1. Some preliminary comments on the future options at Fermilab (T600 + short baseline options) A. Guglielmi INFN Padova, Italy On behalf of the ICARUS Collaboration 1

2. The ICARUS Collaboration M. Antonello 1, B. Baibussinov 2, V. Bellini 4,5, H. Bilokon 6, F. Boffelli 7, M. Bonesini 9, E. Calligarich 8, S. Centro 2,3, K. Cieslik 10, D. B. Cline 11, A. G. Cocco 12, A. Curioni 9, A. Dermenev 13, R. Dolfini 7,8, A. Falcone 7,8, C. Farnese 2, A. Fava 3, A. Ferrari 14, D. Gibin 2,3, S. Gninenko 13, F. Guber 13, A. Guglielmi 2, M. Haranczyk 10, J. Holeczek 15, A. Ivashkin 13, M. Kirsanov 13, J. Kisiel 15, I. Kochanek 15, A. Kurepin 13, J. Łagoda 16, F. Mammoliti 4, S. Mania 15, G. Mannocchi 6, V. Matveev 13, A. Menegolli 7,8, G. Meng 2, G. B. Mills 17, C. Montanari 8, F. Noto 4, S. Otwinowski 11, T. J. Palczewski 16, P. Picchi 6, F. Pietropaolo 2, P. Płonski 18, R. Potenza 4,5, A. Rappoldi 8, G. L. Raselli 8, M. Rossella 8, C. Rubbia 19,14,a, P. Sala 20, A. Scaramelli 20, E. Segreto 1, D. Stefan 1, J. Stepaniak 16, R. Sulej 16, C. M. Sutera 4, D. Tlisov 13, M. Torti 7,8, R. G. Van de Water 17, F. Varanini 3, S. Ventura 2, C. Vignoli 1, H. G. Wang 11, X. Yang 11, A. Zani 7,8, K. Zaremba 18 INFN, LNGS, Assergi (AQ), Italy 1), INFN, Sezione di Padova, Padova, Italy 2), Dipartimento di Fisica, Università di Padova, Padova, Italy 3), Dipartimento di Fisica, Università di Catania, Catania, Italy 4) INFN, Sezione di Catania, Catania, Italy 5), INFN, Laboratori Nazionali di Frascati (LNF), Frascati (Roma), Italy 6), Dipartimento di Fisica, Università di Pavia, Pavia, Italy 7), INFN, Sezione di Pavia, Pavia, Italy 8), INFN, Sezione di Milano Bicocca, Dipartimento di Fisica G. Occhialini, Milano, Italy 9), The H. Niewodniczanski Institute of Nuclear Physics, Polish Academy of Science, Kraków, Poland 10), Department of Physics and Astronomy, University of California, Los Angeles, USA 11), INFN, Sezione di Napoli, Dipartimento di Scienze Fisiche, Università Federico II, Napoli, Italy 12), INR-RAS, Moscow, Russia 13), CERN, Geneva, Switzerland 14), Institute of Physics, University of Silesia, Katowice, Poland 15), National Center for Nuclear Research, Warszawa, Poland 16), Los Alamos National Laboratory, New Mexico, USA 17), Institute for Radioelectronics, Warsaw University of Technology, Warsaw, Poland 18), GSSI, L’Aquila (AQ), Italy 19), INFN, Sezione di Milano, Milano, Italy 20) IF in RED, ALSO at LBNE ICARUS presentation at FNAL April 30, 2014Slide: 2

3. P-1052 and P-1053 joint proposals Slide: 3ICARUS presentation at FNAL April 30, 2014 Our proposal for a definitive search for sterile neutrinos has been submitted to CERN on Oct. 14, 2011, based on the (simultaneous) observation at different distances from target with 2 identical LAr-TPC detectors, namely ICARUS T600 complemented by a “clone’’ T150 new module or other option. lThe CERN experiment P-347, approved by the SPS-C, has not been granted due to cancellation of a neutrino beam at CERN. lTherefore on December 2013 we have presented an alternative proposal with the T600 for the FermiLab along the lines of the proposal P-347 originally presented at CERN. lICARUS detector at (600±100) m may extend MicroBooNE foreseen to start earlier operation at ~470 m distance from target. FNAL-PAC response is still pending from last January. Constructive discussions are presently on the way in view of a new joint collaboration.

4. P-1052 layout at the FNAL neutrino beam lines Slide: 4ICARUS presentation at FNAL April 30, 2014 lICARUS T600 detector should be located along the Booster Neutrino Beam line. lAnother similar detector but with a smaller sensitive mass — presently under active discussion— should be located at the required near position. l T600 at FNAL will also provide additional information in the framework of LBNE with ’s from the off-axis kaon- neutrino NUMI beam peaked at ~2 GeV and an enriched flux of νe events as large as ~ 5%.

5. Slide: 5 Basic features lOur proposed experiment, collecting a large amount of data, may be able to give a likely definitive answer to the 3 following queries after a 3 years exposure :  the LSND/+MiniBooNe appearance of the  e oscillation  anomaly;  The Gallex + Reactor oscillatory disappearance of the initial  e signal;  an oscillatory disappearance maybe also be present in the  signal, so far unknown. lIn absence of these “anomalies”, the signals of the detectors should be a closer copy of each other for all experimental signatures and without strong need of Monte Carlo comparisons. lA future program may extend the study to antineutrino, but with the addition of the foreseen magnetic field in the LAr-TPC. ICARUS presentation at FNAL April 30, 2014

6. LSND anomaly: ICARUS at FNAL Slide: 6 T150 at 150 m ? – T600 at 550 m A ≈ 5  confidence level after 3 years  CC at T600617 K Intrinsic e CC3.11 K Signal + e3.71 K Best fit parameters: sin 2 (2  )=0.0015,  m 2 =1.5 eV 2 ICARUS presentation at FNAL April 30, 2014

7. Sensitivity to e disappearance signals Slide: 7 The energy distributions of the electron neutrino events is shown respectively for the “Far” and “Near” and a number of possible values in the region of  m 2 > 1eV 2 and sin 2 (2  ) ≈ 0.16 for 2600 neutrino events. The LAr-TPC energy resolution should be adequate to resolve the oscillation pattern in a wide range of  m 2 values. Near detector ? Standard deviation on 15000 events T600 Far detector Standard deviation on 2600 events ICARUS presentation at FNAL April 30, 2014

8. Effect of the variations with distance lPredicted differences of the near detector at 100 m and the one at 550 m from target both for electron and muon neutrino events. lWhich is the optimum distance of the near detector ? Slide: 8ICARUS presentation at FNAL April 30, 2014

9. A serious problem: the effects of Cosmic ray backgrounds lThree main backgrounds are expected due to the presence of cosmic rays:  Muon associated tracks, which can presumably be eliminated visually if incoming from outside,  Neutron induced tracks and  Gamma ray induced tracks lThese rates were calculated in the original P-347–CERN proposal and on shallow surface and found to occur at an acceptable level. lHowever at FNAL, because of the lower neutrino energies and the lower rates of beam associated event they may represent serious backgrounds which must be carefully estimated and demonstrated that they can be reduced to a negligible level. lAs a reference we show some events from the Pavia CR –signal. Slide: 9ICARUS presentation at FNAL April 30, 2014

10. A new situation w.r.t. LNGS: lower energy neutrino events Slide: 10 CNGS beam 423 cm Cathode plane Wire plane 150 cm CC E dep = 2.17 GeV 296 cm NC E dep = 3.61 GeV (fully contained) Wire plane 150 cm Cathode plane 265 cm Cathode plane CC E dep = 1.07 GeV (fully contained) Wire plane 150 cm ICARUS presentation at FNAL April 30, 2014

11. A NC neutrino event Slide: 11 NC: E dep = 2.69 GeV (fully contained) with a very long meson track (3.90 m) and a neutral hadron from a secondary vertex 338 cm Cathode CNGS beam Wire plane 300 cm Wire plane ICARUS presentation at FNAL April 30, 2014

12. Drift time 1.6 ms The complexity of automatic analysis is evident 2001 images in ICARUS T300 in Pavia and CNGS v-events ICARUS presentation at FNAL April 30, 2014Slide: 12 Cosmic rays (black) + low energy CNGS beam events (red)

13. Integrated intensity of CR neutrons and photons on surface Slide: 13 lNote the very large neutron and gamma backgrounds and their fast increases at low energies. For instance at 200 MeV the neutron and gamma fluxes are comparable and of the order of as much as 10 ev/m 2 /sterad/s, >> than the expectations for P-347. X 20 ICARUS presentation at FNAL April 30, 2014

14. Comparing the FNAL and CERN conditions for T600 lA very more elaborated new detector of the light emitted by the LAr-TPC will be a main issue of an improved T600 when at CERN:  The cosmic muon flux is of ≈ 32 tracks in the ≈1 ms sensitive drift time. Presumably this background can be isolated.  The neutron and  fluxes which are about 20 x larger at FNAL are primarily coming from the outside ( rad = 14 cm, hadr = 80 cm). In contrast, neutrino associated event are uniform.  The angular distributions at FNAL are much more widely “opened” than in the CERN case and the number of offending CR events within the signal angular window is about 6 x larger.  In the e case, the fraction of Compton signals which may lead to a singly ionizing electron are about a factor 5 x larger. An extended and elaborated Montecarlo is on its way based on the T600 spatially related big differences in the CR and distributions and the presently ≈ 600 x larger backgrounds. The signal at FNAL is ≈ factor 4 smaller than at CERN. lA similar analysis is necessary also for the near detector. Slide: 14ICARUS presentation at FNAL April 30, 2014

15. A new alternative approach with already existing LAr-TPCs lICARUS-T600 could be operational at FNAL in three years time from now, after extensive overhauling at CERN. lMicroBooNE is approaching the commissioning phase. It will take data in the booster neutrino beam in the next years. lAt the arrival of ICARUS at FNAL, the continuing activities as Far detector could be taken over by the T600. lAn outstanding evolution of MicroBooNE program would then be its relocation at the near position (150 ± 50 m), offering an almost perfect combination for the definitive dual experiment. lBoth ICARUS and MicroBooNE are operational or nearly operational detectors and there will be no need for constructing additional and necessarily elaborate elements. lThis will represent saving time, human resources and money and ensure a clearly defined objective for both collaborating teams ! lThis will also ensure the fastest implementation of the sterile neutrino physics at Fermilab. ICARUS presentation at FNAL April 30, 2014Slide: 15

16. PAC_FNAL 23 January 2014 LNGS_May2011Slide 16 Thank you ! Slide: 16