Measurements of Lambda[sub C][sup +] Branching Fractions of Cabibbo-Suppressed Decay Modes


Book Description

The authors have measured the branching fractions of the Cabibbo-suppressed decays [Lambda][sub c][sup +] --> [Lambda][sup 0]K[sup +] and [Lambda][sub c][sup +] --> [Sigma][sup 0]K[sup +] relative to the Cabibbo-allowed decay modes [Lambda][sub c][sup +] --> [Lambda][sup 0][pi][sup +] and [Lambda][sub c][sup +] --> [Sigma][sup 0][pi][sup +] to be 0.044 [+-] 0.004 (stat.) [+-] 0.002 (syst.) and 0.040 [+-] 0.005 (stat.) [+-] 0.004 (syst.), respectively. They also present the first observation of [Lambda][sub c][sup +] --> [Lambda][sup 0]K[sup +][pi][sup +][pi][sup -] and have measured the branching fraction relative to [Lambda][sub c][sup +] --> [Lambda][sup 0][pi][sup +] to be 0.266 [+-] 0.027 (stat.) [+-] 0.032 (syst.). The upper limit of the branching fraction into the decay [Lambda][sub c][sup +] --> [Sigma][sup 0]K[sup +][pi][sup +][pi][sup -] relative to [Lambda][sub c][sup +] --> [Sigma][sup 0][pi][sup +] has been measured to be




Measurements of Lambda{sub C} Branching Fractions of Cabibbo-Suppressed Decay Modes


Book Description

The authors have measured the branching fractions of the Cabibbo-suppressed decays?{sub c} -->?°K+ and?{sub c}+ -->?°K+ relative to the Cabibbo-allowed decay modes?{sub c}+ -->?°?+ and?{sub c}+ -->?°?+ to be 0.044 ± 0.004 (stat.) ± 0.002 (syst.) and 0.040 ± 0.005 (stat.) ± 0.004 (syst.), respectively. They also present the first observation of?{sub c}+ -->?°K+?+?− and have measured the branching fraction relative to?{sub c}+ -->?°?+ to be 0.266 ± 0.027 (stat.) ± 0.032 (syst.). The upper limit of the branching fraction into the decay?{sub c}+ -->?°K+?+?− relative to?{sub c}+ -->?°?+ has been measured to be







Measurements of Lambda{sub C}{sup +} Branching Fractions of Cabibbo-Suppressed Decay Modes


Book Description

The authors have measured the branching fractions of the Cabibbo-suppressed decays {Lambda}{sub c}{sup +} --> {Lambda}{sup 0}K{sup +} and {Lambda}{sub c}{sup +} --> {Sigma}{sup 0}K{sup +} relative to the Cabibbo-allowed decay modes {Lambda}{sub c}{sup +} --> {Lambda}{sup 0}{pi}{sup +} and {Lambda}{sub c}{sup +} --> {Sigma}{sup 0}{pi}{sup +} to be 0.044 {+-} 0.004 (stat.) {+-} 0.002 (syst.) and 0.040 {+-} 0.005 (stat.) {+-} 0.004 (syst.), respectively. They also present the first observation of {Lambda}{sub c}{sup +} --> {Lambda}{sup 0}K{sup +}{pi}{sup +}{pi}{sup -} and have measured the branching fraction relative to {Lambda}{sub c}{sup +} --> {Lambda}{sup 0}{pi}{sup +} to be 0.266 {+-} 0.027 (stat.) {+-} 0.032 (syst.). The upper limit of the branching fraction into the decay {Lambda}{sub c}{sup +} --> {Sigma}{sup 0}K{sup +}{pi}{sup +}{pi}{sup -} relative to {Lambda}{sub c}{sup +} --> {Sigma}{sup 0}{pi}{sup +} has been measured to be




A Measurement of the Lambda-c Baryon Decays to Proton Kaon( - ) Pion(+) Absolute Branching Fraction with the BaBar Detector


Book Description

A measurement of [Beta]([Lambda][sub c][sup +] [yields] pK[sup -] [pi][sup +]) is presented based on data collected with the BaBar detector at the Stanford Linear Accelerator Center. Branching fraction measurements represent a large portion of what is known about short-lived particles, the strong force that binds them, and the weak force that causes them to decay. While the majority of branching fraction measurements are done as ratios between two decay modes, it is the absolute measurements of a few particular decay modes that set the scale for these relative measurements. The [Lambda][sub c][sup +] particle is one of the four weakly decaying hadrons into which more than 90% of the known heavy quark hadrons will eventually decay. Thus, an absolute measurement of the branching fraction for [Lambda][sub c][sup +] [yields] pK[sup -][pi][sup +] is important for many studies of the heavy quark sector, from spectroscopy to B meson decays. The number of produced [Lambda][sub c][sup +]'s is inferred from the number of events reconstructed with an antiproton and an accompanying D meson. The final result of [Beta]([Lambda][sub c][sup +] [yields] pK[sup -] [pi][sup +]) = [6.12 [+-] 0.31(stat.) [+-] 0.42(syst.)]% represents more than a two-fold improvement in precision over the world average. The dominant source of systematic uncertainty is the irreducible background of [Xi][sub c] baryons.




Hadronic B Decays to Open Charm at the BaBar Experiment


Book Description

Using about 23M B[bar B] events collected in 1999-2000 with the BABAR detector, they report on the decays B[yields] D(*)[bar D](*)K and B[sup 0][yields] D*[sup+]D*[sup -]. The branching fractions of the low background decay modes B[sup 0][yields] D*[sup -] D(*)[sup 0]K[sup+] are determined to be[Beta](B[sup 0][yields] D*[sup -] D[sup 0]K[sup+])= (2.8[+-] 0.7[+-] 0.5) x 10[sup -3] and[Beta](B[sup 0][yields] D*[sup -]D*[sup 0]K[sup+])= (6.8[+-] 1.7[+-] 1.7) x 10[sup -3], where the first error quoted is statistical and the second systematic. Observation of a significant number of candidates in the color-suppressed decay mode B[sup+][yields] D*[sup+]D*[sup -] K[sup+] is reported with a branching fraction[Beta](B[sup+][yields] D*[sup+]D*[sup -] K[sup+])= (3.4[+-] 1.6[+-] 0.9) x 10[sup -3]. Decays of the type B[yields] D(*)[bar D](*) can be used to provide a measurement of the parameter sin2[beta] of the Unitarity Triangle. For this decay mode they measure a branching fraction of[Beta](B[sup 0][yields] D*[sup+]D*[sup -])= (8.0[+-] 1.6[+-] 1.2) x 10[sup -4].




A Measurement of the Lambda-c Baryon Decays to Proton Kaon( - ) Pion(+) Absolute Branching Fraction with the BaBar Detector


Book Description

A measurement of {Beta}({Lambda}{sub c}{sup +} {yields} pK{sup -} {pi}{sup +}) is presented based on data collected with the BaBar detector at the Stanford Linear Accelerator Center. Branching fraction measurements represent a large portion of what is known about short-lived particles, the strong force that binds them, and the weak force that causes them to decay. While the majority of branching fraction measurements are done as ratios between two decay modes, it is the absolute measurements of a few particular decay modes that set the scale for these relative measurements. The {Lambda}{sub c}{sup +} particle is one of the four weakly decaying hadrons into which more than 90% of the known heavy quark hadrons will eventually decay. Thus, an absolute measurement of the branching fraction for {Lambda}{sub c}{sup +} {yields} pK{sup -}{pi}{sup +} is important for many studies of the heavy quark sector, from spectroscopy to B meson decays. The number of produced {Lambda}{sub c}{sup +}'s is inferred from the number of events reconstructed with an antiproton and an accompanying D meson. The final result of {Beta}({Lambda}{sub c}{sup +} {yields} pK{sup -} {pi}{sup +}) = [6.12 {+-} 0.31(stat.) {+-} 0.42(syst.)]% represents more than a two-fold improvement in precision over the world average. The dominant source of systematic uncertainty is the irreducible background of {Xi}{sub c} baryons.