In the standard model of particle physics (specifically in QCD), a baryon is bound state of three quarks via the strong nuclear force. Baryons are the “heavy” types of hadrons, the other being the mesons.

Examples of baryons are the nucleons: protons and neutrons. Other examples are Lambda baryons.

Also pentaquarks are counted as baryons.


Conceptualization and computation in AdS/QCD

In the Witten-Sakai-Sugimoto model for strongly coupled QCD via an intersecting D-brane model, the hadrons in QCD correspond to string-theoretic-phenomena in an ambient bulk field theory on an approximately anti de Sitter spacetime:

  1. the mesons (bound states of 2 quarks) correspond to open strings in the bulk, whose two endpoints on the asymptotic boundary correspond to the two quarks;

  2. baryons (bound states of N cN_c quarks) appear in two different but equivalent (Sugimoto 16, 15.4.1) guises:

    1. as wrapped D4-branes with N cN_c open strings connecting them to the D8-brane

      (Witten 98b, Gross-Ooguri 98)

    2. as skyrmions

      (Sakai-Sugimoto 04, section 5.2, Sakai-Sugimoto 05, section 3.3, see Bartolini 17).

For review see Sugimoto 16, also Rebhan 14, around (18).

graphics grabbed from Sugimoto 16

This produces baryon mass spectra with moderate quantitative agreement with experiment (HSSY 07):

graphics grabbed from Sugimoto 16



See also

  • Wikipedia, Baryon

  • Aarts, Baryons at finite temperature (pdf)

In the large NN limit

In the large N limit:

In Witten-Sakai-Sugimoto model for AdS-QCD

Realization of baryons as wrapped D4-branes/M5-branes via the AdS/QCD correspondence/Witten-Sakai-Sugimoto model:


Last revised on February 13, 2020 at 07:44:31. See the history of this page for a list of all contributions to it.