1. The status and performance of ESSnuSB
KEK and J-PARK 5 and 6 June 2019
Tord Ekelöf
Uppsala University
KEK and J-PARC Tord Ekelof, Uppsala University
/06

2. Why is there only matter and no antimatter in Universe?.
Why is there only matter and
no antimatter in Universe?
The Sakharov conditions (necessary but not sufficient) to explain the Baryon Asymmetry of the Universe (BAU): 1. At least one B-number violating process. 2. C- and CP-violation 3. Interactions outside of thermal equilibrium Grand Unified Theories can fulfill the Sakharov conditions. However, in each m3 of the Universe there are on average ca 109 photons, one proton and no antiproton. The CP violation measured in the quark sector is far too small (by a factor 109) to explain this 109 photon to baryon ratio. Now, neutrino CP-violation, so far not observed, may very well be large enough to permit an explanation of BAU through the leptogenesis mechanism which relates the matter-antimatter asymmetry of the universe to neutrino properties: decays of heavy Majorana neutrinos generate a lepton asymmetry which is partly converted to a baryon asymmetry via sphaleron processes.
Tord Ekelöf, Uppsala University

3. Three neutrino mixing Non-CP terms CP violating atmospheric solar
interference
CP violating
Tord Ekelöf, Uppsala University
Spåtnid Conference 2018

4. Neutrino Oscillations with "large" θ13
for small θ13 1st oscillation maximum is better
for "large" θ13 1st oscillation maximum is dominated by atmospheric term
CP interference
solar
atmospheric
θ13=1º
θ13=8.8º
(arXiv: )
L/E
P(νμ→νe)
2nd oscillation maximum
θ13=8.8º
("large" θ13)
dCP=-90
dCP=0
dCP=+90
L/E
1st oscillation max.: A=0.3sinδCP
2nd oscillation max.: A=0.75sinδCP
(see arXiv: and arXiv: )
more sensitivity at 2nd oscillation max.
Tord Ekelöf, Uppsala University
Spåtnid Conference 2018

5. The ESS neutron and neutrino beams6
KEK and J-PARC Tord Ekelof, Uppsala University
201M8-0a9-y112017
/06

6. Required modifications of the ESS accelerator architecture for ESSnuSB
 F. Gerigk and E. Montesinos CERN-ACC-NOTE July 2016
to accelerate to 2.5 GeV
“No show stoppers have been identified for a possible future addition of the capability of a 5 MW H- beam to the 5 MW H+ beam of the ESS linac built as presently foreseen. Its additional cost is roughly estimated at 250 MEuros.”
Cf total cost of the ESS 5 MW linac of ca 1000 MEuros
KEK and J-PARC Tord Ekelof, Uppsala University
/06

7. The Megaton Water Cherenkov neutrino detector
MEMPHYS like Cherenkov detector(MEgaton Mass PHYSics studied by LAGUNA
Two cylindrical tanks
Total fiducial volume 500 kt (~20xSuperK)
Readout: ~240k 8” PMTs
30% optical coverage
(arXiv: hep-ex/ )
KEK and J-PARC Tord Ekelof, Uppsala University
/06

8. Garpenberg Mine 540 km from ESS
The MEMPHYS type detector to be located 1000 m down in a mine
Garpenberg mine depth 1200 m
Truck access tunnel
A new ore-hoist shaft has been taken into operation,
leaving an older shaft free to use for transport of ESSnuSB-detector cavern excavation-debris
Granite drill cores
KEK and J-PARC Tord Ekelof, Uppsala University
/06

9. Zinkgruvan Mine 360 km from ESS
Zinggruvan mine depth 1500 m
Truck access tunnel
The main ore transport-shaft hoist has a capacity of 6000 tons per 24 hours of which only 2/3 is used. To bring up the 2.5 Mton of cruched rock will take order 3 years.
KEK and J-PARC Tord Ekelof, Uppsala University
/06

10. The second ν oscillation maximum
The ultimate precision in the determination of the leptonic CP violating angle δCP from
neutrinos oscillation measurements will be set by systematic errors.
The motivation for the effort to generate a world-uniquely intense neutrino beam using the ESS 5 MW linac is to have enough statistics to reach the second maximum where the CP signal is 3 times higher than at
the first maximum, thus reducing the uncertainty in δCP due to systematic errors by a factor 3.
KEK and J-PARC Tord Ekelof, Uppsala University
/06

11. The effect of the sharply decreasing ν detection cross-section
flux(E)
2.5 GeV
xs CC, wat.dat file (Enrique)
nue
anue
numu
anumu
(prob*xs)(E)
dcp=0, NH
KEK and J-PARC Tord Ekelof, Uppsala University
/06

12. Comparison of the two mines Garpenberg Zinkgruvan
KEK and J-PARC Tord Ekelof, Uppsala University
/06

13. Systematic errors
Systematic uncertainties in long-baseline neutrino oscillations for large θ13
Pilar Coloma, Patrick Huber, Joachim Kopp, and Walter Winter
Phys. Rev. D 87, – Published 11 February 2013
KEK and J-PARC Tord Ekelof, Uppsala University
/06

14. Sensitivity to the different error types
Fraction of values of CP for which a 5 discovery would be possible is shown when each of the systematic errors from table is varied individually between one half of the "optimistic" values and twice the "pessimistic" ones. A 540 km baseline and 5 yrs in neutrino and antineutrino mode have been assumed. The different systematics studied in the plot are the far and near detector fiducial volumes (FD and ND), the signal and background components of the beam running in neutrino and antineutrino modes (S v , B v , S v , and B v ), the cross section uncertainties for neutrinos and antineutrinos (X v and X v ) as well as for the NC interactions (NC v and NC v ) and the ratio of the muon to electron neutrino cross sections (RX v and RX v ).
KEK and J-PARC Tord Ekelof, Uppsala University
/06

15. Comarison of the two mines
KEK and J-PARC Tord Ekelof, Uppsala University
/06

16. ESSnuSB performance at Garpenberg (blue) and Zinkgruvan (red) and the two error sets ‘Def.’ and ‘ Opt’
KEK and J-PARC Tord Ekelof, Uppsala University
/06

17. ESSnuSB, DUNE and Hyper-K
The performances of
ESSnuSB, DUNE and Hyper-K
The performance of ESSnuSB, DUNE and Hyper-K
assuming the same systematic error 3% for all
three experiments to compare them on the same footing
(detailed explanation on the next slide)
Courtesy Enrique F. Martinez
KEK and J-PARC Tord Ekelof, Uppsala University
/06

18. Explanation of the figures in slide 14
In these figures are shown results for two 250 kt detectors in the Garpenberg mine (540 km baseline, blue curves), two 250 kt detectors in the Zinkgruvan mine (360 km baseline, green curves) and one 250 kt detector in the Garpenberg mine and one in the Zinkgruvan mine (black curves). 
The Hyper-K curve in the middle and right plots and the two resolution values in the left plot for δCP = 0 and δCP = π/2, indicated by the two dotted horizontal lines, are those presented by Hyper-K at the Neutrino 2018 conference.
The DUNE curves have been derived using the public GLoBES file released by the DUNE collaboration with its Conceptual Design Report in Performance predictions for DUNE, assuming 7 years of data taking, were shown by the DUNE collaboration at the Neutrino 2018 conference. For the comparison, in this plot the same simulations were repeated, assuming 10 years of data taking to be in line with the assumptions made for the Hyper-K simulations.
The ESSνSB curves have been derived setting the systematic errors to 3% to be in line with the systematic error levels set by DUNE and Hyper-K. The θ13 and θ23 values for DUNE and ESSνSS have been set to the same values as those used by Hyper-K, again to compare the three experiments on the same footing.
KEK and J-PARC Tord Ekelof, Uppsala University
/06

19. Preliminary plots from a paper in preparation by Monojit Ghosh and Tommy Ohlsson at KTH Stockholm
KEK and J-PARC Tord Ekelof, Uppsala University
/06

20. The interest of measuring δCP precisely
Test of flavor models
Baryon Asymmetry of the Universe
See Silvia Pascoli’s talk at this workshop from which these two slides are taken
KEK and J-PARC Tord Ekelof, Uppsala University
/06

21. Future further option form a ESS neutrino and muon facility
Neutrons to ESS
ESS proton driver
Protons dump
nm or nm
Long
Baseline
Detector
ESSnuSB
2.7x1023 p.o.t/year
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
Muons of average energy ~0.5 GeV at the level of the beam dump (per proton)
Storage
ring
RLA
acceleration
Long
Baseline
Detector
Neutrino
Factory
Cooling
Muon Collider
RCS
acceleration
Collider
ring
→ ←
μ+ μ-
See Carlo Rubbias talk at the NeuTel2019 workshop
more than 4x1020 μ/year from ESS
KEK and J-PARC Tord Ekelof, Uppsala University
/06

22. ESSnuSB organization and time plan
EU grant 3 MEUR
Kick-off meeting in January 2018.
ESSνSB has currently engaged 10 postdocs.
First ESSnuSB and EuroNuNet annual meeting held in Strasbourg November 2018
partners: IHEP, BNL, SCK•CEN, SNS, PSI, RAL
More information at:
KEK and J-PARC Tord Ekelof, Uppsala University
/06

23. ESSnuSB organization and time plan
A 2nd generation neutrino Super Beam :
Start Data taking
7 years
Construction of the facility and detectors, including commissioning
2-5 years, International Agreement
2024:End
Preparatory Phase, TDR
2021: End
of ESSνSB Design Study, CDR and preliminary costing
2018:
beginnin g of ESSνSB
Design Study
(EU- H2020)
2016-
2019:
beginnin g of COST
Action
EuroNuN et
2012:
Θ13
measurement
published - inception of the ESSnuSB project
Nucl. Phys. B 885 (2014) 127
KEK and J-PARC Tord Ekelof, Uppsala University
/06

24. “The potential of the world-uniquely powerful ESS linear accelerator for intensity-frontier particle physics” There are plans to organize a workshop with this title at ESS in the late autumn 2019 to overview the possibilities for a long term program on neutrino och muon physics, including the muon collider, based on the ESS high power linac.
KEK and J-PARC Tord Ekelof, Uppsala University
/06

25. Concluding remarks
ESSnuSB, the design of which is currently being studied, is complementary to other existing and planned super beam experiments by the fact
that it focusses at the second maximum where the sensitivity to systematic errors is 3 times lower than at the first maximum,
the correlation with other parameter of the ν mixing matrix is different and
that the neutrino energy is low enough for the resonant and deep inelastic backgrounds to be strongly suppressed.
If and when the current experimental hints of CP violation will have been confirmed on the level of 5σ, the next important step will be to make an accurate measurement of the CP violating angle δCP , which will require the CP violation signal to maximized. Accurate measurement of δCP has the potential to provide decisive information on flavour models and on the baryon asymmetry.
The use of the ESS linac for the producing a world-uniquely intense neutrino beam can pave the way for making use of the concurrent production of an equally intense muon beam to realize the Muon Collider or Neutrino Factory project.
KEK and J-PARC Tord Ekelof, Uppsala University
/06

26. Thank you
KEK and J-PARC Tord Ekelof, Uppsala University
/06