ESSνSB 1477 Measuring leptonic CP violation at the second ν oscillation maximum ENUBET Meeting in Padova 23June 2016 Tord Ekelof, Uppsala University 2016-06-23 ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University 1

ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University The unique feature of ESSnuSB is to make use of the ca 3 times higher sensitivity to δCP at the second oscillation maximum thereby reducing by the same factor the sensitivity to systematic errors. For this purpose we plan to provide enough beam power - 5 MW - to be able to record enough statistics of electron neutrinos and anti-neutrinos in a Megaton neutrino detector located at the second oscillation maximum 2016-06-23 ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University

ESSnuSB is optimized for the large Θ13 measured in 2012 Θ13=1º Θ13=8.5º P. Coloma and E. F. Martinez 1110.4583   With Θ13=8.5ºthe relative signal is low at the first maximum and systematic errors is the bottleneck This is not the case at the second maximum. 2016-06-23 ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University

Θ13=8.73o 3σ 5σ ESSnuSB was designed for the larger value of Θ13 CP violation discovery sensitivity is significantly larger at the second oscillation maximum as compared to the first Garpenberg Θ13=8.73o 3σ 5σ 1st osc. max 2nd osc. max 3rd osc. max 2016-06-23 4 ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University

The sensitivity of the neutrino energy distribution to δCP Hyper-K first maximum LBNE/DUNE first maximum ESSnuSB second maximum Hyper-K Hyper-K Events/100MeV Relative difference in counts at maximum between δCP = 3π/2 and π/2 : 430/275 = 1.6 150/100 = 1.5 105/22 = 4.8 2016-06-23 ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University

ESSnuSB a energy distribution shape measuring experiment Second maximum M. Olvegård Systematic normalization errors suppressed Only very modest discrimination between the different δCP values 2016-06-23 ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University

ESSnuSB as counting experiment Second maximum Statistical errors about equal to than the 7% systematic errors Even better discrimination between the different δCP values M. Olvegård 2016-05-30 2016-06-23 Nu Infrastructures at KEK 30-31 may 2016 Tord Ekelöf Uppsala University ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University 7

ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University ESSnuSB as neutrino/antineutrino ratio counting expt First maximum Second maximum M. Olvegård Syst. and stat. errors not balanced Range of variation +.06->-0.05 Limited discrimination between the different δCP values Syst. and stat. errors balanced Range of variation +0.75->-0.6 Excellent discrimination between the different δCP values 2016-06-23 ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University

ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University From Stephen Parke/ FNAL; “Neutrinos: Theory and Phenomenology” arXiv:1310.5992v1 [hep-ph] 22 Oct2013, page 12; “At the first oscillation maximum (OM), as is in the running experiments, T2K and NOνA and possible future experiments HyperK and LBNE experiments, the vacuum asymmetry is given by A ~ 0.30 *sin δ at Δ31=π/2 which implies that P(ν̅μ→ν̅e) is between 1/2 and 2 times P(νμ→νe). Whereas at the second oscillation maximum, the vacuum asymmetry is A ~ 0.75 *sin δ at Δ31=3π/2 which implies that P(ν̅μ→ν̅e) is between 1/7 and 7 times P(νμ→νe). So that experiments at the second oscillation maximum, like ESSnuSB [15], have a significantly larger divergence between the neutrino and anti-neutrino channels.” 2016-06-23 ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University

δCP accuracy performance (USA snowmass process, P. Coloma) “Default" errors for the “Default” systematic errors see: Phys. Rev. D 87 (2013) 3, 033004 [arXiv:1209.5973 [hep-ph]] arXiv:1310.4340 [hep-ex] Neutrino "snowmass" group conclusions 2016-06-23 ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University

ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University Systematic errors Phys. Rev. D 87 (2013) 3, 033004 [arXiv:1209.5973 [hep-ph]] 2016-06-23 ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University

ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University Is 2% achievable? Page 3-41 2016-06-23 ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University

ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University Is 4% enough at the first maximum? 31 March 2015 Page 27 2016-06-23 ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University

ESSnuSB coverage of δCP vs statistics “Opt." case for systematics “1.0”=10 years 2016-06-23 ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University

We propose to use the ESS proton linac for this purpose HEBT & upgrade: 2.5 GeV+68 m, 3.0 GeV +60 m, 3.5 GeV +66 m, The ESS will be a copious source of spallation neutrons 5 MW average beam power 125 MW peak power 14 Hz repetition rate (2.86 ms long pulses each of 1015 protons) 2.0 GeV protons (up to 3.5 GeV with linac upgrades) >2.7x1023 p.o.t/year Linac ready by 2023 (full power and energy) 2016-06-23 ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University

Artists view of the future ESS site 2015-11-26 16 2016-06-23 ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University

How to add a neutrino facility to ESS? Increase the linac average power from 5 MW to 10 MW by increasing the linac pulse rate from 14 Hz to 28 Hz, implying that the linac duty cycle increases from 4% to 8%. Inject into an accumulator ring (circumference ca 400 m) to compress the 3 ms proton pulse length to 1.5 μs, which is required by the operation of the neutrino horn (fed with 350 kA current pulses). The injection into the ring requires H- pulses to be accelerated in the linac. Add a neutrino target station (studied in EUROν) Build near and far neutrino detectors (studied in LAGUNA) How to add a neutrino facility to ESS? 2016-06-23 ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University

ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University The ESS LINAC tunnel nowcompleted 2016-06-23 ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University

ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University Point of H- beam exit through the linac tunnel wall into the transfer tunnel to the accumulator 2016-06-23 ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University

ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University The Clystron Gallery Building The view from ESS to MAXIV 2016-06-23 ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University

ESS construction site February 2016 ν p n H- 2016-06-23 2016-05-20 ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University RECFA Meeting Lund 20 May 2016 Tord Ekelöf Uppsala University 21

ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University Preparing the ESS linac for operation at 10 MW/8% duty cycle/28 Hz For the medium-beta elliptical-cavity part ESS is planning to use tetrodes. Thales has developed a new screen grid with graded wire thickness such that the heating is evenly distributed over the hight of the screen grid, thereby making operation at 10 % duty cycle possible. For the warm low-energy part of the ESS linac and the medium energy Elliptical-cavities part, ESS is planning to use modulators of the modular klystron modulator type which can be run at 28 Hz at double power by adding a capacitor charger-unit at the input. For the high energy elliptical Cavities IOTs will be used which by design can operate CW. 2016-06-23 ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University

ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University FREIA The picture shows the cryostat and test bunker at the FREIA Lab in Uppsala where a first prototype of the ESS 352 MHz spoke accelerating cavity is currently under test at 14 Hz and later on will be tested at 28 Hz. Modulators for the high beta part of the linac will also be tested at 28 Hz. 2016-06-23 ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University

Muon at the level of the beam dump 2.7x1023 p.o.t/year muons at the level of the beam dump (per proton) y (cm) x (cm) 4.2x1020 μ/year (16.3x1020 for 4 m2) 4.1x1020 μ/year 10-3 x (cm) input beam for future 6D m cooling experiments (for muon collider) good to measure neutrino x- sections (νμ, νe) around 200-300 MeV (low energy nuSTORM) muons/proton <Eμ>~0.46 GeV <Lμ>~2.9 km 2016-06-23 ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University Rio, August 2015 M. Dracos IPHC/IN2P3-CNRS-UNISTRA

Carlo Rubbia:The ESS - a muon collider for Europe? Several accelerator programs at higher energies for µ+µ- factories have been described in the US (both BNL and FNAL) and elsewhere, but all requiring substantial improvements. Amongst the various LHC upgrade programs recently under discussion, CERN had considered the SPL, a H- beam at 5 GeV kinetic energy with 50 Hz, 4 MWatt and 1.0 x 1014 p/ pulse. However in 2010 CERN has decided on different alternatives and therefore this project has been cancelled. The European Spallation Source, now in construction in Lund, with 5 MWatt of protons accelerated to a kinetic energy of 2.0 GeV at 14 Hz and 1 x 1015 p/pulse may provide the adequate intensity and repetition rate for the presently discussed collider program, With the addition of a small accumulating ring the ESS may strip negative hydrogen ions H- to protons and compress their bunch length to a few ns. In order to increase the repetition three proton bunches could be extracted in a small ring at each ESS injection bringing the beam collision rate to 14 x 3 = 43 c/s.. 2016-06-23 Uppsala_Feb_2016 ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University Slide# : 25

Carlo Rubbia:Higgs luminosity at ESS From 3.3 x 1014 p/pulse 3.5 x 1013 µ+ and 2.4 x 1013 µ- are generated. The cooling process efficiency is 0.4 and the acceleration efficiency to √s = 125 GeV is 0.6. The luminosity is given by a formula where: N+ = N- = 7 x 1012 µ/pulse f is the number of effective luminosity crossings: 43 x 555 =23’865/s e rms =e N/589.5 = 0.36 x 10-4 rad cm, with H2 but no PIC cooling. B* = 5 cm is beta at crossing in both dimensions Luminosity is L = 5 x 1032 cm-2 s-1 for one collision crossing The cross section at the maximum averaged with with DE = 3.4 MeV is 1.0 x 10-35 cm2. Hence the Ho event rate is 18 ev/h or 5 x 104 ev for 107 s/y . In 10 y and 2 crossings one million Ho events If PIC (Parametric Resonance Coooling) is successful e rms/ 10 and 5 x 105 events/year/i.p. 2016-06-23 ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University

The MEMPHYS WC Detector (MEgaton Mass PHYSics) Neutrino Oscillations (Super Beam, Beta Beam) Proton decay Astroparticles Understand the gravitational collapsing: galactic SN ν Supernovae "relics" Solar Neutrinos Atmospheric Neutrinos 500 kt fiducial volume (~20xSuperK) Readout: ~240k 8” PMTs 30% optical coverage (arXiv: hep-ex/0607026) ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University 2016-06-23

ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University So where can we find a deep mine at the second oscillation maximum distance ca 540 km from ESS? The map shows the depth and distance from ESS/ Lund of different mines in Scandinavia. Kongsberg L=480, D=1200m 2016-06-23 ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University

The ESSnuSB Collaboration 40 participating scientists from 12 institutes in Sweden, France, Spain, England, Switzerland, Italy, Poland, Bulgaria and Greece The ESSnuSB Proposal published in Nuclear Physics B885(2014)127-149 Also available as arXiv:1309.7022 2016-06-23 ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University

ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University Accepted for publication Hindawi Publishing Corporation Advances in High Energy Physics Article ID 873567 The Opportunity Offered by the ESSnuSB Project to Exploit the Larger Leptonic CP Violation Signal at the Second Oscillation Maximum and the Requirements of This Project on the ESS Accelerator Complex E. Wildner,1 E. Baussan,2 M. Blennow,3 M. Bogomilov,4 A. Burgman,5 E. Bouquerel,2 C. Carlile,6 J. Cederkäll,5 P. Christiansen,5 P. Cupial,7 H. Danared,8 M. Dracos,2 T. Ekelöf,6 M. Eshraqi,8 R. Hall-Wilton,8 J.-P. Koutchouk,1,6 M. Lindroos,8 M. Martini,1 R. Matev,4 D. McGinnis,8 R. Miyamoto,8 T. Ohlsson,3 H. Öhman,6 M. Olvegård,6 R. Ruber,6 H. Schönauer,1 J. Y. Tang,9 R. Tsenov,4 G. Vankova-Kirilova,4 and N. Vassilopoulos9 ,,CERN, 1211 Geneva 23, Switzerland2I PHC, Universite´ de Strasbourg, CNRS/IN2P3, 67037 Strasbourg, France3 Department of Theoretical Physics, School of Engineering Sciences, KTH Royal Institute of Technology, AlbaNova University Center, 106 91 Stockholm, Sweden 4Department of Atomic Physics, St. Kliment Ohridski University of Sofia, 1164 Sofia, Bulgaria 5Department of Physics, Lund University, P.O. Box 118, 221 00 Lund, Sweden 6Department of Physics and Astronomy, Uppsala University, P.O. Box 516, 75120 Uppsala, Sweden 7 AGH University of Science and Technology, Aleja Mickiewicza 30, 30-059 Krakow, Poland 8 European Spallation Source, ESS ERIC, P.O. Box 176, 221 00 Lund, Sweden Institute of High Energy Physics, CAS, Beijing 100049, China 2016-06-23 ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University

ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University Supported by the owner of the mine and by the local authorities In a memorandum of Understanding the owner of the Garpenberg Mine, Boliden AB, authorizes ESSnuSB to access and investigate the mine and to consult with the personnel of its personnel. We have discussed with the Chair of the Dalarna Region and the Mayor of the local commune, where the mine is located, and have met a great local enthusiasm for having the detector located in Garpenberg mine. Garpenberg Mine Dalahäst Mascot of Dalarna 2016-06-23 ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University

ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University Required modifications of the ESS accelerator architecture for ESSnuSB  F. Gerigk and E. Montesinos CERN, Geneva, Switzerland Abstract  This report is a summary of major modifications to the ESS nominal linac layout, which are needed to enable the operation of the ESS linac as 5 MW proton driver for the ESSnuSB initiative in addition to its regular operation as 5 MW ESS proton source. A draft costing is also provided using extrapolations from the ESS official cost numbers and values, which are familiar to the authors. This assessment was made during a visit by F Gerigk (CERN) and E Montesinos (CERN) to ESS on 1 – 2 June 2016 together with staff members of ESS. The visit took place on the initiative and with the support of the University of Uppsala (Tord Ekelöf). We are very grateful to Mamad Eshraqi who organized our visit at ESS and who made it possible for us to discuss with the relevant ESS experts and work package leaders. In the following we start with the charge for the review, the considered ESSnuSB scenarios, an executive summary and then a detailed list of findings, comments and recommendations ordered by subject.  Contents 1 The charge for the assessment 2 Scenarios for ESSnuSB 3 Executive Summary 4 Detailed upgrade measures 4.1 Civil engineering & integration 4.2 Electrical network 4.3 RF sources, RF distribution & modulators 4.4 Cryogenics (plant + distribution) 4.5 Water cooling 4.6 Superconducting cavities, couplers & cryomodules 4.7 Beam physics 5. Appendix 1: Visit time table 6. Appendix 2: Indicative costing of the upgrade To appear as a CERN Internal Report within a week 2016-06-23 ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University

ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University Support by ESS In a letter to the EC H2020 Research Infrastructure Office the ESS CEO Jim Yeck writes: “Given the high scientific interest in exploring the possibility of using the future ESS linear accelerator for neutrino physics…ESS management agrees to provide information and general support for the ESSnuSB collaboration’s ongoing studies.” Collaboration on preparations during linac build-up of power up-grade: power upgrades of tetrodes and modulators, keeping site areas for accumulator, target with decay tunnel and near detector free from other use A Workshop on “Upgrading Existing High Power Proton Linacs” will be organized 8-9 November 2017 at ESS in Lund by ESS and Uppsala University with sessions “Increasing the duty cycle”, “Energy upgrades”, “Increasing the current”, and “H- acceleration in proton linacs and pulse compression rings”. The study of the upgrade of the ESS linac has an interest for several applications in addition to that which ESSnuSB represents like spallation neutrons, ADS, transmutation of nuclear waste, muSTORM, Neutrino Factory, Muon Collider… 2016-06-23 ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University

ESS neutrino and muon facility ESS neutrino and muons facility ESS neutrino and muon facility Ref. M.Darcos and J.P. Delahaye 2.7x1023 p.o.t/year Neutrons to ESS ESS proton driver Protons dump nm or nm Long Baseline Detector ESSnuSB p decay Test Facility nm + ne m+ or m- Short Baseline Detector Accumulator Decay channel or ring nuSTORM Short Baseline Detector ne + nm Front end Storage ring RLA acceleration Muons at the level of the beam dump (per proton) Long Baseline Detector Neutrino Factory Cooling 3434 y (cm) RCS acceleration Collider ring Muon Collider Target Station Proton beam x (cm) 4.2x1020 μ/year (16.3x1020 for 4 m2) 4.1x1020 μ/year 2016-06-23 ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University Target 25 m long decay tunnel

Muon decay in a storage ring Muon decay in a straight channel Muon decay: two technical options Muon decay in a storage ring The NuSTORM approach Muon decay in a straight channel The MOMENT approach 2016-06-23 ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University

ESS-NUSTORM: a tentative layout 2016-06-23 ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University

ESS-MOMENT: a tentative layout 2016-06-23 ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University

ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University The Swedish Government During the two last years we have had three meetings with the Director General of Research at the Swedish Ministry of Research and Education to report on the progress in the planning of ESSnuSB. On 15 April 2015 we had a very constructive discussion with the State Secretary at the Ministry, thereby bringing the ESSnuSB project to the agenda of the Swedish government. The Scientific Councellor Mats Engström at the Embassy of Sweden in Japan participated in the The Third International Meeting for LArge Neutrino Infrastructures 30-31 maj 2016 in Tsukuba, including the closed agency meeting there, with the mission to report back to the Swedish Government. 2016-06-23 ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University

ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University ESSnuSB Design Study funding Recently an EU COST network application for ESSuSB was accepted with 57 out of 65 marks. Quotation from the evaluation report: “The main strengths are that the present project is unique in Europe, and at this moment there are no other similar plans in the continent and it is building on a number of previous European projects. Only two other, similar projects exist in the USA and Japan. In addition, the project is not only complementary to the projects in the USA and Japan but clearly competitive with them, because the infrastructure proposed, which plans to locate the detector at the second neutrino oscillation maximum, will provide a much better and larger accuracy than the other two projects.” Currently we are waiting for the outcome of ESSnuSB applications submitted to the Swedish SRC and to the European Economic Growth Foundation. Submission of a EU Design Study application is planned for autumn 2016. Funding of the Design Study remains a critical item. 2016-06-23 ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University

ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University Conclusions and summary We conclude that the ESSnuSB project has: - the best physics potential for CP violation studies, compared to the other proposed Super Beam projects in the world, - a limited cost as the baseline accelerator is already financed and under construction, - a strong group of 11 institutes that plan to undertake specific, well planned and prepared tasks to bring the project up to a Design Report 2016-06-23 ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University

ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University The ESSnuSB project - is sufficiently advanced in its concept, benefitting from the European EUROnu and Laguna-LBNO design studies and from the ESS studies, to be ready to start data taking in about 10 years from now and - has the potential to do new science through its unique feature of providing enough beam power to focus all its statistics at the second maximum, and thereby has a clear lead for CP violation discovery, in addition to its high performance for proton decay and neutrino astroparticle research 2016-06-23 ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University

Thanks for your attention 2016-06-23 ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University