Neutrino Experiment with SpectrometerS in Europe

SPECTROMETER(S) Proposal for a New Neutrino CERN-SPS Experiment:

on the quest for STERILE neutrinos

CTS, 12 July 2013 Luca Stanco for NESSiE

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Proposal SPSC-P347 (March 2012) (ICARUS + NESSIE)

1.  Situation at CERN

2.  Physics and Experiment update 3.  Collaboration issues

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Status of the experiment at CERN

To make a long history short: ü  January 2013: Approval by SPSC after first submission in October 2011 (!)

pending the beam approval by CERN ü  March 2013: Research Board, no outcome.. ü  April 2013: SPC Board, no outcome… ü  May 2013: European Strategy support neutrino physics (4th item) ü  June 2013 Middle Term Plan, MTP for 2014-2018. Outcome ?

ü  Working groups at CERN on weekly or bi-weekly basis ü  Marzio Nessi (Cern CENF Project Leader), Sergio Bertolucci (Director Research),

Carlo Rubbia (Icarus Spokeperson), myself (for NESSiE): lot of pressure on CERN boards and DG, R. Heuer *

•  Letter to CERN DG on April 19th

•  Paper on June 13th

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●  SPSC 108 recommendation (SPS experimental committee): ➤ “The SPSC supports the physics cases of both projects and recognizes

their timely relevance in the rapidly evolving neutrino physics landscape. In this context the SPSC considers it important to strengthen neutrino activities at CERN in order to help focus those future European contributions to neutrino physics extending beyond the ongoing approved programmes. The SPSC consider that a new short baseline neutrino beam at the SPS could be an adequate facility to foster this focus in the near future, provided that the beam operation, in addition to making progress on the sterile neutrino question, can also contribute significantly to the preparation of the future long baseline neutrino projects.”

●  Extract of European strategy document: ➤ “CERN should develop a neutrino program to pave the way for a

substantial European role in future long-baseline experiments.” ●  MTP 2014 – 2018

➤ The goals of the management …….are to: 1.  Exploit the full potential for the LHC…. 2.  Position and maintain CERN as the laboratory at the energy frontier…… 3.  Prepare CERN to bid for a future large project in particle physics.. 4.  Develop a neutrino programme to pave the for a substantial European role in a future long

baseline experiment. 5.  Broaden the vibrant and unique fixed target programme.

Feedback from the committees

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5"

Excerpt from MTP 2014-2018:

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6" 6

ü  CERN decided NOT to go for a SBL neutrino beam, by now ü  However, it is willing to invest on Neutrino (4th priority of ESG):

- 2.0 MCHS in 2013 for Neutrino studies - Icarus refurbishing - Nessie test-integration - Laguna R&D

FORMALLY confirmed this week

What about INFN and NESSiE ?

ü  Request to evaluate: - CERN involvement - different beam possibilities (e.g. FNAL)

ü  Requests to CSN2 for 2014 undergoing

My (extrapolated) conclusions:"

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11 July 2013

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Why a new CERN Neutrino Facility?

● Interesting experimental proposal by ICARUS-NESSiE (CERN-SPSC-P-347) for the search to sterile neutrinos.

● Demonstrate new generation of neutrino detectors of double phase LAr TPC proto-type by the LAGUNA-LBNO consortium.

● New opportunity for the experimental European neutrino community to reorganize itself (around CERN).

Still true:"

CERN©  9

Requirements & Where at CERN ? ●  Some main physics requirements:

➤ Near and far detectors locations, positioned at the correct L/E. ➤ Central νµ energy of 1 to 2 GeV. ➤ About 4.5x1019 protons on target per year for at least 3 years.

●  Where ? ➤ The PS solution (PSNF) was discarded end 2011 for various reasons ➤ Adding experimental facilities behind the CNGS facility is too

expensive and complicated ➤ Reviving the West Area facility (WANF/NOMAD) was also

discarded for several reasons

Still true:"

CERN©  10

The Selected Location at CERN ●  After investigating the different options the SPS North Area

was retained as location: ➤ Use the existing TT20 beam line and the SPS Long

Straight Section 2 extraction. ➤ Extend the existing Experimental Hall North 1 (EHN1),

using existing infrastructure. ➤ Possibility to calibrate detectors with charged particle

beam. ➤ Compatibility with a possible future, long baseline facility

(LAGUNA-LBNO). ➤ Remain within CERN territory with the far detector.

Still true:"

CERN©  11

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Near  Detector  Facility  •  Extension  of  EHN1.  

ICARUS  150T  

NESSiE  

LAGUNA-­‐PROTO  requires  also  charged  par*cle  beam  

Use  exis*ng  EHN1  services  and  infrastructure  where  possible  

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νµ disappearance search at SBL

- Move the physics goal from sterile neutrinos to the gain of 1 order of magnitude in the measurement of nu-mu disappearance. -  Set the issue of using only iron magnets, with a small scintillator target

to measure NC -  Define a way to extract oscillation by using a new variable

New paper (L.Stanco et al.): arXiv:1306.3455

Physics

Note:  more  and  more  consensus  in  the  Community  that  Spectrometer(s)                        are  needed  either  for  SBL  or  LBL   15

Neutrino interaction in the iron •  Beside the fact that the NESSiE spectrometer has been designed to

measure the muon escaping ICARUS it can act also as a target to measure the muon-neutrino disappearance.

•  Given the digital readout of the RPC and the thick iron wall the energy of the neutrino can only be measured for QE for which the momentum of the muon is obviously correlated to the energy.

•  For the events in the magnet we can use the momentum of the muon as estimator to search for nu-mu disappearance.

•  The sensitivity of the double ratio (F/N)data / (F/N)no-osci has been investigated

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[MeV])ν

(1/E10

log-4 -3.8 -3.6 -3.4 -3.2 -3 -2.8 -2.6 -2.4 -2.2 -2

Surv

ival p

roba

bility

0.8

0.85

0.9

0.95

1

1.05

1.1

Near0.5 GeV1 GeV2 GeV8 GeV

[MeV])ν

(1/E10

log-4 -3.8 -3.6 -3.4 -3.2 -3 -2.8 -2.6 -2.4 -2.2 -2

Surv

ival p

roba

bility

0.8

0.85

0.9

0.95

1

1.05

1.1

Far0.5 GeV1 GeV2 GeV8 GeV

Figure 3: Disappearance probabilities in the two–flavour limit at Near (top) and Far (bottom) sites, at 460and 1600 m, respectively, by using the amplitude provided by the reactor anomaly, 0.146, and the mass scale�m2 = 1 eV2. The x-axis corresponds to log10(1/E�), with E in MeV.

[MeV])ν

(1/E10

log-4 -3.8 -3.6 -3.4 -3.2 -3 -2.8 -2.6 -2.4 -2.2 -2

Surv

ival p

roba

bility

: Far

/Nea

r

0.85

0.9

0.95

1

1.05

1.1

1.150.5 GeV1.0 GeV2.0 GeV8.0 GeV

Figure 4: The ratio of the disappearance probabilities in the two–flavour limit at Near (top) and Far (bottom)sites, at 460 and 1600 m, respectively, by using the amplitude provided by the reactor anomaly, 0.146, andthe mass scale �m2 = 1 eV2. The x-axis corresponds to log10(1/E�), with E in MeV.

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P⌫µ!⌫µ = 1� sin2(2�) sin2(1.267�m2 L

E)

L = 460 m

L = 1600 m

[MeV])ν

(1/E10

log-4 -3.8 -3.6 -3.4 -3.2 -3 -2.8 -2.6 -2.4 -2.2 -2

Surv

ival p

roba

bility

0.8

0.85

0.9

0.95

1

1.05

1.1

Near0.5 GeV1 GeV2 GeV8 GeV

[MeV])ν

(1/E10

log-4 -3.8 -3.6 -3.4 -3.2 -3 -2.8 -2.6 -2.4 -2.2 -2

Surv

ival p

roba

bility

0.8

0.85

0.9

0.95

1

1.05

1.1

Far0.5 GeV1 GeV2 GeV8 GeV

Figure 3: Disappearance probabilities in the two–flavour limit at Near (top) and Far (bottom) sites, at 460and 1600 m, respectively, by using the amplitude provided by the reactor anomaly, 0.146, and the mass scale�m2 = 1 eV2. The x-axis corresponds to log10(1/E�), with E in MeV.

[MeV])ν

(1/E10

log-4 -3.8 -3.6 -3.4 -3.2 -3 -2.8 -2.6 -2.4 -2.2 -2

Surv

ival p

roba

bility

: Far

/Nea

r

0.85

0.9

0.95

1

1.05

1.1

1.150.5 GeV1.0 GeV2.0 GeV8.0 GeV

Figure 4: The ratio of the disappearance probabilities in the two–flavour limit at Near (top) and Far (bottom)sites, at 460 and 1600 m, respectively, by using the amplitude provided by the reactor anomaly, 0.146, andthe mass scale �m2 = 1 eV2. The x-axis corresponds to log10(1/E�), with E in MeV.

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sin2(2�) = 0.146

�m2 = 1eV 2

Double ratio (F/N)data / (F/N)no-osci

New variable: log10(1/E)

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[MeV])ν

(1/E10

log-3.6 -3.4 -3.2 -3 -2.8 -2.6 -2.4 -2.2 -2

CC µνFA

R/NE

AR ra

tio fo

r

0.12

0.14

0.16

0.18

0.2

0.22

0.24

0.26

0.28

CCµνFAR/NEAR ratio for

no oscillations

oscillations

0.5 GeV1.0 GeV2.0 GeV4.0 GeV

CCµνFAR/NEAR ratio for

[MeV])ν

(1/E10

log-3.6 -3.4 -3.2 -3 -2.8 -2.6 -2.4 -2.2 -2

(FAR

/NEA

R os

c.)/(

FAR/

NEAR

no

osc.

)

0.6

0.7

0.8

0.9

1

1.1

1.2

1.3

1.4

(FAR/NEAR osc.)/(FAR/NEAR no osc.)

0.5 GeV1.0 GeV2.0 GeV4.0 GeV

(FAR/NEAR osc.)/(FAR/NEAR no osc.)

Figure 5: The oscillated and unoscillated �µ

event distributions, parametrized in log10(1/E⌫

), fora luminosity of 4.5 � 1019 p.o.t. of �

µ

beam flux over the two magnet system described in thetext. On the top the Far/Near collected ratios are drawn, while on the bottom the double ratio(Far/Near)

oscillated

/(Far/Near)unoscillated

is shown.

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Andrea’s CENF beam simulation

with a length of about 110 m and a diameter of 3 m. The beam dump of 15 m in length,will be composed of iron blocks with a graphite inner core. Downstream of the beam dumpa set of muon chambers stations will act as beam monitors. The beam will point upwards,with a slope of about 5 mrad, resulting in a depth of 3 m for the detectors in the Far site.

The current design of the focusing optics foresees a pair of pulsed magnetic horns operatedat relatively low currents. A graphite target of about 1 m in length is deeply inserted intothe first horn allowing a large acceptance for the focusing of low momentum pions emittedat large angles. This design allows to produce a spectrum peaking at about 2 GeV thusmatching the most interesting domain of �m2 with the detector locations at 460 and 1600 mfrom the target.

The charged current event rates for �µ and �̄µ at the near detector are shown in Fig. 1for the positive and negative focusing configuration.

[MeV])ν

(1/E10

log-4 -3.5 -3 -2.5 -2

CC in

tera

ctio

ns

0

50

100

150

200

250

310×

(+ polarity)CCµν

(+ polarity)CCµν

0.5 GeV1 GeV2 GeV4 GeV

[MeV])ν

(1/E10

log-4 -3.5 -3 -2.5 -2

CC in

tera

ctio

ns

01000020000300004000050000600007000080000

(- polarity)CCµν

(- polarity)CCµν

0.5 GeV1 GeV2 GeV4 GeV

Figure 1: Expected neutrino CC interactions in the no–oscillation hypothesis for positive polarity (left)and negative polarity (right) for the new proposed CERN neutrino beam (elaborated from [30]) and for anintegrated luminosity of 1 year. We prefer to use a new variable for the neutrino energy, log10(1/E) (seeSect. 3).

A relevant contamination of �µ in the negative polarity configuration is visible especiallyat high energy where this component arises as a result of the decays of high energy not wellde–focused mesons produced at small angles. The charge discrimination of the magneticsystem described below will allow an e⇤cient discrimination of these two components witha charge confusion below or of the order of 1% from sub–GeV up to momenta around 8–10GeV [27].

2.2 Spectrometer requirements

The main purpose of the spectrometers placed downstream of the LAr-TPC is to providecharge identification and momentum reconstruction for the muons produced in neutrinointeractions occurring in the LAr volume or in the magnetized iron of the spectrometers. Inorder to perform this measurement with high precision and in a wide energy range, fromsub-GeV to multi-GeV, a massive iron-core dipole magnet (ICM) is coupled to an air–coremagnet (ACM) in front of it [27]. Low momentum muons will be measured by the ACMwhile the ICM will be employed at higher momenta.

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Convoluting with the CENF beam flux

4.5E10 pot

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conservative attempt where the muon reconstructed momentum in CC events only mimicsthe true ⇥µ energy due to the kinematics and the interaction processes (mostly quasi–elasticones in the current energy range but with significant other contributions).

Figure 6: The double ratio of the disappearance probabilities at Near (top) and Far (bottom) sites, 460and 1600 m, respectively, by using the amplitude provided by the reactor anomaly, 0.146, and mass scales�m2 ranging from 0.1 to 5 eV2 as a function of log10(1/pµ), where p is the muon reconstructed momentumin MeV. The reconstructed momentum is defined by a minimum cut on the muon path length (25 cm ofiron trespassing), a minimum momentum (500 MeV), 90% fiducial acceptance of the magnet volume and anadded uncorrelated 1% systematical error (from OPERA experience [36]). Data collection corresponds to 1year, i.e. 4.5 · 1019 p.o.t.

Finally, in Fig. 7 the estimated limits on ⇥µ disappearance that can be achieved via theFar/Near estimator are shown for di⇥erent data taking (3, 5 and 10 years, corresponding to13.5 · 1019, 22.5 · 1019 and 45.0 · 1019 p.o.t, respectively). The di⇥erent results for ⇥µ and ⇥µ

beams were evaluated together with the two variables, p and log10(1/p). In negative polarityruns the muon charge identification allows an independent, in parallel and of similar sensi-tivity measurements of the ⇥µ and ⇥µ disappearance rates, due to the large ⇥µ contaminationin the ⇥µ beam.

The new parametrization used for the neutrino energy, log10(1/E), which we conserva-tively prefer to address as log10(1/pµ�rec), provides slightly better limits in almost all the(�m2, sin2(2�)) excluded regions. This is partially due to the gaussian shape sensitivity of1/p when cuts are applied to the corresponding variable. Moreover, the elucidation of thebehaviour of the Far/Near ratio in terms of depletions and excesses in di⇥erent region of thespectra allows a better comparison between unoscillated and oscillated hypotheses.

The relevance of statistics in presence of systematical e⇥ects is depicted in Figs. 8. Itis evident that the intrinsic overall error, dominated by the sensitivity on the measurementof the muon momentum, puts an intrinsic limitation to the data statistics which can be

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Simulation •  for this analysis an “ideal” setup has been chosen:

–  90% muon detection efficiency for P>0.5 GeV –  10% momentum resolution –  1% charge miss-ID –  0.3 kton near, 0.7 kton far detector (no geometry/acceptance contours) –  uncorrelated systematic error added in quadrature to the statistical

Double ratio of the muon-momentum distributions

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Figure 7: The estimated limits at 95% C.L. for �µ disappearance at a Short Baseline beam at CERN forseveral luminosity running periods and di�erent beam polarities, with a two–site massive spectrometer (770tons and 330 tons, respectively) with 90% inner fiducial volume.The top figure refers to the positive polarity beam. The continuous (dashed) lines correspond to the sensitivitylimits obtained with the log10(1/p) (p) variable. 3 years correspond to 13.5 · 1019 p.o.t., 5 years to 22.5 · 1019p.o.t. and 10 years to 45.0 · 1019 p.o.t. The exclusion limit from combined MiniBooNE and SciBooNE �µdisappearance result at 90% C.L. from Ref. [19] is shown for comparison by the black curve in the right.The bottom figure refers to the negative polarity beam. Sensitivity limits are evaluated with the log10(1/p)variable. Clearly the negative polarity run allows the contemporary analysis of the �µ and �µ disappearanceexclusion regions thanks to the disentangling of the muon charge on an event–by–event–basis. The black curvein the right shows for comparison the central value of the sensitivity at 90% C.L. from combined MiniBooNEand SciBooNE �µ disappearance result (Ref. [20]).

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ONLY SPECTROMETERS…

Non oscillation hypothesis is tested with a χ2 test to a flat (= 1) distribution

(considered 4.5x1019 pot / year)

νµ

νµ

beam

beam

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Figure 8: Systematics e�ects for the estimated limits at 95% C.L. for �µ disappearance at a Short Baselinebeam at CERN for 5 (positive polarity, top) and 10 (negative polarity, bottom) years of data taking, witha two–site massive spectrometer (770 tons and 330 tons, respectively) with 90% inner fiducial volume. Theexclusion regions are evaluated by using the log10(1/p) (continuous lines) and p (dashed lines) variables incase of the positive polarity beam data taking.

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Including systematics (totally uncorrelated)

νµ

νµ

beam

beam

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The Experiment has to be approved by CERN at the Council meeting of June 2013 to fit the physics needs. Once approved several non-INFN institutions are expected to join the Collaboration. Most of the hardware are supposed to be provided in-kind by the OPERA experiment, mainly the two Spectrometers (Italy), the Precision Trackers (Germany) and part of the Scintillators (France). The foreseen MoU will be developed on the above constraints. The in-kind contributions in term of massive materials (as from the OPERA MoU) will correspond for INFN to 5940 Keuro of material, for Germany to 1830 Keuro, for France to 1850 Keuro. The total cost in 5a is divided into two samples: the 1rst corresponds to the necessary upgrades of all the Electronics, the handling and testing of detectors (to be moved from LNGS to CERN) as well as the rearrangements of the mechanical tools and parts. The overall cost for sample (1) is about 4000 Keuro and it will be practically shared following the original values of the in-kind material. The 2nd source of the total cost (of about 3000 Keuro) will correspond to a totally new object, the Air-Core-MagnetS, which is about 3000 Keuro. The contributing Funding Agencies will be asked to re-furbish the provided in-kind items. There are three additional relevant Institutions which are considering to participate to the Experiment, from Switzerland, United Kingdom and CERN. Moreover minor groups from Canada and Algeria will probably join the Collaboration. Contacts are on- going with groups in China, South-Korea and USA. The MoU will request a contribution for the ACM costs from all the participating Funding Agencies. The running costs of the Experiment will be around 300 Keuro (not including the Power Supplies for the ACMs, to be sustained on CERN) and they will be shared among the different financial actors following the Collaboration membership. The ACMs (or just the Far one) could be staged for the 2nd phase of the experiment, after the CERN Long-Shutdown-2 foreseen in 2018.

Possible MoU content

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2000 2000

Work Packages: 1.  ICM 2.  ACM 3.  RPC 4.  Precision Tracker 5.  Scintillators 6.  RPC Electronics 7.  DAQ &Trigger

INFN

INFN

INFN

Germany

France

common

common

The maintenance costs of the in-kind detectors which are property of different Funding Agencies will be on charge of the Agencies themselves. The running costs will amount to about 300 Keuro per year, mainly for the gas consumption of RPC and PT. They will be shared among the Collaboration following membership percentage. At present we foresee 1 year of running, in 2017, before the Long-Shutdown-2, and 2 year after the LS2. The cost for Power Supplies of ACMs, when ready, will be taken by CERN. Shifts for operations will be also shared among the collaborators, following the above rule.

Running

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MONEY estimation

Iron magnets: in-kind value 5940 K€ (from OPERA MoU) Cost for transportation to CERN and refurbishing: 3000 K€ In-kind value of Precision Tracker: 1900 K€ possible refurbishing: 700 K€ In-kind value of Scintillators: 1900 K€ possible refurbishing: 300 K€ Cost ACM: 1000 (Near) + 1200 (Far) TOTAL: 3+1+1+1 = 6 M€

ACM-FAR might be staged at 2nd phase (after LS2)

ACM-NEAR, including R&D, designs, certifications

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Collaboration

Bari: 1.0 FTE/5 Bologna: 2.1 /6 Frascati: 0.5/2 Lecce: 1.9/4 TOTAL: 8.8 FTE / 29 People Padova: 2.7/9 Roma1: 0.6/3 Less FTE than last year, due to the stop of SBL Neutrino Project

In the near future: -  CERN clarification of its willingness -  Search for other neutrino beams

ITA

LY

Two new groups: -  SINP-MSU, Moscow

Tatiana ROGANOVA (group leader) -  Lebedev, LPI, Moscow

Natalia POLUHINA (group leader)

Welcome to four Observers: Strasbourg(FR), Hamburg(G), Zagreb(KR), Napoli (IT)

t.b.c.

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INFN involvements in NESSiE : BARI: Front-End, Simulation, Analysis, Detectors BOLOGNA: ACM Mechanic, Design, Software, DAQ-ACM, ACM-tracker FRASCATI: ICM Mechanic, Design, Beam-simulation, Detectors LECCE: Mechanic, Simulation, Analysis PADOVA: Infrastructures, Simulations, Analysis, DAQ, Mechanics, Detectors ROMA-1: Software and Analysis MOSCOW: Software and Analysis

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USA options to be investigated: 1) interplay with LNBE collaboration 2) FNAL possibility ? 3) nuSTORM integration (EOI presented at FNAL-PAC and CERN-SPSC)

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FNAL option ?

350 kW 35 kW

A priori, we are only interested to On-Axis

Premises:

1.  Leptonic Flavor investigation should be a MUST for the HEP future 2.  NESSiE Collaboration is a group of ≥ 60 physicists from ≥ 8 Institutions (≥ 6 INFN)

which would like (strongly) to do PHYSICS at SBL. 3.  Without us no SBL program will be achieved in the next 10 years, in particular

no measurement of νe appearance (Icarus) and νµ disappearance at the 1 eV scale. 4.  Under Gran Sasso there is material 10 M€ valued to be perfectly usable,

with a relative modest investment, for Spectrometers

WTDW (What-To-Do-When) ? A.  Continue study CERN option, be ready in case CERN approve SBL. B.  Elaborate displacement to FNAL (either for Long-BS or Short-BL)

following Icarus, sustaining the idea of coupling LAr with Mag.Field in LBL In case B: -  Open discussion with FNAL about SBL option -  Look for other sites to make the SBL experiment.

Conclusions

Thank you !

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Backup slides

Conclusive Studies"Oscillation

type Neutrinos Experiments

θ12 νe(solar, reactors) SNO, SK, Borexino, Kamland

θ23 νµ (atmospheric, accelerators) SK, Minos, T2K

θ13 νe(reactors) Daya Bay, RENO, Double Chooz, T2K

θ14 νe(reactors, radioactive sources)

SBL Reactors, Gallex, Sage. This Proposal

θ24 νµ (accelerators) CDHS, Miniboone. MINOS+ This Proposal

νµ AND νµ in Appearance (νe)

Measure at L/E corresponding to Δm2∼1 eV2

in Disappearance (νµ) AND

AND with ≥ 2 sites

23 combs

L.Stanco©  

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