The Y(4140) particle is an electrically neutral exotic hadron candidate that is about 4.4 times heavier than the proton. It was observed at Fermilab and announced on 17 March 2009.[1] This particle is extremely rare and was detected in only 20 of billions of collisions.[2]
Since it decays into J/ψ and φ mesons, it has been suggested that this particle is composed of charm quarks and charm antiquarks, possibly even a four quark combination.[3]
The existence of the particle has been confirmed by members of the CMS collaboration at the Large Hadron Collider on November 14, 2012[4][5] and by the DØ experiment at the Tevatron on September 25, 2013.[6][7] The Belle experiment[8] has searched for this particle but found no evidence for its existence.
The LHCb experiment observes a peak at the same position in the J/ψϕ invariant mass, but it is best described as a Ds±Ds∗∓ cusp, and is much broader than the previous measurements of the Y(4140).[9][10]
The Particle Data Group has renamed Y(4140) to follow naming conventions to X(4140).
See also
References
- ↑
"Oddball Particle Surprises Physicists at Fermilab". redOrbit. 19 March 2009. http://www.redorbit.com/news/science/1657139/oddball_particle_surprises_physicists_at_fermilab/index.html.
- ↑
Handwerk, Brian (20 March 2009). "Strange Particle Created; May Rewrite How Matter's Made". National Geographic News. http://news.nationalgeographic.com/news/2009/03/090320-new-particle.html.
- ↑
Minard, Anne (18 March 2009). "New Particle Throws Monkeywrench in Particle Physics". Universe Today. http://www.universetoday.com/2009/03/18/new-particle-throws-monkeywrench-in-particle-physics/.
- ↑ Riesselmann, Kurt (December 4, 2012). "Experiment confirms existence of odd particle". Phys.Org.
- ↑ Hidalgo-Duque, C; Nieves, J; Pavón Valderrama, M (2012). "Heavy Quark Spin Symmetry and SU(3)-Flavour Partners of the X(3872)". Nuclear Physics A 914: 482–487. doi:10.1016/j.nuclphysa.2013.01.025. Bibcode: 2013NuPhA.914..482H.
- ↑ Dorigo, Tommaso (September 26, 2013). "DZERO Confirms The Y(4140) And Its Excitation"
- ↑ D0 Collaboration; Abbott, B; Acharya, B. S; Adams, M; Adams, T; Agnew, J. P; Alexeev, G. D; Alkhazov, G et al. (2014). "Search for the X(4140) state in B+→J/ψφK+ decays with the D0 detector". Physical Review D 89 (12004): 012004. doi:10.1103/PhysRevD.89.012004. Bibcode: 2014PhRvD..89a2004A.
- ↑ Shen, C. P. (2010). "Evidence for a New Resonance and Search for the Y(4140) in the γγ→ϕJ/ψ Process". Physical Review Letters 104 (11): 112004. doi:10.1103/PhysRevLett.104.112004. PMID 20366468. Bibcode: 2010PhRvL.104k2004S.
- ↑ LHCb collaboration; Aaij, R; Adeva, B; Adinolfi, M; Ajaltouni, Z; Akar, S; Albrecht, J; Alessio, F et al. (2017). "Observation of J/ψφ structures consistent with exotic states from amplitude analysis of B+→J/ψφK+ decays". Physical Review Letters 118 (2): 022003. doi:10.1103/PhysRevLett.118.022003. PMID 28128595. Bibcode: 2017PhRvL.118b2003A.
- ↑ LHBc collaboration; Aaij, R; Adeva, B; Adinolfi, M; Ajaltouni, Z; Akar, S; Albrecht, J; Alessio, F et al. (2017). "Amplitude analysis of B+→J/ψφK+ decays". Physical Review D 95 (12002): 012002. doi:10.1103/PhysRevD.95.012002. Bibcode: 2017PhRvD..95a2002A.
External links
Further reading
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