Experimental Status of Neutrino Physics

Experimental status of neutrino physics

Fanny Dufour1 and David Wark2 1Section de Physique, Universitéde Genève, 1205 Genève, Switzerland 2Imperial College London, Department of Physics, London, United Kingdom E-mail: [email protected] and [email protected]

Abstract. After a fascinating phase of discoveries, neutrino physics still has a few mysteries such as the absolute mass scale, the mass hierarchy, the existence of CP violation in the lepton sector and the existence of right-handed neutrinos. It is also entering a phase of precision measurements. This is what motivates the NUFACT 11 conference which prepares the future of long baseline neutrino experiments. In this paper, we report the status of experimental neutrino physics. We focus mainly on absolute mass measurements, oscillation parameters and future plans for oscillation experiments [1].

1. Introduction Over the last 15 years experiments have demonstrated that neutrinos oscillate and therefore mix and have masses, however few oscillation parameters are well measured. In addition, their absolute mass scale is still only described by upper limits. Finally, we do not know the nature of neutrino masses. Therefore despite the tremendous results of the last decade, there is still a vast open ﬁeld with many discoveries in the making. In this paper we present the status of the absolute mass scale measurements and oscillation parameters measurements, and describe several possible new experiments for improving these measurements. This paper has been updated to take into account the results presented at the Neutrino 2012 conference in June 2012 in Kyoto [2].

2. Measurements of the absolute neutrino mass Absolute neutrino masses can be measured in several ways. Astrophysical neutrinos, kinematic limits and neutrinoless double beta decay are all used to measure the absolute neutrino mass scale or set a limit on it.

2.1. Supernovae and cosmological constraints Supernovae are copious sources of neutrinos: by measuring time shifts, it is in principle possible to measure neutrino masses down to 30 eV as in the case of SN1987a [3]. Since neutrinos are so numerous in the universe, even a tiny neutrino mass can have cosmological implications. Current cosmological bounds are down around Mν < 0.17 − 0.33 eV [4, 5] and new data from the Planck observatory should be available soon [6]. These results are quite model dependent and mostly illustrate the sensitivity of structure formation to neutrinos masses. They cannot replace direct laboratory experiments. KATRIN experiment

(KArlsruhe TRItium Neutrino experiment, location: Forschungszentrum Karlsruhe)

70 m

electron transport tritium decay CMS atenergy same scaleanalysis Tritium2.2. Tritium E-decay beta decay and KATRIN tritium retention Double beta decay experiments study the end of the beta decay spectrum in order to measure Fermi2 theory ofP E3-decay: 2 2 mνe = i=1 |Uei| mi . The current upper electron-neutrino mass limit from beta decay experiments is mνe < 2.3 eV [7]. The next generation experiment is KATRIN at Karlsruhe. It is sensitive down to 0.2 eV [8, 9].

observable: E-decay rate: 1011 Hz -2 about 14 orders of magnitude background rate: 10 Hz -6 -20 tritium as E emitter: T2 pressure: 10 mbar T2 pressure: 10 mbar • high specific activity (half-life: 12.3 years) • low endpoint energy E 0 adiabatic guiding of electrons on meV level (18.57 keV) • super-allowed

Flor ia n Fr ä nk le KIT - The cooperation of Forschungszentrum 6 EPS HEP 2009 Kar ls r uhe Gm bH and Unive r sität Kar ls ruhe (TH) ! Florian Fränkle KIT - The cooperation of Forschungszentrum 3 EPS HEP 2009 Karlsruhe GmbH and Universität Karlsruhe (TH) Krakow Krakow Figure 1. Left: Beta decay spectrum. Right: KATRIN detector [8].

2.3. Neutrinoless double beta decay Neutrinoless double beta decay (0νββ) experiments are the main method to investigate whether neutrinos have a Majorana mass term which couples left-handed neutrinos to right-handed anti- neutrinos. It is also an excellent tool to probe the absolute mass scale and, in combination with

oscillation experiments, gives a hint567'89 on):;<< the) mass hierarchy (Fig. 2).

K K DC Claim (best fit 0.32 eV)

Final Cuoricino limit arXiv:1012.3266v1 [nucl-ex] G E RDA Target

CUO RE Target

With SuperNE M O, SNO+, M AJO RANA, many others should reach here in ~ 7-10 yrs.

Need new ideas to reach < 10 meV, but kiloton scale low background experiments are not impossible! 1'2$)3'%4)) Figure 2. Left: CUORE-0 detector [10]. Right: Neutrinoless double beta!"#$%&'()*+(($,$-./0 decay. Target) sensitivity of several experiments [1].

A whole set of 0νββ-decay experiments are currently running or are about to start taking data: GERDA, CUORE-0, EXO and KamLAND-Zen began in 2011. SNO+, Majorana and NEXT should start in 2013, and SuperNEMO, Lucifer, EXO-gas, XMASS and CUORE are scheduled to start later. While we cannot report every result here, we report that KamLAND-Zen found that hmββi < 0.26 − 0.54 eV at 90% C.L. [11] and that EXO-200 found hmββi < 0.14 − 0.38 eV at the same signiﬁcance [12]. 3. Oscillation parameters measurements Since solar neutrino experiments revealed the famous solar neutrino problem, we have known that neutrinos behave atypically. Since then the fact neutrinos transmute and thus have mass has been established by the Super-Kamiokande measurement of atmospheric neutrinos [13] and by solar data from SNO [14]. Neutrino oscillations is governed by a 3 × 3 unitary mixing matrix and by mass diﬀerences. The mixing angles (Fig. 3, left) have all been measured but even though the two mass splittings have also been measured (Fig. 3, right), the mass hierarchy and the CP violating phase are still unknown. In this section, we will present the current status of the measurement of each oscillation parameter.

Figure 3. Left: Neutrino mixing angles. Right: Neutrino mass hierarchy (normal, inverted).

3.1. Measurement of θ13 Until last year, θ13 was the sole remaining unknown mixing angle, the only knowledge of this parameter came from the Chooz experiment and was an upper limit of 0.15 at 90% C.L. [15]. A hint that θ13 was non-zero did however come from global ﬁt of available oscillation data [16]. In June of 2011, T2K presented their ﬁrst electron neutrino appearance measurement, six events on a predicted background of 1.5±0.3(syst.) indicating a non-zero value of θ13 at 2.5σ [17]. The analysis was not strictly speaking blind but all the cuts for the electron neutrino event selection in the Super-Kamiokande detector were decided well before T2K even started taking data. At Neutrino 2012, all the data up to May 15th 2012 were analyzed and presented [18]. Ten events are observed in the far detector and θ13 is excluded at 3.2σ. At 90% C.L., the T2K results 2 +0.60 is sin 2θ13 = 0.104−0.45 for δCP = 0 and normal hierarchy. The T2K selected νe candidates are shown in Fig. 4. Two weeks after T2K released their results, the MINOS collaboration presented results which disfavour θ13 = 0 at 89% C.L. with 62 events on a background of 49.6 ± 7.0(stat) ± 2.7(syst.) [19]. At Neutrino 2012, MINOS disfavors θ13 = 0 at 96% C.L. [20].

Finally in March 2012, outstanding results came from the reactor experiments Daya Bay [21, 22] and Reno [23]. The Daya Bay collaboration excluded θ13 = 0 at 5.2σ [21, 22], 2 while RENO excluded it at 4.9σ [23]. Their best ﬁt values are respectively sin 2θ13 = 2 0.089 ± 0.010(stat.) ± 0.005(syst.) and sin 2θ13 = 0.113 ± 0.013(stat.) ± 0.019(syst.) and their data is also shown in Fig. 6. Double Chooz excluded θ13 = 0 at 3.1σ and their best ﬁt 2 is sin 2θ13 = 0.109 ± 0.030(stat.) ± 0.025(syst.) [24]. All experiments are still statistically dominated and the clearly demonstrate that θ13 is greater than zero. Reactor experiments measure the disappearance of electron anti-neutrinos to measure θ13 as shown in Fig. 5 and Eq. 1. Current accelerator experiments measure the appearance of electron neutrinos in a muon-neutrino beam (Eq. 3). In addition the accelerator measurement depends on RUN1-3 data (2.556×1020POT) ν 6 Osc. e CC νµ+νµ CC ν ν e+ e CC NC 2 θ (MC w/ sin 2 13=0.1) 4

Number of events 2

0 0 1000 2000 3000 Reconstructed ν energy (MeV)

Figure 4. Left: An electron neutrino event in SK. Right: Reconstructed neutrino energy distribution for fully-contained, ﬁducial volume, single-ring e-like events with Evis > 100 MeV, no decay-e!"##$%&$'((#$)*##+,$ and POLﬁt mass less than 105 MeV/c2 in RUN1+2+3 [18].

-./.%0$ 1234(5+,$6+"784+2+9:$(;$<#+=:4(9>"9?9+8:4*9($@*7"33+"4"9=+$ -$ Figure 5. Left: Picture of Daya Bay detectors [22]. Right: Survival probability of electron neutrino as a function of the distance.

the value of the CP phase δ while the reactor measurement does not. Because these experiments are fundamentally diﬀerent it is very interesting to continue both in parallel.

2 2 2 Pν¯e→ν¯e ≈ 1 − sin 2θ13 sin (1.267∆m13L/E) (1)

∆m2 L 1 ∆m2 L ∆m2 L P [ν → ν ] = sin2 2θ s2 sin2 31 − s2 sin2 2θ s2 21 sin 31 µ e 13 23 4E 2 12 13 23 2E 2E ∆m2 L ∆m2 L ∆m2 L ∆m2 L + 2J cos δ 21 sin 31 − 4J sin δ 21 sin2 31 r 2E 2E r 2E 4E 2 2 2 4Ea(x) 2 ∆m31L + cos 2θ13sin 2θ13s23 2 sin ∆m31 4E a(x)L ∆m2 L ∆m2 L2 − sin2 2θ cos 2θ s2 sin 31 + c2 sin2 2θ 21 , (2) 2 13 13 23 2E 23 12 4E !"#$%&'$()"#$*+,-"#.&+/$$ *+,-"#)$:>)$9"#1/)"#$,)"&?#);$#":)&$"/;$&-)=:#"$ 5

2 25 " Far hall 40 Fast neutron 2000 Accidental 20 Near halls (weighted) 9Li/8He 4 # 30 15 1500 1000 20 10 @/$"#)$:>)$,)"&?#);$#":)&$./$)"=>$;):)=:+#'$ Entries / 0.25MeV A).B>:&$C DE $"#)$;):)#,./);$9#+,$7"&)6./)&$Entries / 0.25MeV 10

5 Entries / 0.25MeV . . 1000 0 1 # "/;$#)"=:+#$F?G)&'$ 0 5 10 0 Prompt energy [MeV] 0.00 0.05 0.10 0.15 0.20 500 sin2 2! 500 13 Far Detector 1.00 R Near Detector 0.980 !"#"$%&''"("$%$$)"*+,-,."("$%$$/"*+0+,." ) 0.96 0 No oscillation *6)"#$+7&)#%"8+/$+9$9"#$&.:)$;)<=.:'$ 0 5 10 1.20.94 Best Fit 1.2 0.92 1 0.90 Far / Near 1 0 200 400 600 800 1000 1200 1400 1600 1800 2000 H-)=:#"6$;.&:+#8+/$=+/&.&:)/:$I.:>$+&=.66"8+/'J$ 0.8 Weighted Baseline [m] $ 0.8 Far / Near (weighted J$*"%)":K$H-)=:#"6$0&L&:),"8=& 5$/+:$9?66L$&:?;.);M$$ 10 02 52 10 Prompt energy [MeV] FIG. 3. The χ distribution as a functionPrompt of sin energy2θ13.Bot- (MeV) N3O$%"6?)$9#+,$&>"-)$"/"6L&.&$.&$/+:$#)=+,,)/;);'$ tom: Ratio of the measured reactor neutrino events relative FIG. 4. Observed spectrum of the prompt signals in the far to the012134$ expected with no oscillation.P,-#+%);$@)"&?#),)/:$+9$Q6)=:#+/R"/8/)?:#./+$S.&"--)"#"/=)$ The curve represents the 35$ oscillation survival probability at the best fit, as a function of detector compared with the non-oscillation predictions from Figurethe flux-weighted 6. Left, baselines. Daya Bay data: Top: Measuredthe measurements prompt in the energy near detector. spectrum The backgrounds of the far hall shown in the inset are subtracted for the far spectrum. The (sum of three ADs) compared with the no-oscillationbackground fraction prediction is 5.5% (2.7%) from for farthe (near) measurements detector. of the two near halls. Spectra were backgroundErrors subtracted. are statistical uncertainties Uncertainties only. Bottom: are statistical The ratio only. of the measured spectrum of far detector to the non-oscillation Bottom:Gd-loaded liquid The scintillator, ratio of and measured a 229 day exposure and predicted to prediction. no-oscillation spectra. The red curve is the six reactors with total thermal energy2 16.5 GW .Inthe best- fit solution with sin 2θ13 =th 0.089 obtained from the rate-only analysis. The dashed far detector, a clear deficit of 8.0% is found by compar- lineing a is total the of 17102 no-oscillation observed events prediction with an expectation [21, 22]. Right, RENO data: Observed spectrum of thebased prompt on the near signals detector in measurement the far detector assuming no compared os- with the non-oscillation predictions from the cillation. From this deficit, a rate-only analysis obtains [4] F. Boehm et al.(PaloVerdeCollaboration),Phys.Rev. measurements2 in the near detector. The backgroundsLett. 84,3764(2000). shown in the inset are subtracted for sin 2θ13 = 0.113 0.013(stat.) 0.019(syst.). The neu- the far spectrum.± The background± fraction is[5] 5. P.5% Adamson (2.7%)et al.(MINOSCollaboration),Phys.Rev.D for far (near) detector. Errors are trino mixing angle θ13 is measured with a significance of 82,051102(2010). statistical4.9 standard uncertaintiesdeviation. only. Bottom: The ratio[6] S. of Yamamoto the measuredet al.(K2KCollaboration),Phys.Rev. spectrum of far detector to theThe non-oscillation RENO experiment prediction is supported [23]. by the Ministry Lett. 96,181801(2006). of Education, Science and Technology of Korea and the [7] R. Wendell et al.(Super-KamiokandeCollaboration), Korea Neutrino Research Center selected as a Science Phys. Rev. D 81,092004(2010). [8] B. Aharmim et al.(SNOCollaboraiton),Phys.Rev.C Research Center by the National Research Foundation 81,055504(2010). of Korea (NRF). Some of us have been supported by [9] A. Gando et al.(KamLANDCollaboration),Phys.Rev. (3) a fund from the BK21√ of NRF. We gratefully acknowl- D 83,052002(2011). edge the cooperation of the Yonggwang Nuclear Power [10] K. Abe et al.(T2KCollaboration),Phys.Rev.Lett.107, where a(x) = 2GF Ne(x), GF is the Fermi constant, Ne(x) is the electron number density at Site and the Korea Hydro & Nuclear2 Power Co., Ltd. 041801 (2011). x(KHNP).in the We earth, thankJr KISTI’s= c12 providings12c12s13 computingc23s23 is and the Jarlslog[11] P. Adamson determinant.et al.(MINOSCollaboration),Phys.Rev. network resources through GSDC, and all the technical Lett. 107,181802(2011). [12] Y. Abe et al.(DoubleChoozCollaboration),Phys.Rev. and administrative people who greatly helped in making 2 3.2. Measurement of the solar parameters: ∆m Lett.and108θ,131801(2012).12 this experiment possible. [13]21 G. L. Fogli et al., Phys. Rev. D 84,053007(2011). The solar parameters are now well constrained[14] by T. Schwetz bothet solar al., New and J. Phys. reactor13,109401(2011). data, and the newly [15] F. P. An et al.(DayaBayCollaboration)(2012), measured value of θ13 further reduces the uncertainty of this measurement. A very good arXiv:hep-ex/1203.1669. summary of current data is presented by T.[16] Schwetz P. Adamson [25]et al.(MINOSCollaboration),Phys.Rev. and the current values of these parameters[1] B. Pontecorvo, are Zh. given Eksp. Theo.below. Fiz. 34,247(1957)[Sov. Lett. 106,181801(2011). Phys. JETP 7,172(1958)]. [17] J.K. Ahn, et al.(RENOCollaboration)(2010), [2] Z. Maki, M. Nakagawa, and S. Sakata, Prog. Theor. Phys. arXiv:hep-ex/1003.1391. 28,870(1962). ∆m2 = 7.59+0.20 × 10−5 eV[18]2 K.and S. Park, sinet2 al.,θ Construction= 0.312 and+0. Properties017 of Acrylic [3] M. Apollonio et al.(ChoozCollaboration),Phys.Lett.21 −0.18 Vessels in the RENO12 Detector, in− preparation.0.015 B466,415(1999);Eur.Phys.J.C2 27,331(2003).2 [19] J. S. Park, et al., Production and Optical Properties of The values of ∆m21 and sin θ12 have been obtained using the KamLAND neutrino data and the Super-Kamiokande and SNO solar data.

2 3.3. Measurement of atmospheric parameters: |∆m31| and θ23 The atmospheric parameters have also been well measured by the Super-Kamiokande atmospheric data and by the MINOS experiment. Their results have also been summarized by T.Schwetz [25] and are given below. ( −3 2 2 2.45 ± 0.09 ×10 eV (NH) 2 |∆m31| = +0.10 −3 2 and sin θ23 = 0.51 ± 0.06 2.34−0.09 ×10 eV (IH) Global neutrino data and recent reactor ﬂuxes:status of three-ﬂavour oscillation parameters5

4 3 ] ] global 2 2 eV eV 3 MINOS -3 -3 2.5 ! ! [ 10 [ 10 2 2 31 2 31 m m " atmospheric " 2

1 0 0.25 0.5 0.75 1 0.3 0.4 0.5 0.6 0.7 2 2 sin !23 sin !23

Figure 7. DeterminationFigure of 3. theDetermination atmospheric of the atmospheric oscillation oscillation parameters. parameters. Left: intLefterplay: interplay of atmospheric (black) andof MINOS atmospheric disappearance (black) and MINOS (blue) disappearance data (blue) and data the andcombination the combination (red/shaded (red/shaded region) for normal hierarchy at 90% CL (dashed) and3σ (solid). Right: region) for normal hierarchycombined at allowed 90% regions C.L. for (dashed) normal (black and curves) 3σ and(solid). inverted hieRightrarchy: (colored combined allowed regions for normal (blackregions) curves) at 90%, and 95%, inverted 99%, 99.73% hierarchy CL. (colored regions) at 90%, 95%, 99%, 99.73% C.L. [25]. data consists of 54 electron neutrino events, while, according to the measurements in the The |∆m2 |MINOSvalue Near is obtained Detector, 49 from.1 ± 7 doing.0(stat) a± combined2.7(syst)backgroundeventswereexpected. fit of MINOS and Super-Kamiokande 31 Hence the observed number of events is in agreement with background expectations atmospheric results. In addition the first measurements of sin2 2θ using an off-axis neutrino within 0.7σ and the hint for a non-zero value of θ13 present in previous23 data [17] has beam has beenlargely presented disappeared. by the In fact, T2K we collaboration see that once we include [26]. The the new value MINOS of datathe in mass our splittings are well known butanalysis, the ordering a smaller ofbest the fit point masses, of θ13 (theis obtained mass and, hierarchy), as a result, is the still hint unknown. for θ13 is Discovering the mass hierarchyless significant is one than of the before: goals for bothof future hierarchies experiments we find only not a 0.8 onlyσ hint because when using it obscures the CP violation measurement,new MINOS data but versus if 1.3 neutrinoσ obtained masses with the were previous inverted MINOS appearanceit would data,be the see first time that fermions do note.g. have [18] for increasing a discussion. masses with increasing generation number. Atmospheric neutrino data from Super-Kamiokande I+II+III described in the previous section implies a best fit point very close to θ13 = 0 [12], with ∆χ =0.0(0.3) 4. Future plansfor θ13 = 0 for NH (IH). However, in the combination with MINOS disappearance and 2 With the discoveryappearance that dataθ13 weis evenlarge, find the a slight gateway preference for forstudyingθ13 > 0, CP with violation∆χ =1.6(1 in.9) the at lepton sector and the mass hierarchyθ13 = 0 for NH has (IH). been As opened. shown in Fig. Future 4 this experiments happens due to plana small to mismatch do justof that. the Three types 3 of proposals havebest fit emerged: values for | high∆m31| powerat θ13 = conventional 0, which can be superresolved beams, by allowing beta-beams for non-zero and neutrino values of θ13 [3]. This is similar to the hint for θ13 > 0 coming from a slight tension factories. In addition given the large value of θ13 Daya Bay could be able to study the mass between solar and KamLAND data, see Ref. [1]. Therefore, the hint for θ13 > 0from hierarchy by placingatmospheric a 20 + kton LBL data detector becomes at slightly 60 km stronger [27, compared 28]. to the previous data.

4.1. Super beams3. New reactor fluxes and implications for oscillation parameters A super beam is a conventional beam, based on pion decays but reaching powers of the order Up to very recently the interpretation of neutrino oscillation searches at nuclear power of the mega-watt. Three such beams have been proposed. In Japan, the current T2K beam plants was based on the calculations of the reactorν ¯e flux from Ref. [19]. Indeed, the will be a superobserved beam once rates at it all reaches reactor itsexperiments design performedluminosity so-far of at 750kW.distances ThisL ! 1kmare beam in combination with the proposedconsistent Hyper-Kamiokande with these fluxes, therefore detector setting [29] limits would onν ¯e disappearance. be a very powerful Recently the tool to measure δCP assuming that the mass hierarchy is known. In the US the LBNE project plans to direct a neutrino beam from FermiLab to the Homestake mine where a large LAr detector would be built. And in Europe the LAGUNA-LBNO project presents three possible setups where the preferred option is a super-beam from CERN-SPS to Pyhäsalmi in Finland (baseline = 2300 km). Today’s large value of θ13 implies that any future experiment will quickly be systematic- limited. Therefore an effort needs to be made to reduce systematic errors. Experiments like NA61 [30], SciBoone [31], MINERνA [32] and nuSTORM [33] are extremely important to constrain hadron production cross-sections and neutrino cross-sections. Fermions Bosons

t 100 GeV H Figure 8. The remaining W Z 10 GeV questions of the Standard b model are: Q.1 Determina- 1 GeV τ c ν tion of the absolute mass scale s 1,2,3;R 100 MeV µ of neutrinos. Q.2 Determi- 10 MeV nation of the mass hierarchy Q.6 of the active neutrinos. Q.3 1 MeV u d CP violation in neutrino os-

100 keV e cillations. Q.4 Violation of unitarity of the neutrino mix- ν3;L ing matrix. Q.5 Neutrinoless < eV ν2;L double beta decay. Q.6 Dis- Q.1 ν1;L Q.2 covery of eﬀects implying un- ambiguously the existence of γ sterile neutrino(s).

4.2. Beta-beams and neutrino factories The super beams can probably give us the value of δCP and the mass hierarchy. But precision similar to the precision of the CKM matrix will only be achieved with more powerful facilities. These facilities will also be needed to test the unitarity of the PMNS matrix and test whether neutrinos oscillate to become sterile neutrinos. Beta-beams [34, 35], where a radioactive ion is accelerated and then beta decays creatingν ¯e beam, could be an option. Another option is the neutrino factory. Here, µ− and µ+ trains simultaneously circulate in opposite direction in the storage ring and are separated in time. They are subsequently allowed to decay in flight to create pure (νµ,ν ¯e) and (¯νµ, νe) beams respectively. The golden channel of the neutrino factory is νe → νµ, but since νµ are also present in the beam, measurements similar to today’s (electron neutrino appearance and muon neutrino disappearance) are also possible. The presence of νµ,ν ¯e, andν ¯µ, νe in different trains is perfect to study CP violation since we can directly compare the oscillation of a neutrino to the oscillation of the anti-neutrino. Furthermore, because νµ,ν ¯e,ν ¯µ and νe are present in the beam, the near detector of a neutrino factory would be able to measure all four types of neutrinos cross-sections and reduce systematics considerably. In order to see oscillations, the far detector needs to be magnetized to differentiate νe → νµ from an interactingν ¯µ. A magnetized iron detector is envisaged as far detector. It was found that an optimal neutrino factory given the current value of θ13 uses 10 GeV muons and a baseline of 2200 km [36, 37].

5. Conclusions The years 2011 and 2012 have without any doubt seen tremendous progress in neutrino physics. Only a year ago, nobody knew if θ13 was even large enough to be measured, yet today the precision on θ13 is already better than the precision on θ23. With this measurement the prospect of measuring the mass hierarchy and especially the CP phase δ is better than ever and the years to come will be fascinating. With the announcement on July 4th 2012 that the Higgs was probably found, the remaining questions in the Standard Model (Fig. 8) are in neutrinos physics. We thank Alain Blondel and Mark Rayner for the careful reading of the manuscript. References [1] Wark D ”Experimental Status of Neutrino Physics”, NuFACT 2011 [2] Neutrino 2012, in Kyoto URL http://neu2012.kek.jp/neu2012/programme.html [3] Arnett W D and Rosner J L 1987 Phys. Rev. Lett. 58 1906 [4] Giunti and Kim ”Fundamentals of Neutrino Physics and Astrophysics”, p.616, Oxford University Press, 2007 [5] Spergel D et al. (WMAP Collaboration) 2003 Astrophys. J. Suppl. 148 175–194 (Preprint astro-ph/0302209) [6] ”Planck Space Observatory”, www.rssd.esa.int/planck/ [7] Kraus C et al. 2005 Eur. Phys. J. C 40 447–468 (Preprint hep-ex/0412056) [8] Fraenkle F 2009 EPS URL http://www.ifj.edu.pl/hep2009/ [9] Bornschein L (KATRIN Collaboration) ”Probing the absolute neutrino mass with KATRIN”, rencontres de Blois 2012 [10] Pedretti M (CUORE Collaboration) ”Status of the CUORE Experiment”, neutrino 2012 [11] Inoue K (KamLAND-Zen Collaboration) ”Results from KamLAND-Zen”, neutrino 2012 [12] Auger M et al. (EXO Collaboration) 2012 (Preprint arXiv:1205.5608 [hep-ex]) [13] Ashie Y et al. (Super-Kamiokande Collaboration) 2005 Phys. Rev. D 71 112005 (Preprint hep-ex/0501064) [14] Ahmad Q et al. (SNO Collaboration) 2002 Phys. Rev. Lett. 89 011301 (Preprint nucl-ex/0204008) [15] Apollonio M et al. (CHOOZ Collaboration) 2003 Eur. Phys. J. C 27 331–374 (Preprint hep-ex/0301017) [16] Fogli G L ”Global Analysis of Neutrino Oscillations”, neutrino 2012 [17] Abe K et al. (T2K Collaboration) 2011 Phys. Rev. Lett. 107 041801 (Preprint arXiv:1106.2822 [hep-ex]) [18] Nakaya T (T2K Collaboration) ”New Results from T2K”, neutrino 2012 [19] Adamson P et al. (MINOS Collaboration) 2011 Phys. Rev. Lett. 107 181802 [20] Nichol R (MINOS Collaboration) ”Final MINOS Results”, neutrino 2012 [21] An F et al. (DAYA-BAY Collaboration) 2012 Phys. Rev. Lett. 108 171803 [22] Dwyer D (DAYA-BAY Collaboration) ”Improved Measurement of Electron-Disappearance at Daya Bay”, neutrino 2012 [23] Ahn J et al. (RENO collaboration) 2012 Phys. Rev. Lett. 108 191802 (Preprint arXiv:1204.0626 [hep-ex]) [24] Ishitsuka M (Double Chooz Collaboration) ”Double Chooz results”, neutrino 2012 [25] Schwetz T, Tortola M and Valle J 2011 New J. Phys. 13 063004 (Preprint hep-ph/1103.0734) [26] Abe K et al. (T2K Collaboration) 2012 (Preprint arXiv:1201.1386 [hep-ex]) [27] NuTURN 2012, at Gran Sasso URL http://nuturn2012.lngs.infn.it/ [28] Cao J (DAYA-BAY Collaboration) ”Observation of Electron Anti-neutrino Disappearance at Daya Bay”, nuTURN 2012 [29] Abe K et al. 2011 (Preprint arXiv:1109.3262 [hep-ex]) [30] Abgrall N et al. (NA61/SHINE Collaboration) 2011 Phys. Rev. C 84 034604 [31] Mariani C (SciBooNE Collaboration) 2011 (Preprint arXiv:1110.1506 [hep-ex]) [32] 2006 MINERvA Technical Design Report [33] Kyberd P et al. (nuSTORM Collaboration) 2012 (Preprint arXiv:1206.0294 [hep-ex]) [34] Zucchelli P 2002 Phys.Lett. B 532 166–172 [35] Wildner E 2011 Nucl. Phys. Proc. Suppl. 217 199–201 [36] International Design Study for Neutrino Factory URL https://www.ids-nf.org/wiki/FrontPage [37] Huber P ”Neutrino facilities comparison of performance”, European Strategy for Neutrino Oscillation Physics, May 2012,