M. Otani

Search for Charged Current Coherent Pion Production on Carbon in a Few-GeV Neutrino Beam

The SciBooNE Collaboration has performed a search for charged current coherent pion production from muon neutrinos scattering on carbon, nu{sub {mu}}{sup 12}C- {yields} {mu}{sup 12}Cpi{sup +}, with two distinct data samples. No evidence for coherent pion production is observed. We set 90% confidence level upper limits on the cross section ratio of charged current coherent pion production to the total charged current cross section at 0.67 x 10{sup -2} at mean neutrino energy 1.1 GeV and 1.36 x 10{sup -2} at mean neutrino energy 2.2 GeV.

Measurement of inclusive charged current interactions on carbon in a few-GeV neutrino beam

The SciBooNE Collaboration reports a measurement of inclusive charged current interactions of muon neutrinos on carbon with an average energy of 0.8 GeV using the Fermilab Booster Neutrino Beam. We compare our measurement with two neutrino interaction simulations: NEUT and NUANCE. The charged current interaction rates (product of flux and cross section) are extracted by fitting the muon kinematics, with a precision of 6-15% for the energy dependent and 3% for the energy integrated analyses. We also extract CC inclusive interaction cross sections from the observed rates, with a precision of 10-30% for the energy dependent and 8% for the energy integrated analyses. This is the first measurement of the CC inclusive cross section on carbon around 1 GeV. These results can be used to convert previous SciBooNE cross section ratio measurements to absolute cross section values.

The T2K fine-grained detectors

T2K is a long-baseline neutrino oscillation experiment searching for νe appearance in a νμ beam. The beam is produced at the J-PARC accelerator complex in Tokai, Japan, and the neutrinos are detected by the SuperKamiokande detector located 295 km away in Kamioka. A suite of near detectors (ND280) located 280 m downstream of the production target is used to characterize the components of the beam before they have had a chance to oscillate and to better understand various neutrino interactions on several nuclei. This paper describes the design and construction of two massive fine-grained detectors (FGDs) that serve as active targets in the ND280 tracker. One FGD is composed solely of scintillator bars while the other is partly scintillator and partly water. Each element of the FGDs is described, including the wavelength shifting fiber and Multi-Pixel Photon Counter used to collect the light signals, the readout electronics, and the calibration system. Initial tests and in situ results of the FGDs’ performance are also presented.

Measurement of Inclusive Neutral Current Neutral

We acknowledge the Physics Department at Chonnam National University, Dongshin University, and Seoul National University for the loan of parts used in SciBar and the help in the assembly of SciBar. We wish to thank the Physics Departments at the University of Rochester and Kansas State University for the loan of Hamamatsu PMTs used in the MRD. We gratefully acknowledge support from Fermilab as well as various grants, contracts and fellowships from the MEXT and JSPS (Japan), the INFN (Italy), the Ministry of Science and Innovation and CSIC (Spain), the STFC (UK), and the DOE and NSF (USA). This work was supported by MEXT and JSPS with the Grant-in-Aid for Scientific Research A 19204026, Young Scientists S 20674004, Young Scientists B 18740145, Scientific Research on Priority Areas “New Developments of Flavor Physics”, and the global COE program “The Next Generation of Physics, Spun from Universality and Emergence”. The project was supported by the Japan/U.S. Cooperation Program in the field of High Energy Physics and by JSPS and NSF under the Japan-U.S. Cooperative Science Program.

\pi^0

We have developed a Multi-Pixel Photon Counter (MPPC) for the neutrino detectors of T2K experiment. About 64,000 MPPCs have been produced and tested in about a year. In order to characterize a large number of MPPCs, we have developed a system that simultaneously measures 64 MPPCs with various bias voltage and temperature. The performance of MPPCs are found to satisfy the requirement of T2K experiment. In this paper, we present the performance of 17,686 MPPCs measured at Kyoto University.

Production on Carbon in a Few-GeV Neutrino Beam

The SciBooNE Collaboration reports a measurement of neutral current coherent {pi}{sup 0} production on carbon by a muon neutrino beam with average energy 0.8 GeV. The separation of coherent from inclusive {pi}{sup 0} production has been improved by detecting recoil protons from resonant {pi}{sup 0} production. We measure the ratio of the neutral current coherent {pi}{sup 0} production to total charged current cross sections to be (1.16{+-}0.24)x10{sup -2}. The ratio of charged current coherent {pi}{sup +} to neutral current coherent {pi}{sup 0} production is calculated to be 0.14{sub -0.28}{sup +0.30}, using our published charged current coherent pion measurement.

Performance of multi-pixel photon counters for the T2K near detectors

The Tokai-to-Kamioka (T2K) neutrino experiment measures neutrino oscillations by using an almost pure muon neutrino beam produced at the J-PARC accelerator facility. The T2K muon monitor was installed to measure the direction and stability of the muon beam which is produced together with the muon neutrino beam. The systematic error in the muon beam direction measurement was estimated, using data and MC simulation, to be 0.28 mrad. During beam operation, the proton beam has been controlled using measurements from the muon monitor and the direction of the neutrino beam has been tuned to within 0.3 mrad with respect to the designed beam-axis. In order to understand the muon beam properties, measurement of the absolute muon yield at the muon monitor was conducted with an emulsion detector. The number of muon tracks was measured to be (4.06 ± 0.05) × 10⁴ cm⁻² normalized with 4 × 10¹¹protons on target with 250 kA horn operation. The result is in agreement with the prediction which is corrected based on hadron production data.

Improved measurement of neutral current coherent

The SciBooNE Collaboration reports a measurement of neutral current coherent {pi}{sup 0} production on carbon by a muon neutrino beam with average energy 0.8 GeV. The separation of coherent from inclusive {pi}{sup 0} production has been improved by detecting recoil protons from resonant {pi}{sup 0} production. We measure the ratio of the neutral current coherent {pi}{sup 0} production to total charged current cross sections to be (1.16{+-}0.24)x10{sup -2}. The ratio of charged current coherent {pi}{sup +} to neutral current coherent {pi}{sup 0} production is calculated to be 0.14{sub -0.28}{sup +0.30}, using our published charged current coherent pion measurement.

\pi^0

The SciBooNE Collaboration reports a measurement of neutral current coherent {pi}{sup 0} production on carbon by a muon neutrino beam with average energy 0.8 GeV. The separation of coherent from inclusive {pi}{sup 0} production has been improved by detecting recoil protons from resonant {pi}{sup 0} production. We measure the ratio of the neutral current coherent {pi}{sup 0} production to total charged current cross sections to be (1.16{+-}0.24)x10{sup -2}. The ratio of charged current coherent {pi}{sup +} to neutral current coherent {pi}{sup 0} production is calculated to be 0.14{sub -0.28}{sup +0.30}, using our published charged current coherent pion measurement.