View source for Physics:Xi baryon

{{Short description|Subatomic particle}}
{{Infobox Particle
| name = Xi baryon
| num_types = 2
| composition = {{plainlist|
*{{SubatomicParticle|Xi0}}: {{SubatomicParticle|Up quark}}{{SubatomicParticle|Strange quark}}{{SubatomicParticle|Strange quark}}
*{{SubatomicParticle|Xi-}}: {{SubatomicParticle|Down quark}}{{SubatomicParticle|Strange quark}}{{SubatomicParticle|Strange quark}}}}
| statistics = [[Physics:Fermion|Fermion]]ic
| group = [[Physics:Baryon|Baryon]]s
| interaction = [[Physics:Strong interaction|Strong]], [[Physics:Weak interaction|weak]], [[Physics:Electromagnetic interaction|electromagnetic]], and [[Physics:Gravity|gravity]]
| antiparticle = 
| status = 
| theorized = 
| discovered = 
| symbol = 
| mass = {{plainlist|
*{{nowrap|{{SubatomicParticle|Xi0}}: {{val|1314.86|0.20|ul=MeV/c2}}<ref name="pdg">{{cite journal| title=Review of Particle Physics | last1=Zyla | first1=P. A. | last2=Barnett | first2=R. M. | display-authors=1 | collaboration = Particle Data Group | journal=Progress of Theoretical and Experimental Physics | volume = 2020 | page = 083C01 | year = 2020 | issue=8 | doi=10.1093/ptep/ptaa104| doi-access=free | hdl=11585/772320 | hdl-access=free }}</ref>}}
*{{nowrap|{{SubatomicParticle|Xi-}}: {{val|1321.71|0.07|u=MeV/c2}}}}}}
| mean_lifetime = 
| width = 
| decay_particle = 
| electric_charge = 
| charge_radius = 
| electric_dipole_moment = 
| electric_polarizability = 
| magnetic_moment = 
| magnetic_polarizability = 
| color_charge = 
| spin = {{frac|1|2}}
| num_spin_states = 
| baryon_number = 
| strangeness = -2
| charm = 
| bottomness = 
| topness = 
| isospin = {{frac|1|2}}
| weak_isospin = 
| weak_isospin_3 = 
| hypercharge = 
| weak_hypercharge = 
| chirality = 
| B-L =
| X_charge =
| parity = 
| g_parity = 
| c_parity = 
| r_parity = 
| condensed_symmetries =
}}

The '''Xi baryons''' or '''cascade particles''' are a family of [[Physics:Subatomic particle|subatomic]] [[Physics:Hadron|hadron]] particles which have the symbol {{math|Ξ}} and may have an [[Physics:Electric charge|electric charge]] ({{mvar|Q}}) of +2&nbsp;{{mvar|e}}, +1&nbsp;{{mvar|e}}, 0, or −1&nbsp;{{mvar|e}}, where {{mvar|e}} is the [[Physics:Elementary charge|elementary charge]].

Like all conventional [[Physics:Baryon|baryon]]s, {{math|Ξ}} particles contain three quarks. {{math|Ξ}} baryons, in particular, contain either one [[Physics:Up quark|up]] or one [[Physics:Down quark|down]] quark and two other, more massive quarks. The two more massive quarks are any two of [[Physics:Strange quark|strange]], [[Physics:Charm quark|charm]], or [[Physics:Bottom quark|bottom]] (doubles allowed). For notation, the assumption is that the two heavy quarks in the {{math|Ξ}} are both [[Physics:Strange quark|strange]]; subscripts "c" and "b" are added for each even heavier [[Physics:Charm quark|charm]] or [[Physics:Bottom quark|bottom quark]] that replaces one of the two presumed [[Physics:Strange quark|strange quark]]s.

They are historically called the ''cascade particles'' because of their unstable state; they are typically observed to decay rapidly into lighter particles, through a chain of decays (cascading decays).<ref name=Nave>
{{cite web
 |first=R. |last=Nave
 |title=The Xi Baryon
 |website=HyperPhysics
 |url=http://hyperphysics.phy-astr.gsu.edu/hbase/particles/xi.html
 |access-date=4 April 2013
}}
</ref> The first discovery of a charged Xi baryon was in cosmic ray experiments by the Manchester group in 1952.<ref>
{{cite journal
 |first1=R. |last1=Armenteros
 |display-authors=0
 |collaboration=Manchester group 
 |year=1952
 |title=The properties of charged V-particles 
 |journal=[[Physics:Philosophical Magazine|Philosophical Magazine]]
 |volume=43 |issue=341 |page=597
 |doi=10.1080/14786440608520216
}}
</ref> The first discovery of the neutral Xi particle was at Lawrence Berkeley Laboratory in 1959.<ref>
{{cite journal
 |first1=L.W. |last1=Alvarez
 |display-authors=0
 |year=1959
 |title=Neutral Cascade Hyperon Event
 |journal=[[Physics:Physical Review Letters|Physical Review Letters]]
 |volume=2 |issue=5 |page=215
 |bibcode=1959PhRvL...2..215A |doi=10.1103/PhysRevLett.2.215
 |url=http://www.escholarship.org/uc/item/2gs1j865
}}
</ref> It was also observed as a daughter product from the decay of the [[Physics:Omega baryon|omega baryon]] ({{math|{{SubatomicParticle|Omega-}}}}) observed at Brookhaven National Laboratory in 1964.<ref name=Nave/> The Xi spectrum is important to nonperturbative [[Physics:Quantum chromodynamics|quantum chromodynamics]] (QCD), such as [[Physics:Lattice QCD|lattice QCD]].{{why|date=December 2016}}

==History==
The {{math|{{SubatomicParticle|Bottom Xi-}}}} particle is also known as the '''cascade&nbsp;B''' particle and contains quarks from all three families. It was discovered by [[Physics:D0 experiment|D0]] and [[Physics:Collider Detector at Fermilab|CDF]] experiments at [[Organization:Fermilab|Fermilab]]. The discovery was announced on 12 June 2007. It was the first known [[Physics:Subatomic particle|particle]] made of quarks from all three [[Physics:Generation (particle physics)|quark generations]] – namely, a [[Physics:Down quark|down quark]], a [[Physics:Strange quark|strange quark]], and a [[Physics:Bottom quark|bottom quark]]. The D0 and CDF collaborations reported the consistent masses of the new state. The [[Physics:Particle Data Group|Particle Data Group]] world average mass is {{val|5.7924|0.0030|u=GeV/c2}}.

For notation, the assumption is that the two heavy quarks are both [[Physics:Strange quark|strange]], denoted by a simple {{math|Ξ}}&nbsp;; a subscript "c" is added for each constituent [[Physics:Charm quark|charm quark]], and a "b" for each [[Physics:Bottom quark|bottom quark]]. Hence {{math|Ξ}}{{sub|c}}, {{math|Ξ}}{{sub|b}}, {{math|Ξ}}{{sub|cc}}, {{math|Ξ}}{{sub|cb}}, etc.
[[Physics:Baryon#Nomenclature|Unless specified]], the non-up/down quark content of Xi baryons is strange (i.e. there is one up or down quark and two strange quarks). However a {{math|{{SubatomicParticle|Bottom Xi0}}}} contains one up, one strange, and one bottom quark, while a {{math|{{SubatomicParticle|Double bottom xi0}}}} contains one up and two bottom quarks.

In 2012, the [[Physics:Compact Muon Solenoid|CMS]] experiment at the [[Physics:Large Hadron Collider|Large Hadron Collider]] detected a {{math|{{SubatomicParticle|bottom xi*0}}}} baryon (reported mass {{val|5945|2.8|u=MeV/c2}}).<ref>
{{cite web
 |first=C. |last=Simpson
 |date=28 April 2013
 |title=New particle discovered with 'Higgs boson' machine
 |website=The Atlantic Wire
 |url=http://www.theatlanticwire.com/technology/2012/04/new-particle-discovered-higgs-boson-machine/51688/
 |access-date=2013-04-04
}}
</ref><ref>
{{cite journal
 |first1=S. |last1=Chatrchyan
 |display-authors=0
 |collaboration=[[Physics:Compact Muon Solenoid|CMS Collaboration]]
 |year=2012
 |title=Observation of a new Ξ<sub>b</sub> baryon
 |journal=[[Physics:Physical Review Letters|Physical Review Letters]]
 |volume=108 |issue=25 |pages=252002
 |arxiv=1204.5955 |bibcode=2012PhRvL.108y2002C |pmid=23004588
 |doi=10.1103/PhysRevLett.108.252002
|s2cid=119204847
 }}
</ref> (Here,"*" indicates a baryon decuplet.) The LHCb experiment at [[Organization:CERN|CERN]] discovered two new Xi baryons in 2014: {{math|{{Subatomic particle|bottom xi'-}}}} and {{math|{{Subatomic particle|bottom xi*-}}}}.<ref>
{{cite press release
 |title=LHCb experiment observes two new baryon particles never seen before
 |date=19 November 2014
 |publisher=[[Organization:CERN|CERN]]
 |place=Bern, CH
 |url = http://press.web.cern.ch/press-releases/2014/11/lhcb-experiment-observes-two-new-baryon-particles-never-seen
}}
</ref>

In 2017, the LHCb researchers reported yet another Xi baryon: the double charmed {{math| {{SubatomicParticle|Double charmed Xi++}} }} baryon, consisting of two heavy charm quarks and one up quark. The mass of {{math|{{SubatomicParticle|Double charmed Xi++}}}} is about 3.8&nbsp;times that of a [[Physics:Proton|proton]].<ref name=CERN-P-R-2017-07-06>
{{cite press release
 |title=The LHCb experiment is charmed to announce observation of a new particle with two heavy quarks
 |date=2017-07-06
 |publisher = [[Organization:CERN|CERN]]
 |url=https://press.cern/press-releases/2017/07/lhcb-experiment-charmed-announce-observation-new-particle-two-heavy-quarks
 |access-date=2017-07-06
}}
</ref><ref name="nyt">
{{cite news
 |last=Chang |first=Kenneth
 |date=2017-07-06
 |title=CERN physicists find a particle with a double dose of charm
 |newspaper={{wipe|The New York Times}}
 |language=en-US  |issn=0362-4331
 |url=https://www.nytimes.com/2017/07/06/science/cern-quarks-charm-baryon.html
 |access-date=2017-07-08
}}
</ref>

==List of Xi baryons==
Isospin and spin values in parentheses have not been firmly established by experiments, but are predicted by the quark model and are consistent with the measurements.
{| class="wikitable sortable"
|+ Xi baryons<ref name="Abazov">
{{cite journal
 |first1=V. |last1=Abazov
 |display-authors=0
 |collaboration=[[Physics:D0 experiment|D0 Collaboration]]
 |year=2007
 |title=Direct observation of the strange b baryon {{math|{{SubatomicParticle|Bottom Xi-}}}}
 |journal=[[Physics:Physical Review Letters|Physical Review Letters]]
 |volume=99 |issue=5 |pages=52001
 |arxiv=0706.1690 |bibcode=2007PhRvL..99e2001A
 |doi=10.1103/PhysRevLett.99.052001 
 |pmid=17930744 |hdl=10211.3/194385 |s2cid=11568965
}}
</ref><ref>
{{cite press release
 |title=Fermilab physicists discover "triple-scoop" baryon
 |date=13 June 2007
 |publisher=[[Organization:Fermilab|Fermilab]]
 |url=http://www.fnal.gov/pub/presspass/press_releases/Dzero_baryon.html
 |access-date=2007-06-14
}}
</ref><ref>
{{cite press release
 |title=Back-to-back b baryons in Batavia
 |date=25 June 2007
 |publisher=[[Organization:Fermilab|Fermilab]]
 |url=http://www.fnal.gov/pub/presspass/press_releases/backtobackBaryons.html
 |access-date=2007-06-25
}}
</ref><ref name="Aaltonen">
{{cite journal
 |first1=T. |last1=Aaltonen
 |display-authors=0
 |collaboration=[[Physics:Collider Detector at Fermilab|CDF Collaboration]]
 |year=2007
 |title=Observation and mass measurement of the baryon Ξ{{su|b=b|p=&minus;}}
 |journal=[[Physics:Physical Review Letters|Physical Review Letters]]
 |volume=99  |issue=5  |page=52002
 |arxiv=0707.0589  |bibcode=2007PhRvL..99e2002A  |s2cid=45025038
 |pmid=17930745  |hdl=10261/8530  |doi=10.1103/PhysRevLett.99.052002
}}
</ref>
|-
! class=unsortable|Particle
! Symbol
! Makeup
! [[Physics:Rest mass|Rest mass]] <br>(MeV/[[Physics:Speed of light|''c'']]<sup>2</sup>)
! [[Physics:Isospin|Isospin]], <br>[[Physics:Isospin|I]]
! [[Physics:Spin|Spin]], [[Physics:Parity|parity]], <br>[[Physics:Spin|J]]<sup>[[Physics:Parity|P]]</sup>
! [[Physics:Charge|Q]]
! [[Physics:Strangeness|S]]
! [[Physics:Charm (quantum number)|C]]
! [[Physics:Bottomness|B]]
! Mean lifetime <br>([[Second|s]])
! class=unsortable|Decays to
|-
| Xi<ref name="PDGXi0">
{{cite journal
 |first1=W.-M. |last1=Yao
 |display-authors=0
 |collaboration=[[Physics:Particle Data Group|Particle Data Group]]
 |year=2006
 |title=Particle listings – Xi{{sup|0}}
 |journal=[[Physics:Journal of Physics G|Journal of Physics G]]
 |volume=33 |issue=1 |pages=1–1232]
 |bibcode=2006JPhG...33....1Y   |arxiv=astro-ph/0601168
 |doi=10.1088/0954-3899/33/1/001
 |url=http://pdg.lbl.gov/2007/listings/s023.pdf
}}
</ref>
|align="center"| {{math| {{SubatomicParticle|Xi0}} }}
|align="center"| {{math| {{SubatomicParticle|link=yes|Up quark}}{{SubatomicParticle|link=yes|Strange quark}}{{SubatomicParticle|link=yes|Strange quark}} }}
|align="center"| {{val|1314.86|0.20}}
|align="center"| {{sfrac|1|2}}
|align="center"| {{sfrac|1|2}}<sup>(+)</sup>
|align="center"| 0
|align="center"| −2
|align="center"| 0
|align="center"| 0
|align="center"| {{val|2.90|0.09|e=-10}}
|align="center"| {{math| {{nowrap|{{SubatomicParticle|link=yes|Lambda0}} + {{SubatomicParticle|link=yes|Pion0}}}} }}
|-
| Xi<ref name="PDGXi-">
{{cite journal
 |first1=W.-M. |last1=Yao
 |display-authors=0
 |collaboration=[[Physics:Particle Data Group|Particle Data Group]]
 |year=2006
 |title=Particle listings – Xi{{sup|&minus;}}
 |url=http://pdg.lbl.gov/2007/listings/s022.pdf
 |journal=[[Physics:Journal of Physics G|Journal of Physics G]]
 |volume=33 |issue=1 |pages=1–1232
 |bibcode=2006JPhG...33....1Y  |doi=10.1088/0954-3899/33/1/001
 |arxiv=astro-ph/0601168
}}</ref>
|align="center"| {{math| {{SubatomicParticle|Xi-}} }}
|align="center"| {{math| {{SubatomicParticle|link=yes|Down quark}}{{SubatomicParticle|link=yes|Strange quark}}{{SubatomicParticle|link=yes|Strange quark}} }}
|align="center"| {{val|1321.71|0.07}}
|align="center"| {{sfrac|1|2}}
|align="center"| {{sfrac|1|2}}<sup>(+)</sup>
|align="center"| −1
|align="center"| −2
|align="center"| 0
|align="center"| 0
|align="center"| {{val|1.639|0.015|e=-10}}
|align="center"| {{math| {{nowrap|{{SubatomicParticle|link=yes|Lambda0}} + {{SubatomicParticle|link=yes|Pion-}} }} }}
|-
|-
| Xi resonance<ref name="PDGXi(1530)">
{{cite journal
 |first1=W.-M. |last1=Yao
 |display-authors=0
 |collaboration=[[Physics:Particle Data Group|Particle Data Group]]
 |year=2006
 |title=Particle Listings – Xi(1530)
 |url=http://pdg.lbl.gov/2007/listings/b049.pdf 
 |journal=[[Physics:Journal of Physics G|Journal of Physics G]]
 |volume=33 |issue=1 |pages=1–1232
 |doi= 10.1088/0954-3899/33/1/001
 |arxiv = astro-ph/0601168 |bibcode = 2006JPhG...33....1Y
}}</ref>
|align="center"| {{math| {{SubatomicParticle|Xi0}}}}(1530)
|align="center"| {{math| {{SubatomicParticle|link=yes|Up quark}}{{SubatomicParticle|link=yes|Strange quark}}{{SubatomicParticle|link=yes|Strange quark}} }}
|align="center"| {{val|1531.80|0.32}}
|align="center"| {{sfrac|1|2}}
|align="center"| {{sfrac|3|2}}<sup>+</sup>
|align="center"| 0
|align="center"| −2
|align="center"| 0
|align="center"| 0
|align="center"| {{val|7.2|0.4|e=-23}}{{efn|name="decaywidth"|The resonance width ({{mvar|Γ}}) was reported for this species. Here the conversion {{mvar|τ&nbsp;{{=}}&nbsp;{{sfrac|ħ|Γ}} }} is given instead.}}
|align="center"| {{math| {{nowrap|{{SubatomicParticle|link=yes|Xi}} + {{SubatomicParticle|link=yes|Pion}} }} }}
|-
| Xi resonance<ref name="PDGXi(1530)" />
|align="center"| {{math| {{SubatomicParticle|Xi-}}}}(1530)
|align="center"| {{math| {{SubatomicParticle|link=yes|Down quark}}{{SubatomicParticle|link=yes|Strange quark}}{{SubatomicParticle|link=yes|Strange quark}} }}
|align="center"| {{val|1535.0|0.6}}
|align="center"| {{sfrac|1|2}}
|align="center"| {{sfrac|3|2}}<sup>+</sup>
|align="center"| −1
|align="center"| −2
|align="center"| 0
|align="center"| 0
|align="center"| {{val|6.6|1.6|1.0|e=-23}}{{efn|name="decaywidth"}}
|align="center"| {{math| {{nowrap|{{SubatomicParticle|link=yes|Xi}} + {{SubatomicParticle|link=yes|Pion}} }} }}
|-
| charmed Xi<ref name="PDGCharmedBaryons">
{{cite journal
 |first1=W.-M. |last1=Yao
 |display-authors=0
 |collaboration=[[Physics:Particle Data Group|Particle Data Group]]
 |year=2006
 |title=Particle listings – Charmed baryons
 |journal=[[Physics:Journal of Physics G|Journal of Physics G]]
 |url=http://pdg.lbl.gov/2007/tables/bxxxcharm.pdf
 |volume=33 |issue=1 |pages=1–1232
 |arxiv= astro-ph/0601168
 |bibcode= 2006JPhG...33....1Y
 |doi= 10.1088/0954-3899/33/1/001
}}</ref>
|align="center"| {{math| {{SubatomicParticle|Charmed Xi+}} }}
|align="center"| {{math| {{SubatomicParticle|link=yes|Up quark}}{{SubatomicParticle|link=yes|Strange quark}}{{SubatomicParticle|link=yes|Charm quark}} }}
|align="center"| {{val|2467.9|0.4}}
|align="center"| {{sfrac|1|2}}
|align="center"| ({{sfrac|1|2}}{{thinsp}}<sup>+</sup>)
|align="center"| +1
|align="center"| −1
|align="center"| +1
|align="center"| 0
|align="center"| {{val|4.42|0.26|e=-13}}
|align="center"| See [http://pdg.lbl.gov/2007/tables/bxxxcharm.pdf {{math| {{SubatomicParticle|charmed Xi+}} }}decay modes]
|-
| charmed Xi<ref name="PDGCharmedBaryons" />
|align="center"| {{math| {{SubatomicParticle|Charmed Xi0}} }}
|align="center"| {{math| {{SubatomicParticle|link=yes|Down quark}}{{SubatomicParticle|link=yes|Strange quark}}{{SubatomicParticle|link=yes|Charm quark}} }}
|align="center"| {{val|2471.0|0.4}}
|align="center"| {{sfrac|1|2}}
|align="center"| ({{sfrac|1|2}}{{thinsp}}<sup>+</sup>)
|align="center"| 0
|align="center"| −1
|align="center"| +1
|align="center"| 0
|align="center"| {{val|1.12|+0.13|-0.10|e=-13}}
|align="center"| See [http://pdg.lbl.gov/2007/tables/bxxxcharm.pdf {{math| {{SubatomicParticle|charmed Xi0}} }}decay modes]
|-
| charmed Xi resonance<ref name="PDGCharmedBaryons" />
|align="center"| {{math| {{SubatomicParticle|Charmed xi'+}} }}
|align="center"| {{math| {{SubatomicParticle|link=yes|Up quark}}{{SubatomicParticle|link=yes|Strange quark}}{{SubatomicParticle|link=yes|Charm quark}} }}
|align="center"| {{val|2575.7|3.1}}
|align="center"| {{sfrac|1|2}}
|align="center"| ({{sfrac|1|2}}<sup>+</sup>)
|align="center"| +1
|align="center"| −1
|align="center"| +1
|align="center"| 0
|align="center"| 
|align="center"| {{math| {{nowrap|{{SubatomicParticle|Charmed xi+}} + {{SubatomicParticle|Photon}} }}(Seen)}}
|-
| charmed Xi resonance<ref name="PDGCharmedBaryons" />
|align="center"| {{math| {{SubatomicParticle|Charmed xi'0}} }}
|align="center"| {{math| {{SubatomicParticle|link=yes|Down quark}}{{SubatomicParticle|link=yes|Strange quark}}{{SubatomicParticle|link=yes|Charm quark}} }}
|align="center"| {{val|2578.0|2.9}}
|align="center"| {{sfrac|1|2}}
|align="center"| ({{sfrac|1|2}}<sup>+</sup>)
|align="center"| 0
|align="center"| −1
|align="center"| +1
|align="center"| 0
|align="center"| 
|align="center"| {{math| {{nowrap|{{math|{{SubatomicParticle|Charmed xi0}} + {{SubatomicParticle|Photon}}}} }}(Seen)}}
|-
| [[Physics:Ξcc++|double charmed Xi]]<ref name=CERN-P-R-2017-07-06/>
|align="center"| {{math| {{SubatomicParticle|Double charmed Xi++}} }}
|align="center"| {{math| {{SubatomicParticle|link=yes|Up quark}}{{SubatomicParticle|link=yes|Charm quark}}{{SubatomicParticle|link=yes|Charm quark}} }}
|align="center"| {{val|3621.40|0.72|errend=&nbsp;± 0.27 ± 0.14}}
|align="center"| ({{sfrac|1|2}})
|align="center"| ({{sfrac|1|2}}{{thinsp}}<sup>+</sup>)
|align="center"| +2
|align="center"| 0
|align="center"| +2
|align="center"| 0
|align="center"| 0.256{{SubSup||−0.022|+0.024}}±0.014×10<sup>−12</sup><ref>
{{cite web
 |title=Long-lived doubly-charmed particle
 |date=May 2018
 |series=Updates
 |publisher=[[Organization:CERN|CERN]]
 |url=https://home.cern/about/updates/2018/05/long-live-doubly-charmed-particle
}}
</ref>
|align="center"| {{math| {{nowrap|{{SubatomicParticle|link=yes|Charmed lambda+}} + {{SubatomicParticle|link=yes|Kaon-}} + {{SubatomicParticle|link=yes|Pion+}} + {{SubatomicParticle|link=yes|Pion+}} }} }}
|-
| double charmed Xi{{efn|name="dispute"|Some controversy exists about this data. See references}}<ref name="PDGDoubleCharmedxi">
{{cite journal
 |first1=W.-M. |last1=Yao
 |display-authors=0
 |collaboration=[[Physics:Particle Data Group|Particle Data Group]]
 |year=2006
 |title=Particle listings – Ξ{{su|p=+|b=cc}}
 |url=http://pdg.lbl.gov/2007/listings/s065.pdf
 |journal=[[Physics:Journal of Physics G|Journal of Physics G]]
 |volume=33 |issue=1 |page=1
 |arxiv= astro-ph/0601168  |bibcode= 2006JPhG...33....1Y
 |doi= 10.1088/0954-3899/33/1/001
}}
</ref>
|align="center"| {{math| {{SubatomicParticle|Double charmed Xi+}} }}
|align="center"| {{math| {{SubatomicParticle|link=yes|Down quark}}{{SubatomicParticle|link=yes|Charm quark}}{{SubatomicParticle|link=yes|Charm quark}} }}
|align="center"| {{val|3518.9|0.9}}{{efn|name="dispute"}}
|align="center"| ({{sfrac|1|2}})
|align="center"| ({{sfrac|1|2}}{{thinsp}}<sup>+</sup>)
|align="center"| +1
|align="center"| 0
|align="center"| +2
|align="center"| 0
|align="center"| &lt;{{val|3.3|e=-14}}{{efn|name="dispute"}}
|align="center"| {{math| {{nowrap|{{SubatomicParticle|link=yes|Charmed lambda+}} + {{SubatomicParticle|link=yes|Kaon-}} + {{SubatomicParticle|link=yes|Pion+}}}}}}<sup>[e]</sup> or <br>{{math| {{nowrap|{{SubatomicParticle|link=yes|Proton+}} + {{SubatomicParticle|link=yes|D+}} + {{SubatomicParticle|link=yes|Kaon-}}}}}}<sup>[e]</sup>
|-
| bottom Xi<ref name="PDGBottomXi">
{{cite journal
 |first1=W.-M. |last1=Yao
 |display-authors=0
 |collaboration=[[Physics:Particle Data Group|Particle Data Group]]
 |title=Particle listings – Xi<sub>b</sub>
 |journal=[[Physics:Journal of Physics G|Journal of Physics G]]
 |year=2006
 |volume=33 |issue=1 |pages=1–1232
 |arxiv = astro-ph/0601168 |bibcode = 2006JPhG...33....1Y
 |doi = 10.1088/0954-3899/33/1/001
 |url=http://pdg.lbl.gov/2007/listings/s060.pdf
}}
</ref>
|align="center"| {{math| {{SubatomicParticle|Bottom Xi0}} }}
|align="center"| {{math| {{SubatomicParticle|link=yes|Up quark}}{{SubatomicParticle|link=yes|Strange quark}}{{SubatomicParticle|link=yes|Bottom quark}} }}
|align="center"| {{val|5792|3}}
|align="center"| ({{sfrac|1|2}})
|align="center"| ({{sfrac|1|2}}{{thinsp}}<sup>+</sup>)
|align="center"| 0
|align="center"| −1
|align="center"| 0
|align="center"| −1
|align="center"| {{val|1.42|+0.28|-0.24|e=-12}}{{efn|name="halflife"|This is actually a measurement of the average lifetime of b-baryons that decay to a jet containing a same-sign {{math| {{SubatomicParticle|Xi}}<sup>±</sup> {{SubatomicParticle|Lepton}}<sup>±</sup>}} pair. Presumably the mix is mainly {{math| {{SubatomicParticle|Bottom xi}},}} with some {{math| {{SubatomicParticle|Bottom lambda}}.}} }}
|align="center"| See [http://pdg.lbl.gov/2007/listings/s060.pdf {{math| {{SubatomicParticle|Bottom Xi}} }}decay modes]
|-
| bottom Xi or<br/>Cascade B<ref name=Abazov/><ref name=Aaltonen/><ref name="PDGBottomXi" />
|align="center"| {{math| {{SubatomicParticle|Bottom Xi-}} }}
|align="center"| {{math| {{SubatomicParticle|link=yes|Down quark}}{{SubatomicParticle|link=yes|Strange quark}}{{SubatomicParticle|link=yes|Bottom quark}} }}
|align="center"| {{val|5792.9|3.0}}
|align="center"| ({{sfrac|1|2}})
|align="center"| ({{sfrac|1|2}}{{thinsp}}<sup>+</sup>)
|align="center"| −1
|align="center"| −1
|align="center"| 0
|align="center"| −1
|align="center"| {{val|1.42|e=-12}}
|align="center"| See [http://pdg.lbl.gov/2007/listings/s060.pdf {{math| {{SubatomicParticle|Bottom Xi}} }}decay modes] <br> ({{math| {{nowrap|{{SubatomicParticle|Xi-}} + {{SubatomicParticle|link=yes|J/Psi}} }} }} was also seen)
|-
|
|align="center"| {{math| {{SubatomicParticle|Bottom Xi'-}}}}<ref name=":0">
{{Cite journal
 |last1 = Aaij |first1 = R.
 |display-authors = etal
 |collaboration=LHCb Collaboration
 |year = 2015
 |title = Observation of two new {{math|Ξ}}{{su|p=−|b=b}} baryon resonances
 |journal = Physical Review Letters
 |volume = 114 |issue = 6 |pages = 062004
 |doi =10.1103/PhysRevLett.114.062004 |pmid = 25723210
 |bibcode = 2015PhRvL.114f2004A  |s2cid = 6055559 |arxiv = 1411.4849
}}
</ref>
|align="center"| {{math| {{SubatomicParticle|link=yes|Down quark}}{{SubatomicParticle|link=yes|Strange quark}}{{SubatomicParticle|link=yes|Bottom quark}} }}
|align="center"| {{val|5935.02|0.02|errend=&nbsp;± 0.01 ± 0.50}}
|align="center"| 
|align="center"| 1/2+
|align="center"| −1
|align="center"| −1
|align="center"| 0
|align="center"| −1
|align="center"| >{{val|8|e=-21}}{{efn|name="dispute"}}{{efn|name="decaywidth"}}
|align="center"| 
|-
|
|align="center"| {{math| {{SubatomicParticle|Bottom Xi*-}}}}<ref name=":0"/>
|align="center"| {{math| {{SubatomicParticle|link=yes|Down quark}}{{SubatomicParticle|link=yes|Strange quark}}{{SubatomicParticle|link=yes|Bottom quark}}  }}
|align="center"| {{val|5955.33|0.12|errend=&nbsp;± 0.06 ± 0.50}}
|align="center"| 
|align="center"| 3/2+
|align="center"| −1
|align="center"| −1
|align="center"| 0
|align="center"| −1
|align="center"| {{val|3.99|0.75|e=-22|errend=&nbsp;± 0.25}}{{efn|name="decaywidth"}}
|align="center"| 
|-
|
|align="center"| {{math| {{SubatomicParticle|Bottom Xi}}}}(6227)<sup>−</sup><ref>
{{Cite journal
 |arxiv = 1805.09418
 |last1 =Aaij |first1 = R.
 |collaboration=CMS Collaboration
 |display-authors=0
 |year = 2018
 |title = Observation of a new {{math|Ξ}}{{su|b=b|p=−}} resonance
 |journal = Physical Review Letters
 |volume = 121 |issue = 72002 |pages = 072002
 |doi = 10.1103/PhysRevLett.121.072002 |pmid = 30169090 |bibcode =2018PhRvL.121g2002A |s2cid =52139397
}}
</ref>
|align="center"| {{math| {{SubatomicParticle|link=yes|Down quark}}{{SubatomicParticle|link=yes|Strange quark}}{{SubatomicParticle|link=yes|Bottom quark}} }}
|align="center"| {{val|6226.9|2.0|errend=&nbsp;± 0.3 ± 0.2}}
|align="center"| 
|align="center"| 
|align="center"| −1
|align="center"| −1
|align="center"| 0
|align="center"| −1 
|align="center"| 3.64{{SubSup||−0.84|+1.55}}±0.36×10<sup>−23</sup>{{efn|name="decaywidth"}}
|align="center"| {{math| {{SubatomicParticle|Bottom lambda}} + {{SubatomicParticle|Kaon-}} }}<br/>{{math| {{SubatomicParticle|Bottom Xi0}} + {{SubatomicParticle|Pion-}} }}
|-
| double bottom Xi{{efn|name="notobservered"|Particle (or quantity, i.e. spin) has neither been observed nor indicated}} 
|align="center"| {{math| {{SubatomicParticle|Double Bottom Xi0}} }}
|align="center"| {{math| {{SubatomicParticle|link=yes|Up quark}}{{SubatomicParticle|link=yes|Bottom quark}}{{SubatomicParticle|link=yes|Bottom quark}} }}
|align="center"|
|align="center"| ({{sfrac|1|2}})
|align="center"| ({{sfrac|1|2}}{{thinsp}}<sup>+</sup>)
|align="center"| 0
|align="center"| 0
|align="center"| 0
|align="center"| −2
|align="center"|
|align="center"|
|-
| double bottom Xi{{efn|name="notobservered"}}
|align="center"| {{math| {{SubatomicParticle|Double Bottom Xi-}} }}
|align="center"| {{math| {{SubatomicParticle|link=yes|Down quark}}{{SubatomicParticle|link=yes|Bottom quark}}{{SubatomicParticle|link=yes|Bottom quark}} }}
|align="center"|
|align="center"| ({{sfrac|1|2}})
|align="center"| ({{sfrac|1|2}}{{thinsp}}<sup>+</sup>)
|align="center"| −1
|align="center"| 0
|align="center"| 0
|align="center"| −2
|align="center"|
|align="center"|
|-
| charmed bottom Xi{{efn|name="notobservered"}}
|align="center"| {{math| {{SubatomicParticle|Charmed bottom Xi+}} }}
|align="center"| {{math| {{SubatomicParticle|link=yes|Up quark}}{{SubatomicParticle|link=yes|Charm quark}}{{SubatomicParticle|link=yes|Bottom quark}} }}
|align="center"|
|align="center"| ({{sfrac|1|2}})
|align="center"| ({{sfrac|1|2}}){{thinsp}}<sup>+</sup>
|align="center"| +1
|align="center"| 0
|align="center"| +1
|align="center"| −1
|align="center"|
|align="center"|
|-
| charmed bottom Xi{{efn|name="notobservered"}}
|align="center"| {{math| {{SubatomicParticle|Charmed bottom Xi0}} }}
|align="center"| {{math| {{SubatomicParticle|link=yes|Down quark}}{{SubatomicParticle|link=yes|Charm quark}}{{SubatomicParticle|link=yes|Bottom quark}} }}
|align="center"|
|align="center"| ({{sfrac|1|2}})
|align="center"| ({{sfrac|1|2}}{{thinsp}}<sup>+</sup>)
|align="center"| 0
|align="center"| 0
|align="center"| +1
|align="center"| −1
|align="center"|
|align="center"|
|}

;Table notes:
{{notelist}}

==See also==
* [[Physics:Delta baryon|Delta baryon]]
* [[Physics:Hyperon|Hyperon]]
* [[Physics:Lambda baryon|Lambda baryon]]
* [[Physics:List of baryons|List of baryons]]
* [[Physics:List of mesons|List of mesons]]
* [[Physics:List of particles|List of particles]]
* [[Physics:Nucleon|Nucleon]]
* [[Physics:Omega baryon|Omega baryon]]
* [[Physics:Sigma baryon|Sigma baryon]]
* [[Physics:Timeline of particle discoveries|Timeline of particle discoveries]]

==References==
{{Reflist|25em}}

==External links==
* {{cite report
 |title=Listings for Xi particles
 |publisher=[[Physics:Particle Data Group|Particle Data Group]]
 |url=http://pdglive.lbl.gov/listing.brl?fsizein=1&exp=Y&group=BXXX030
 |access-date=2007-07-31  |url-status=dead
 |archive-url=https://archive.today/20121212045433/http://pdglive.lbl.gov/listing.brl?fsizein=1&exp=Y&group=BXXX030
 |archive-date=2012-12-12
}}
* {{cite web
 |title=Direct observation of the strange b baryon Xi(b)-
 |publisher=[[Organization:Stanford University|Stanford University]]
 |url=https://archive.today/20121215010243/http://www.slac.stanford.edu/spires/find/hep/www?eprint=arXiv:0706.1690
}}
* {{cite press release
 |title=Fermilab physicists discover "triple-scoop" baryon
 |date=2007-06-18
 |publisher=[[Organization:Fermilab|Fermilab]]
 |url=http://www.fnal.gov/pub/presspass/press_releases/Dzero_baryon.html
 |access-date=2007-06-18
}}
* {{cite press release
 |title=Back-to-back b&nbsp;baryons in Batavia
 |date=2007-06-25
 |publisher=[[Organization:Fermilab|Fermilab]]
 |url=http://www.fnal.gov/pub/presspass/press_releases/backtobackBaryons.html
 |access-date=2007-06-25
}}
* {{cite web
 |title=Observation and mass measurement of the baryon Xi(b)-
 |publisher=[[Organization:Stanford University|Stanford University]]
 |url=https://archive.today/20120526104150/http://www.slac.stanford.edu/spires/find/hep/www?eprint=arXiv:0707.0589
}}

{{Particles}}

{{DEFAULTSORT:Xi Baryon}}
[[Category:Baryons]]
[[Category:Nuclear physics]]

{{Sourceattribution|Xi baryon}}