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| The '''Lambda baryons''' are a family of [[subatomic particle|subatomic]] [[hadron]] particles that have the symbols
| | Emilia Shryock is my name but you can contact me anything you like. South Dakota is exactly where me and my husband reside. Doing ceramics is what love doing. He used to be unemployed but now he is a pc operator but his promotion by no means comes.<br><br>Also visit my website; [http://nfldev.com/index.php?do=/profile-12302/info/ nfldev.com] |
| {{SubatomicParticle|Lambda0}}, {{SubatomicParticle|Charmed Lambda+}}, {{SubatomicParticle|Bottom Lambda0}}, and {{SubatomicParticle|Top Lambda+}} and have +1 [[elementary charge]] or are [[neutral particle|neutral]]. They are [[baryon]]s containing three different quarks: one [[up quark|up]], one [[down quark|down]], and one third quark, which can be either a [[strange quark|strange]] ({{SubatomicParticle|Lambda0}}), a [[charm quark|charm]] ({{SubatomicParticle|Charmed Lambda+}}), a [[bottom quark|bottom]] ({{SubatomicParticle|Bottom Lambda0}}), or a [[top quark|top]] ({{SubatomicParticle|Top Lambda+}}) quark. The top Lambda is not expected to be observed as the [[Standard Model]] predicts the [[mean lifetime]] of top quarks to be roughly {{val|5|e=-25|u=s}}.<ref name=Quadt>
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| {{cite journal
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| |author=A. Quadt
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| |year=2006
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| |title=Top quark physics at hadron colliders
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| |journal=[[European Physical Journal C]]
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| |volume=48
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| |issue=3 |pages=835–1000
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| |doi=10.1140/epjc/s2006-02631-6
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| |bibcode = 2006EPJC...48..835Q }}</ref> This is about 20 times shorter than the timescale for strong interactions, and therefore it does not [[Hadronization|form hadrons]].
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| The Lambda baryon {{SubatomicParticle|Lambda0}} was first discovered in October 1950, by V D Hopper and S Biswas of the University of Melbourne, as a neutral [[V particle]] with a [[proton]] as a decay product, thus correctly distinguishing it as a [[baryon]] rather than a [[meson]] <ref>{{cite journal|last=V D Hopper|first=S Biswas|title=Evidence Concerning the Existence of the New Unstable Elementary Neutral Particle|journal=Phys. Rev. | volume = 80 | page = 1099|year=1950}}</ref> (i.e. different in kind from the [[K-meson]] discovered in 1947 by Rochester and Butler <ref>{{cite journal|last=G.D.Rochester|first=C.C.Butler|title=Evidence for the Existence of New Unstable Elementary Particles|journal=Nature | volume = 160 | page = 855|year=1947}}</ref>); they were produced by cosmic rays and detected in photographic emulsions flown in a balloon at 70,000 ft. <ref>{{cite book|last=Pais|first=Abraham|title=Inward Bound|publisher=Oxford University Press, p 21, 511-517|year=1986}}</ref> Though the particle was expected to live for {{val|p=~|e=-23|u=seconds}},<ref name="LambdaFound">[http://hyperphysics.phy-astr.gsu.edu/Hbase/Particles/quark.html#c4 The Strange Quark]</ref> it actually survived for {{val|p=~|e=-10|u=seconds}}.<ref name="Lambda0"/> The property that caused it to live so long was dubbed ''strangeness'' and led to the discovery of the strange quark.<ref name="LambdaFound"/> Furthermore, these discoveries led to a principle known as the ''conservation of strangeness'', wherein lightweight particles do not decay as quickly if they exhibit strangeness (because non-weak methods of particle decay must preserve the strangeness of the decaying baryon).<ref name="LambdaFound"/>
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| The Lambda baryon has also been observed in atomic nuclei called [[Hypernuclei]]. These nuclei contain the same number of protons and neutrons as a known nucleus, but also contains one or in rare cases two Lambda particles.<ref>{{cite web|title=Media Advisory: The Heaviest Known Antimatter|url=http://www.bnl.gov/rhic/news2/news.asp?a=1236&t=pr|publisher=bnl.gov}}</ref> In such a scenario, the Lambda slides into the center of the nucleus (it is not a proton or a neutron, and thus is not affected by the [[Pauli exclusion principle]]), and it binds the nucleus more tightly together due to its interaction via the strong force. In a [[lithium]] isotope (Λ7Li), it made the nucleus 19% smaller.<ref>{{cite web|last=Brumfiel|first=Geoff|title=Focus: The Incredible Shrinking Nucleus|url=http://physics.aps.org/story/v7/st11}}</ref>
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| ==List==
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| The symbols encountered in this list are: I (''[[isospin]]''), J (''[[total angular momentum]]''), P (''[[Parity (physics)|parity]]''), Q (''[[charge (physics)|charge]]''), S (''[[strangeness (particle physics)|strangeness]]''), C (''[[Charm (quantum number)|charmness]]''), B′ (''[[bottomness]]''), T (''[[topness]]''), B (''[[baryon number]]''), u (''[[up quark]]''), d (''[[down quark]]''), s (''[[strange quark]]''), c (''[[charm quark]]''), b (''[[bottom quark]]''), t (''[[top quark]]''), as well as other subatomic particles (hover for name).
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| Antiparticles are not listed in the table; however, they simply would have all quarks changed to antiquarks, and Q, B, S, C, B′, T, would be of opposite signs. I, J, and P values in red have not been firmly established by experiments, but are predicted by the [[quark model]] and are consistent with the measurements.<ref>C. Amsler et al. (2008): [http://pdg.lbl.gov/2008/tables/rpp2008-sum-baryons.pdf Particle summary tables – Baryons]</ref><ref>J. G. Körner et al. (1994)</ref> The top lambda ({{SubatomicParticle|Top Lambda+}}) is listed for comparison, but is not expected to be observed, because top quarks decay before they have time to [[hadronize]].<ref name="HoKim">{{cite book| last = Ho-Kim| first = Quang | first2 = Xuan Yem | last2 = Pham| title = Elementary Particles and Their Interactions: Concepts and Phenomena| year = 1998| publisher = Springer-Verlag| location = Berlin| isbn = 3-540-63667-6|oclc=38965994| page = 262| chapter = Quarks and SU(3) Symmetry| quote = Because the top quark decays before it can be hadronized, there are no bound <math alt="t anti-t">t\bar{t}</math> states and no top-flavored mesons or baryons[...].}}</ref>
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| {| class="wikitable sortable" style="text-align: center;"
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| |+Lambda baryons
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| |-
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| ! class=unsortable|Particle name
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| ! Symbol
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| ! class=unsortable|Quark<br>content
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| ! [[Rest mass]] ([[electron volt|MeV]]/[[speed of light|c]]<sup>2</sup>)
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| ! width="50"|[[Isospin|I]]
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| ! width="50"|[[Total angular momentum|J]]<sup>[[Parity (physics)|P]]</sup>
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| ! width="50"|[[charge (physics)|Q]] ([[elementary charge|e]])
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| ! width="50"|[[strangeness|S]]
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| ! width="50"|[[charm (quantum number)|C]]
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| ! width="50"|[[bottomness|B']]
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| ! width="50"|[[topness|T]]
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| ! [[Mean lifetime]] ([[second|s]])
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| ! class=unsortable|Commonly decays to
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| |- style="height:40px"
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| |align="left"| Lambda<ref name="Lambda0">C. Amsler et al. (2008): [http://pdg.lbl.gov/2008/listings/s018.pdf Particle listings – {{SubatomicParticle|Lambda}}]</ref>
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| | {{SubatomicParticle|Lambda0}}
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| | {{SubatomicParticle|link=yes|Up quark}}{{SubatomicParticle|link=yes|Down quark}}{{SubatomicParticle|link=yes|Strange quark}}
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| | {{val|1115.683|0.006}}
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| | 0
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| | {{frac|1|2}}<sup>+</sup>
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| | 0
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| | −1
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| | 0
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| | 0
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| | 0
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| | {{val|2.631|0.020|e=-10}}
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| | {{nowrap|{{SubatomicParticle|link=yes|Proton+}} + {{SubatomicParticle|link=yes|Pion-}} or}} <br/> {{nowrap|{{SubatomicParticle|link=yes|Neutron0}} + {{SubatomicParticle|link=yes|Pion0}}}}
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| |- style="height:40px"
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| |align="left"| charmed Lambda<ref name=PDGCharmedLamdba>C. Amsler et al. (2008): [http://pdg.lbl.gov/2008/listings/s033.pdf Particle listings – {{SubatomicParticle|Charmed Lambda}}]</ref>
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| | {{SubatomicParticle|Charmed Lambda+}}
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| | {{SubatomicParticle|link=yes|Up quark}}{{SubatomicParticle|link=yes|Down quark}}{{SubatomicParticle|link=yes|Charm quark}}
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| | {{val|2286.46|0.14}}
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| | 0
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| | <span style="color:red">{{frac|1|2}}</span> <sup>+</sup>
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| | +1
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| | 0
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| | +1
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| | 0
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| | 0
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| | {{val|2.00|0.06|e=-13}}
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| | See [http://pdg.lbl.gov/2008/listings/s033.pdf {{SubatomicParticle|Charmed lambda+}} decay modes]
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| |- style="height:40px"
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| |align="left"| bottom Lambda<ref name=PDGBottomLambda0>C. Amsler et al. (2008): [http://pdg.lbl.gov/2008/listings/s040.pdf Particle listings – {{SubatomicParticle|Bottom Lambda}}]</ref>
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| | {{SubatomicParticle|Bottom Lambda0}}
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| | {{SubatomicParticle|link=yes|Up quark}}{{SubatomicParticle|link=yes|Down quark}}{{SubatomicParticle|link=yes|Bottom quark}}
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| | {{val|5620.2|1.6}}
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| | <span style="color:red">0</span>
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| | <span style="color:red">{{frac|1|2}}</span> <sup><span style="color:red">+</span></sup>
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| | 0
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| | 0
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| | 0
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| | −1
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| | 0
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| | {{val|1.409|0.055|-0.054|e=-12}}
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| | See [http://pdg.lbl.gov/2008/listings/s040.pdf {{SubatomicParticle|Bottom Lambda0}} decay modes]
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| |- style="height:40px"
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| |align="left"| top Lambda<sup>{{ref|Undiscovered|†}}</sup>
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| | {{SubatomicParticle|Top Lambda+}}
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| | {{SubatomicParticle|link=yes|Up quark}}{{SubatomicParticle|link=yes|Down quark}}{{SubatomicParticle|link=yes|Top quark}}
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| | —
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| | <span style="color:red">0</span>
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| | <span style="color:red">{{frac|1|2}}</span> <sup><span style="color:red">+</span></sup>
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| | +1
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| | 0
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| | 0
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| | 0
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| | +1
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| | —
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| | —
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| |}
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| <sup>†</sup> {{note|Undiscovered}} Particle unobserved, because the top-quark decays before it hadronizes.
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| ==See also==
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| {{Portal|Physics}}
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| * [[List of baryons]]
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| ==References==
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| <references/>
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| === Bibliography ===
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| * {{cite journal
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| |author=C. Amsler ''et al.'' ([[Particle Data Group]])
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| |year=2008
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| |title=Review of Particle Physics
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| |journal=[[Physics Letters B]]
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| |volume=667 |pages=1
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| |doi=10.1016/j.physletb.2008.07.018
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| |bibcode = 2008PhLB..667....1P }}
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| *{{cite journal
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| |author=C. Caso ''et al.'' ([[Particle Data Group]])
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| |year=1998
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| |title=Review of Particle Physics
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| |journal=[[European Physical Journal C]]
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| |volume=3 |pages=1
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| |doi=10.1007/s10052-998-0104-x
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| |bibcode = 1998EPJC....3....1P }}
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| * {{cite journal
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| |author=J. G. Körner, M. Krämer, and D. Pirjol
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| |year=1994
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| |title=Heavy Baryons
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| |journal=[[Progress in Particle and Nuclear Physics]]
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| |volume=33 |pages=787–868
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| |doi=10.1016/0146-6410(94)90053-1
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| |arxiv=hep-ph/9406359
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| |bibcode = 1994PrPNP..33..787K }}
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| *{{cite web
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| |author=R. Nave
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| |date=12 April 2005
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| |title=The Lambda Baryon
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| |url=http://hyperphysics.phy-astr.gsu.edu/hbase/particles/lambda.html
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| |work=[[HyperPhysics]]
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| |accessdate=2010-07-14
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| }}
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| {{Particles}}
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| {{DEFAULTSORT:Lambda Baryon}}
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| [[Category:Baryons]]
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| [[Category:Particle physics]]
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Emilia Shryock is my name but you can contact me anything you like. South Dakota is exactly where me and my husband reside. Doing ceramics is what love doing. He used to be unemployed but now he is a pc operator but his promotion by no means comes.
Also visit my website; nfldev.com