Analysis of the Semileptonic Decay D⁰ → $$\bar{K}$$⁰ π^-μ⁺v

Thesis/Dissertation · Thu Jan 01 00:00:00 EST 2004

DOI:https://doi.org/10.2172/15020199· OSTI ID:15020199

Segoni, Ilaria Maria Lucia ^[1]

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1. Univ. of Colorado, Boulder, CO (United States)

This thesis describes the analysis of the semileptonic decay D⁰ → $$\bar{K}$$⁰ π^-μ⁺v using FOCUS data. FOCUS is a fixed target experiment at Fermilab that studies the physics of the charm quark. Particles containing charm are produced by photon-gluon fusion from the collision of a photon beam on a BeO target. The experiment is characterized by excellent vertex resolution and particle identification. The spectrometer consists of three systems for track reconstruction (two silicon systems and one multiwire proportional chamber system) and two magnets of opposite polarity. The polarity of the magnet is such that the events of e⁺e^- pairs produced in the target (which constitutes the main background) travel through a central opening in the detectors without interactions. Particle momentum is measured from the deflection angle in the magnets. Three multicell Cerenkov counters are used for charged particle identification (for e, π, K, and p). Two different tracking systems located after several interaction lengths of shielding material are used for muon identification. The energy of neutral pions and electrons is measured in two electromagnetic calorimeters, while an hadron calorimeter is used for measuring the neutron energy. During the last four years the FOCUS collaboration provided results on several charm topics: CP violation, D⁰-$$\bar{D}$$⁰ mixing, rare and forbidden decays, precision measurements of semileptonic decays, baryon and meson lifetimes, fully hadronic baryon and meson branching ratios, charm spectroscopy, Dalitz analyses of resonant structures, charm anti-charm production, QCD studies involving double charm particles, and pentaquarks. Semileptonic decays, besides having a clear signature for experiments, provide crucial information for theoretical studies. These decays carry information on the weak coupling of quarks since they can be used for measuring Cabibbo-Kobayashi-Maskawa matrix elements. Although the decay occurs through weak interaction, QCD effects due to quark confinement affect the decay amplitude. These effects can be included through the form factors, which are predicted by different theoretical approaches (quark models, lattice QCD, and sum rules). Experiments can measure form factor ratios, and from the comparison with theory they provide guidance for building a successful theory to describe hadrons.

• Research Organization: Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC02-76CH03000
• OSTI ID: 15020199
• Report Number(s): FERMILAB-THESIS-2004-60; TRN: US0605113
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BAG MODEL
BRANCHING RATIO
CHARGED PARTICLES
CHARM PARTICLES
DECAY
DECAY AMPLITUDES
FORM FACTORS
MATRIX ELEMENTS
MULTIWIRE PROPORTIONAL CHAMBERS
PARTICLE IDENTIFICATION
PHOTON BEAMS
QUANTUM CHROMODYNAMICS
SEMILEPTONIC DECAY
SHIELDING MATERIALS
WEAK INTERACTIONS
Experiment-HEP