Particle and Nuclear Physics Seminar at J-PARC
DATE: 2015 July. 7th 15:00-16:00
PLACE:Tokai 1st Buiding Room115
TITLE: New results of θ13 measurement via the Hydrogenchannel using full data with the Double Chooz Far detector
SPEAKER: Prof. Ralitsa Sharankova
(Tokyo University of Technology)
CONTACT: Prof. Shunzo Kumano, j-parc-pn-seminar-(AT)-ml.post.kek.jp
Abstract:Double Chooz is a reactor neutrino experiment aimedat precise measurement of the neutriro mixing angle θ13.Inverse beta decays from antineutrino interactions areobserved as coincidences of a prompt signal (positron)and a delayed signal (neutron capture). The main analysischannel uses neutron captures on Gadolinium. Howevera supplementary channel exists that uses captures onHydrogen.In this talk we report new results of the Double Choozθ13 measurement via the Hydrogen capture channelusing the full Far detector-only dataset. In this analysisbackgrounds are greatly suppressed due to innovativebackground rejection techniques. These include aneural-network- based multivariate analysis and pulseshape discrimination that takes advantage of the fullchannel readout by Flash-ADCs. The neutrino spectrumdistortion that was observed in the Gd analysis ischecked using the independent H capture sample.Combining the H and Gd samples results in morethan a factor two increase in statistics.This could beused to enhance the sensitivity of our Near+Far detectoranalysis, especially in the early phase.