Neutrino-nucleus neutral current elastic interactions measurement in MiniBooNE

Thesis/Dissertation · Tue Dec 01 00:00:00 EST 2009

DOI:https://doi.org/10.2172/970065· OSTI ID:970065

Perevalov, Denis ^[1]

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1. Univ. of Alabama, Tuscaloosa, AL (United States)

The MiniBooNE experiment at the Fermi National Accelerator Laboratory (Fermilab) was designed to search for v_μ → v_e neutrino oscillations at Δm² ~ 1 eV² using an intense neutrino flux with an average energy E_v ~ 700 MeV. From 2002 to 2009 MiniBooNE has accumulated more than 1.0 x 10²¹ protons on target (POT) in both neutrino and antineutrino modes. MiniBooNE provides a perfect platform for detailed measurements of exclusive and semiinclusive neutrino cross-sections, for which MiniBooNE has the largest samples of events up to date, such as neutral current elastic (NCE), neutral current π⁰, charged current quasi-elastic (CCQE), charged current π⁺, and other channels. These measured cross-sections, in turn, allow to improve the knowledge of nucleon structure. This thesis is devoted to the study of NCE interactions. Neutrino-nucleus neutral current elastic scattering (vN → vN) accounts for about 18% of all neutrino interactions in MiniBooNE. Using a high-statistics, high purity sample of NCE interactions in MiniBooNE, the flux-averaged NCE differential cross-section has been measured and is being reported here. Further study of the NCE cross-section allowed for probing the structure of nuclei. The main interest in the NCE cross-section is that it may be sensitive to the strange quark contribution to the nucleon spin, Δs, this however requires a separation of NCE proton (vp → vp) from NCE neutron (vn → vn) events, which in general is a challenging task. MiniBooNE uses a Cherenkov detector, which imposes restrictions on the measured nucleon kinematic variables, mainly due to the impossibility to reconstruct the nucleon direction below the Cherenkov threshold. However, at kinetic energies above this threshold MiniBooNE is able to identify NCE proton events that do not experience final state interactions (FSI). These events were used for the Δs measurement. In this thesis MiniBooNE reports the NCE (n+p) cross-section, the measurement of the axial mass, M_A, and the Δs parameter from the NCE data.

• Research Organization: Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC02-07CH11359
• OSTI ID: 970065
• Report Number(s): FERMILAB-THESIS-2009-47; TRN: US1000728
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ANTINEUTRINOS
CHARGED CURRENTS
CHERENKOV COUNTERS
CROSS SECTIONS
DIFFERENTIAL CROSS SECTIONS
ELASTIC SCATTERING
FERMILAB
FERMILAB ACCELERATOR
FINAL-STATE INTERACTIONS
KINETICS
NEUTRAL CURRENTS
NEUTRINO OSCILLATION
NEUTRINOS
NEUTRONS
NUCLEI
NUCLEONS
PROTONS
QUARKS
SPIN
TARGETS
Experiment-HEP