Antineutron

Antineutron
	Kvarkna struktura antineutrona.
Klasifikacija	Antibarion
Kompozicija	1 gornji antikvark, 2 donji antiquarks
Statistike	Fermionski
Interakcije	Jaka, slaba, gravitaciona, elektromagnetna
Status	Otkriven
Simbol	n
Antičestica	Neutron
Otkriven	Brus Kork (1956)
Masa	939,565560(81) MeV/c2
Naelektrisanje	0
Magnetni moment	+1,91 µN
Spin	1⁄2
Izospin	1⁄2

Antineutron je antičestica neutrona sa simbolom n.^[1]^[2]^[3] On se razlikuje od neutrona samo po tome što neka od njegovih svojstava imaju jednaku veličinu ali suprotan znak.^[4] On ima istu masu kao i neutron, i nema neto električni naboj, ali ima suprotan barionski broj (+1 za neutron, -1 za antineutron). To je zato što je antineutron sačinjen od antikvarkova, dok su neutroni sastavljeni od kvarkova. Antineutron se sastoji od jednog gornjeg antikvarka i dva donja antikvarka.

Pošto je antineutron električno neutralan, on se ne može lako posmatrati direktno. Umesto toga, posmatraju se proizvodi njegove anihilacije običnom materijom. Teoretski, slobodni antineutron treba da se raspadne u antiproton,^[5] pozitron i neutrino u procesu analognom beta raspadanju slobodnih neutrona. Postoje teorijski predlozi oscilacija neutron-antineutrona, procesa koji podrazumeva kršenje očuvanja barionskog broja.^[6]^[7]^[8]

Antineutron je otkriven u sudaru protona-antiprotona u Bevatronu^[9] (Larens Berkli nacionalnoj laboratoriji) zaslugom Brusa Korka 1956. godine, godinu dana nakon što je antiproton otkriven.^[10]^[11]

Magnetni moment

Magnetni moment antineutrona je suprotan magnetnom momentu neutrona.^[12] On je 7000191000000000000♠+1,91 µ_N za antineutron, dok je 2999809000000000000♠−1,91 µ_N za neutron (relativno na pravac spina). Ovde je µ_N nuklearni magneton.

Vidi još

Reference

^ „The Nobel Prize in Physics 1959”.
^ „Antimatter Atoms Trapped for First Time—"A Big Deal"”. 19. 11. 2010.
^ Weinberg, Steve (1995-06-30). The quantum theory of fields, Volume 1 : Foundations. стр. 14. ISBN 0-521-55001-7.
^ Lancaster, Tom; Blundell, Stephen J.; Blundell, Stephen (април 2014). Quantum Field Theory for the Gifted Amateur (на језику: енглески). OUP Oxford. стр. 61. ISBN 9780199699339.
^ Dirac, Paul (1930). „A Theory of Electrons and Protons”. Proceedings of the Royal Society A. 126 (801): 360—365. Bibcode:1930RSPSA.126..360D. doi:10.1098/rspa.1930.0013 .
^ R. N. Mohapatra (2009). „Neutron-Anti-Neutron Oscillation: Theory and Phenomenology”. Journal of Physics G. 36 (10): 104006. Bibcode:2009JPhG...36j4006M. arXiv:0902.0834 . doi:10.1088/0954-3899/36/10/104006.
^ C. Giunti; M. Laveder (19. 8. 2010). „Neutron Oscillations”. Neutrino Unbound. Istituto Nazionale di Fisica Nucleare. Архивирано из оригинала 27. 9. 2011. г. Приступљено 19. 8. 2010.
^ Y. A. Kamyshkov (16. 1. 2002). „Neutron → Antineutron Oscillations” (PDF). NNN 2002 Workshop on "Large Detectors for Proton Decay, Supernovae and Atmospheric Neutrinos and Low Energy Neutrinos from High Intensity Beams" at CERN. Приступљено 19. 8. 2010.
^ „The History of Antimatter - From 1928 to 1995”. CERN. Архивирано из оригинала 2008-06-01. г. Приступљено 2008-05-24. (The cited page is noted as "3 of 5". The heading on the cited page is "1954: power tools".)
^ „The History of Antimatter - From 1928 to 1995”. CERN. Архивирано из оригинала 2008-06-01. г. Приступљено 2008-05-24. (The cited page is noted as "3 of 5". The heading on the cited page is "1954: power tools".)
^ Cork, Bruce; Lambertson, Glen R.; Piccioni, Oreste; Wenzel, William A. (15. 11. 1956). „Antineutrons Produced from Antiprotons in Charge-Exchange Collisions”. Physical Review. 104 (4): 1193—1197. Bibcode:1956PhRv..104.1193C. S2CID 123156830. doi:10.1103/PhysRev.104.1193.
^ Lorenzon, Wolfgang (6. 4. 2007). „Physics 390: Homework set #7 Solutions” (PDF). Modern Physics, Physics 390, Winter 2007. Приступљено 22. 12. 2009.

Literatura

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Weinberg, S. (1995). The Quantum Theory of Fields, Volume 1: Foundations. Cambridge University Press. ISBN 0-521-55001-7.
G. Fraser (18. 5. 2000). Antimatter: The Ultimate Mirror. Cambridge University Press. ISBN 978-0-521-65252-0.
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Spoljašnje veze

LBL Particle Data Group: summary tables
-author= -
Elementary particles: includes information about antineutron discovery (archived link)
"Is Antineutron the Same as Neutron?" explains how the antineutron differs from the regular neutron despite having the same, that is zero, charge.
Antiparticle (physics) на сајту Енциклопедија Британика

[1] „The Nobel Prize in Physics 1959”.

[2] „Antimatter Atoms Trapped for First Time—"A Big Deal"”. 19. 11. 2010.

[3] Weinberg, Steve (1995-06-30). The quantum theory of fields, Volume 1 : Foundations. стр. 14. ISBN 0-521-55001-7.

[4] Lancaster, Tom; Blundell, Stephen J.; Blundell, Stephen (април 2014). Quantum Field Theory for the Gifted Amateur (на језику: енглески). OUP Oxford. стр. 61. ISBN 9780199699339.

[5] Dirac, Paul (1930). „A Theory of Electrons and Protons”. Proceedings of the Royal Society A. 126 (801): 360—365. Bibcode:1930RSPSA.126..360D. doi:10.1098/rspa.1930.0013 .

[6] R. N. Mohapatra (2009). „Neutron-Anti-Neutron Oscillation: Theory and Phenomenology”. Journal of Physics G. 36 (10): 104006. Bibcode:2009JPhG...36j4006M. arXiv:0902.0834 . doi:10.1088/0954-3899/36/10/104006.

[7] C. Giunti; M. Laveder (19. 8. 2010). „Neutron Oscillations”. Neutrino Unbound. Istituto Nazionale di Fisica Nucleare. Архивирано из оригинала 27. 9. 2011. г. Приступљено 19. 8. 2010.

[8] Y. A. Kamyshkov (16. 1. 2002). „Neutron → Antineutron Oscillations” (PDF). NNN 2002 Workshop on "Large Detectors for Proton Decay, Supernovae and Atmospheric Neutrinos and Low Energy Neutrinos from High Intensity Beams" at CERN. Приступљено 19. 8. 2010.

[9] „The History of Antimatter - From 1928 to 1995”. CERN. Архивирано из оригинала 2008-06-01. г. Приступљено 2008-05-24. (The cited page is noted as "3 of 5". The heading on the cited page is "1954: power tools".)

[:0-10] „The History of Antimatter - From 1928 to 1995”. CERN. Архивирано из оригинала 2008-06-01. г. Приступљено 2008-05-24. (The cited page is noted as "3 of 5". The heading on the cited page is "1954: power tools".)

[11] Cork, Bruce; Lambertson, Glen R.; Piccioni, Oreste; Wenzel, William A. (15. 11. 1956). „Antineutrons Produced from Antiprotons in Charge-Exchange Collisions”. Physical Review. 104 (4): 1193—1197. Bibcode:1956PhRv..104.1193C. S2CID 123156830. doi:10.1103/PhysRev.104.1193.

[12] Lorenzon, Wolfgang (6. 4. 2007). „Physics 390: Homework set #7 Solutions” (PDF). Modern Physics, Physics 390, Winter 2007. Приступљено 22. 12. 2009.

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