120 likes | 183 Views
n e search @ SK (update with 40GeV flux). S.Mine (UCI). cf.) original report with 50GeV flux http://jnusrv01.kek.jp/jhfnu/NP04nu/PresenFiles/sk/ explanation of 40GeV flux by A.K.Ichikawa http://jnusrv01.kek.jp/jhfnu/internal/OfficialPlots/flux/.
E N D
ne search @ SK (update with 40GeV flux) S.Mine (UCI) • cf.) • original report with 50GeV flux • http://jnusrv01.kek.jp/jhfnu/NP04nu/PresenFiles/sk/ • explanation of 40GeV flux by A.K.Ichikawa • http://jnusrv01.kek.jp/jhfnu/internal/OfficialPlots/flux/ S.Mine
n flux · cross section @ SK(w/o oscillation) • 2.5o off-axis beam (04b, 40GeV) • The latest NEUT (ver4.5) • n int.(22.5kt/yr) ~ 2250(nm), ~ 50(ne) • ne/nm ratio at peak ~ 0.4% nm ne S.Mine
Selection criteria for ne appearance • standard SK cuts: • further p0 cuts: • fully contained(FC) in fiducial volume(FV), • visible energy>100MeV • single-ring • electron-like PID • no decay-e • 0.35<Enrec<0.85GeV • cosqne<0.9 • DL<80 & Mp0<100MeV/c2 of p0 fitter S.Mine
Enrec & cosqne(FCFV 1R-e)Dm2=2.5x10-3eV2, sin22q13=0.1 ne signal nm BG (hatch) ne BG (blank) ne signal nm BG (hatch) ne BG (blank) events/22.5kt/5yrs events/22.5kt/5yrs reconstructed n energy (GeV) cosqne S.Mine
p0 fitter (“POLfit”) p0 fitter • Target: FCFV 1R-elike events • DL≡Likelihood(2g assump.) • – Likelihood(1 electron assump.) • 2g assump.: • vary E2/(E1+E2) & E2 dir. • → Mp0 etc. standard fitter g2 g1 500MeV/c p0 true Pg2 = 55.5MeV/c rec.Mp0 =140.4MeV/c2 S.Mine
DL&p0 mass (all cuts except p0 cuts)Dm2=2.5x10-3eV2,sin22q13=0.1 ne signal nm BG (hatch) ne BG (blank) ne signal DL events/22.5kt/5yrs nm BG DL DL ne signal nm BG (hatch) ne BG (blank) beam ne BG events/22.5kt/5yrs DL p0 mass (MeV/c2) p0 mass (MeV/c2) S.Mine
Events vs. selections (1)Dm2=2.5x10-3eV2,sin22q13=0.1 • FCFV, visible energy>100MeV • single ring • e-like PID • no decay-e • 0.35<Enrec<0.85GeV • cosqne<0.90 • Mp0<100MeV/c2(p0 fitter) • DL<80(p0 fitter) nm BG ne signal ne BG S.Mine
Events vs. selections (2)Dm2=2.5x10-3eV2,sin22q13=0.1 (events / 22.5kt / 5yrs) “p0 cuts” *0.7(nm CC BG)+9(nm NC BG) S.Mine
ne sensitivity (1) Dm2=2.5x10-3eV2 3s P(nm→ne) = sin2q23 sin22q13 sin2(1.27 Dm232L/E) (sin22q23=1, d=0 are assumed) 90%CL S.Mine
ne sensitivity (2) 90%CL DBG=10% 5years CHOOZ excluded P(nm→ne) = sin2q23 sin22q13 sin2(1.27 Dm232L/E) (sin22q23=1, d=0 are assumed) S.Mine
Enrec (all cuts except this)Dm2=2.5x10-3eV2,sin22q13=0.1 events/22.5kt/5yrs S.Mine
Measurement error • Dm2=2.5x10-3eV2 • ssys=0.1xNexp • ~18%@sin22q13=0.1 • ~80%@sin22q13=0.01 0.100+0.018 -0.015 expected signal+BG/22.5kt/5yrs 0.030+0.010 -0.008 0.010+0.008 -0.006 0.003+0.007 -0.002 S.Mine