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D meson

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Particle in physics

D meson
Composition	D⁺ :cd D⁻ :dc D⁰ :cu D⁰ :uc D⁺ _s:cs D⁻ _s:sc
Statistics	Bosonic
Family	Mesons
Interactions	Strong,weak,electromagnetic,gravitational
Symbol	D⁺ ,D⁻ ,D⁰ ,D⁰ ,D⁺ _s,D⁻ _s
Antiparticle	D⁺ :D⁻ D⁰ :D⁰ D⁺ _s:D⁻ _s
Discovered	SLAC (1976)
Mass	D^± :1869.62±0.20 MeV/c² D⁰ ,D⁰ :1864.84±0.17 MeV/c² D^± _s:1968.47±0.33 MeV/c²
Mean lifetime	D^± :(1.040±0.007)×10⁻¹² s D⁰ ,D⁰ :(4.101±0.015)×10⁻¹³ s D^± _s:(5.00±0.07)×10⁻¹³ s
Electric charge	D^± ,D^± _s: ±1e D⁰ ,D⁰ : 0e
Spin	0 ħ
Strangeness	D^± ,D⁰ ,D⁰ : 0 D^± _s:±1
Charm	+1
Isospin	D⁺ ,D⁰ : +⁠1/2⁠ D⁻ ,D⁰ : −⁠1/2⁠ D^± _s: 0
Parity	−1

TheD mesons are the lightest particle that containcharm quarks. They are often studied to gain knowledge on theweak interaction.^[1] Thestrange D mesons (D_s) were called "F mesons" prior to 1986.^[2]

Overview

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The D mesons were discovered in 1976 by theMark I detector at theStanford Linear Accelerator Center.^[3]

Since the D mesons are the lightest mesons containing a single charmquark (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 internalcharm quantum number, and can take place only via theweak interaction. In D mesons, the charm quark preferentially changes into a strange quark via an exchange of aW particle, therefore the D meson preferentially decays intokaons (K) andpions (π).^[1]

List of D mesons

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D mesons
Particle name	Particle symbol	Antiparticle symbol	Quark content^[4]	Rest mass [MeV/c²]	I	J^P	S	C	Mean lifetime [s]	Commonly decays to (>5% of decays)
Charged D meson^[5]	D⁺	D⁻	cd	1869.62±0.20	⁠1/2⁠	0⁻	0	+1	(1.040±0.007)×10⁻¹²	^[6]
Neutral D meson^[7]	D⁰	D⁰	cu	1864.84±0.17	⁠1/2⁠	0⁻	0	+1	(4.101±0.015)×10⁻¹³	^[8]
Strange D meson^[9]	D⁺ _s	D⁻ _s	cs	1968.47±0.33	0	0⁻	+1	+1	(5.00±0.07)×10⁻¹³	^[10]
Excited charged D meson^[11]	D^∗+ (2010)	D^∗− (2010)	cd	2010.27±0.17	⁠1/2⁠	1⁻	0	+1	(6.9±1.9)×10⁻²¹^{^‡}	D⁰ +π⁺ or D⁺ +π⁰
Excited neutral D meson^[12]	D^∗0 (2007)	D^∗0 (2007)	cu	2006.97±0.19	⁠1/2⁠	1⁻	0	+1	> 3.1×10⁻²²^{^‡}	D⁰ +π⁰ or D⁰ +γ

‡^ PDG reports the resonance width (⁠ $\Gamma$ ⁠). Here the conversion $\tau ={\hbar }/{\Gamma }$ is given instead.

CP violation

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In 2019, an analysis by theLHCb experiment reported the first observation ofCP violation in the decays of the neutralD⁰
meson, with a significance of over fivestandard deviations.^[13] The results of a subsequent data analysis by the same collaboration was presented in 2022, which announced that they found evidence of directCP violation in the decay of theD⁰
meson intopions.^[14]

D–D oscillations

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In 2021 it was confirmed with a significance of more than sevenstandard deviations, that the neutralD⁰
meson spontaneously transforms into its own antiparticle and back. This phenomenon is calledflavor oscillation and was prior known to exist in the neutralK meson andB meson.^[15]

References

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^^a ^bNave, G., ed. (2016)."D meson". Department of Physics & Astronomy.HyperPhysics. Atlanta, GA:Georgia State University.
^Wohl, C.G. (1984)."Review of Particle Physics"(PDF).Reviews of Modern Physics.56 (2, Part II).Particle Data Group.doi:10.1103/RevModPhys.56.S1.
^Kudryavtsev, Vitaly A."Charmed mesons" (course files). Physics 466.University of Sheffield.^{[permanent dead link]}
^Amsler, C.; et al. (Particle Data Group) (2008)."Quark Model"(PDF).Lawrence Berkeley Laboratory.
^Amsler, C.; et al. (Particle Data Group) (2008)."D^±
"(PDF). Particle listings.Lawrence Berkeley Laboratory.
^Amsler, C.; et al. (Particle Data Group) (2008)."D^±
"(PDF). Decay modes.Lawrence Berkeley Laboratory.
^Amsler, C.; et al. (Particle Data Group) (2008)."D⁰
"(PDF). Particle listings.Lawrence Berkeley Laboratory.
^Amsler, C.; et al. (Particle Data Group) (2008)."D⁰
"(PDF). Decay modes.Lawrence Berkeley Laboratory.
^Nakamura, N.; et al. (Particle Data Group) (2010)."D^±
_s"(PDF). Particle listings.Lawrence Berkeley Laboratory.
^Nakamura, N.; et al. (Particle Data Group) (2010)."D⁺
_s"(PDF). Decay modes.Lawrence Berkeley Laboratory.
^Amsler, C.; et al. (Particle Data Group) (2008)."D^∗±
"(PDF). Decay modes.Lawrence Berkeley Laboratory.
^Amsler, C.; et al. (Particle Data Group) (2008)."D^∗0
(2007)"(PDF). Decay modes.Lawrence Berkeley Laboratory.
^Aaij, R.; et al. (LHCb collaboration) (29 May 2019) [21 March 2019]. "Observation of CP Violation in Charm Decays".Physical Review Letters.122 (21) 211803.arXiv:1903.08726.Bibcode:2019PhRvL.122u1803A.doi:10.1103/PhysRevLett.122.211803.PMID 31283320. 1903.08726.
^Aaij, R.; et al. (LHCb collaboration) (29 August 2023) [9 September 2022]. "Measurement of the Time-Integrated CP Asymmetry in D0 -> KK Decays".Physical Review Letters.131 (9) 091802.arXiv:2209.03179.doi:10.1103/PhysRevLett.131.091802.PMID 37721849. 1903.08726.
^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 inPhysical Review Letters127, 111801. Report numbers: LHCb-PAPER-2021-009, CERN-EP-2021-099.

Particles in physics

Elementary

Fermions

Quarks	Up (quark antiquark) Down (quark antiquark) Charm (quark antiquark) Strange (quark antiquark) Top (quark antiquark) Bottom (quark antiquark)
Leptons	Electron Positron Muon Antimuon Tau Antitau Neutrino Electron neutrino Electron antineutrino Muon neutrino Muon antineutrino Tau neutrino Tau antineutrino

Bosons

Gauge	Photon Gluon W and Z bosons
Scalar	Higgs boson

Ghost fields

Faddeev–Popov ghosts

Hypothetical

Superpartners

Gauginos	Gluino Gravitino Photino
Others	Axino Chargino Higgsino Neutralino Sfermion (Stop squark)

Others

Composite

Hadrons

Baryons	Nucleon Proton Antiproton Neutron Antineutron Delta baryon Lambda baryon Sigma baryon Xi baryon Omega baryon
Mesons	Pion Rho meson Eta and eta prime mesons Bottom eta meson Phi meson J/psi meson Omega meson Upsilon meson Kaon B meson D meson Quarkonium
Exotic hadrons	Tetraquark (Double-charm tetraquark) Pentaquark