We report the observation of B{sub s}{sup 0}{yields}J/{psi}f{sub 0}(980) and evidence for B{sub s}{sup 0}{yields}J/{psi}f{sub 0}(1370), which are CP eigenstate decay modes. These results are obtained ...from 121.4 fb{sup -1} of data collected at the {Upsilon}(5S) resonance with the Belle detector at the KEKB e{sup +}e{sup -} collider. We measure the branching fractions B(B{sub s}{sup 0}{yields}J/{psi}f{sub 0}(980);f{sub 0}(980){yields}{pi}{sup +}{pi}{sup -})=(1.16{sub -0.19}{sup +0.31}(stat){sub -0.17}{sup +0.15} (syst){sub -0.18}{sup +0.26}(N{sub B{sub s}{sup (*)}}{sub B{sub s}{sup (*)}}))x10{sup -4} with a significance of 8.4{sigma}, and B(B{sub s}{sup 0}{yields}J/{psi}f{sub 0}(1370);f{sub 0}(1370){yields}{pi}{sup +}{pi}{sup -})=(0.34{sub -0.14}{sup +0.11}(stat){sub -0.02}{sup +0.03} (syst){sub -0.05}{sup +0.08} (N{sub B{sub s}{sup (*)}}{sub B{sub s}{sup (*)}}))x10{sup -4} with a significance of 4.2{sigma}. The last error listed is due to uncertainty in the number of produced B{sub s}{sup (*)}B{sub s}{sup (*)} pairs.
We search for lepton-flavor-violating τ decays into a lepton (electron or muon) and an f0(980) meson using 671 fb−1 of data collected with the Belle detector at the KEKB asymmetric-energy e+e− ...collider. No events are observed and we set the following 90% C.L. upper limits on the branching fraction products: B(τ−→e−f0(980))×B(f0(980)→π+π−)<3.2×10−8 and B(τ−→μ−f0(980))×B(f0(980)→π+π−)<3.4×10−8. This is the first search performed for these modes.
Anapole moment of an exotic nucleus Arinstein, K. E.; Dmitriev, V. F.; Khriplovich, I. B.
Physics of atomic nuclei,
1/2004, Letnik:
67, Številka:
1
Journal Article
We search for dimuon decays of a low mass particle in the decays B{sup 0{yields}}K{sup *0}X and B{sup 0{yields}{rho}0}X using a data sample of 657x10{sup 6}BB events collected with the Belle detector ...at the KEKB asymmetric-energy e{sup +}e{sup -} collider. We find no evidence for such a particle in the mass range from 212 MeV/c{sup 2} to 300 MeV/c{sup 2} for lifetimes below 10{sup -12} s, and set upper limits on its branching fractions. In particular, we search for a particle with a mass of 214.3 MeV/c{sup 2} reported by the HyperCP experiment, and obtain upper limits on the products B(B{sup 0}{yields}K{sup *0}X)xB(X{yields}{mu}{sup +}{mu}{sup -})<2.26(2.27)x10{sup -8} and B(B{sup 0}{yields}{rho}{sup 0}X)xB(X{yields}{mu}{sup +}{mu}{sup -})<1.73(1.73)x10{sup -8} at 90% C.L. for a scalar (vector) X particle.
We search for CP violation in Cabibbo-suppressed charged D meson decays by measuring the difference between the CP-violating asymmetries for the Cabibbo-suppressed decays D±→K⁺ K⁻ π± and the ...Cabibbo-favored decays Ds± → K⁺K⁻ π± in the K⁺K⁻ mass region of the Φ resonance. Using 955 fb⁻¹ of data collected with the Belle detector, we obtain ACPD⁺→Φπ⁺ = (+0.51±0.28±0.05)%. The measurement improves the sensitivity of previous searches by more than a factor of 5.We find no evidence for direct CP violation.
First observations of the B{sub s}{sup 0{yields}}D{sub s}*{sup -{pi}+}, B{sub s}{sup 0{yields}}D{sub s}{sup -{rho}+} and B{sub s}{sup 0{yields}}D{sub s}*{sup -{rho}+} decays are reported together ...with measurements of their branching fractions: B(B{sub s}{sup 0{yields}}D{sub s}*{sup -{pi}+})=2.4{sub -0.4}{sup +0.5}(stat){+-}0.3(syst){+-} 0.4(f{sub s})x10{sup -3}, B(B{sub s}{sup 0{yields}}D{sub s}{sup -{rho}+})=8.5{sub -1.2}{sup +1.3}(stat){+-}1.1(syst){+-}1.3(f{sub s})x10{sup -3} and B(B{sub s}{sup 0{yields}}D{sub s}*{sup -{rho}+})=11.9{sub -2.0}{sup +2.2}(stat){+-}1.7(syst){+-}1.8(f{sub s})x10{sup -3} (f{sub s}=N{sub B{sub s}{sup (*)}B{sub s}{sup (*)}/N{sub bb}}). From helicity-angle distributions, we measured the longitudinal polarization fraction in B{sub s}{sup 0{yields}}D{sub s}*{sup -{rho}+} decays to be f{sub L}(B{sub s}{sup 0{yields}}D{sub s}*{sup -{rho}+})=1.05{sub -0.10}{sup +0.08}(stat){sub -0.04}{sup +0.03}(syst). These results are based on a 23.6 fb{sup -1} data sample collected at the {Upsilon}(5S) resonance with the Belle detector at the KEKB e{sup +}e{sup -} collider.
The process {gamma}{gamma}->{phi}J/{psi} is measured using a data sample of 825 fb{sup -1} collected with the Belle detector. A narrow peak of 8.8{sub -3.2}{sup +4.2} events, with a significance of ...3.2 standard deviations including systematic uncertainty, is observed. The mass and natural width of the structure named X(4350) are measured to be 4350.6{sub -5.1}{sup +4.6}(stat)+-0.7(syst) MeV/c{sup 2} and 13{sub -9}{sup +18}(stat)+-4(syst) MeV, respectively. The product of its two-photon decay width and branching fraction to {phi}J/{psi} is 6.7{sub -2.4}{sup +3.2}(stat)+-1.1(syst) eV for J{sup P}=0{sup +}, or 1.5{sub -0.6}{sup +0.7}(stat)+-0.3(syst) eV for J{sup P}=2{sup +}. No signal for the Y(4140)->{phi}J/{psi} structure reported by the CDF Collaboration in B->K{sup +}{phi}J/{psi} decays is observed, and limits of {Gamma}{sub {gamma}}{sub {gamma}}(Y(4140))B(Y(4140)->{phi}J/{psi})<41 eV for J{sup P}=0{sup +} or <6.0 eV for J{sup P}=2{sup +} are determined at the 90% C.L. This disfavors the scenario in which the Y(4140) is a D{sub s}*{sup +}D{sub s}{sup *-} molecule.
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