Strangeness

In particle physics, strangeness (symbol S)[1][2] is a property of particles, expressed as a quantum number, for describing decay of particles in strong and electromagnetic interactions that occur in a short period of time. The strangeness of a particle is defined as: where n
s
represents the number of strange quarks (
s
) and n
s
represents the number of strange antiquarks (
s
). Evaluation of strangeness production has become an important tool in search, discovery, observation and interpretation of quark–gluon plasma (QGP).[3] Strangeness is an excited state of matter and its decay is governed by CKM mixing.

The terms strange and strangeness predate the discovery of the quark, and were adopted after its discovery in order to preserve the continuity of the phrase: strangeness of particles as −1 and anti-particles as +1, per the original definition. For all the quark flavour quantum numbers (strangeness, charm, topness and bottomness) the convention is that the flavour charge and the electric charge of a quark have the same sign. With this, any flavour carried by a charged meson has the same sign as its charge.

  1. ^ Jacob, Maurice (1992). The Quark Structure of Matter. World Scientific Lecture Notes in Physics. Vol. 50. World Scientific. doi:10.1142/1653. ISBN 978-981-02-0962-9.
  2. ^ Tanabashi, M.; Hagiwara, K.; Hikasa, K.; Nakamura, K.; Sumino, Y.; Takahashi, F.; Tanaka, J.; Agashe, K.; Aielli, G.; Amsler, C.; Antonelli, M. (2018-08-17). "Review of Particle Physics". Physical Review D. 98 (3): 030001. Bibcode:2018PhRvD..98c0001T. doi:10.1103/PhysRevD.98.030001. hdl:10044/1/68623. ISSN 2470-0010. PMID 10020536. pages 1188 (Mesons), 1716 ff (Baryons)
  3. ^ Margetis, Spyridon; Safarík, Karel; Villalobos Baillie, Orlando (2000). "Strangeness Production in Heavy-Ion Collisions". Annual Review of Nuclear and Particle Science. 50 (1): 299–342. Bibcode:2000ARNPS..50..299S. doi:10.1146/annurev.nucl.50.1.299. ISSN 0163-8998.