Measurement of the branching fraction of $Lambda_c^+ to p omega$ decay at Belle

Using 980.6 $rm fb^{-1}$ of data collected with the Belle detector operating at the KEKB asymmetric-energy $e^+e^-$ collider, we present a measurement of the branching fraction of the singly Cabibbo-suppressed decay $Lambda_c^+ to p omega$. A clear $Lambda_c^+$ signal is observed for $Lambda_c^+ to p omega$ with a statistical significance of 9.1 standard deviations, and we measure the ratio of branching fractions ${cal B}(Lambda_c^+ to p omega)/{cal B}(Lambda_c^+ to p K^- pi^+) = (1.32 pm 0.12 (rm stat) pm 0.10 (rm syst))times 10^{-2}$, from which we infer the branching fraction ${cal B}(Lambda_c^+ to p omega) = (8.27 pm 0.75 (rm stat) pm 0.62 (rm syst) pm 0.42 (rm ref))times 10^{-4}$. The first quoted uncertainty is statistical, the second systematic, and the third from the reference mode $Lambda_c^+ to p K^- pi^+$.

Measurement of the Branching Fraction Br(Lambda_c+ -> p K- pi+)

We present the first model-independent measurement of the absolute branching fraction of the Lambda_c+ -> p K- pi+ decay using a data sample of 978 fb^-1 collected with the Belle detector at the KEKB asymmetric-energy e+e- collider. The number of Lambda_c+ baryons is determined by reconstructing the recoiling D(*)- anti-p pi+ system in events of the type e+e- -> D(*)- anti-p pi+ Lambda_c+. The branching fraction is measured to be Br(Lambda_c+ -> p K- pi+) = (6.84 +- 0.24^{+0.21}_{-0.27})%, where the first and second uncertainties are statistical and systematic, respectively.

Measurement of the absolute branching fraction of the inclusive semileptonic $Lambda_c^+$ decay

Using a data sample corresponding to an integrated luminosity of 567 pb$^{-1}$ collected at a center-of-mass energy of $sqrt{s}=4.6$ GeV with the BESIII detector, we measure the absolute branching fraction of the inclusive semileptonic $Lambda_c^+$ decay with a double-tag method. We obtain $mathcal{B}(Lambda_c^+ rightarrow X e^+ u_e) = (3.95pm0.34pm0.09)%$, where the first uncertainty is statistical and the second systematic. Using the known $Lambda_c^+$ lifetime and the charge-averaged semileptonic decay width of nonstrange charmed measons ($D^0$ and $D^+$), we obtain the ratio of the inclusive semileptonic decay widths $Gamma(Lambda_c^+ rightarrow X e^+ u_e)/bar{Gamma}(Drightarrow X e^+ u_e)= 1.26pm0.12$.

Precision measurement of the $Lambda_c^+$, $Xi_c^+$ and $Xi_c^0$ baryon lifetimes

We report measurements of the lifetimes of the $Lambda_c^+$, $Xi_c^+$ and $Xi_c^0$ charm baryons using proton-proton collision data at center-of-mass energies of 7 and 8tev, corresponding to an integrated luminosity of 3.0 fb$^{-1}$, collected by the LHCb experiment. The charm baryons are reconstructed through the decays $Lambda_c^+to pK^-pi^+$, $Xi_c^+to pK^-pi^+$ and $Xi_c^0to pK^-K^-pi^+$, and originate from semimuonic decays of beauty baryons. The lifetimes are measured relative to that of the $D^+$ meson, and are determined to be begin{align*} tau_{Lambda_c^+} &= 203.5pm1.0pm1.3pm1.4~{rm fs}, ewline tau_{Xi_c^+} &= 456.8pm3.5pm2.9pm3.1~{rm fs}, ewline tau_{Xi_c^0} &= 154.5pm1.7pm1.6pm1.0~{rm fs}, end{align*} where the uncertainties are statistical, systematic, and due to the uncertainty in the $D^+$ lifetime. The measurements are approximately 3--4 times more precise than the current world average values. The $Lambda_c^+$ and $Xi_c^+$ lifetimes are in agreement with previous measurements; however, the $Xi_c^0$ baryon lifetime is approximately 3.3 standard deviations larger than the world average value.

Search for $Lambda_c^+tophi p pi^0$ and branching fraction measurement of $Lambda_c^+to K^-pi^+ p pi^0$

We have searched for the Cabibbo-suppressed decay $Lambda_c^+tophi ppi^0$ in $e^+e^-$ collisions using a data sample corresponding to an integrated luminosity of 915 $rm fb^{-1}$. The data were collected by the Belle experiment at the KEKB $e^+e^-$ asymmetric-energy collider running at or near the $Upsilon(4S)$ and $Upsilon(5S)$ resonances. No significant signal is observed, and we set an upper limit on the branching fraction of $mathcal{B}(Lambda_c^+to phi ppi^0) <15.3times10^{-5}$ at 90% confidence level. The contribution for nonresonant $Lambda_c^+to K^+K^- ppi^0$ decays is found to be consistent with zero and the corresponding upper limit on its branching fraction is set to be $mathcal{B}(Lambda_c^+to K^+K^-ppi^0)_{rm NR} <6.3times10^{-5} $ at 90% confidence level. We also measure the branching fraction for the Cabibbo-favored decay $Lambda_c^+to K^-pi^+ppi^0$; the result is $mathcal{B}(Lambda_c^+to K^-pi^+ppi^0)= (4.42pm0.05, (rm stat.) pm 0.12, (rm syst.) pm 0.16, (mathcal{B}_{rm Norm}))%$, which is the most precise measurement to date. Finally, we have searched for an intermediate hidden-strangeness pentaquark decay $P^+_stophi p$. We see no evidence for this intermediate decay and set an upper limit on the product branching fraction of ${cal B}(Lambda_c^+to P^+_s pi^0)times {cal B}(P^+_stophi p) <8.3times 10^{-5}$ at 90% confidence level.