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Observation of two resonancelike structures in the {pi}{sup +}{chi}{sub c1} mass distribution in exclusive B{sup 0}{yields}K{sup -}{pi}{sup +}{chi}{sub c1} decays

Journal Article · · Physical Review. D, Particles Fields
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  1. Institute for Theoretical and Experimental Physics, Moscow (Russian Federation)
  2. High Energy Accelerator Research Organization (KEK), Tsukuba (Japan)
We report the first observation of two resonancelike structures in the {pi}{sup +}{chi}{sub c1} invariant mass distribution near 4.1 GeV/c{sup 2} in exclusive B{sup 0}{yields}K{sup -}{pi}{sup +}{chi}{sub c1} decays. From a Dalitz plot analysis in which the {pi}{sup +}{chi}{sub c1} mass structures are represented by Breit-Wigner resonance amplitudes, we determine masses and widths of: M{sub 1}=(4051{+-}14{sub -41}{sup +20}) MeV/c{sup 2}, {gamma}{sub 1}=(82{sub -17-22}{sup +21+47}) MeV, M{sub 2}=(4248{sub -29-35}{sup +44+180}) MeV/c{sup 2}, and {gamma}{sub 2}=(177{sub -39-61}{sup +54+316}) MeV; and product branching fractions of B(B{sup 0}{yields}K{sup -}Z{sub 1,2}{sup +})xB(Z{sub 1,2}{sup +}{yields}{pi}{sup +}{chi}{sub c1})=(3.0{sub -0.8-1.6}{sup +1.5+3.7})x10{sup -5} and (4.0{sub -0.9-0.5}{sup +2.3+19.7})x10{sup -5}, respectively. Here the first uncertainty is statistical, the second is systematic. The significance of each of the {pi}{sup +}{chi}{sub c1} structures exceeds 5{sigma}, including the systematic uncertainty from various fit models. This analysis is based on 657x10{sup 6} BB events collected at the {upsilon}(4S) resonance with the Belle detector at the KEKB asymmetric-energy e{sup +}e{sup -} collider.
OSTI ID:
21254250
Journal Information:
Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 7 Vol. 78; ISSN PRVDAQ; ISSN 0556-2821
Country of Publication:
United States
Language:
English