arXiv subjects

S. AlSaid

Publications and source records attributed to S. AlSaid.

3 recordsLinked to original sources

arXiv2021

Measurement of the Masses and Widths of the $\Sigma_c(2455)^+$ and $\Sigma_c(2520)^+$ Baryons

Using 980 ${\rm fb}^{-1}$ of data {collected} with the Belle detector operating at the KEKB asymmetric-energy $e^+e^-$ collider, we report the measurements of the masses, and the first measurements of the instrinsic widths, of the $\Sigma_c(2455)^+$ and $\Sigma_c(2520)^+$ charmed baryons. We find $M(\Sigma_c(2455)^+)-M(\Lambda_c^+) = 166.17\pm 0.05^{+0.16}_{-0.07}\ {\rm MeV}/c^2$, $\Gamma(\Sigma_c(2455)^+) = 2.3 \pm 0.3 \pm 0.3\ {\rm MeV/c^2}$, $M(\Sigma_c(2520)^+)-M(\Lambda_c^+) = 230.9 \pm 0.5 ^{+0.5}_{-0.1}\ {\rm MeV}/c^2$, and $\Gamma(\Sigma_c(2520)^+) = 17.2^{+2.3\ +3.1}_{-2.1\ -0.7}\ {\rm MeV}/c^2$, where the uncertainties are statistical and systematic, respectively. These measurements can be used to test models of the underlying quark structure of the $\Sigma_c$ states.

hep-ex↗

arXiv2020

Study of Electromagnetic Decays of Orbitally Excited $\Xi_c$ Baryons

Using 980 $fb^-1$ of data collected with the Belle detector operating at the KEKB asymmetric-energy e^+e^- collider, we report a study of the electromagnetic decays of excited {charmed baryons} $\Xi_c(2790)$ and $\Xi_c(2815)$. A clear signal (8.6 standard deviations) is observed for $\Xi_c(2815)^0 \to \Xi_c^0\gamma$, and we measure: $B[\Xi_c(2815)^0 \to \Xi_c^0\gamma]/B[\Xi_c(2815)^0 \to \Xi_c(2645)^+\pi^- \to \Xi_c^0\pi^+\pi^-] = 0.41 \pm 0.05 \pm 0.03$. We also present evidence (3.8 standard deviations) for the similar decay of the $\Xi_c(2790)^0$ and measure: $B[\Xi_c(2790)^{0}\to\Xi_c^{0}\gamma]/B[\Xi_c(2790)^0\to\Xi_c^{\prime +}\pi^{-}\to\Xi_c^{+}\gamma \pi^-] = 0.13 \pm 0.03 \pm 0.02$. The first quoted uncertainties are statistical and the second systematic. We find no hint of the analogous decays of the $\Xi_c(2815)^+$ and $\Xi_c(2790)^+$ baryons and set upper limits at the 90% confidence level of: $B[\Xi_c(2815)^{+}\to\Xi_c^{+}\gamma]/B[\Xi_c(2815)^+\to\Xi_c(2645)^0\pi^+\to\Xi_c^+\pi^-\pi^+] < 0.09,$ and $B[\Xi_c(2790)^{+}\to\Xi_c^{+}\gamma]/B[\Xi_c(2790)^+\to\Xi_c^{\prime 0}\pi^{+}\to\Xi_c^{0}\gamma \pi^+] < 0.06.$ Approximate values of the partial widths of the decays are extracted, which can be used to discriminate between models of the underlying quark structure of these excited states.

hep-ex↗

arXiv2017

Measurement of Branching Fractions of Hadronic Decays of the $\Omega_c^0$ Baryon

Using a data sample of 980 ${\rm fb}^{-1}$ of $e^+e^-$ annihilation data taken with the Belle detector operating at the KEKB asymmetric-energy $e^+e^-$ collider, we report the results of a study of the decays of the $\Omega_c^0$ charmed baryon into hadronic final states. We report the most precise measurements to date of the relative branching fractions of the $\Omega_c^0$ into $\Omega^-\pi^+\pi^0$, $\Omega^-\pi^+\pi^-\pi^+$, $\Xi^-K^-\pi^+\pi^+$, and $\Xi^0K^-\pi^+$, as well as the first measurements of the branching fractions of the $\Omega_c^0$ into $\Xi^-\bar{K}^0\pi^+$, $\Xi^0\bar{K}^0$, and $\Lambda \bar{K}^0\bar{K}^0$, all with respect to the $\Omega^-\pi^+$ decay. In addition, we investigate the resonant substructure of these modes. Finally, we present a limit on the branching fraction for the decay $\Omega_c^0\to\Sigma^+K^-K^-\pi^+$.

hep-ex↗