Pablo DEL AMO SANCHEZ Henri PESSARD 18/12/2012 Demande ANR STEREO Pablo DEL AMO SANCHEZ Henri PESSARD 18/12/2012

Conseil Labo Demande ANR STEREO Pablo DEL AMO SANCHEZ, LAPP, UniSavoie Overview Neutrino anomalies The STEREO experiment ANR request LAPP’s contribution Conclusions 18/12/2012 Conseil Labo Demande ANR STEREO Pablo DEL AMO SANCHEZ, LAPP, UniSavoie

Conseil Labo Demande ANR STEREO Pablo DEL AMO SANCHEZ, LAPP, UniSavoie Open questions in oscillation physics Oscillations extremely successful description of ν flavour change during propagation, θ13 just measured! Mass hierarchy and leptonic CP in ~ 2025 (LAGUNA/LBNO) Meanwhile, some open questions: Anomaly Type Significance Gallium νe disappearance 2.7σ Reactor 3.0σ LSND νμ → νe 3.8σ MiniBoone 18/12/2012 Conseil Labo Demande ANR STEREO Pablo DEL AMO SANCHEZ, LAPP, UniSavoie

Gallium anomaly GALLEX and SAGE experiments looked for low energy solar neutrinos using Gallium-based detectors (νe+71Ga → e–+71Ge) Deficit observed during calibration runs: Robs/pred=0.86±0.05 (Bahcall’s σν) Detectors calibrated with ~MCi νe sources 0.86 18/12/2012 Conseil Labo Demande ANR STEREO Pablo DEL AMO SANCHEZ, LAPP, UniSavoie

Conseil Labo Demande ANR STEREO Pablo DEL AMO SANCHEZ, LAPP, UniSavoie Reactor anomaly Reactor ν spectrum predicted from β spectrum → compare w/ experiment Emitted b spectra per fission THEORY!!! ν spectra per fission Comparison 18/12/2012 Conseil Labo Demande ANR STEREO Pablo DEL AMO SANCHEZ, LAPP, UniSavoie

Conseil Labo Demande ANR STEREO Pablo DEL AMO SANCHEZ, LAPP, UniSavoie Reactor anomaly Reactor antineutrino flux re-evaluated (2011): +3.5% Phys.Rev. C83 (2011) 054615 & Phys.Rev. C84 (2011) 024617 Neutron lifetime decrease → σν(Inverse Beta Decay) increase +1% Previously non-accounted long-lived isotopes in reactors +1% 18/12/2012 Conseil Labo Demande ANR STEREO Pablo DEL AMO SANCHEZ, LAPP, UniSavoie

Conseil Labo Demande ANR STEREO Pablo DEL AMO SANCHEZ, LAPP, UniSavoie Reactor anomaly → Re-analyse reactor neutrino experiments Result: 7% less events than expected! (3.0 σ) Can be explained with a sterile neutrino with Losc ~ 2-10m Robs/pred=0.927±0.023 Phys.Rev. D83 (2011) 073006 18/12/2012 Conseil Labo Demande ANR STEREO Pablo DEL AMO SANCHEZ, LAPP, UniSavoie

Reactor+Ga anomalies fit Both reactor and Ga anomalies can be explained by 1 sterile ν Δm2 ~ 2 eV2 sin2(2θee) ~ 0.2 Losc ~ 7m Phys.Rev. D83 (2011) 073006 18/12/2012 Conseil Labo Demande ANR STEREO Pablo DEL AMO SANCHEZ, LAPP, UniSavoie

Conseil Labo Demande ANR STEREO Pablo DEL AMO SANCHEZ, LAPP, UniSavoie Future experiments Several reactor (short term), sources (short term) & accelerator (mid-term) experiments under consideration Probe Reactor+Ga anomalies and sterile ν at the same time: Measure rate of reactor Look at L/E dependence close to reactor (L ~ Losc ~ 10 m) Reactor core size important – large cores wash out oscillation Grenoble’s ILL most compact! 18/12/2012 Conseil Labo Demande ANR STEREO Pablo DEL AMO SANCHEZ, LAPP, UniSavoie

Conseil Labo Demande ANR STEREO Pablo DEL AMO SANCHEZ, LAPP, UniSavoie 2m3 Gd-doped liquid scintillator detector 8m away of ILL reactor Signature: νe+p→e++n Segmented target to see L/E dependence at different L’s 18/12/2012 Conseil Labo Demande ANR STEREO Pablo DEL AMO SANCHEZ, LAPP, UniSavoie

Conseil Labo Demande ANR STEREO Pablo DEL AMO SANCHEZ, LAPP, UniSavoie STEREO should see sterile ν oscillation if it’s there Good performance compared to competition (timing important!) Liquid scintillator technology well known (DoubleChooz, Nucifer) Potentially big impact Cheap : ~ 1,5 M€ Quick experiment! Timeline: 11/2012 ILL Scientific Committee 2013-2014 Design & construction 2015 Installation at ILL 2015-2016 Physics Run ergewqrg 18/12/2012 Conseil Labo Demande ANR STEREO Pablo DEL AMO SANCHEZ, LAPP, UniSavoie

Conseil Labo Demande ANR STEREO Pablo DEL AMO SANCHEZ, LAPP, UniSavoie STEREO Collaboration ILL, host laboratory: site characterisation. Three French laboratories: CEA Saclay: Inner detector LAPP: Radioactive source calibration system + possibility of mechanics of shielding LPSC: Acquisition electronics + µ veto + shieldings (workshop) Foreign collaborators: Germany, TUM & Max-Plank-Institut Heidelberg: Liquid scintillator + LED calibration system Morocco, University Hassan II & CNESTEN. 18/12/2012 Conseil Labo Demande ANR STEREO Pablo DEL AMO SANCHEZ, LAPP, UniSavoie

Conseil Labo Demande ANR STEREO Pablo DEL AMO SANCHEZ, LAPP, UniSavoie ANR Proposal Porteur: David LHUILLIER (CEA Saclay) 800 k€ + 2 postdocs (+1 ENIGMASS postdoc => 1postdoc/french lab) Timescale: 04/2013 ANR funding decision 2013-2014 Design & construction Late 2014 Lab tests 2015 Installation at ILL 2015-2016 Physics Run 18/12/2012 Conseil Labo Demande ANR STEREO Pablo DEL AMO SANCHEZ, LAPP, UniSavoie

Conseil Labo Demande ANR STEREO Pablo DEL AMO SANCHEZ, LAPP, UniSavoie LAPP’s contribution Calibration system with radioactive sources γ sources (Na, Co, n capture by H & Gd)+ n sources (Am-Be) Mechanics + automatism + workshop In touch with B. Lieunard ITA manpower under evaluation, seems feasible Possibility of engineering shielding support under study m-veto - water 10 cm lead Polyethylene Tube 20 cm acrylic buffer 10 cm lead front wall Source 5 target cells 40 cm thick 18/12/2012 Conseil Labo Demande ANR STEREO Pablo DEL AMO SANCHEZ, LAPP, UniSavoie ~ 3.30 m

Conseil Labo Demande ANR STEREO Pablo DEL AMO SANCHEZ, LAPP, UniSavoie Conclusions Strong international interest in neutrino anomalies Grenoble’s ILL unique for Reactor+Gallium anomalies STEREO has the potential to address Reactor+Gallium anomalies in a short (~5yr) timescale; excellent bang for buck! ANR request (CEA, LAPP, LPSC): 800 k€ + 2 postdocs LAPP’s rôle : Radioactive source calibration system. Possibility of mechanics of shielding. Engineering manpower seems available for the requested period 18/12/2012 Conseil Labo Demande ANR STEREO Pablo DEL AMO SANCHEZ, LAPP, UniSavoie

Conseil Labo Demande ANR STEREO Pablo DEL AMO SANCHEZ, LAPP, UniSavoie BACKUP SLIDES 18/12/2012 Conseil Labo Demande ANR STEREO Pablo DEL AMO SANCHEZ, LAPP, UniSavoie