Neutrino beams from the decay of muons Muon

Neutrino beams from the decay of muons Muon Beams Meeting CERN Paul Soler, 18 November 2015

Neutrino beams o Neutrino beams have been producing major discoveries since 1962 ― o Two neutrino experiment at AGS Neutrino beams have not evolved conceptually since 1963, with the invention of the van der Meer horn ― ― ― Proton beam hits target to create secondary pions, kaons Secondaries are focused by horns Secondaries decay in decay pipe Absorber material and “beam dump” removes charged particles Detectors along beam line are used to monitor flux and direction Muon Beam Meeting, CERN: 18 November 2015 2

Neutrino beams o Accuracy in predicting neutrino flux is dominated by secondary pion and kaon production from protons on target o Hadronic models (ie. GEANT, MARS, FLUKA …) are used to describe hadron production data Requires also hadron production experiments to predict yields for each experiment (ie. HARP, NA 61/SHINE, MIPP, …) Absolute flux prediction is known at best to 10 -20% accuracy For oscillation experiments can use near/far ratio: 2 -5% o o o ― Issues: not all decay phase space is covered, less accuracy for secondary kaons and protons, focussing effects in horn conductors, etc. Muon Beam Meeting, CERN: 18 November 2015 3

Hyper-Kamiokande o Expected flux errors ~10%, Dd. CP~20 o ar. Xiv: 1502. 05199 Muon Beam Meeting, CERN: 18 November 2015 4

DUNE o Expected flux errors ~5%, Dd. CP~10 o-15 o DUNE Physics Volume CDR, 2015 Muon Beam Meeting, CERN: 18 November 2015 5

Neutrino landscape post-2025 o o o More than a 50% probability that there could be evidence for CP violation from DUNE or Hyper-Kamiokande ~2028 Error in the measurement of CP phase Dd. CP ~ 20 o Cannot distinguish between models – require Dd. CP ~ 3 -4 o Muon Beam Meeting, CERN: 18 November 2015 6

Neutrino landscape post-2025 o This is motivation for precision in neutrino physics: neutrino factory should have similar precision to CKM precision ar. Xiv: 1209. 5973 Muon Beam Meeting, CERN: 18 November 2015 7

nu. STORM: Neutrinos from STORed Muons o nu. STORM: storage ring for 3. 8 Ge. V/c muons that can be realised now without any new technology 3. 8 Ge. V/c – – – Pions of 5 Gev/c captured and injected into ring. 52% of pions decay to muons before first turn: This creates a first flash of neutrinos from pion decays Ring designed to store muons with p = 3. 8 Ge. V ± 10% Muons decay producing neutrinos: Creates hybrid beam of neutrinos from pion & muon decay Muon Beam Meeting, CERN: 18 November 2015 8

Physics motivation of nu. STORM: – Creation of a neutrino beam with a flux accuracy of 10 -3 for neutrino scattering physics: “the neutrino light source” – Measurement of ne cross sections and nuclear effects in neutrino-nucleus collisions, essential for long baseline neutrino oscillation programme – Definitive resolution of sterile neutrino problem and search for short-baseline neutrino oscillations – Creation of a test bed for muon accelerator R&D for future high intensity neutrino factories and muon collider A new way of doing neutrino physics Adey, Bayes, Bross, Snopok, Ann. Rev. Nucl. Part. Sci. 2015 65: 145 -75. Muon Beam Meeting, CERN: 18 November 2015 9

nu. STORM Facility o nu. STORM facility: – – 120 Ge. V protons on carbon or inconel target (100 k. W) Nu. MI-style horn for pion collection Injection pions (5 Ge. V/c ± 10%) into storage ring: 0. 09 p/POT Storage ring: large aperture FODO lattice (3. 8 Ge. V/c ± 10%) muons: 8× 10 -3 m/PO Muon Beam Meeting, CERN: 18 November 2015 10

nu. STORM Flux and Spectrum o nu. STORM flux and energy spectrum Use muon decay neutrinos to calibrate hadron decay neutrinos – – nm from pion decay flux: 6. 3× 1016 n/m 2 at 50 m ne from muon decay flux: 3. 0× 1014 n/m 2 at 50 m nm from kaon decay flux: 3. 8× 1014 n/m 2 at 50 m Used for cross-section measurements and short baseline oscillations Muon Beam Meeting, CERN: 18 November 2015 11

nu. STORM Event Rates o o Flux uncertainties for nu. STORM from beam diagnostics: < 1% Event rates per 1021 POT in 100 ton Liquid Argon at 50 m – Limited by detector systematics: Muon Beam Meeting, CERN: 18 November 2015 12

Neutrino interactions at nu. STORM o Very rich physics programme (just some examples): – – – Electron neutrino and cross-section measurements p 0 production in neutrino interactions Charged p and K production Over 60 physics topics already identified: Ph. D theses Neutrino-electron scattering Neutrino-nucleon scattering: charged current and neutral current (NC/CC ratio and sin 2 q. W) – Nuclear effects in neutrino interactions – Semi-exclusive and exclusive processes: measurement of production – New physics and exclusive processes: test of universality, heavy neutrinos, e. V-scale pseudo-scalar penetrating particles …. Muon Beam Meeting, CERN: 18 November 2015 13

Neutrino interactions at nu. STORM o Example of CCQE measurement: – Data for and cross-sections Muon Beam Meeting, CERN: 18 November 2015 14

Long baseline physics o o Influence of measurement of cross-sections with less than 1% precision as potentially provided by nu. STORM Significantly improves d. CP accuracy in DUNE and Hyper. K Huber, Palmer, Bross ar. Xiv: 1411: 0629 Muon Beam Meeting, CERN: 18 November 2015 15

nu. STORM for accelerator R&D o nu. STORM: testbed for 6 D muon cooling experiment – At end of straight: 3. 5 m iron pion absorber – After absorber: 1010 m/pulse between 100 -300 Me. V/c 3. 8 Ge. V± 10% Muons for 6 D Muon Beam Meeting, CERN: 18 November 2015 16

nu. STORM at Fermilab o nu. STORM could be sited at Fermilab Near Detector Hall Proposal to FNAL PAC: ar. Xiv: 1308. 6822 Far Detector Hall (D 0) Target building Decay ring 17

nu. STORM at CERN o nu. STORM could be sited at CERN o Target station in North Area Eo. I to CERN: ar. Xiv: 1305. 1419 o For two detector oscillation search: near detector in North Area and far detector in Point 1. 8 Muon Beam Meeting, CERN: 18 November 2015 18

nu. STORM at CERN o nu. STORM serving the Neutrino Platform at CERN Muon Beam Meeting, CERN: 18 November 2015 19

nu. STORM at CERN o nu. STORM serving the Neutrino Platform at CERN Muon Beam Meeting, CERN: 18 November 2015 20

nu. STORM at CERN o nu. STORM serving the Neutrino Platform at CERN Muon Beam Meeting, CERN: 18 November 2015 21

Sterile neutrino search o Assume two detectors: o Super-saturated Magnetised Iron: Super. BIND Magnetic field: 1. 5 -2. 6 T o 240 k. A from 8 Superconducting Trasmission Lines Muon Beam Meeting, CERN: 18 November 2015 22

Sterile neutrino search o Appearance search: Adey et al. , PRD 89 (2014) 071301 With full reconstruction and efficiencies, 1021 POT o Disappearance search: Muon Beam Meeting, CERN: 18 November 2015 23

Sterile neutrino search o o Short-baseline oscillation search with near detector at 50 m and far detector at 2 km, 1021 POT exposure Appearance and disappearance multi-variate analyses Adey et al. , PRD 89 (2014) 071301 Appearance efficiencies Disappearance efficiencies Muon Beam Meeting, CERN: 18 November 2015 24

Sterile neutrino search o o Short-baseline oscillation search with near detector at 50 m and far detector at 2 km, 1021 POT exposure Appearance and disappearance multi-variate analyses Adey et al. , PRD 89 (2014) 071301 Appearance sensitivity Disappearance sensitivity Can perform combined analysis appearance/disappearance Muon Beam Meeting, CERN: 18 November 2015 25

Neutrino Factory from IDS-NF Baseline: 10 Ge. V muons, one storage ring with detector at ~2000 km, due to large q 13 562 m o Magnetised Iron Neutrino Detector (MIND): – 100 kton at ~2000 km IDS-NF Interim Design Report ar. Xiv: 1112. 2853 Muon Beam Meeting, CERN: 18 November 2015 26

Optimisation of Neutrino Factory o Optimisation for high q 13: 10 Ge. V muons and 2000 km Contours of CP coverage 100 kton MIND Muon Beam Meeting, CERN: 18 November 2015 27

Neutrino Factory Baseline o Proton driver – Proton beam ~8 Ge. V on target o Target, capture and decay – Create p, decay into m MERIT) o (R&D: Bunching and phase rotation 562 m – Reduce DE of bunch o Ionization Cooling – Reduce transverse emittance (R&D: MICE) o Acceleration – 120 Me. V 10 Ge. V with RLAs o Decay ring – Store for ~100 turns – Long straight sections – 1021 muons/year IDS-NF Reference Design Report to be published in JINST special issue on Muon Accelerators Muon Beam Meeting, CERN: 18 November 2015 28

MIND efficiencies and background BDT efficiency, focussing m+ BDT background (stored m-, focussing m+) Tau signal Courtesy R. Bayes BDT efficiency, focussing m- BDT background (stored m+, focussing m+) Tau signal Muon Beam Meeting, CERN: 18 November 2015 29

Performance 10 Ge. V Neutrino Factory o Analysis shows that 10 Ge. V Neutrino Factory, with 1021 m/year, 100 kton MIND at 2000 km gives best sensitivity to CP violation More than 85% 5 s coverage (ie. 85% probability of CPV discovery!) ar. Xiv: 1203. 5651 Muon Beam Meeting, CERN: 18 November 2015 30

Muon Accelerator Staging Programme o o Nu. MAX is Neutrino Factory in Fermilab context (5 Ge. V to Sanford Lab, at 1300 km) – similar sensitivity to IDS-NF Synergy with Muon Collider components See talk M. Palmer Muon Beam Meeting, CERN: 18 November 2015 31

Physics performance of Nu. MAX o Physics performance in terms of fraction of CP phase d with measurement accuracy at or below Dd P. Huber Muon Beam Meeting, CERN: 18 November 2015 32

Conclusions o o o Expect discovery of CP violation in neutrinos within 15 years Neutrino beams from muon decay can bring neutrino physics into precision era First stage: nu. STORM to resolve neutrino cross-sections for long baseline experiments, sterile neutrino searches and 6 D cooling R&D facility nu. STORM would be a fantastic contribution by CERN to world -wide neutrino programme Second stage: develop neutrino factory for ultimate precision of CP phase delta Dd. CP~ 4 o. Neutrino factories are a stepping stone towards a muon collider – R&D is always delivering physics along the way Muon Beam Meeting, CERN: 18 November 2015 33

How can we improve CP precision? o Precision requirement for CP violation: – For 75% of CP asymmetry coverage at 3 s: ACP as low as 5% – Requires 1. 5% measurement of (~1% syst. error), but we measure rate: See next talk P. Huber, Palmer, Bross ar. Xiv: 1411: 0629 Muon Beam Meeting, CERN: 18 November 2015 34

Long baseline physics o Precision requirement for CP violation: – In disappearance experiment we can satisfy: Huber, Mezzetto, Schwetz ar. Xiv: 0711. 2950 – In an appearance experiment so na beam cannot measure , CP violation sensitivity for 75% d. CP coverage at LBNF/DUNE – Syst. error on ratio – Difference in and large Huber, Palmer, Bross ar. Xiv: 1411: 0629 Muon Beam Meeting, CERN: 18 November 2015 in T 2 HK can be 35

Short baseline physics o LSND and Mini. Boo. NE hints of and appearance and reactor anomaly (6% deficit) LSND Reactor anomaly Mini. Boo. NE 36

Short baseline physics o Consistency between appearance and disappearance measurements for sterile neutrino hypothesis: – nu. STORM could probe all possible sterile neutrino appearance and disappearance channels (if En>t threshold) to test paradigm Muon Beam Meeting, CERN: 18 November 2015 37

Sterile neutrino search o o Short-baseline oscillation search with near detector at 50 m and far detector at 2 km, 1021 POT exposure Appearance and disappearance multi-variate analyses Adey et al. , PRD 89 (2014) 071301 Appearance sensitivity Disappearance sensitivity Can perform combined analysis appearance/disappearance Muon Beam Meeting, CERN: 18 November 2015 38

Nu. MAX: Neutrino Factory FNAL/Sanford o Neutrinos from a Muon Accelerator Comple. X (Nu. MAX) – Neutrino Factory with 1020 straight muons decays/year @ 5 Ge. V – Muon ring at 5 Ge. V pointing neutrino beam towards Sanford – A 10 k. T MIND or magnetized LAr detector upgraded from LBNE J. P. Delahaye Nu. MAX commissioning PIPIII 0. PIPII 8 G e. V Ge Dual use Linac m Preinjector 3. 75 Ge. V 650 MHz 2. 2 V 1. 0 Ge. V 325 MHz No cooling 6. 75 Ge. V Protons 255 Me. V/c Muons Front-end Target Accumulator Buncher Main Injector Muon Beam Meeting, CERN: 18 November 2015 39

Nu. MAX: Neutrino Factory FNAL/Sanford o Neutrinos from a Muon Accelerator Comple. X (Nu. MAX) – Add small amount of 6 D cooling – Neutrino Factory with 5× 1020 straight muon decays/year @ 5 Ge. V – Muon ring at 5 Ge. V pointing neutrino beam towards Sanford J. P. Delahaye 0. PIPII 8 G e. V Nu. MAX and Nu. MAx+ PIPIII Ge Dual use Linac m Preinjector 3. 75 Ge. V 650 MHz 2. 2 V 1. 0 Ge. V 325 MHz Add cooling 6. 75 Ge. V Protons 255 Me. V/c Muons Cooling Front-end Target Accumulator Buncher Main Injector Muon Beam Meeting, CERN: 18 November 2015 40

Nu. MAX+: upgrade Nu. Max o Neutrinos from a Muon Accelerator Comple. X (Nu. MAX+) – Neutrino Factory with 1021 straight muons decays/year @ 5 Ge. V – Muon ring at 5 Ge. V pointing neutrino beam towards Sanford – Increased proton power and/or larger detectors J. P. Delahaye 0. PIPII 8 G e. V Nu. MAX and Nu. MAx+ PIPIII Ge Dual use Linac m Preinjector 3. 75 Ge. V 650 MHz 2. 2 V 1. 0 Ge. V 325 MHz Add cooling 6. 75 Ge. V Protons 255 Me. V/c Muons Cooling Front-end Target Accumulator Buncher Main Injector Muon Beam Meeting, CERN: 18 November 2015 41

Higgs Factory o Higgs Factory: production of Higgs at 126 Ge. V CM – Collider capable of providing ~13, 500 Higgs events per year with exquisite energy resolution: direct Higgs mass and width – Possible upgrade to a Top Factory with production of up to 60000 top particles per year Higgs factory 0 PIPII. 8 J. P. Delahaye Ge V PIPIII Ge Dual use Linac m Preinjector 3. 75 Ge. V 650 MHz 2. 2 V Add 6 D cooling Bunch merge 6 D cooling Charge separator 1. 0 Ge. V 325 MHz 255 Me. V/c Muons 6. 75 Ge. V Protons 125 Ge. V 300 m RLA Compressor Accumulator Initial Cooling Buncher Front-end Target Main Muon Beam Meeting, CERN: 18 November 2015 Injector 42

High Energy Muon Collider o Multi-Te. V muon collider: – If warranted by LHC results a muon collider can reach up to 10 Te. V – Likely offers the best performance, least cost and power consumption of any lepton collider operating in the multi-Te. V regime. – Muon collider 0. PIPII 8 Ge J. P. Delahaye V PIPIII Post cooling Dual use 2. 2 acceleration Ge V 0. 25 Ge. V Final cooling 6 D cooling Bunch merge 6 D cooling Charge separator 1. 0 Ge. V 325 MHz 255 Me. V/c Muons Linac 3. 75 Ge. V 650 MHz 6. 75 Ge. V Protons RLA Compressor Accumulator Initial Cooling Buncher Front-end Target Muon Beam Meeting, CERN: 18 November 2015 RCS Muon Collider 1. 5 to 6 (10) Te. V 2. 5 to 6 km 43