Ogled vira Mezon D

{{Infopolje Delec
| name            = mezon D
| image           = 
| caption         = 
| num_types       = 
| mean_lifetime   = 
| statistics      = [[bozon]]ska
| group           = [[mezon]]
| generation      = 
| interaction     = [[močna jedrska sila|močna]], [[šibka jedrska sila|šibka]]
| antiparticle    = 
| theorized       =
| discovered      = 
| symbol          = <math> D^0 \,</math>,  <math> D^+ \,</math>, </br><math> D^- \,</math>, <math> D^{*0} \,</math>, </br> <math>D^{*+} \,</math>
| mass            = D<sup>+</sup> : 1869,62±0,20 [[elektronski volt|MeV]]/[[hitrost svetlobe|c<sup>2</sup>]] </br> D<sup>0</sup> : 1864,62±0,17 MeV/c<sup>2</sup>
| electric_charge = D<sup>0</sup> : 0 [[osnovni naboj|''e''<sub>0</sub>]]</br> D<sup>+</sup> +1 e<sub>0</sub>
| spin            = celo število
| isospin = 1/2
|weak_isospin    = 
 |weak_hypercharge= 
}}
'''Mezon D''' [mezón D] (pred letom 1986 tudi mezon F) (oznaka <math> D \,</math>) je najlažji [[mezon]], ki vsebuje [[kvark c]]. Za fiziko osnovnih delcev je zanimiv, ker omogoča raziskovanje [[šibka jedrska sila|šibke interakcije]]. 

Mezon D so prvič opazili na [[Stanfordski linearni pospeševalnik|Stanfordskem linearnem pospeševalniku]] v letu [[1976]] <ref>{{Navedi splet |url=http://www.daviddarling.info/encyclopedia/D/D_meson.html |title=Mezon D v Encyclopedia of Science |accessdate=2010-09-08 |archive-date=2011-02-25 |archive-url=https://web.archive.org/web/20110225042615/http://www.daviddarling.info/encyclopedia/D/D_meson.html |url-status=dead }}</ref>.

Ker je mezon D najlažji mezon, ki vsebuje [[kvark c]], mora pred razpadom spremeniti ta kvark v drugi kvark. Sprememba kvarka poteka preko [[šibka jedrska sila|šibke sile]]. Po spremembi kvarka mezon razpade v [[pion]]e in [[kaon]]e <ref name=autogenerated1>[http://hyperphysics.phy-astr.gsu.edu/hbase/particles/dmeson.html Mezon D]</ref>. 

== Razpad mezonov D ==
Mezon D lahko razpade na veliko načinov. Navedeni so samo nekateri :
*<math>D^0 \,</math> lahko razpade
: <math>D^0 \, \to K^{-} + \pi^{+}</math>
:<math>D^0 \, \to K^{-} + \pi^{+} + \pi^{0}</math>
:<math>D^0 \, \to K^{-} + \pi^{+} + \pi^{+} + \pi^{-}</math>
:<math>D^0 \, \to K^{-} + \mu^{+} + \nu_{\mu}</math>
*<math>D^+ \,</math> lahko razpade
:<math>D^+ \, \to K^{-} + \pi^{+} + \pi^{+}</math>
:<math>D^+ \, \to K^{-} + \mu^{+} + \pi^{+} + \nu_{\mu}</math>
* <math>D^s \,</math> lahko razpade
:<math>D_s^+ \to K^{-} + \pi^{+} + K^{+}</math>

== Pregled mezonov D ==
Pojavlja se v nekaj različicah. Njegove lastnosti so podane v spodnji preglednici.
{| class="wikitable" style="text-align: center;" width=100%
|-
! ime delca
! oznaka
! antidelec <br>oznaka
! kvarki
! [[mirovna masa]] ([[elektronski volt|MeV]]/[[hitrost svetlobe|c]]<sup>2</sup>)
! width="50"|[[izospin|I]]<sup>[[parnost G|G]]</sup>
! width="50"|[[skupna vrtilna količina|J]]<sup>[[parnost (fizika)|P]][[parnost C|C]]</sup>
! width="50"|[[čudnost (fizika)|S]]
! width="50"|[[čar (fizika)|C]]
! width="50"|[[dno (fizika)|B']]
! [[srednji življenjski čas]] </br>([[sekunda|s]])
! razpad</br>
(>5% vseh razpadov)
|-
| mezon D <ref name=PDGD+>C. Amsler ''et al.''. (2008): [http://pdg.lbl.gov/2008/listings/s031.pdf Pregled delcev – D<sup>±</sup>]</ref>
|align="center"| <math>D^+ \,</math>
|align="center"| <math>D^- \,</math>
|align="center"| <math>c \bar d \,</math>
|align="center"| 1869,62&nbsp;±&nbsp;0,20
|align="center"| 1/2
|align="center"| 0<sup>&minus;</sup>
|align="center"| 0
|align="center"| +1
|align="center"| 0
|align="center"| 1,040±0,007.10<sup>-12</sup>
|align="center"| [http://pdg.lbl.gov/2008/listings/s031.pdf Glej načine razpada D<sup>+</sup>]
|-
| mezon D <ref name=PDGD0>C. Amsler ''et al.''. (2008): [http://pdg.lbl.gov/2008/listings/s032.pdf Pregled delcev – D<sup>0</sup>]</ref>
|align="center"| <math>D^0 \,</math>
|align="center"| <math> \bar D^0 \,</math>
|align="center"| <math>c \bar u \,</math>
|align="center"| 1864,84&nbsp;±&nbsp;0,17
|align="center"| 1/2
|align="center"| 0<sup>&minus;</sup>
|align="center"| 0
|align="center"| +1
|align="center"| 0
|align="center"| 4,101±0,015.10<sup>−13</sup>
|align="center"| [http://pdg.lbl.gov/2008/listings/s032.pdf Glej načine razpada D<sup>0</sup>]
|-
| mezon D*<ref name=PDGD*+>C. Amsler ''et al.''. (2008): [http://pdg.lbl.gov/2008/listings/m062.pdf Pregled delcev – D*<sup>±</sup>(2010)]</ref>
|align="center"| <math>D^{*+}(2010) \,</math>
|align="center"| <math> D^ {*-} (2010) \,</math>
|align="center"| <math>c \bar d \,</math>
|align="center"| 2010,27&nbsp;±&nbsp;0,17
|align="center"| 1/2
|align="center"| 1<sup>-</sup>
|align="center"| 0
|align="center"| +1
|align="center"| 0
|align="center"| 6,9±1,9.10<sup>−21</sup>
|align="center"| D<sup>0</sup> + [[pion|π<sup>+</sup>]] ali <br> D<sup>+</sup> + [[pion|π<sup>0</sup>]] 
|-
| mezon D* <ref name=PDGD*0>C. Amsler ''et al.''. (2008): [http://pdg.lbl.gov/2008/listings/m061.pdf Pregled delcev – D*<sup>0</sup>(2007)]</ref>
|align="center"| <math> D^{*0}(2007) \,</math>
|align="center"| <math> \bar D^{*0}(2007) \,</math>
|align="center"| <math>c \bar u \,</math>
|align="center"| 2006,97&nbsp;±&nbsp;0,19
|align="center"| 1/2
|align="center"| 1<sup>-</sup>
|align="center"| 0
|align="center"| +1
|align="center"| 0
|align="center"| >3,1.10<sup>-22</sup>
|align="center"| D<sup>0</sup> + [[pion|π<sup>0</sup>]] ali <br> D<sup>0</sup>  + [[foton|γ]]
|-
|}

== Opombe in sklici ==
{{opombe}}

== Glej tudi ==
* [[seznam mezonov]]

== Zunanje povezave ==
* [http://hyperphysics.phy-astr.gsu.edu/hbase/particles/dmeson.html Lastnosti mezona D na Hyperphysics] {{ikona en}}

[[Kategorija:Mezoni]]
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