in 1961.

The rho mesons can be interpreted as a bound state of a quark and an anti quark and is an excited version of the pion. Unlike the pion, the rho meson has spin j = 1 (a vector meson) and a much higher value of the mass. This mass difference between the pions and rho mesons is attributed to a large hyperfine interaction between the quark and anti quark. The main objection with the De Rujula–Georgi–Glashow description is that it attributes the lightness of the pions as an accident rather than a result of chiral symmetry breaking. The rho mesons can be thought of as the gauge bosons of a spontaneously broken gauge symmetry whose local character is emergent (arising from QCD); Note that this broken gauge symmetry (sometimes called hidden local symmetry) is distinct from the global chiral symmetry acting on the flavors. This was described by Howard Georgi in a paper titled "The Vector Limit of Chiral Symmetry" where he ascribed much of the literature of hidden local symmetry to a non linear sigma model. + Rho mesons Particle name Particle symbol Antiparticle symbol Quark content Mass (MeV/c2) Commonly decays to (>5% of decays) Charged rho meson (770) (770) 775.11 1+ 1− 0 0 0 4.415 Neutral rho meson (770) Self 775.26 1+ 1−− 0 0 0 4.453