Browsing by Subject "Particle Physics"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Inclusive Semielectronic Decays of the $D_s^+$ Meson
    (2020-09) Gilman, Alex
    We present an analysis of the semielectronic decays of the $\Ds$ meson. We analyze data collected by the BESIII experiment from $e^+e^-$ collisions provided by the BEPCII collider with center-of-mass energies between $4.18\text{ GeV}$ and $4.23\text{ GeV}$. We employ a double-tag technique with the $D_s^-\to K^-K^+\pi^-$ tag mode, which yields $ 262660. \pm 1137$ signal $D_s^+$ for analysis. The inclusive electronic momentum spectrum in the lab frame is recovered with the use of matrix unfolding procedures for electrons with measured momentum greater than $200 \text{ MeV}/c$. By extrapolating the measured spectrum below $200 \text{ MeV}/c$, we determine the inclusive semielectronic branching fraction to be $\semilepBF=\left(6.34\pm0.13\pm 0.10\right)\%$. We determine the branching fraction of unobserved exclusive $\Ds$ semielectronic modes to be $\left(0.05\pm 0.24\right)\%$ and the ratio of $\Ds$ and $D^0$ semielectronic widths to be $\frac{\Gamma(D_{s}^{+}\rightarrow Xe^+\nu_e)}{\Gamma(D^0\rightarrow Xe^+\nu_e)}=0.793\pm 0.026$ by employing other known results. An input/output check with a Monte Carlo sample five times larger than data is also presented as a demonstration of the validity of our analysis method. Our results are consistent with and more precise than the previous measurement by the CLEO-$c$ collaboration, $\semilepBF=\left(6.52\pm0.39\pm 0.15\right)\%$.
  • Thumbnail Image
    Item
    Muon Energy Reconstruction Through the Multiple Scattering Method in the NOvA Detectors
    (2013-06) Psihas Olmedo, Silvia Fernanda
    Neutrino energy measurements are a crucial component in the experimental study of neutrino oscillations. These measurements are done through the reconstruction of neutrino interactions and energy measurements of their products. This thesis presents the development of a technique to reconstruct the energy of muons from neutrino interactions in the NOvA experiment. This is achieved through the understanding of muon multiple scattering within the NOvA detectors. This technique is particularly useful for estimating energies of muons which escape the detector.