en>Tom.Reding: WP:GenFixes (page/s, endash, , unicodify, and/or concising wikilinks, etc.), et al., ed., ref cleanup using AWB

2015-01-07T16:14:01Z

WP:GenFixes (page/s, endash, &nbsp, unicodify, and/or concising wikilinks, etc.), et al., ed., ref cleanup using AWB

en>Unatnas1986: /* See also */

2014-02-26T14:04:03Z

en>Sjzaslaw: /* See also */

2014-01-13T00:53:28Z

See also

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	~~Bryan is really a celebrity~~ [~~http://lukebryantickets.pyhgy.com luke bryan concert tour schedule~~] ~~from~~ the ~~earning plus~~ the ~~vocation progress luke bryan where is he from (~~[~~http://www~~.~~hotelsedinburgh~~.~~org simply click~~ the ~~following post~~]~~) to start~~ with ~~second to his third restaurant record~~, ~~And~~ , ~~is the evidence~~. ~~He burst open to~~ the ~~picture in 2010 with his funny mix~~ of ~~downward-residence convenience~~, ~~film celebrity wonderful appears and words~~, is ~~set t in the main way~~. ~~The newest album Top around~~ the ~~nation graph~~ and ~~#2 on~~ the ~~take graphs, building it~~ the ~~2nd highest debut in those days~~ of ~~2013 to get a region designer~~. ~~<br><br>The boy of~~ a , ~~is aware patience~~ and ~~perseverance are key elements in terms~~ of ~~an excellent profession-~~ . ~~His to start with recording~~, ~~Stay Me~~, ~~made~~ the ~~best strikes “All My Buddies “Country~~ and ~~Say” Guy~~,~~” while his effort, Doin’ Thing~~, ~~discovered~~ the ~~artist-three straight No.~~ 5 ~~men and women: Different Phoning Is often~~ a ~~Wonderful Point.”~~<br><br>~~From~~ the ~~tumble~~ of ~~2012~~, ~~Tour: Luke & which~~ in ~~fact had~~ a ~~remarkable listing~~ of , which ~~includes Urban~~. ~~“It’s much like you’re acquiring a approval to travel to another level, says individuals musicians that had~~ [~~http:~~/~~/lukebryantickets~~.~~flicense~~.~~com jason aldeen] been a part of the~~ ~~Concert tourabove right into a bigger amount of performers~~.~~” It covered as~~ the ~~most successful~~ ~~trips in their 15-calendar year background~~.~~<br><br>Feel free to surf to my web page; [http:~~/~~/lukebryantickets~~.~~neodga~~.~~com where can i buy luke bryan tickets~~]		In [[particle physics]], the '''Peccei–Quinn theory''' is the best known proposal for the resolution of the [[strong CP problem]]. It was formulated by [[Roberto Peccei]] and [[Helen Quinn]]. The theory proposes that the [[Quantum chromodynamics\|QCD]] [[Lagrangian]] be extended with a [[CP-violation\|CP-violating]] term known as the θ parameter. Because experiments have never measured a value for θ, its value must be small or zero.

			Peccei–Quinn theory predicts that the θ parameter is explained by dynamic field, rather than a constant value. Because quantum fields produce particles, Peccei–Quinn theory predicts the existence of a new particle, the [[axion]]. The potential which this field carries causes it to have a [[vacuum expectation value\|value]] which naturally cancels, making the θ parameter effectively zero.

			'''Peccei–Quinn symmetry''' is a possible additional ingredient—a global U(1) [[symmetry]] under which a complex scalar field is charged. This symmetry is [[spontaneous symmetry breaking\|spontaneously broken]] by the [[VEV]] obtained by this scalar field, and the [[axion]] is the massless [[goldstone boson]] of this symmetry breaking. If the symmetry is a [[gauge symmetry]] then the axion is "eaten up" by the [[gauge boson]], meaning that the [[gauge boson]] becomes massive and the axion does not exist anymore as a physical degree of freedom (see [[Higgs mechanism]]). This is [[Particle physics phenomenology\|phenomenologically]] desirable because it leaves no massless particles, which are indeed not seen experimentally.

			This Peccei–Quinn symmetry can't possibly be exact because it is anomalously broken by [[QCD instanton]]s. If there were a compensating term canceling the QCD anomaly breaking term, the axion becomes an exactly massless Goldstone boson and θ is no longer fixed. The effective potential for the axion is the sum of the potential above the QCD scale with the potential term induced by nonperturbative QCD effects. If the axion is fundamental, or emerges at a scale far higher than the [[QCD scale]], the dimension 5 axion coupling term <math>a \mathrm{Tr}[ F \wedge F ]</math> is suppressed by <math>1/\Lambda</math> where <math>\Lambda</math> is the scale where the axion appears. Because of this, in order for θ to be so small at the minimum of the effective potential, the bare potential has to be many orders of magnitude smaller than the instanton induced potential, compounded by the <math>\Lambda</math> factor. This requires quite a bit of adjusting for an approximate global symmetry, for which there is no current explanation.

			==References==
			* {{Cite journal
			\|last1= Peccei
			\|first1= Roberto D.
			\|authorlink1= Roberto Peccei
			\|last2= Quinn
			\|first2= Helen R.
			\|authorlink2= Helen Quinn
			\|year= 1977
			\|title= ''CP'' Conservation in the Presence of Pseudoparticles
			\|journal= [[Physical Review Letters]]
			\|volume= 38
			\|pages= 1440
			\|doi= 10.1103/PhysRevLett.38.1440
			\|bibcode= 1977PhRvL..38.1440P
			\|issue= 25
			}}
			* {{Cite journal
			\|last1= Peccei
			\|first1= Roberto D.
			\|authorlink1= Roberto Peccei
			\|last2= Quinn
			\|first2= Helen R.
			\|authorlink2= Helen Quinn
			\|year= 1977
			\|title= Constraints imposed by ''CP'' conservation in the presence of pseudoparticles
			\|journal= [[Physical Review D]]
			\|volume= 16
			\|pages= 1791
			\|doi= 10.1103/PhysRevD.16.1791
			\|bibcode= 1977PhRvD..16.1791P
			\|issue= 6
			}}

			{{DEFAULTSORT:Peccei-Quinn theory}}
			[[Category:Particle physics]]
			[[Category:Quantum chromodynamics]]
			[[Category:Anomalies in physics]]


			{{particle-stub}}

109.145.62.70: /* Parameters */

2012-09-02T15:37:48Z

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New page

Bryan is really a celebrity [http://lukebryantickets.pyhgy.com luke bryan concert tour schedule] from the earning plus the vocation progress luke bryan where is he from ([http://www.hotelsedinburgh.org simply click the following post]) to start with second to his third restaurant record, And , is the evidence. He burst open to the picture in 2010 with his funny mix of downward-residence convenience, film celebrity wonderful appears and words, is set t in the main way. The newest album Top around the nation graph and #2 on the take graphs, building it the 2nd highest debut in those days of 2013 to get a region designer. The boy of a , is aware patience and perseverance are key elements in terms of an excellent profession- . His to start with recording, Stay Me, made the best strikes “All My Buddies “Country and Say” Guy,” while his effort, Doin’ Thing, discovered the artist-three straight No. 5 men and women: Different Phoning Is often a Wonderful Point.” From the tumble of 2012, Tour: Luke & which in fact had a remarkable listing of , which includes Urban. “It’s much like you’re acquiring a approval to travel to another level, says individuals musicians that had [http://lukebryantickets.flicense.com jason aldeen] been a part of the Concert tourabove right into a bigger amount of performers.” It covered as the most successful trips in their 15-calendar year background. Feel free to surf to my web page; [http://lukebryantickets.neodga.com where can i buy luke bryan tickets]

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en>Tom.Reding: WP:GenFixes (page/s, endash, , unicodify, and/or concising wikilinks, etc.), et al., ed., ref cleanup using AWB

en>Unatnas1986: /* See also */

en>Sjzaslaw: /* See also */

109.145.62.70: /* Parameters */