View source for Physics:Muon capture

{{Short description|Capture of a negative muon by a proton}}
[[File:Feynman diagram of muon caputure.svg|thumb|Feynman diagram of the muon capture. A negatively charged muon is captured by a proton. The proton is transformed into a neutron and a muon-neutrino is emitted. The interaction is mediated by a W-boson.]]
'''Muon capture''' is the capture of a negative [[Physics:Muon|muon]] by a [[Physics:Proton|proton]], usually resulting in production of a [[Physics:Neutron|neutron]] and a [[Physics:Neutrino|neutrino]], and sometimes a [[Physics:Gamma ray|gamma]] [[Physics:Photon|photon]].

Muon capture by heavy nuclei often leads to emission of particles; most often [[Physics:Neutron|neutron]]s, but charged particles can be emitted as well.

'''Ordinary muon capture''' ('''OMC''') involves capture of a negative muon from the atomic orbital without emission of a gamma photon:

:{{SubatomicParticle|muon}}&nbsp;+&nbsp;{{SubatomicParticle|Proton+}}&nbsp;→&nbsp;{{SubatomicParticle|Neutrino}}<sub>μ</sub>&nbsp;+&nbsp;{{SubatomicParticle|Neutron0}}

'''Radiative muon capture''' ('''RMC''') is a radiative version of OMC, where a gamma photon is emitted:
:{{SubatomicParticle|muon}}&nbsp;+&nbsp;{{SubatomicParticle|Proton+}}&nbsp;→&nbsp;{{SubatomicParticle|Neutrino}}<sub>μ</sub>&nbsp;+&nbsp;{{SubatomicParticle|Neutron0}}&nbsp;+&nbsp;{{SubatomicParticle|Gamma}}

Theoretical motivation for the study of muon capture on the proton is its connection to the proton's induced pseudoscalar [[Physics:Form factor (quantum field theory)|form factor]] g<sub>p</sub>.

== Practical application - Nuclear waste disposal ==
Muon capture is being investigated for practical application in radioactive waste disposal, for example in the [[Physics:Nuclear transmutation|artificial transmutation]] of large quantities of long-lived [[Physics:Radioactive waste|radioactive waste]] that have been produced globally by [[Physics:Nuclear reactor|fission reactors]]. Radioactive waste can be transmuted to stable isotopes following irradiation by an incident muon ({{SubatomicParticle|muon}}) beam from a compact [[Physics:Particle accelerator|proton accelerator]] source.

==References==
*    {{cite journal | author=T. Gorringe and H.W. Fearing | title= Induced pseudoscalar coupling of the proton weak interaction | journal=Rev. Mod. Phys.  | year=2004 | volume=76 | issue= 1 | pages= 31&ndash;91 | arxiv=nucl-th/0206039 | doi= 10.1103/RevModPhys.76.31   |bibcode = 2003RvMP...76...31G }}
*    {{cite journal | author=V.A. Andreev| title= Measurement of the Rate of Muon Capture in Hydrogen Gas and Determination of the Proton's Pseudoscalar Coupling g<sub>P</sub>  | year=2007 | arxiv=0704.2072 |display-authors=0 | doi=10.1103/PhysRevLett.99.032002 | pmid= 17678281  | volume=99 | issue= 3  | pages= 032002  | journal=Physical Review Letters | bibcode=2007PhRvL..99c2002A}}
* [https://worldwide.espacenet.com/patent/search/family/056878645/publication/WO2016143144A1?q=pn%3DWO2016143144A1 Nagamine, Kanetada (2016) "Nuclear Waste Disposal Method and its apparatus using muon-nuclear-absorption". (WO2016143144A1)] Espacenet (Patent database).

[[Category:Nuclear physics]]



{{Sourceattribution|Muon capture}}