Plans for future neutrino oscillation beams in Europe

ESSnuSBProject for Leptonic CP Violation Discovery based on the European Spallation Source LinacNOW 2014, 10/9E. Wildner, CERN2Elena WILDNERCERNfor the ESSnuSB Collaboration

2The European Spallation Source (ESS)ESS is a neutron spallation source that will be built by a collaboration of 17 European countries.ESS is located in southern Sweden (Lund)

NOW 2014, 10/9E. Wildner, CERN3ESS Technical Design Report, April 23, 2013, ESS-doc-274http://europeanspallationsource.se/documentation/tdr.pdf

ESS as proton driver for spallationNOW 2014, 10/9E. Wildner, CERN4

4European Spallation SourceNOW 2014, 10/9E. Wildner, CERN5

http://europeanspallationsource.se/ess-gets-green-lightSweden35%Switzerland3.5%Denmark12.5%Norway2.5%Germany11%Poland2%U.K.10%Hungary1.5%France8%Czech0.3%Italy6%Estonia0.25%Spain5%TBD2.5%Contributions by Member CountryThe ESS has broken ground last week5ESS 5MW proton linac NOW 2014, 10/9E. Wildner, CERN6The ESS will be a copious source of spallation neutrons5 MW average beam power125 MW peak power14 Hz repetition rate (2.86 ms pulse duration, 1015 protons)2.0 GeV protons (up to 3.5GeV with linac upgrades)>2.7x1023 p.o.t/year

Linac ready by 2023 (full power and energy)ESS Technical Design Report, April 23, 2013ESS-doc-274http://europeanspallationsource.se/documentation/tdr.pdf6NOW 2014, 10/9E. Wildner, CERN7ESSnuSB on ESS site

2 GeV > 2 GeV Neutron spallation targetH-p~1 BEuros for the neutrino facility including detectorPreliminary !Civil engineering to be taken into account for accumulator!7

ESS H- acceleration for neutrinosThe ESS linac for neutron spallation: proton acceleration 14 HzDuty factor low (4%); some additional capacity is availableRepetition rate can be increased to 70 Hz to permit 4 extra acceleration cycles 2.86 / 4 ms long (= 5 MW)

Charge in the accumulator (1.1 1015)/4 p, 2 GeV>2.7x1023 p.o.t/year for neutrinosESS would accelerate in total 10 MW! NOW 2014, 10/98

H-??E. Wildner, CERN8NOW 2014, 10/9E. Wildner, CERN9ESS Accumulator for neutrino productionConstraints on present neutrino target focusing system: short pulses

Solution: reduce beam pulse length:Shorten the linac pulse by accumulating the linac beam

Accumulator constraints Reasonably-sized accumulator ring circumference and aperturesMultiturn injection of high intensity linac beam: we need H- High intensities in the ring may cause collective effects and beam loss

Linac Pulsing 70 Hz, baseline13/03/14Nufact14, Glasgow, E. Wildner1035.7 ms2.86 ms28 HzNeutron (proton pulse)Neutrino (H- -pulse)71.4 ms, 14 Hz14.28 ms0.7 ms71.4 ms, 14 Hz70 Hz2.86 msInsert one H- pulse 28 Hz Mitigation of charges in accumulator, 70 Hz, implies some overhead (cavity filling)10NOW 2014, 10/9E. Wildner, CERN11ESSnuSB on ESS site

2 GeV > 2 GeV Neutron spallation targetH-p

H 1.5 s0 = 100 sBending Radius:133 m for 3 GeV (70 m for 2 GeV)Target Station 25 m below ground levelDecay tunnel under the linac!URGENT STUDY of ground water!11The Linac has to be upgradedModulators and infrastructure (C. Martins)E. Wildner, CERN12NOW 2014, 10/9

To be prepared for at an early stagePrevious ExpertiseNOW 2014, 10/9E. Wildner, CERN13

13The MEMPHYS WC Detector(MEgaton Mass PHYSics)NOW 2014, 10/9E. Wildner, CERN14Proton decayAstroparticlesUnderstand the gravitational collapsing: galactic SN Supernovae "relics"Solar NeutrinosNeutrino Oscillations (Super Beam, Beta Beam)Atmospheric Neutrinos

500 kt fiducial volume (~20xSuperK)Readout: ~240k 8 PMTs30% optical coverage

(arXiv: hep-ex/0607026)Possible locations for far detectorNOW 2014, 10/9E. Wildner, CERN15

CERNESSKongsbergLkken15

Neutrino Oscillations with "large" 13NOW 2014, 10/9E. Wildner, CERN16P(e)L/E1st oscillation maximum2nd oscillation maximum13=1("small" 13)13=8.8("large" 13)for small 13 1st oscillation maximum is betterfor "large" 13 1st oscillation maximum is dominated by atmospheric term, CP interferenceCP interferencesolarsolaratmosphericatmospheric13=113=8.8dCP=-90dCP=0dCP=+90(arXiv:1110.4583)more sensitivity at 2nd oscillation max.L/EL/EL/E1st oscillation max.: A=0.3sinCP2nd oscillation max.: A=0.75sinCP(see arXiv:1310.5992 and arXiv:0710.0554)ESS neutrino energy distributionNOW 2014, 10/9E. Wildner, CERN17

at 100 km from the target and per year

Neutrino spectraNOW 2014, 10/9E. Wildner, CERN18540 km (2 GeV)below production neutrinosanti-neutrinos2 years8 yearsCP=0E. Fernandez18

CP accuracy performance(USA snowmass process, P. Coloma)NOW 2014, 10/9E. Wildner, CERN19for systematic errors see:Phys. Rev. D 87 (2013) 3, 033004 [arXiv:1209.5973 [hep-ph]]arXiv:1310.4340 [hep-ex] Neutrino "snowmass" group conclusions"default" column19Results including nuSTORM E. Wildner, CERNNOW 2014, 10/920

Pilar Coloma et al.LBNF (40 kton detector, 1.2MW beam power)Systematics are basically the same as before.nuSTORM plots assume that cross sections are determined at the 1% level of precision, removing the constraint between the cross sections for different flavors, they are all allowed to vary independently in the fit.

2nd Oscillation max. coverageNOW 2014, 10/9E. Wildner, CERN212nd oscillation max.well covered by the ESS neutrino spectrum1st oscillation max.E. FernandezWhich baseline?NOW 2014, 10/9E. Wildner, CERN22

ZinkgruvanGarpenbergZinkgruvan is better for 2 GeV 360 kmGarpenberg is better for > 2.5 GeV 540 kmsystematic errors: 5%/10% (signal/backg.)

CPVMHZinkgruvan is betteratmospheric neutrinos are needed (at least at low energy)E. Fernandez22Systematic errorsNOW 2014, 10/9E. Wildner, CERN23Phys. Rev. D 87 (2013) 3, 033004 [arXiv:1209.5973 [hep-ph]]

23Systematic errors and exposureNOW 2014, 10/9E. Wildner, CERN24

for ESSnuSB systematic errors see 1209.5973 [hep-ph] (lower limit "default" case, upper limit "optimistic" case)P5 requirement: 75% at 3 Neutrino Factory reach10 years20 years(courtesy P. Coloma)High potentiality24Effect of the unknown MH on CPV performanceNOW 2014, 10/9E. Wildner, CERN25

"default" case for systematicssmall effectpractically no need to re-optimize when MH will be known25ESS Neutrino Super BeamNOW 2014, 10/926 arXiv:1212.5048arXiv:1309.702214 participating institutes from 10 different countries,among them ESS and CERN

EU H2020 Design Study application has been submitted recently !When and to what price ?NOW 2014, 10/9E. Wildner, CERN27Total price of ESSnuSB including the detector is 1.2 BEUR:100 MEUR linac200 MEUR accumulator 200 MEUR target station 700 MEUR the far detector

If we have our CDR in 2018 and if we convince everybody to build this facilities, we could start construction at the moment when the neutron facility will be ready, i.e., 2023. The construction could last up to 2030-2032 when we will be able to start data taking.

If LBNE starts earlier (e.g. 2029-2030), in one or two years ESSnuSB will accumulate more protons on the target than LBNE.27

ConclusionsNOW 2014, 10/9E. Wildner, CERN28For MH and mainly for CP Violation intense neutrino beams are needed.Better CPV sensitivity at the 2nd oscillation maximum.EU FP7 LAGUNA-LBNO Design Study is finishing.The European Spallation Source Linac will be ready in less than 10 yearsESS will have enough protons to go to the 2nd oscillation maximum and increase its CPV sensitivity.CPV: 5 could be reached over 60% of CP range (ESSSB) with large potentiality.Large associated detectors have a rich astroparticle physics program.Full complementarity with a long baseline experiment on the 1st oscillation maximum using a LAr detector.A feasibility Design Study for ESSnuSB is now proposed (H2020).28

BackupNOW 2014, 10/9E. Wildner, CERN2929

CP Violating ObservablesNOW 2014, 10/9E. Wildner, CERN30matter effect accessibility to mass hierarchy long baselineNon-CP termsCP violating0 CP Violationbe careful, matter effects also create asymmetryatmosphericsolarinterference

Neutrino Oscillations with "large" 13NOW 2014, 10/9E. Wildner, CERN31(see arXiv:1310.5992 and arXiv:0710.0554)2nd oscillation maximum is better

at the 1st oscillation max.: A=0.3sinCPat the 2nd oscillation max.: A=0.75sinCPPhysics Performance for ESSSB(Enrique Fernantez, Pilar Coloma)NOW 2014, 10/9E. Wildner, CERN32

for 2 GeVoptimum 300-400 kmfor 3.5 GeVoptimum 500-600 kmbut the variation is smallCPV discovery implies exclusion at 5 of 0 and 180high CP resolution around these values is needed1 gain around these values increase the discovery CP range by ~4x5x1 (1st approx.)CP precision (unknown MH)32