D meson

The D mesons are the lightest particle containing charm quarks. They are often studied to gain knowledge on the weak interaction.^[1] The strange D mesons (D_s) were called "F mesons" prior to 1986.^[2]

D meson

Composition	D^+ : c d D^− : d c D^0 : c u D^0 : u c D^+ s: c s D^− s: s c
Statistics	Bosonic
Family	Mesons
Interactions	Strong, weak, electromagnetic, gravitational
Symbol	D^+ , D^− , D^0 , D^0 , D^+ s, D^− s
Antiparticle	D^+ : D^− D^0 : D^0 D^+ s: D^− s
Discovered	SLAC (1976)
Mass	D^± : 1869.62±0.20 MeV/c^2 D^0 , D^0 : 1864.84±0.17 MeV/c^2 D^± s: 1968.47±0.33 MeV/c^2
Mean lifetime	D^± : (1.040±0.007)×10^−12 D^0 , D^0 : (4.101±0.015)×10^−13 D^± s: (5.00±0.07)×10^−13
Electric charge	D^± , D^± s: ±1 e D^0 , D^0 : 0 e
Spin	0
Strangeness	D^± , D^0 , D^0 : 0 D^± s: ±1
Charm	+1
Isospin	D^+ , D^0 : +1/2 D^− , D^0 : −1/2 D^± s: 0
Parity	−1

Overview

The D mesons were discovered in 1976 by the Mark I detector at the Stanford Linear Accelerator Center.^[3]

Since the D mesons are the lightest mesons containing a single charm quark (or antiquark), they must change the charm (anti)quark into an (anti)quark of another type to decay. Such transitions involve a change of the internal charm quantum number, and can take place only via the weak interaction. In D mesons, the charm quark preferentially changes into a strange quark via an exchange of a W particle, therefore the D meson preferentially decays into kaons (
K
) and pions (
π
).^[1]

List of D mesons

D mesons

Particle name	Particle symbol	Antiparticle symbol	Quark content^[4]	Rest mass (MeV/c^2)	I	J^P	S	C	B'	Mean lifetime (s)	Commonly decays to (>5% of decays)
Charged D meson^[5]	D^+	D^−	c d	1869.62±0.20	1/2	0^−	0	+1	0	(1.040±0.007)×10^−12	^[6]
Neutral D meson^[7]	D^0	D^0	c u	1864.84±0.17	1/2	0^−	0	+1	0	(4.101±0.015)×10^−13	^[8]
Strange D meson^[9]	D^+ s	D^− s	c s	1968.47±0.33	0	0^−	+1	+1	0	(5.00±0.07)×10^−13	^[10]
Excited charged D meson^[11]	D^∗+ (2010)	D^∗− (2010)	c d	2010.27±0.17	1/2	1^−	0	+1	0	(6.9±1.9)×10^−21^‡	D^0 + π^+ or D^+ + π^0
Excited neutral D meson^[12]	D^∗0 (2007)	D^∗0 (2007)	c u	2006.97±0.19	1/2	1^−	0	+1	0	>3.1×10^−22^‡	D^0 + π^0 or D^0 + γ

‡ ^ PDG reports the resonance width ${\displaystyle ~\left(\Gamma \right)~.}$  Here the conversion ${\displaystyle \;\tau ={\frac {\hbar }{\Gamma }}\;}$  is given instead.

D
–
D
oscillations

In 2021 it was confirmed with a significance of more than seven standard deviations, that the neutral
D⁰
meson spontaneously transforms into its own antiparticle and back. This phenomenon is called flavor oscillation and was prior known to exist in the neutral K meson and B meson.^[13]

See also

• List of mesons
• List of particles
• Timeline of particle discoveries

References

1. Nave, G., ed. (2016). "D meson". Department of Physics & Astronomy. HyperPhysics. Atlanta, GA: Georgia State University.
2. Wohl, C.G. (1984). "Review of Particle Physics" (PDF). Reviews of Modern Physics. Particle Data Group. 56 (2, Part II). doi:10.1103/RevModPhys.56.S1.
3. Kudryavtsev, Vitaly A. "Charmed mesons" (course files). Physics 466. University of Sheffield.^{[permanent dead link]}
4. Amsler, C.; et al. (Particle Data Group) (2008). "Quark Model" (PDF). Lawrence Berkeley Laboratory.
5. Amsler, C.; et al. (Particle Data Group) (2008). "
   D^±
   " (PDF). Particle listings. Lawrence Berkeley Laboratory.
6. Amsler, C.; et al. (Particle Data Group) (2008). "
   D^±
   " (PDF). Decay modes. Lawrence Berkeley Laboratory.
7. Amsler, C.; et al. (Particle Data Group) (2008). "
   D⁰
   " (PDF). Particle listings. Lawrence Berkeley Laboratory.
8. Amsler, C.; et al. (Particle Data Group) (2008). "
   D⁰
   " (PDF). Decay modes. Lawrence Berkeley Laboratory.
9. Nakamura, N.; et al. (Particle Data Group) (2010). "
   D^±
   _s" (PDF). Particle listings. Lawrence Berkeley Laboratory.
10. Nakamura, N.; et al. (Particle Data Group) (2010). "
    D⁺
    _s" (PDF). Decay modes. Lawrence Berkeley Laboratory.
11. Amsler, C.; et al. (Particle Data Group) (2008). "
    D^∗±
    " (PDF). Decay modes. Lawrence Berkeley Laboratory.
12. Amsler, C.; et al. (Particle Data Group) (2008). "
    D^∗0
    (2007)" (PDF). Decay modes. Lawrence Berkeley Laboratory.
13. Aaij, R.; et al. (LHCb collaboration) (14 September 2021) [7 June 2021]. "Observation of the mass difference between neutral charm-meson eigenstates". Physical Review Letters. 127 (11): 111801. arXiv:2106.03744. Bibcode:2021PhRvL.127k1801A. doi:10.1103/PhysRevLett.127.111801. PMID 34558945. S2CID 235358523. 2106.03744. Published 2021 in Physical Review Letters 127, 111801. Report numbers: LHCb-PAPER-2021-009, CERN-EP-2021-099.