We present the first observation of τ lepton decays to hadronic final states with a ϕ-meson. This analysis is based on 401 fb−1 of data accumulated at the Belle experiment. The branching fraction ...obtained is B(τ−→ϕK−ντ)=(4.05±0.25±0.26)×10−5.
We report the first observation of the doubly Cabibbo-suppressed decay D{sub s}{sup +}{yields}K{sup +}K{sup +}{pi}{sup -} using 605 fb{sup -1} of data collected with the Belle detector at the KEKB ...asymmetric-energy e{sup +}e{sup -} collider. The branching ratio with respect to its Cabibbo-favored counterpart B(D{sub s}{sup +}{yields}K{sup +}K{sup +}{pi}{sup -})/B(D{sub s}{sup +}{yields}K{sup +}K{sup -}{pi}{sup +}) is (0.229{+-}0.028{+-}0.012)%, where the first uncertainty is statistical and the second is systematic. We also report a significantly improved measurement of the doubly Cabibbo-suppressed decay D{sup +}{yields}K{sup +}{pi}{sup +}{pi}{sup -}, with a branching ratio B(D{sup +}{yields}K{sup +}{pi}{sup +}{pi}{sup -})/B(D{sup +}{yields}K{sup -}{pi}{sup +}{pi}{sup +})=(0.569{+-}0.018{+-}0.014)%.
We have searched for the lepton-flavor-violating decays τ−→ℓ−KS0 and ℓ−KS0KS0 (ℓ=e or μ), using a data sample of 671 fb−1 collected with the Belle detector at the KEKB asymmetric-energy e+e− ...collider. No evidence for a signal was found in any of the decay modes, and we set the following upper limits for the branching fractions: B(τ−→e−KS0)<2.6×10−8, B(τ−→μ−KS0)<2.3×10−8, B(τ−→e−KS0KS0)<7.1×10−8 and B(τ−→μ−KS0KS0)<8.0×10−8 at the 90% confidence level.
(ProQuest: ... denotes formulae and/or non-USASCII text omitted; see image).We report a search for B decays to selected final states with the eta sub( c) meson: B super( plus or minus ) arrow right K ...super( plus or minus ) eta sub(c) pi super(+) pi super(-), B super( plus or minus ) arrow right K super( plus or minus ) eta sub(c) omega , B super( plus or minus ) arrow right K super( plus or minus ) eta sub(c) eta and B super( plus or minus ) arrow right K super( plus or minus ) eta sub(c) pi super(0). The analysis is based on 772 10 super(6) ... pairs collected at the Upsilon (4S) resonance with the Belle detector at the KEKB asymmetric-energy e super(+) e super(-) collider. We set 90% confidence level upper limits on the branching fractions of the studied B decay modes, independent of intermediate resonances, in the range (0.6-5.3) 10 super(-4). We also search for molecular-state candidates in the ... and ... combinations, neutral partners of the Z(3900) super( plus or minus ) and Z(4020) super( plus or minus ), and a poorly understood state X(3915) as possible intermediate states in the decay chain, and set 90% confidence level upper limits on the product of branching fractions to the mentioned intermediate states and decay branching fractions of these states in the range (0.6-6.9) 10 super(-5). Figure not available: see fulltext.
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