1. Neutrino Physics with SHiP
Eric van Herwijnen
5 August 2016

2. SHiP’s objective
Standard Model consistent, no deviations found from flavour physics or direct searches at the LHC
Experimental facts of incompleteness:
Neutrino masses and oscillations
Dark Matter
Excess of matter over anti-matter (“Baryon Asymmetry of the Universe, BAU”)
No clear theoretical guidance on the scale of new physics
Many theoretical possibilities
SHiP can give experimental support for these models, or exclude them
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Neutrino Physics with SHiP

3. E.g. neutrino masses & see-saw
Generic see-saw: 𝒎 ν = 𝒎 𝑫 𝟐 𝑴 ( 𝒎 𝑫 = Dirac mass, 𝑀= Majorana/Heavy Neutral Lepton mass)
𝒎 𝑫 ~ 𝒀 𝜶 <𝝋> typical value of Dirac mass term
For 𝑀=𝟏 𝑮𝒆𝑽, 𝒎 ν ~ 𝟎.𝟎𝟓 𝒆𝑽→ 𝒎 𝑫 ~𝟏𝟎 𝒌𝒆𝑽, 𝒀 ~ 𝟏𝟎 −𝟕
(c.f. 𝒀 𝒆 ~ 𝟏𝟎 −𝟏 )
No see-saw: neutrino masses too large
Small neutrino mass suggests very large 𝑀 or a very small 𝒀 𝑰𝜶
Abazjan et al
8/5/2016
Neutrino Physics with SHiP

4. Another example: Dark Matter
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Neutrino Physics with SHiP

5. Constraints on U2 and HNL mass
Coupling to active neutrinos
𝑼 𝟐 = 𝑼 𝒆 𝟐 + 𝑼 𝝁 𝟐 + 𝑼 𝝉 𝟐
(𝑼 𝜶 𝟐 ≡ <𝝋 > 𝟐 𝒀 𝜶 𝟐 𝑴 𝟐 , 𝑽 𝝁𝟒 𝟐 = 𝑼 𝝁 𝟐 )
Constraints on 𝑴 𝑯𝑵𝑳 < 𝑴 𝑲
Mass range above charm poorly explored
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Neutrino Physics with SHiP

6. Constraints from DM searches
104
Dark matter not seen in mass range M(DM) > few GeV
Light DM naturally accommodated in ‘Hidden Sector’ models
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Neutrino Physics with SHiP

7. Mediators (portals) to the Hidden Sector
𝓛 = 𝓛 𝑺𝑴 + 𝓛 𝑴𝒆𝒅𝒊𝒂𝒕𝒐𝒓 + 𝓛 𝑯𝑺
Visible sector
Hidden sector
Mediator/portals to the HS:
Vector, scalar, axial, neutrino
HS production and decay rates strongly suppressed
Production branching ratios 𝐎( 𝟏𝟎 −𝟏𝟎 ), 𝐜𝝉: 𝐎(𝐤𝐦)
Travel unperturbed through matter
Models
Final States
HNL, SUSY neutralino
𝑙 + 𝜋 − , 𝑙 + 𝐾 − , 𝑙 + 𝜌 − 𝜌 + → 𝜋 + 𝜋 0
Vector, scalar, axion portals, SUSY sgoldstino
𝑙 + 𝑙 −
HNL, SUSY neutralino, axino
𝑙 + 𝑙 − ν
Axion portal, SUSY sgoldstino 𝛾𝛾
SUSY sgoldstino
𝜋 0 𝜋 0
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Neutrino Physics with SHiP

8. νMSM: T. Asaka, M. Shaposhnikov
Adding three right-handed Majorana HNLs: 𝑵 𝟏 , 𝑵 𝟐 and 𝑵 𝟑 :
𝑵 𝟏 light, 𝑶(𝟏 𝒌𝒆𝑽) : Dark Matter candidate
𝑵 𝟐,𝟑 degenerate, 𝑶 𝟏𝟎𝟎 𝑴𝒆𝑽−𝒇𝒆𝒘 𝑮𝒆𝑽 : neutrino masses via see-saw
𝑵 𝟐,𝟑 leptogenesis →baryogenesis by increased CP violation
PL B620 (2005) 17
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Neutrino Physics with SHiP

9. 𝐇𝐍𝐋 production and decay
Produce HNL in semi-leptonic decays from charm ( 𝑴 𝑯𝑵𝑳 <𝟐 𝑮𝒆𝑽) and beauty ( 𝑴 𝑯𝑵𝑳 <𝟓 𝑮𝒆𝑽)
Very weak HNL - active neutrino mixing → 𝝉 (~ 𝑼 −𝟐 )>𝟏𝟎𝝁𝒔, 𝐜𝝉: 𝐎(𝐤𝐦)
Production:
𝑩𝒓 𝑫→𝑯𝑵𝑳 𝑿)~ 𝟏𝟎 −𝟖 − 𝟏𝟎 −𝟏𝟐
𝑩𝒓 𝑩→𝑯𝑵𝑳 𝑿)~ 𝟏𝟎 −𝟏𝟐 − 𝟏𝟎 −𝟏𝟔
Decay:
𝑩𝒓(𝑯𝑵𝑳→𝝁 𝒆 𝝅)~𝟎.𝟏−𝟓𝟎%)
𝑩𝒓(𝑯𝑵𝑳→𝝁 𝒆 𝝆)~𝟎.𝟓−𝟐𝟎%)
𝑩𝒓(𝑯𝑵𝑳→𝝁𝒆 ν 𝒆 )~𝟏−𝟏𝟎%)
HNL
HNL
HNL
HNL
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Neutrino Physics with SHiP

10. Experimental Requirements
Search for HS in Heavy Flavour decays
Charm and Beauty cross sections strongly energy dependent
@ LHC ( 𝒔 =𝟏𝟒 𝑻𝒆𝑽): in 3-4 years ~𝟐 ×𝟏𝟎 𝟏𝟔 𝒄 𝒄 in 𝟒𝝅
SPS (400 GeV, 𝒔 =𝟐𝟕 𝑮𝒆𝑽), 𝟐×𝟏𝟎 𝟐𝟎 p.o.t, 3-4 years ~𝟖×𝟏𝟎 𝟏𝟕 𝒄 𝒄
Fermilab: (120 GeV), 𝟏𝟎× smaller 𝝈 𝒄 𝒄
HS from charm & beauty have significant Pt: place detector as close as possible to target
Full reconstruction and PID
SHiP TP
𝝁 shield to suppress background
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Neutrino Physics with SHiP

11. Zero background detector
Target
Active Muon Shield
Magnet
Muon Magnetic Spectrometer
Neutrino Emulsion Target and Target Tracker
Drift Tube Tracker
Upstream Veto Tagger
Straw Veto Tagger
Surround Background Tagger
HS Vacuum Vessel
HS Spectrometer Magnet
Spectrometer Timing Detector
Electromagnetic/Hadronic Calorimeter
Spectrometer Straw Tracker
Muon Detector
Zero background detector
~100m
𝟏𝟎 −𝟔 bar vacuum:
remove ~𝟐× 𝟏𝟎 𝟒 ν ints
B=0.65 Tm
𝑵 𝟐,𝟑
Hadron absorber 5m
10m
𝝁 −
𝝅 +
Straw trackers: measure p
for decay vtx reco
NA62 straw tubes
𝝈 𝒙 =𝟏𝟐𝟎𝝁𝒎, 𝝈 𝒑 𝒑 ~𝟎.𝟓%
EM calo: 𝒆, 𝜋 𝟎 ,𝜸 like LHCb
Upstream Veto: 𝝁, ν, K, Λ
𝒆,𝝅,𝜸
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Neutrino Physics with SHiP

12. HNL signal yields χ 𝒑𝒑→𝒄 𝒄 =𝟏.𝟕× 𝟏𝟎 −𝟑 , χ 𝒑𝒑→𝒃𝒃 =𝟏.𝟔× 𝟏𝟎 −𝟕
χ 𝒑𝒑→𝒄 𝒄 =𝟏.𝟕× 𝟏𝟎 −𝟑 , χ 𝒑𝒑→𝒃𝒃 =𝟏.𝟔× 𝟏𝟎 −𝟕
𝓟 𝒗𝒕𝒙 - probability decay vertex inside SHiP fiducial volume
𝓐 𝒕𝒐𝒕 - detector acceptance for all HNL final states
𝑫→𝝁 𝑯𝑵𝑳 𝑿, 𝑯𝑵𝑳→𝝁𝝅, 𝑵 𝒑.𝒐.𝒕 =𝟐× 𝟏𝟎 𝟐𝟎 (5 years running)
𝑼 𝝁 𝟐
𝑴 𝑯𝑵𝑳
𝒏(𝑯𝑵𝑳)
𝟏𝟎 −𝟖
1 GeV
120
𝟏𝟎 −𝟕
12000
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Neutrino Physics with SHiP

13. Sensitivities SHiP probes a unique range of couplings and masses HNL
Dark photon
Hidden scalars
SHiP probes a unique range of couplings and masses
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Neutrino Physics with SHiP

14. ν 𝝉 detector ν 𝝉 least known SM particle; ν 𝝉 not yet observed
Donut ~7, Opera 5 ν 𝝉 candidates
𝟓.𝟕 × 𝟏𝟎 𝟏𝟓 ν 𝝉 and ν 𝝉 @SHiP over 5 yrs
via 𝒑𝑵→𝑿 𝑫 𝒔 →𝝉 ν 𝝉
“mini-Opera” between μ-shield and decay vessel
magnet
emulsion
μ-shield
decay vessel
μ-spectrometer
~𝟏𝟎 𝟒 ( 𝟏𝟎 𝟑 ) ν 𝝉 ( ν 𝝉 ) , 𝟏𝟎 𝟓 ν 𝒆 ( ν 𝒆 ), 𝟏𝟎 𝟔 ν 𝝁 ( ν 𝝁 ), interactions
First observation of ν 𝝉 (B-field in emulsion)
First independent measurement of 𝝈 ν 𝝉 and 𝝈 ν 𝝉
8/5/2016
Neutrino Physics with SHiP

15. Status of SHiP
Technical Proposal submitted and positively reviewed by the SPSC
Detector optimization studies ongoing
CERN management encourages SHiP to perform Comprehensive Design Study in the context of the “Physics Beyond Colliders” study group
Kick-off workshop at CERN 6/7 Sept.
Study to be completed for the next update of the European Strategy for Particle Physics ( )
Decision on approval following conclusion of the update
Construction:
Start of data taking: 2026
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Neutrino Physics with SHiP

16. Conclusions
SHiP has discovery potential in unexplored domain of weakly interacting particles with masses 𝑶 𝑮𝒆𝑽
Improve current limits by several orders of magnitude
Search for:
HNL
Dark Photons
Hidden scalars
Axions
SUSY
And a unique detector for neutrino/charm physics
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Neutrino Physics with SHiP

17. SHiP @ CERN (400 GeV) vs FNAL (120 Gev)
Available beam time
20% ?
Assumed beam time
80% (to compare)
80%
pot/yr
(for 1s spill length; more pot: target unstable)
Spill length 1s
10𝜇𝑠 in 1.2 s cycle: 10 orders of magnitude more combinatorial bg
Length of decay volume
62m
40m
𝝈 𝒄 𝒄 , 𝝈 𝒑 𝒑
1, 1
0.16, 0.95
HNL yield (0.6x0.16/0.95x7) 1
0.7
Dark photon yield
slightly better
Dark scalar yield
0.0025
ν 𝝉 , ν 𝝉 cc interactions
0.14
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Neutrino Physics with SHiP