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Neutrino Experiments 15 20 Reference Geo 4 20 40 4! Data - BG - best-fit osci. 2 Neutrino Experiments 15 20 Reference Geo "e [8] # $ 10 3! 0 5 2! 1! 120 KamLAND data best-fit osci. 1 2 3 4 5 6 ! ! KamLAND ! ! ! ! accidental Fundamental95% C.L. Symmetries100 and Neutrinos: 99% C.L. ) 99.73% C.L. 80 2 -4 best fit 10 Events / 0.2 MeV 60 13 16 (eV C(!,n) O 2 In21 Search of the New40 Standard Model best-fit Geo "e m best-fit osci. + BG $ 20 + best-fit Geo "e Solar 0 95% C.L. 1 1.2 1.4 1.6 1.8 2 2.2 2.4 2.6 99% C.L. Ep (MeV) 99.73% C.L. excluding absolutebest fit neutrino mass and 0νββ experiments FIG. 3: The low-energy region of the νe spectrum relevant for geo- 10-1 1 10 20 30 40 neutrinos. The main panel shows the data with the fitted background and geo-neutrino contributions; the upper panel compares the back- tan2" $#2 12 ground and reactor νe subtracted data to the number of geo-neutrinos for the decay chains of U (dashed) and Th (dotted) calculated from a FIG. 2: Allowed region for neutrino oscillation parameters from geological reference model [8]. KamLAND and solar neutrino experiments. The side-panels show 2 the ∆⇥ -profiles for KamLAND (dashed) and solar experiments 1.15 Data - BG - Geo ! 70 (dotted) individually, as well as the combination of the two (solid). e 60 Expectation based on osci. parameters expected 50 1 1.1 2 determined by KamLAND / N 40 30 5 detected 20 we also expect geo-neutrinos. We observe 1609 events. 0.8 3 N 1.05 10 1 Figure 1 shows the prompt energy spectrum of selected 0 0 0.05 0.1 0.15 electron anti-neutrino events and the fitted backgrounds. The 0.6 2 sin 213 unbinned data is assessed with a maximum likelihood fit to 1 two-flavor neutrino oscillation (with θ13 = 0), simultaneously 0.4 EH1 EH2 fitting the geo-neutrino contribution. The method incorporates Survival Probability 0.95 0.2 the absolute time of the event to account for time variations EH3 in the reactor flux and includes Earth-matter oscillation ef- 0.9 0 fects. The best-fit is shown in Fig. 1. The joint confidence 20 30 40 50 60 70 80 90 100 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 2 +0.14 +0.15 5 2 intervals give ∆m = 7.58 (stat) (syst) 10− eV Weighted Baseline [km] 21 0.13 0.15 L0/E (km/MeV) 2 +0.10 − +0.10 − ×2 !e and tan θ12 = 0.56 0.07(stat) 0.06(syst) for tan θ12<1. A − − scaled reactor spectrum without distortions from neutrino os- FIG. 4: Ratio of the background and geo-neutrino subtracted νe cillation is excluded at more than 5⇤. An independent anal- spectrum to the expectation for no-oscillation as a function of 2 +0.22 ysis using cuts similar to Ref. [2] finds ∆m21 = 7.66 0.20 L0/E. L0 is the effective baseline taken as a flux-weighted aver- − × 5 2 2 +0.16 age (L0 = 180 km); the energy bins are equal probability bins of the 10− eV and tan θ12 = 0.52 0.10. − best-fit including all backgrounds (see Fig. 1). The histogram and The allowed contours in the neutrino oscillation parame- 2 curve show the expectation accounting for the distances to the indi- ter space, including ∆⌅ -profiles, are shown in Fig. 2. Only vidual reactors, time-dependent flux variations and efficiencies. The the so-called LMA I region remains, while other regions error bars are statistical and do not include correlated systematic un- previously allowed by KamLAND at 2.2⇤ are disfavored certainties in the energy scale. ⇥ at more than 4⇤. When considering three-neutrino oscilla- Karsten2 M. Heeger tion, the KamLAND data give the same result for ∆m21, and a slightly increased uncertainty on θ12. The parame- Fig. 3. The time of the event gives additional discrimination ter space can be further constrained by incorporatingUniversitythe re- power sinceof theWisconsinreactor contribution varies. The fit yields 25 sults of SNO [15] and solar flux experiments [16] in a two- and 36 detected geo-neutrino events from the U and Th-decay neutrino analysis with KamLAND assuming CPT invariance. chains, respectively, but there is a strong anti-correlation. Fix- The oscillation parameters from this combined analysis are ing the Th/U mass ratio to 3.9 from planetary data [17], we 2 +0.21 5 2 2 +0.06 ∆m21 = 7.59 0.21 10− eV and tan θ12 = 0.47 0.05. obtain a combined U+Th best-fit value of 73 27 events cor- − × − 6 ±2 1 In order to assess the number of geo-neutrinos, we fit the responding to a flux of (4.4 1.6) 10 cm− s− , in agree- ± × normalization of the energy spectrum of ⇥e from the U and ment with the geological reference model. Th-decay chains simultaneously with the neutrino oscillation The ratio of the background-subtracted ⇥e candidate events, parameter estimation using the KamLANDNSAC,and solar data; seeSeptemberincluding the subtraction of7,geo-neutrinos, 2012to the expectation Karsten Heeger, Univ. of Wisconsin NSAC, September 7, 2012 1 Towards Precision Neutrino Physics solar neutrino problem oscillation searches precision measurements SNO, KamLAND 2010 Ga Cl SK Daya Bay, DC, RENO 2012 1960-1990 1990-2000 2000 - Present Neutrino mass and mixing first physics beyond the SM → precision studies Karsten Heeger, Univ. of Wisconsin NSAC, September 7, 2012 2 Neutrino Oscillation Measurements Recent Observations • atmospheric νμ and νμ disappear most likely to ντ (SK, MINOS) • accelerator νμ and νμ disappear at L~250, 700 km (K2K, T2K, MINOS) • some accelerator νμ appear as νμ at L~250, 700 km (T2K, MINOS) • solar νe convert to νμ/ντ (Cl, Ga, SK, SNO, Borexino) • reactor νe disappear at L~200 km (KamLAND) • reactor νe disappear at L~1 km (DC, Daya Bay RENO) KamLAND 2010 SK MINOS Experiments have demonstrated vacuum oscillation L/E pattern ⎛ L ⎞ P = sin2 2θ sin2⎜1.27 Δm2 ⎟ i→i ⎝ E ⎠ Karsten Heeger, Univ. of Wisconsin NSAC, September 7, 2012 3 € Neutrino Oscillation Measurements Recent Observations • atmospheric νμ and νμ disappear most likely to ντ (SK, MINOS) • accelerator νμ and νμ disappear at L~250, 700 km (K2K, T2K, MINOS) • some accelerator νμ appear as νμ at L~250, 700 km (T2K, MINOS) • solar νe convert to νμ/ντ (Cl, Ga, SK, SNO, Borexino) • reactor νe disappear at L~200 km (KamLAND) • reactor νe disappear at L~1 km (DC, Daya Bay RENO) Borexino, SNO low-energy (LETA) solar ν Vacuum to matter transition (MSW conversion) in Sun has been observed Karsten Heeger, Univ. of Wisconsin NSAC, September 7, 2012 4 Neutrino Oscillation Measurements Recent Observations • atmospheric νμ and νμ disappear most likely to ντ (SK, MINOS) • accelerator νμ and νμ disappear at L~250, 700 km (K2K, T2K, MINOS) • some accelerator νμ appear as νμ at L~250, 700 km (T2K, MINOS) • solar νe convert to νμ/ντ (Cl, Ga, SK, SNO, Borexino) • reactor νe disappear at L~200 km (KamLAND) • reactor νe disappear at L~1 km (DC, Daya Bay RENO) Dominant Important NP HEP Gonzalez-Garcia et al, ICHEP2012 complete suite of measurements can over-constrain the 3-ν framework NP neutrino experiments address unique set of questions and scientific goals US nuclear physicists have also played leading roles in HEP-funded experiments, such as reactor θ13 Karsten Heeger, Univ. of Wisconsin NSAC, September 7, 2012 5 Measurement of Fundamental Parameters Mass Splittings KamLAND 2010 MINOS Nu2012 normal inverted Karsten Heeger, Univ. of Wisconsin NSAC, September 7, 2012 6 Measurement of Fundamental Parameters Mass Splittings normal inverted KamLAND has measured Δm122 to ~2.8% Karsten Heeger, Univ. of Wisconsin NSAC, September 7, 2012 7 Measurement of Fundamental Parameters Mixing Angles U Matrix # & MNSP# Ue1 Ue2 Ue3 & 0.8 0.5 Ue3 Maki,% Nakagawa, Sakata,( Pontecorvo% ( U U U U 0.4 0.6 0.7 = % µ1 µ2 µ 3( = % ( % ( % ( $ U"1 U" 2 U" 3 ' # $ 0.4 0.6 0.7& ' # Ue1 Ue2 Ue3 & 0.8 0.5 Ue3 % ( % ( U U U U 0.4 0.6 0.7 = % µ1 µ2 µ 3( = % ( % ( % ( $ U"1 U" 2 U" 3 ' $ 0.4 0.6 0.7 ' # *i, CP & # 1 0 0 & cos)13 0 e sin)13 # cos)12 sin)12 0& # 1 0 0 & % ( % ( % ( % i / 2 ( 0 cos sin 0 1 0 sin cos 0 0 e - 0 = % )23 )23 ( +% ( +% * )12 )12 ( +% ( % ( % i, CP ( % ( % i- / 2+i. ( $ 0 *sin)23 cos)23' # *e sin)13 0 *i, CPcos)13 & $ 0 0 1' $ 0 0 e ' # 1 0 0 & $ cos)13 0 e sin)13 ' # cos)12 sin)12 0& # 1 0 0 & % ( % ( % ( % i / 2 ( 0 cos sin 0 1 0 sin cos 0 0 e - 0 = % )23 )23 ( +% ( +% * )12 )12 ( +% ( % atmospheric, K2K( % reactori, CP and accelerator ( SNO,% solar SK, KamLAND( % 0νββi- / 2+i. ( $ 0 *sin)23 cos)23' $ *e sin)13 0 cos)13 ' $ 0 0 1' $ 0 0 e ' ! ! maximal? not so small large, but not maximal! As of 2012, all three neutrino mixing angles are known! Karsten Heeger, Univ. of Wisconsin NSAC, September 7, 2012 8 Measurement of Fundamental Parameters Mixing Angles U Matrix # & MNSP# Ue1 Ue2 Ue3 & 0.8 0.5 Ue3 Maki,% Nakagawa, Sakata,( Pontecorvo% ( U U U U 0.4 0.6 0.7 = % µ1 µ2 µ 3( = % ( % ( % ( $ U"1 U" 2 U" 3 ' # $ 0.4 0.6 0.7& ' # Ue1 Ue2 Ue3 & 0.8 0.5 Ue3 % ( % ( U U U U 0.4 0.6 0.7 = % µ1 µ2 µ 3( = % ( % ( % ( $ U"1 U" 2 U" 3 ' $ 0.4 0.6 0.7 ' # *i, CP & # 1 0 0 & cos)13 0 e sin)13 # cos)12 sin)12 0& # 1 0 0 & % ( % ( % ( % i / 2 ( 0 cos sin 0 1 0 sin cos 0 0 e - 0 = % )23 )23 ( +% ( +% * )12 )12 ( +% ( % ( % i, CP ( % ( % i- / 2+i.
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