Ξ-baryon
|
Xi-Baryon (Ξ 0 ) |
|
|---|---|
| classification | |
|
Fermion Hadron Baryon |
|
| properties | |
| electric charge | neutral |
| Resting energy | 1314.86 ± 0.20 MeV |
| magnetic moment | −1.250 ± 0.014 μ N |
| Spin parity | 1/2 + |
| Isospin | 1/2 (z component +1/2) |
| Strangeness | −2 |
| average lifespan | (2.90 ± 0.09) 10 −10 s |
|
Quark composition |
uss |
|
Ξ - |
|
|---|---|
| classification | |
|
Fermion Hadron Baryon |
|
| properties | |
| electric charge | −1 e (−1.602 · 10 −19 C ) |
| Resting energy | 1321.71 ± 0.07 MeV |
| magnetic moment | −0.6057 ± 0.0025 μ N |
| Spin parity | 1/2 + |
| Isospin | 1/2 (z component −1/2) |
| Strangeness | −2 |
| average lifespan | (1.639 ± 0.015) 10 −10 s |
|
Quark composition |
dss |
The two Ξ-baryons, also Xi-baryons or cascade particles , are baryons that consist of two strange quarks and an up or a down quark . They have spin 1/2, isospin 1/2 and are characterized by their different electrical charges: Ξ 0 and Ξ - .
You belong to the hyperons .
description
The Ξ-baryons belong to the SU (3) octet.
Almost 100% of them break down into a Λ-baryon and a pion . The Ξ 0 splits into a Λ and a π 0 , while the Ξ - into a Λ and a π - takes place. The Λ then breaks down further, usually into a nucleon and another pion. Because of this two-stage decay the Ξ-baryons are also called Kaskadenteilchen ( English cascade called).
Excited states
The Ξ-baryon have excited states , which as Ξ * -Baryonen be called. They have the same quark content as the Ξ-baryons, but spin 3/2, and are part of the baryon decuplet. They are a little heavier than the Ξ-baryons (Ξ 0 * ≈ 1531 MeV / c², Ξ - * ≈ 1535 MeV / c²) and significantly shorter-lived, since they decay into a pion and a Ξ-baryon under the strong nuclear force .
See also
Individual evidence
- ↑ a b c The information on the particle properties (info box) are, unless otherwise stated, taken from: J. Beringer et al. ( Particle Data Group ): 2013 Review of Particle Physics. In: Physical Review D . Vol. 86, 2012, 010001 and 2013 partial update for the 2014 edition. Particle Data Group, accessed May 23, 2018 .