Xi baryon

Xi baryon ( Ξ0 )

Ξ -

The two Ξ - baryons, and Xi baryons or Kaskadenteilchen, are baryons, which consist of two strange quarks as well as an up or a down quark. They have spin 1 /2, isospin 1/2 and are characterized by their different electric charges: Ξ0 and Ξ -.

They are among the hyperons.


The Ξ - baryons belong to the SU (3) octet.

They decay to almost 100 % in a Λ - baryon and a pion. Here, the Ξ0 decays into a Λ and a π0, while the decay of the Ξ - in a Λ and a π - done. The Λ then decays further, usually in a nucleon and pion another. Because of this two-stage decay, the Ξ - baryons are also referred to as Kaskadenteilchen (english cascade ).

Excited States

The Ξ - baryons have excited states, which are referred to as Ξ * baryons. They have the same quark content as the Ξ - baryons, however, spin 3/2, and are part of the baryon Dekupletts. They are slightly heavier than the Ξ - baryons ( Ξ0 * ≈ ², Ξ * 1531 - MeV / c ≈ 1535 MeV / c ² ), since they decay and significant short-lived under the strong nuclear force in a pion and a Ξ - baryon.