D meson

D +
classification
Boson Hadron Meson
properties
electric charge	1  e (+1.602 10 −19  C )
Resting energy	1869.65 (5)  MeV
Spin parity	0 -
Isospin	1/2
Charm	+1
average lifespan	1.040 (7) · 10 −12  s
Interactions	strong weak electromagnetic gravitation
Quark composition	1 Charm and 1 Anti-Down ( ) ${\displaystyle c{\bar {d}}}$

D 0
classification
Boson Hadron Meson
properties
electric charge	neutral
Resting energy	1864.83 (5)  MeV
Spin parity	0 -
Isospin	1/2
Charm	+1
average lifespan	0.4101 (15) · 10 −12  s
Interactions	strong weak electromagnetic gravitation
Quark composition	1 Charm and 1 Anti-Up ( ) ${\displaystyle c{\bar {u}}}$

D s +
classification
Boson Hadron Meson
properties
electric charge	1  e (+1.602 10 −19  C )
Resting energy	1968, 34 (7)  MeV
Spin parity	0 -
Isospin	0
Strangeness	+1
Charm	+1
average lifespan	0.504 (4) · 10 −12  s
Interactions	strong weak electromagnetic gravitation
Quark composition	1 Charm and 1 Anti-Strange ( ) ${\displaystyle c{\bar {s}}}$

As D-mesons are called the mesons which exactly one charm quark contain the heaviest quark. Their mass is in the range of about 1.9 GeV / c² and they live on average for a few 10 ⁻¹³ seconds .

	D anti-mesons			D mesons
	${\displaystyle D_{s}^{-}\!\,}$	${\displaystyle D^{-}\!\,}$	${\displaystyle {\bar {D}}^{0}}$	${\displaystyle D^{0}\!\,}$	${\displaystyle D^{+}\!\,}$	${\displaystyle D_{s}^{+}\!\,}$
Isospin ${\displaystyle I_{z}}$	0	−½	+ ½	−½	+ ½	0
Strangeness ${\displaystyle S}$	−1	0	0	0	0	+1
Quark composition	${\displaystyle s\!\,}$	${\displaystyle d\!\,}$	${\displaystyle u\!\,}$	${\displaystyle {\bar {u}}}$	${\displaystyle {\bar {d}}}$	${\displaystyle {\bar {s}}}$
	${\displaystyle {\bar {c}}}$	${\displaystyle {\bar {c}}}$	${\displaystyle {\bar {c}}}$	${\displaystyle c\!\,}$	${\displaystyle c\!\,}$	${\displaystyle c\!\,}$
Charm ${\displaystyle C}$	−1			+1

D mesons are test particles for investigating the quark conversion via the weak interaction .

Similar to kaons and B mesons , neutral D mesons also mix, so they can turn into their own antiparticles . This is examined, among other things, to find indications of a CP violation as well as physics outside the Standard Model .

Examples of decay channels

${\displaystyle D^{0}\,\to K^{-}+\pi ^{+}}$

${\displaystyle D^{0}\,\to K^{-}+\pi ^{+}+\pi ^{0}}$

${\displaystyle D^{0}\,\to K^{-}+\pi ^{+}+\pi ^{+}+\pi ^{-}}$

${\displaystyle D^{0}\,\to K^{-}+\mu ^{+}+\nu _{\mu }}$

${\displaystyle D^{0}\,\to K^{-}+K^{+}}$

${\displaystyle D^{0}\,\to \pi ^{-}+\pi ^{+}}$

${\displaystyle D^{+}\,\to K^{-}+\pi ^{+}+\pi ^{+}}$

${\displaystyle D^{+}\,\to K^{-}+\mu ^{+}+\pi ^{+}+\nu _{\mu }}$

${\displaystyle D_{s}^{+}\to K^{-}+\pi ^{+}+K^{+}}$

Web links

• Hyperphysics: D meson
• Particle Data Group
• Heavy Flavor Averaging Group Current data collection on the physics of heavy quarks
• CERN : LHCb sees a new flavor of matter – antimatter asymmetry , press release from March 21, 2019. In
  addition: Robert Gast: New puzzle piece in the antimatter riddle , on: Spektrum.de from March 21, 2019

See also

• List of mesons

Individual evidence

1. ↑ ^{a b c} The information on the particle properties (Infobox) is, unless otherwise stated, taken from:
   M. Tanabashi et al .: 2018 Review of Particle Physics. In: Phys. Rev. D 98, 030001 (2018). Particle Data Group, accessed June 6, 2018 .