140 likes | 344 Views
Estimated theta13 measurement at RENO. 전은주 , 강운구 , 김영덕 , 마경주 ( 세종대학교 ), 공대정 , 김동희 , 김우영 , 사무엘스테파냔 , 서준석 , 아딜 칸 , 안드레이 김 ( 경북대학교 ), 박인곤 ( 경상대학교 ), 박명렬 ( 동신대학교 ), 안정근 , 이효상 ( 부산대학교 ), 김수봉 , 김현수 , 박강순 , 박정식 , 신경하 , 이재승 , 최선호 , 황원석 ( 서울대학교 ),
E N D
Estimated theta13 measurement at RENO 전은주, 강운구, 김영덕, 마경주 (세종대학교), 공대정,김동희,김우영,사무엘스테파냔, 서준석,아딜 칸,안드레이 김 (경북대학교), 박인곤 (경상대학교), 박명렬 (동신대학교), 안정근, 이효상(부산대학교), 김수봉,김현수,박강순,박정식,신경하,이재승,최선호,황원석 (서울대학교), 권은향,김동현,박차원,백승록,유인태,최수용,최영일 (성균관대학교), 김성현,김재률,주경광,임인택,장지승,정신석 (전남대학교), 오영도 (포항공과대학교), N.Danilov,YU.Krylov,G.Novikova,E.Yanovich (INR and IPCE, Russia) KPS 한국물리학회 Apr. 18, 2008
Outline • What is RENO? • Detector design • Background estimation • Systematic uncertainty • Sensitivity • Summary
sin22θ13 Determination of q13 using ne from reactors Well understood, isotropic source of electron anti-neutrinos Oscillations observed as a deficit of νe Eν<10 MeV 1.0 Unoscillated flux observed here Probability νe Survival Probability Distance 1200 to 1800 meters
+ e γ γ ν e prompt signal p n Delayed signal 30μs γ å ~ γ E 8 MeV g Gd γ γ Detection of neutrino events Inverse Beta Decay En<10 MeV
RENO Detector • Four concentric cylindrical parts • Identical detectors for near and far • Target and gamma catcher are filled with liquid scintillator aiming at detecting inverse beta decay • 342 10-inch PMTs on the surface of buffer • 67 10-inch PMTs on the VETO 15 ton targets (=1.3x1030 protons) total ~450 tons
Muon veto system • Cosmic muon induced neutron backgrounds: • Fast neutrons from rock • Neutrons by untagged muons in VETO • Beta-neutron cascades: muon spallation on 12C 8He and 9Li • 1.5m water VETO works also as neutron and gamma shielding. target g-catcher buffer veto Fast neutron rate < 1/day@ Far detector Background/signal < 1%
Reconstruction of Cosmic Muons Event Number A Veto mounted PMTs Veto (OD) Buffer mounted PMTs B Buffer (ID) First-hit hit time Log scale C D Event Info Number of photoelectrons Ne Radius
Through-going muon reconstruction using RENO-specific muon spectrum • Total number of events generated= 7300 • Through-going muons= 6622 (Xtrue-Xrec)_OD_entrance (Xtrue-Xrec)_ID_entrance angle difference between tracktrue and trackrec angle(degree) (Xtrue-Xrec)_OD_exit (Xtrue-Xrec)_ID_exit
Calculation of gBackground at the RENO Underground • g rate from rock [Hz]
(rate only analysis) SK Sensitivity 90%CL sensitivity after 3 years of data taking GLoBES group workshop@Heidelberg – Mention’s talk SK
Summary • Systematic analysis for RENO • total systematic error: less than 0.5% as our goal • Most backgrounds are estimated. (< 1% B/S) • sin2(2q13)= 0.02 sensitivity can be reached with 3 year data.
2009 2006 2007 2008 12 12 12 12 3 3 3 3 6 6 6 6 9 9 9 9 Schedule Activities Detector Design & Specification Geological Survey & Tunnel Design Detector Construction Excavation & Underground Facility Construction Detector Commissioning We are here