Search for Pentaquarks in the Hadronic Decays of the Z Boson with the DELPHI Detector at LEPVise andre og tillknytning
2007 (engelsk)Inngår i: Physics Letters B, ISSN 0370-2693, E-ISSN 1873-2445, Vol. 653, nr 2-4, s. 151-160Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]
The quark model does not exclude states composed of more than three quarks, like pentaquark systems. Controversial evidence for such states has been published in the last years, in particular: for a strange pentaquark Theta(1540)(+); for a double-strange state, the Xi(1862)(--), subsequently called Phi(1860)--; and for a charmed state, the Theta(c)(3100)(0). If confirmed, a full pentaquark family might exist; such pentaquark states could be produced in e(+)e(-) annihilations near the Z energy. In this Letter a search for pentaquarks is described using the DELPHI detector at LEP, characterized by powerful particle identification sub-systems crucial in the separation of the signal from the background for these states. At 95% CL, upper limits are set on the production rates N of such particles and their charge-conjugate state per Z decay: N-Theta+ x Br(Theta(+) -> pK(S)(0)) < 5.1 x 10(-4), N Theta++ < 1.6 x 10(-3), N Phi(1860)-- x Br((P(1860)-- -> Xi(-)pi(-)) < 2.9 x 10(-4), N-Theta c(3100)0 x Br(Theta(c)(3100)(0) -> D*(+)p) < 8.8 x 10(-4).
sted, utgiver, år, opplag, sider
2007. Vol. 653, nr 2-4, s. 151-160
Emneord [en]
PRODUCTION-RATES; BARYON PRODUCTION; RESONANCE; THETA(+); PHYSICS; VECTOR; MASSES; STATES; MESON; LIGHT
HSV kategori
Identifikatorer
URN: urn:nbn:se:su:diva-12436DOI: 10.1016/j.physletb.2007.08.005ISI: 000250074000007OAI: oai:DiVA.org:su-12436DiVA, id: diva2:178956
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