Measurements of relative branching ratios of Λc+ decays into states containing Σ (original) (raw)

First Observation of the Cabibbo-suppressed Decays Xi+(c) ---> Sigma+ pi- pi+ and Xi+(c) ---> Sigma- pi+ pi+ and Measurement of their Branching Ratios

We report the first observation of two Cabibbo-suppressed decay modes, Xi_c+ -> Sigma+ pi- pi+ and Xi_c+ -> Sigma- pi+ pi+. We observe 59+/-14 over a background of 87, and 22+/-8 over a background of 13 events, respectively, for the signals. The data were accumulated using the SELEX spectrometer during the 1996-1997 fixed target run at Fermilab, chiefly from a 600GeV/c Sigma- beam. The branching ratios of the decays relative to the Cabibbo--favored Xi_c+ -> Xi- pi+ pi+ are measured to be B(Xi_c+ -> Sigma+ pi- pi+)/B(Xi_c+ -> Xi- pi+ pi+) = 0.48+/-0.20, and B(Xi_c+ -> Sigma- pi+ pi+)/B(Xi_c+ -> Xi- pi+ pi+) = 0.18+/-0.09, respectively. We also report branching ratios for the same decay modes of the Lambda_c+ relative to Lambda_c+ -> p K- pi+.

Measurement of the branching ratio of the decay D0→π−μ+ν relative to D0→K−μ+ν

Physics Letters B, 2005

We present a new measurement of the branching ratio of the Cabibbo suppressed decay D 0 → π − µ + ν relative to the Cabibbo favored decay D 0 → K − µ + ν and an improved measurement of the ratio f π + (0) f K + (0). Our results are 0.074 ± 0.008 ± 0.007 for the branching ratio and 0.85 ± 0.04 ± 0.04 ± 0.01 for the form factor ratio, respectively.

Measurement of the branching ratio of the decay relative to

Physics Letters B, 2005

We present a new measurement of the branching ratio of the Cabibbo suppressed decay D 0 → π − µ + ν relative to the Cabibbo favored decay D 0 → K − µ + ν and an improved measurement of the ratio |f π + (0)/f K + (0)|. Our results are 0.074 ± 0.008 ± 0.007 for the branching ratio and 0.85 ± 0.04 ± 0.04 ± 0.01 for the form factor ratio, respectively.

Measurement of Singly Cabibbo Suppressed Decays Λ_{c}^{+}→pπ^{+}π^{-} and Λ_{c}^{+}→pK^{+}K^{-}

Physical review letters, 2016

Using 567 pb^{-1} of data collected with the BESIII detector at a center-of-mass energy of sqrt[s]=4.599 GeV, near the Λ_{c}^{+}Λ[over ¯]_{c}^{-} threshold, we study the singly Cabibbo-suppressed decays Λ_{c}^{+}→pπ^{+}π^{-} and Λ_{c}^{+}→pK^{+}K^{-}. By normalizing with respect to the Cabibbo-favored decay Λ_{c}^{+}→pK^{-}π^{+}, we obtain ratios of branching fractions: [B(Λ_{c}^{+}→pπ^{+}π^{-})/B(Λ_{c}^{+}→pK^{-}π^{+})]=(6.70±0.48±0.25)%, [B(Λ_{c}^{+}→pϕ)/B(Λ_{c}^{+}→pK^{-}π^{+})]=(1.81±0.33±0.13)%, and [B(Λ_{c}^{+}→pK^{+}K_{non-ϕ}^{-})/B(Λ_{c}^{+}→pK^{-}π^{+})]=(9.36±2.22±0.71)×10^{-3}, where the uncertainties are statistical and systematic, respectively. The absolute branching fractions are also presented. Among these measurements, the decay Λ_{c}^{+}→pπ^{+}π^{-} is observed for the first time, and the precision of the branching fraction for Λ_{c}^{+}→pK^{+}K_{non-ϕ}^{-} and Λ_{c}^{+}→pϕ is significantly improved.

Precise branching ratio measurements of the decays D0-> pi-pi+ pi0 and D0-> K-K+ pi0 relative to the D0-> K-pi+ pi0 decay

Physical Review D, 2006

Cabibbo-suppressed charm decays offer a good laboratory for studying weak interactions as they provide a unique window on the physics governing the decay-rate dynamics and CP violation. The branching ratios of the singly Cabibbo-suppressed decays of D0 meson are anomalous since the branching fraction of D0! m mÿ is observed to be suppressed relative to that of D0! K Kÿ by a factor of almost three [1], even though the phase space for the former is larger. The branching ratios of three-body decays of the D0 [2, 3] have larger uncertainties ...

Measurement of the branching ratios of the decays and

Physics Letters B, 2007

Measurement of the branching ratios of the decays Ξ 0 → Σ + e − ν e and Ξ 0 → Σ + e + ν e NA48/1 Collaboration Abstract From 56 days of data taking in 2002, the NA48/1 experiment observed 6316 Ξ 0 → Σ + e − ν e candidates (with the subsequent Σ + → pπ 0 decay) and 555 Ξ 0 → Σ + e + ν e candidates with background contamination of 215 ± 44 and 136 ± 8 events, respectively. From these samples, the branching ratios BR(Ξ 0 → Σ + e − ν e ) = (2.51 ± 0.03 stat ±0.09 syst )×10 −4 and BR(Ξ 0 → Σ + e + ν e ) = (2.55±0.14 stat ±0.10 syst )×10 −4 were measured allowing the determination of the CKM matrix element |V us | = 0.209 +0.023 −0.028 . Using the Particle Data Group average for |V us | obtained in semileptonic kaon decays, we measured the ratio g 1 /f 1 = 1.20 ± 0.05 of the axial-vector to vector form factors.

Measurement of the branching ratios for the decays of D_{s}^{+} to ηπ^{+}, η^{′}π^{+}, ηρ^{+}, and η^{′}ρ^{+}

Physical Review D, 1998

Using a data sample with integrated luminosity of 3.9 fb −1 collected in e + e − annihilation with the CLEO-II detector at the Cornell Electron Storage Ring, we have measured the branching ratios for the decay modes D + s → (η, η ′)π + and D + s → (η, η ′)ρ + relative to D + s → φπ +. These decay modes are among the most common hadronic decays of the D + s , and can be related by factorization to the semileptonic decays D + s → (η, η ′)ℓ + ν l. The results obtained are compared with previous CLEO results and with the branching ratios measured for the related semileptonic decays. We also report results on the Cabibbosuppressed decays of the D + to the same final states.