2 Search Results

The Pandora Software Development Kit and algorithm libraries provide pattern-recognition logic essential to the reconstruction of particle interactions in liquid argon time projection chamber detectors. Pandora is the primary event reconstruction software used at ProtoDUNE-SP, a prototype for the Deep Underground Neutrino Experiment far detector. ProtoDUNE-SP, located at CERN, is exposed to a charged-particle test beam. This paper gives an overview of the Pandora reconstruction algorithms and how they have been tailored for use at ProtoDUNE-SP. In complex events with numerous cosmic-ray and beam background particles, the simulated reconstruction and identification efficiency for triggered test-beam particles is above 80% formore » the majority of particle type and beam momentum combinations. Specifically, simulated 1 GeV/c charged pions and protons are correctly reconstructed and identified with efficiencies of 86.1$$\pm 0.6$$% and 84.1$$\pm 0.6$$%, respectively. The efficiencies measured for test-beam data are shown to be within 5% of those predicted by the simulation.« less

The spectroscopy of ${}^{19}\mathrm{F}$ is of interest for nuclear astrophysics and nuclear structure. In astrophysics, fluorine and the reactions producing and destroying it play a key role in constraining models of stars in different evolutionary stages, such as the asymptotic giant branch (AGB) stars, responsible of the production of about half of the elements heavier than Fe. In nuclear structure, ${}^{19}\mathrm{F}$ has been subject to many investigations aiming at the identification of α and more exotic cluster structures. Also, its spectroscopy is very usefulmore » to constrain the nuclear properties of the ¹⁹Ne mirror nucleus. Here in this work, we report on the measurement of the ¹⁵N α elastic scattering using the thick target inverse kinematics approach, allowing us to span a very large fluorine excitation energy range (~6-10 MeV). The use of ¹⁵N α scattering proves very useful to study α clustering in ${}^{19}\mathrm{F}$ thanks to the likelihood for populating states with such a structure. Indeed, the R-matrix analysis of the measured differential cross sections shows the occurrence of many candidate α-cluster states of ${}^{19}\mathrm{F}$. It also calls for the redefinition of the spin-parity and widths of a number of ${}^{19}\mathrm{F}$ states with respect to what reported in the literature.« less