3,013 research outputs found
Precise measurement of the branching fractions for B-s(0) -> D-s(()*()+) D-s(()*()-) and first measurement of the D-s*(+) D-s*(-) polarization using e(+)e(-) collisions
No full textWe have made a precise measurement of the absolute branching fractions of B-s(0) -> D-s(()*()+) D-s(()*()-) decays using 121.4 fb(-1) of data recorded by the Belle experiment running at the Upsilon(5S) resonance. The results are B(B-s(0) -> D-s(+) D-s(-)) = 0.58(-0.09)(+0.11) +/- 0.13)%, B(B-s(0) -> D-s*(+/-) D-s(-/+)) = (1.76(-0.22)(+0.23) +/- 0.40)%, and B(B-s(0) -> D-s*(+) D-s*(-)) = (1.98(-0.31-0.50)(+0.33+0.52))%; the sum is B(B-s(0) -> D-s(()*()+) D-s(()*()-)) = (4.32(-0.39-1.03)(+0.42+1.04))%. Assuming B-s(0) -> D-s(()*()+) D-s(()*()-) saturates decays to CP-even final states, the branching fraction constrains the ratio Delta Gamma(s)/cos phi(12), where Delta Gamma(s) is the difference in widths between the two B-s-(B) over bar (s) mass eigenstates, and phi(12) is the CP-violating phase in B-s-(B) over bar (s) mixing. We also measure for the first time the longitudinal polarization fraction of B-s(0) -> D-s*(+) D-s*(-); the result is 0.06(-0.17)(+0.18) +/- 0.03. DOI: 10.1103/PhysRevD.87.031101LPH
Study of e+e- → D (1 S,2 S)η and e+e- → D (1S)η′ at s =10.866 GeV with the Belle detector
No full textWe report the first observation of the processes e+e-→D(1S,2S)η at s=10.866 GeV, with significance exceeding 10σ for both processes. The measured Born cross sections are σ(e+e-→D(2S)η)=2.07±0.21±0.19 pb, and σ(e+e-→D(1S)η)=0.42±0.08±0.04 pb. We also set the upper limit on the cross section of the process e+e-→D(1S)η′ to be σ(e+e-→D(1S)η′)<0.037 pb at 90% C.L. The results are obtained with the data sample collected with the Belle detector at the KEKB asymmetric-energy e+e- collider in the energy range from 10.63 to 11.02 GeV
Measurement of the branching fractions for Cabibbo-suppressed decays D+→K+K−π+π0 and D(s)+→K+π−π+π0 at Belle
No full textWe present measurements of the branching fractions for the singly Cabibbo-suppressed decays D+→K+K−π+π0 and D+s→K+π−π+π0, and the doubly Cabibbo-suppressed decay D+→K+π−π+π0, based on 980 fb−1 of data recorded by the Belle experiment at the KEKB e+e− collider. We measure these modes relative to the Cabibbo-favored modes D+→K−π+π+π0 and D+s→K+K−π+π0. Our results for the ratios of branching fractions are B(D+→K+K−π+π0)/B(D+→K−π+π+π0)=(11.32±0.13±0.26)%, B(D+→K+π−π+π0)/B(D+→K−π+π+π0)=(1.68±0.11±0.03)%, and B(D+s→K+π−π+π0)/B(D+s→K+K−π+π0)=(17.13±0.62±0.51)%, where the uncertainties are statistical and systematic, respectively. The second value corresponds to (5.83±0.42)×tan4θC, where θC is the Cabibbo angle; this value is larger than other measured ratios of branching fractions for a doubly Cabibbo-suppressed charm decay to a Cabibbo-favored decay. Multiplying these results by world average values for B(D+→K−π+π+π0) and B(D+s→K+K−π+π0) yields B(D+→K+K−π+π0)=(7.08±0.08±0.16±0.20)×10^−3, B(D+→K+π−π+π0)=(1.05±0.07±0.02±0.03)×10^−3, and B(D+s→K+π−π+π0)=(9.44±0.34±0.28±0.32)×10^−3, where the third uncertainty is due to the branching fraction of the normalization mode. The first two results are consistent with, but more precise than, the current world averages. The last result is the first measurement of this branching fraction
Search for violation in decays and observation of the Cabibbo-suppressed decay
No full textWe search for violation by measuring a -odd asymmetry in the
Cabibbo-suppressed decay, and
in the Cabibbo-favored and
decays. We use 980 of data collected by the Belle detector running at the KEKB
asymmetric-energy collider. The -violating -odd parameter
is measured to be
and
where the first
uncertainty is statistical and the second is systematic. We also report the
first observation of the Cabibbo-suppressed decay . The branching fraction is measured relative to
that of the analogous Cabibbo-favored decay :
Measurement of the absolute branching fraction of D*(s0) (2317)(+/-) -> pi D-0(s)+/-
No full textThe process e(+)e(-) -> D*D-+(s)*(s0) (2317)(-) + c.c. is observed for the first time with the data sample of 567 pb(-1) collected with the BESIII detector operating at the BEPCII collider at a center-of-mass energy root s = 4.6 GeV. The statistical significance of the D*(s0) (2317)(+/-) signal is 5.8 sigma and the mass is measured to be (2318.3 +/- 1.2 +/- 1.2) MeV/c(2). The absolute branching fraction B(D*(s0) (2317)(+/-) -> pi D-0(s)+/-) is measured as 1.00(-0.14)(+0.00) (stat)(-0.14)(+0.00) (syst) for the first time. The uncertainties are statistical and systematic, respectively
Search for rare decays , , , and
No full text7 pages, 2 figuresInternational audienceWe present a study of rare decay modes , , and , where denotes the neutral mesons or , using a data sample of events produced at the resonance. The data were collected by the Belle detector operating at the asymmetric-energy KEKB collider. We observe no evidence for these decays, so we provide upper limits at the 90 confidence level on the branching fractions of , , and decay modes. Along with rare decay modes, we report improved measurements of the color-suppressed decay branching fractions = (26.6 1.2 2.1) and = (5.6 0.5 0.2) . The first and second uncertainties are statistical and systematic, respectively
Measurement of D^{+}→K_{S}^{0}K^{+} and D_{s}^{+}→K_{S}^{0}π^{+} branching ratios
No full textWe report an improved measurement of D+->(KSK+)-K-0 and D-s(+)-> K-S(0)pi(+) branching ratios using 605 fb(-1) of data collected with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. The measured branching ratios with respect to the Cabibbo-favored modes are B(D+->(KSK+)-K-0)/B(D+-> K-S(0)pi(+))=0.1899 +/- 0.0011 +/- 0.0022 and B(D-s(+)-> K-S(0)pi(+))/B(D-s(+)->(KSK+)-K-0)=0.0803 +/- 0.0024 +/- 0.0019 where the first uncertainties are statistical and the second are systematic.LPH
Measurement of the charm-mixing parameter y(CP) in D-0 -> K-S(0)omega decays at Belle
No full textWe report the first measurement of the charm-mixing parameter y(CP) in D-0 decays to the CP-odd final state K-S(0 omega). The study uses the full Belle e(+)e(-) annihilation data sample of 976 fb(-1) taken at or near the gamma (4S) centre-of-mass energy. We find y(CP) = (0.96 +/- 0.91 +/- 0.62(-0.00)+0.17)%, where the first uncertainty is statistical, the second is systematic due to event selection and background, and the last is due to possible presence of CP-even decays in the data sample.LPH
Measurement of the branching fractions of D-s(+) -> eta ' X and D-s(+) -> eta 'rho(+) in e(+)e(-) -> Ds+Ds-
No full textWe study D-s(+) decays to final states involving the eta' with a 482 pb(-1) data sample collected at root s = 4.009 GeV with the BESIII detector at the BEPCII collider. We measure the branching fractions B(D-s(+) -> eta'X) = (8.8 +/- 1.8 +/- 0.5)% and B(D-s(+) > eta'rho(+)) = (5.8 +/- 1.4 +/- 0.4)% where the first uncertainty is statistical and the second is systematic. In addition, we estimate an upper limit on the non-resonant branching ratio B(D-s(+) -> eta'pi(+)pi(0)) < 5.1% at the 90% confidence level. Our results are consistent with CLEO's recent measurements and help to resolve the disagreement between the theoretical prediction and CLEO's previous measurement of B(D-s(+) -> eta'rho(+))
Measurements of time-dependent CP asymmetries in B -> D*-+ pi+- decays using a partial reconstruction technique
No full textWe report results on time-dependent CP asymmetries in B -> D*(-/+)pi(+/-) decays based on a data sample containing 657 x 10(6) B (B) over bar pairs collected with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider at the Y(4S) resonance. We use a partial reconstruction technique, wherein signal B -> D*(-/+)pi(+/-) events are identified using information only from the fast pion from the B decay and the slow pion from the subsequent decay of the D*(-/+), where the former (latter) corresponds to D*(+)(D*(-)) final states. We obtain CP violation parameters S+ = +0.061 +/- 0.018 (stat) +/- 0.012 (syst) and S- = +0.031 +/- 0.019 (stat) +/- 0.015 (syst).LPH
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