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).
D0 Collaboration; Abbott, B; Acharya, B. S; Adams, M; Adams, T; Agnew, J. P; Alexeev, G. D; Alkhazov, G; Alton, A; Askew, A; Atkins, S; Augsten, K; Avila, C; Badaud, F; Bagby, L; Baldin, B; Bandurin, D. V; Banerjee, S; Barberis, E; Baringer, P; Bartlett, J. F; Bassler, U; Bazterra, V; Bean, A; Begalli, M; Bellantoni, L; Beri, S. B; Bernardi, G; Bernhard, R; et al. (2014). "Search for the X(4140) state in B+→J/ψφK+ decays with the D0 detector". Physical Review D. 89 (12004): 012004. arXiv:1309.6580. Bibcode:2014PhRvD..89a2004A. doi:10.1103/PhysRevD.89.012004. S2CID 119226762.{{cite journal}}
: CS1 maint: numeric names: authors list (link) LHCb collaboration; Aaij, R; Adeva, B; Adinolfi, M; Ajaltouni, Z; Akar, S; Albrecht, J; Alessio, F; Alexander, M; Ali, S; Alkhazov, G; Alvarez Cartelle, P; Alves Jr, A. A; Amato, S; Amerio, S; Amhis, Y; An, L; Anderlini, L; Andreassi, G; Andreotti, M; Andrews, J. E; Appleby, R. B; Aquines Gutierrez, O; Archilli, F; d'Argent, P; Arnau Romeu, J; Artamonov, A; Artuso, M; Aslanides, E; 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. arXiv:1606.07895. Bibcode:2017PhRvL.118b2003A. doi:10.1103/PhysRevLett.118.022003. PMID 28128595. S2CID 206284149. LHBc collaboration; Aaij, R; Adeva, B; Adinolfi, M; Ajaltouni, Z; Akar, S; Albrecht, J; Alessio, F; Alexander, M; Ali, S; Alkhazov, G; Alvarez Cartelle, P; Alves Jr, A. A; Amato, S; Amerio, S; Amhis, Y; An, L; Anderlini, L; Andreassi, G; Andreotti, M; Andrews, J. E; Appleby, R. B; Aquines Gutierrez, O; Archilli, F; d'Argent, P; Arnau Romeu, J; Artamonov, A; Artuso, M; Aslanides, E; et al. (2017). "Amplitude analysis of B+→J/ψφK+ decays". Physical Review D. 95 (12002): 012002. arXiv:1606.07898. Bibcode:2017PhRvD..95a2002A. doi:10.1103/PhysRevD.95.012002. S2CID 73689011.