Bottom quark

Bottom quark
Compositionelementary particle
Statisticsfermionic
Familyquark
Generationthird
Interactionsstrong, weak, electromagnetic, gravity
Symbol
b
Antiparticlebottom antiquark (
b
)
TheorizedMakoto Kobayashi and Toshihide Maskawa (1973)[1]
DiscoveredLeon M. Lederman et al. (1977)[2]
Mass4.18+0.04
−0.03 GeV/c2 (MS scheme)[3]
4.65+0.03
−0.03 GeV/c2 (1S scheme)[4]
Decays intocharm quark or
up quark
Electric charge−⁠1/3⁠ e
Color chargeyes
Spin⁠1/2⁠ ħ
Weak isospinLH: ⁠−+1/2⁠, RH: 0
Weak hyperchargeLH: ⁠1/3⁠, RH: ⁠−+2/3⁠

The bottom quark, beauty quark, or b quark, is an elementary particle of the third generation. It is a heavy quark with a charge of −⁠1/3⁠ e.

All quarks are described in a similar way by electroweak interaction and quantum chromodynamics, but the bottom quark has exceptionally low rates of transition to lower-mass quarks. The bottom quark is also notable because it is a product in almost all top quark decays, and is a frequent decay product of the Higgs boson.

  1. ^ Cite error: The named reference KM was invoked but never defined (see the help page).
  2. ^ "Discoveries at Fermilab – Discovery of the Bottom Quark" (Press release). Fermilab. 7 August 1977. Retrieved 24 July 2009.
  3. ^ M. Tanabashi et al. (Particle Data Group) (2018). "Review of Particle Physics". Physical Review D. 98 (3): 030001. Bibcode:2018PhRvD..98c0001T. doi:10.1103/PhysRevD.98.030001. hdl:10044/1/68623.
  4. ^ J. Beringer (Particle Data Group); et al. (2012). "PDGLive Particle Summary 'Quarks (u, d, s, c, b, t, b', t', Free)'" (PDF). Particle Data Group. Archived from the original (PDF) on 12 May 2013. Retrieved 18 December 2012.