Elena Graverini Particle Physics Seminar University of Birmingham - - PowerPoint PPT Presentation

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Elena Graverini Particle Physics Seminar University of Birmingham March 7, 2018 E. Graverini (Universitt Zrich) SHiP: Search for Hidden Particles 1/45 Search for Hidden Particles 1 / 45 Introduction 2/45 matter-antimatter

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SLIDE 1

Search for Hidden Particles Elena Graverini

Particle Physics Seminar — University of Birmingham March 7, 2018

  • E. Graverini (Universität Zürich)

SHiP: Search for Hidden Particles 1/45

1/45

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SLIDE 2

Introduction

Model e, µ, τ, γ Jets Emiss T
  • L dt[fb−1]
Mass limit Reference Inclusive Searches 3rd gen. ˜ g med. 3rd gen. squarks direct production EW direct Long-lived particles RPV Other MSUGRA/CMSSM 0-3 e, µ /1-2 τ 2-10 jets/3 b Yes 20.3 m(˜ q)=m(˜ g) 1507.05525 1.8 TeV ˜ q, ˜ g ˜ q˜ q, ˜ q→q˜ χ0 1 2-6 jets Yes 20.3 m(˜ χ0 1)=0 GeV, m(1st gen. ˜ q)=m(2nd gen. ˜ q) 1405.7875 850 GeV ˜ q ˜ q˜ q, ˜ q→q˜ χ0 1 (compressed) mono-jet 1-3 jets Yes 20.3 m(˜ q)-m(˜ χ0 1)<10 GeV 1507.05525 100-440 GeV ˜ q ˜ q˜ q, ˜ q→q(ℓℓ/ℓν/νν)˜ χ0 1 2 e, µ (off-Z) 2 jets Yes 20.3 m(˜ χ0 1)=0 GeV 1503.03290 780 GeV ˜ q ˜ g˜ g, ˜ g→q¯ q˜ χ0 1 2-6 jets Yes 20.3 m(˜ χ0 1)=0 GeV 1405.7875 1.33 TeV ˜ g ˜ g˜ g, ˜ g→qq˜ χ± 1 →qqW± ˜ χ0 1 0-1 e, µ 2-6 jets Yes 20 m(˜ χ0 1)<300 GeV, m(˜ χ±)=0.5(m(˜ χ0 1)+m(˜ g)) 1507.05525 1.26 TeV ˜ g ˜ g˜ g, ˜ g→qq(ℓℓ/ℓν/νν)˜ χ0 1 2 e, µ 0-3 jets
  • 20
m(˜ χ0 1)=0 GeV 1501.03555 1.32 TeV ˜ g GMSB (˜ ℓ NLSP) 1-2 τ + 0-1 ℓ 0-2 jets Yes 20.3 tanβ >20 1407.0603 1.6 TeV ˜ g GGM (bino NLSP) 2 γ
  • Yes
20.3 cτ(NLSP)<0.1 mm 1507.05493 1.29 TeV ˜ g GGM (higgsino-bino NLSP) γ 1 b Yes 20.3 m(˜ χ0 1)<900 GeV, cτ(NLSP)<0.1 mm, µ<0 1507.05493 1.3 TeV ˜ g GGM (higgsino-bino NLSP) γ 2 jets Yes 20.3 m(˜ χ0 1)<850 GeV, cτ(NLSP)<0.1 mm, µ>0 1507.05493 1.25 TeV ˜ g GGM (higgsino NLSP) 2 e, µ (Z) 2 jets Yes 20.3 m(NLSP)>430 GeV 1503.03290 850 GeV ˜ g Gravitino LSP mono-jet Yes 20.3 m( ˜ G)>1.8 × 10−4 eV, m(˜ g)=m(˜ q)=1.5 TeV 1502.01518 865 GeV F1/2 scale ˜ g˜ g, ˜ g→b¯ b˜ χ0 1 3 b Yes 20.1 m(˜ χ0 1)<400 GeV 1407.0600 1.25 TeV ˜ g ˜ g˜ g, ˜ g→t¯ t ˜ χ0 1 7-10 jets Yes 20.3 m(˜ χ0 1) <350 GeV 1308.1841 1.1 TeV ˜ g ˜ g˜ g, ˜ g→t¯ t ˜ χ0 1 0-1 e, µ 3 b Yes 20.1 m(˜ χ0 1)<400 GeV 1407.0600 1.34 TeV ˜ g ˜ g˜ g, ˜ g→b¯ t ˜ χ+ 1 0-1 e, µ 3 b Yes 20.1 m(˜ χ0 1)<300 GeV 1407.0600 1.3 TeV ˜ g ˜ b1 ˜ b1, ˜ b1→b˜ χ0 1 2 b Yes 20.1 m(˜ χ0 1)<90 GeV 1308.2631 100-620 GeV ˜ b1 ˜ b1 ˜ b1, ˜ b1→t˜ χ± 1 2 e, µ (SS) 0-3 b Yes 20.3 m(˜ χ± 1 )=2 m(˜ χ0 1) 1404.2500 275-440 GeV ˜ b1 ˜ t1˜ t1, ˜ t1→b˜ χ± 1 1-2 e, µ 1-2 b Yes 4.7/20.3 m(˜ χ± 1 ) = 2m(˜ χ0 1), m(˜ χ0 1)=55 GeV 1209.2102, 1407.0583 110-167 GeV ˜ t1 230-460 GeV ˜ t1 ˜ t1˜ t1, ˜ t1→Wb˜ χ0 1 or t˜ χ0 1 0-2 e, µ 0-2 jets/1-2 b Yes 20.3 m(˜ χ0 1)=1 GeV 1506.08616 90-191 GeV ˜ t1 210-700 GeV ˜ t1 ˜ t1˜ t1, ˜ t1→c˜ χ0 1 mono-jet/c-tag Yes 20.3 m(˜ t1)-m(˜ χ0 1)<85 GeV 1407.0608 90-240 GeV ˜ t1 ˜ t1˜ t1(natural GMSB) 2 e, µ (Z) 1 b Yes 20.3 m(˜ χ0 1)>150 GeV 1403.5222 150-580 GeV ˜ t1 ˜ t2˜ t2, ˜ t2→˜ t1 + Z 3 e, µ (Z) 1 b Yes 20.3 m(˜ χ0 1)<200 GeV 1403.5222 290-600 GeV ˜ t2 ˜ ℓL,R ˜ ℓL,R, ˜ ℓ→ℓ ˜ χ0 1 2 e, µ Yes 20.3 m(˜ χ0 1)=0 GeV 1403.5294 90-325 GeV ˜ ℓ ˜ χ+ 1 ˜ χ− 1 , ˜ χ+ 1 →˜ ℓν(ℓ˜ ν) 2 e, µ Yes 20.3 m(˜ χ0 1)=0 GeV, m(˜ ℓ, ˜ ν)=0.5(m(˜ χ± 1 )+m(˜ χ0 1)) 1403.5294 140-465 GeV ˜ χ± 1 ˜ χ+ 1 ˜ χ− 1 , ˜ χ+ 1 →˜ τν(τ˜ ν) 2 τ
  • Yes
20.3 m(˜ χ0 1)=0 GeV, m(˜ τ, ˜ ν)=0.5(m(˜ χ± 1 )+m(˜ χ0 1)) 1407.0350 100-350 GeV ˜ χ± 1 ˜ χ± 1 ˜ χ0 2→˜ ℓLν˜ ℓLℓ(˜ νν), ℓ˜ ν˜ ℓLℓ(˜ νν) 3 e, µ Yes 20.3 m(˜ χ± 1 )=m(˜ χ0 2), m(˜ χ0 1)=0, m(˜ ℓ, ˜ ν)=0.5(m(˜ χ± 1 )+m(˜ χ0 1)) 1402.7029 700 GeV ˜ χ± 1 , ˜ χ0 2 ˜ χ± 1 ˜ χ0 2→W ˜ χ0 1Z ˜ χ0 1 2-3 e, µ 0-2 jets Yes 20.3 m(˜ χ± 1 )=m(˜ χ0 2), m(˜ χ0 1)=0, sleptons decoupled 1403.5294, 1402.7029 420 GeV ˜ χ± 1 , ˜ χ0 2 ˜ χ± 1 ˜ χ0 2→W ˜ χ0 1h ˜ χ0 1, h→b¯ b/WW/ττ/γγ e, µ, γ 0-2 b Yes 20.3 m(˜ χ± 1 )=m(˜ χ0 2), m(˜ χ0 1)=0, sleptons decoupled 1501.07110 250 GeV ˜ χ± 1 , ˜ χ0 2 ˜ χ0 2 ˜ χ0 3, ˜ χ0 2,3 →˜ ℓRℓ 4 e, µ Yes 20.3 m(˜ χ0 2)=m(˜ χ0 3), m(˜ χ0 1)=0, m(˜ ℓ, ˜ ν)=0.5(m(˜ χ0 2)+m(˜ χ0 1)) 1405.5086 620 GeV ˜ χ0 2,3 GGM (wino NLSP) weak prod. 1 e, µ + γ
  • Yes
20.3 cτ<1 mm 1507.05493 124-361 GeV ˜ W Direct ˜ χ+ 1 ˜ χ− 1 prod., long-lived ˜ χ± 1
  • Disapp. trk
1 jet Yes 20.3 m(˜ χ± 1 )-m(˜ χ0 1)∼160 MeV, τ(˜ χ± 1 )=0.2 ns 1310.3675 270 GeV ˜ χ± 1 Direct ˜ χ+ 1 ˜ χ− 1 prod., long-lived ˜ χ± 1 dE/dx trk
  • Yes
18.4 m(˜ χ± 1 )-m(˜ χ0 1)∼160 MeV, τ(˜ χ± 1 )<15 ns 1506.05332 482 GeV ˜ χ± 1 Stable, stopped ˜ g R-hadron 1-5 jets Yes 27.9 m(˜ χ0 1)=100 GeV, 10 µs<τ(˜ g)<1000 s 1310.6584 832 GeV ˜ g Stable ˜ g R-hadron trk
  • 19.1
1411.6795 1.27 TeV ˜ g GMSB, stable ˜ τ, ˜ χ0 1→˜ τ(˜ e, ˜ µ)+τ(e, µ) 1-2 µ
  • 19.1
10<tanβ<50 1411.6795 537 GeV ˜ χ0 1 GMSB, ˜ χ0 1→γ ˜ G, long-lived ˜ χ0 1 2 γ
  • Yes
20.3 2<τ(˜ χ0 1)<3 ns, SPS8 model 1409.5542 435 GeV ˜ χ0 1 ˜ g˜ g, ˜ χ0 1→eeν/eµν/µµν
  • displ. ee/eµ/µµ
  • 20.3
7 <cτ(˜ χ0 1)< 740 mm, m(˜ g)=1.3 TeV 1504.05162 1.0 TeV ˜ χ0 1 GGM ˜ g˜ g, ˜ χ0 1→Z ˜ G
  • displ. vtx + jets
  • 20.3
6 <cτ(˜ χ0 1)< 480 mm, m(˜ g)=1.1 TeV 1504.05162 1.0 TeV ˜ χ0 1 LFV pp→˜ ντ + X, ˜ ντ→eµ/eτ/µτ eµ,eτ,µτ
  • 20.3
λ′ 311=0.11, λ132/133/233=0.07 1503.04430 1.7 TeV ˜ ντ Bilinear RPV CMSSM 2 e, µ (SS) 0-3 b Yes 20.3 m(˜ q)=m(˜ g), cτLS P<1 mm 1404.2500 1.35 TeV ˜ q, ˜ g ˜ χ+ 1 ˜ χ− 1 , ˜ χ+ 1 →W ˜ χ0 1, ˜ χ0 1→ee˜ νµ, eµ˜ νe 4 e, µ
  • Yes
20.3 m(˜ χ0 1)>0.2×m(˜ χ± 1 ), λ1210 1405.5086 750 GeV ˜ χ± 1 ˜ χ+ 1 ˜ χ− 1 , ˜ χ+ 1 →W ˜ χ0 1, ˜ χ0 1→ττ˜ νe, eτ˜ ντ 3 e, µ + τ
  • Yes
20.3 m(˜ χ0 1)>0.2×m(˜ χ± 1 ), λ1330 1405.5086 450 GeV ˜ χ± 1 ˜ g˜ g, ˜ g→qqq 6-7 jets
  • 20.3
BR(t)=BR(b)=BR(c)=0% 1502.05686 917 GeV ˜ g ˜ g˜ g, ˜ g→q˜ χ0 1, ˜ χ0 1 → qqq 6-7 jets
  • 20.3
m(˜ χ0 1)=600 GeV 1502.05686 870 GeV ˜ g ˜ g˜ g, ˜ g→˜ t1t, ˜ t1→bs 2 e, µ (SS) 0-3 b Yes 20.3 1404.250 850 GeV ˜ g ˜ t1˜ t1, ˜ t1→bs 2 jets + 2 b
  • 20.3
ATLAS-CONF-2015-026 100-308 GeV ˜ t1 ˜ t1˜ t1, ˜ t1→bℓ 2 e, µ 2 b
  • 20.3
BR(˜ t1→be/µ)>20% ATLAS-CONF-2015-015 0.4-1.0 TeV ˜ t1 Scalar charm, ˜ c→c˜ χ0 1 2 c Yes 20.3 m(˜ χ0 1)<200 GeV 1501.01325 490 GeV ˜ c Mass scale [TeV] 10−1 1 √s = 7 TeV √s = 8 TeV ATLAS SUSY Searches* - 95% CL Lower Limits Status: July 2015 ATLAS Preliminary √s = 7, 8 TeV *Only a selection of the available mass limits on new states or phenomena is shown. All limits quoted are observed minus 1σ theoretical signal cross section uncertainty.
  • Higgs found! SM complete and consistent up to Plank scale. But...

– matter-antimatter asymmetry – neutrino masses/mixing – dark matter – flavour anomalies... New physics?

  • NO smoking gun in direct searches up to ∼5 TeV...
  • E. Graverini (Universität Zürich)

SHiP: Search for Hidden Particles 2/45

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SLIDE 3

What is the energy scale of new physics?

➜ Neutrino masses and oscillations: Right Handed see-saw neutrino masses from 1 eV to 1015 GeV ➜ Dark matter: From 10−22 eV (super-light scalar) to ≥ 1020 GeV (wimpzilla, Q-ball) ➜ Baryogenesis: Mass of new particle from 10 MeV to 1015 GeV ➜ Higgs mass hierarchy: SUSY, GUT, composite Higgs, large extra dimensions theories require the presence of new particles above the Fermi scale.

  • E. Graverini (Universität Zürich)

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SLIDE 4

Where is new physics? Experimental approach

Richard J acobsson and D aniel D

  • m

inguez

➜ Unsolved problems = ⇒ new particles ➜ Why didn’t we detect them? Too heavy or too weakly interacting

  • E. Graverini (Universität Zürich)

SHiP: Search for Hidden Particles 4/45

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SLIDE 5

Hidden particles

Lworld = LSM + Lportal + LHS

  • Hidden Sector (HS) naturally accomodates Dark Matter

– it may have a rich structure

  • Interaction with visible sector (SM) proceeds through mediators
  • HS processes very strongly suppressed relative to SM

– production BRs ∼ 10−10 – very weak interaction with matter – very long-lived objects!

  • Can search HS through decays to visible particles
  • E. Graverini (Universität Zürich)

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SLIDE 6

SHiP: Search for Hidden Particles

SHiP is a new proposed intensity-frontier experiment aiming to search for HNLs and other neutral hidden particles with mass up to O(10) GeV and extremely weak couplings. Aims to be a zero background experiment! Facility also ideally suited for studying ντ and ¯ ντ properties and testing lepton flavour universality by comparing interactions

  • f µ and τ neutrinos.

Hidden Sector decay volume ν/iSHiP Hidden Sector detector T a r g e t a n d h a d r

  • n

a b s

  • r

b e r μ sweeping magnets

  • E. Graverini (Universität Zürich)

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SLIDE 7

Outline

➜ The SHiP experiment – Detector system – Background strategies ➜ Physics with ντ ➜ The search for Heavy Neutral Leptons – Evaluating SHiP sensitivity ➜ Probing the Hidden Sector – Vector portal – Scalar portal – Axion-like particles ➜ Conclusions

  • E. Graverini (Universität Zürich)

SHiP: Search for Hidden Particles 7/45

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slide-8
SLIDE 8

Outline

➜ The SHiP experiment – Detector system – Background strategies ➜ Physics with ντ ➜ The search for Heavy Neutral Leptons – Evaluating SHiP sensitivity ➜ Probing the Hidden Sector – Vector portal – Scalar portal – Axion-like particles ➜ Conclusions

  • E. Graverini (Universität Zürich)

SHiP: Search for Hidden Particles 7/45

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slide-9
SLIDE 9

Experimental requirements

➜ Hidden particles production in charm (and beauty) charm

– Intense proton beam from the SPS (400 GeV) – Very dense target of 10 × λint

  • abundant production of heavy flavours
  • reduce neutrino production from π and K decays

➜ decay of hidden particles: target beam hidden particle visible decay

– large decay volume followed by spectrometer, calorimeter, PID – shielding from SM particles: hadron absorber + VETO detectors (*)

➜ τ neutrinos:

– Nτ = 4Np (σc¯

c/σpN) fDs × Br(Ds → τ) ≃ 6 × 1015

TEASER: sensitivity

targets!

– distinguish ντ / ¯ ντ: magnetized emulsion target + high-res tracker

  • E. Graverini (Universität Zürich)

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SLIDE 10

Experimental requirements

➜ Hidden particles production in charm (and beauty) charm

– Intense proton beam from the SPS (400 GeV) – Very dense target of 10 × λint

  • abundant production of heavy flavours
  • reduce neutrino production from π and K decays

➜ decay of hidden particles: target beam hidden particle visible decay

– large decay volume followed by spectrometer, calorimeter, PID – shielding from SM particles: hadron absorber + VETO detectors (*)

➜ τ neutrinos:

– Nτ = 4Np (σc¯

c/σpN) fDs × Br(Ds → τ) ≃ 6 × 1015

TEASER: τ → 3µ sensitivity ∼ 10−10/√Ntargets!

– distinguish ντ / ¯ ντ: magnetized emulsion target + high-res tracker

  • E. Graverini (Universität Zürich)

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SLIDE 11

...and the muons (*)?

Residual µ flux after the hadron absorber is dangerous: – background for HS physics – ageing of ντ emulsions – active muon shield based on sweeping magnets – “conical”-shaped vessel

  • E. Graverini (Universität Zürich)

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SLIDE 12

History

2013:

– submission of the EOI (October, 16 authors) ➝ arXiv:1310.1762

2014:

– SPSC discusses EOI (January) – 1st workshop (June, 100 participants)

2015:

– submission of TP (April, 233 authors)

➝ arXiv:1504.04956

– submission of PP (April, 85 authors)

➝ arXiv:1504.04855

– discussion with SPSC referees

2016:

– endorsement by the SPSC (February)

2014–today:

– 12 collaboration meetings, workshops...

  • E. Graverini (Universität Zürich)

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