LHC-friendly minimal freeze-in models Julia Harz in collaboration - - PowerPoint PPT Presentation

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LHC-friendly minimal freeze-in models Julia Harz in collaboration - - PowerPoint PPT Presentation

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LHC-friendly minimal freeze-in models Julia Harz in collaboration with G. Blanger, N. Desai, A. Goudelis, A. Lessa, J.M. No, A. Pukhov, S. Sekmen, D. Sengupta, B. Zaldivar, J. Zurita based on JHEP 1902 (2019) 186, [arXiv:1811.05478] The

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LHC-friendly minimal freeze-in models

Julia Harz

  • G. Bélanger, N. Desai, A. Goudelis, A. Lessa, J.M. No, A. Pukhov, S. Sekmen, D. Sengupta,
  • B. Zaldivar, J. Zurita

JHEP 1902 (2019) 186, [arXiv:1811.05478]

in collaboration with based on

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LHC friendly minimal freeze-in models 2 Julia Harz

The motivation

  • Minimal WIMP models are currently under tension due to no observations at

the LHC, direct or indirect detection

  • Reason could be the realisation of

(a) a complex WIMP model that can evade bounds e.g. higher DM mass, complex dark sector, coannihilation scenarios etc. (b) the freeze-in mechanism instead of freeze-out

WIMP miracle?

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LHC friendly minimal freeze-in models 3 Julia Harz

Freeze-in versus Freeze-out

Freeze-out DM = WIMP

(1) Thermal equilibrium regime (T >> m) (2) Annihilation regime (T ~ m/10) (3) Freeze-out (T ~ m/30) annihilation and production of DM in thermal equilibrium SM particles not energetic enough to create DM particles Annihilation rate falls behind expansion rate →! DM abundance

cooling down

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LHC friendly minimal freeze-in models 4 Julia Harz

Freeze-in versus Freeze-out

(1) DM not in thermal equilibrium with SM bath (3) Freeze-in DM is feebly interacting with the SM bath; abundance negligible when T falls below mass

  • f parent particle Y,

production gets Boltzmann suppressed

cooling down

Freeze-in DM = FIMP

(2) DM production DM gets produced via decay of a heavier particle Y that is in equilibrium with the SM bath

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LHC friendly minimal freeze-in models 5 Julia Harz

The model

We consider an extension of the SM by a Z2-odd real scalar singlet s (DM) and a Z2-odd vector-like SU(2) singlet fermion F (parent) Free parameters: (1,1,-1) (3,1,-2/3) (3,1,1/3) heavy lepton heavy up-type quark heavy down-type quark two separate studies:

  • heavy lepton & heavy up-type quark
  • nly 1st and 2nd generation
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LHC friendly minimal freeze-in models 6 Julia Harz

(In)direct constraints

Heavy lepton

  • Electroweak precision data

Heavy quark

  • muon lifetime
  • Lepton-Flavour-Violation

no mixing with SM fermions, SU(2)L singlets →! no relevant contributions

Ellis, Godbole, Gopalakrishna, Wells, 1404.4398

below current experimental limits

  • Running of the strong coupling

Llorente, Nachman, 1807.00894

  • LHC searches for multi-jet plus

missing energy subdominant

  • Meson mixing / K+ → π+ss

suppressed by small couplings ys

f

  • LEP

OPAL, hep-ex/0507048

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LHC friendly minimal freeze-in models 7 Julia Harz

Cosmological constraints

  • Relic density
  • Lyman-α forest

Boulebnane, Heeck, Nguyen, Teresi, 1709.07283

  • Big-Bang Nucleosynthesis

we consider 1cm < cτ < 104m T~150 MeV →! →! heavy fermions decay well before onset of BBN relic density implies for a certain reheating temperature TR a specifjc DM mass ms

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LHC friendly minimal freeze-in models 8 Julia Harz

Link to Baryogenesis

Theoretically, we know the conditions on interactions that have to be fulfjlled →! 3 Sakharov conditions

  • Baryon number violation
  • C and CP violation
  • Out-of-equilibrium

Standard Model! New physics!

zero temperature: instantons are suppressed above EWPT: sphalerons unsuppressed Baryon asymmetry: For many leptogenesis & baryogenesis models, sphalerons have to be effjcient. Hence, the reheating temperature TR has to be above Tc [or to be precise above T*(ΓSph/H < 1)].

sphalerons

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LHC friendly minimal freeze-in models 9 Julia Harz

Collider constraints

Long-lived particles (LLPs)

  • Large mass hierarchies /
  • fg-shell mediator
  • Compressed spectra
  • Small couplings /

small rates

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LHC friendly minimal freeze-in models 10 Julia Harz

1 Heavy Stable Charged Particles (HSCP)

  • charged particle F is suffjciently long lived such that it decays
  • utside of the detector

→! ionizing tracks or “R-hadrons”

CMS Coll., Searches for long-lived charged particles in pp collisions at √s=7 and 8 TeV, JHEP 07 (2013) 122, [arXiv:1305.0491] CMS Coll., Search for heavy stable charged particles with 12.9 fb−1 of 2016 data, CMS-PAS-EXO-16-036 (2016).

  • decay outside the tracker

→! tracker-only analysis

  • decay outside the muon chamber →! tracker + TOF analysis (cτ > 10m)
  • as heavier than SM particles
  • →! higher ionization energy loss / larger time-of-fmight (TOF) than SM particles
  • comparison with upper limits obtained by production of staus (leptonic model)
  • r stops (hadronic model) in a gauge mediated SUSY breaking model

8 TeV CMS analysis 18.8 fb-1 13 TeV CMS analysis 12.9 fb-1

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LHC friendly minimal freeze-in models 11 Julia Harz

1 Heavy Stable Charged Particles (HSCP)

CMS Coll., Searches for long-lived charged particles in pp collisions at √s=7 and 8 TeV, JHEP 07 (2013) 122, [arXiv:1305.0491] CMS Coll., Search for heavy stable charged particles with 12.9 fb−1 of 2016 data, CMS-PAS-EXO-16-036 (2016).

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LHC friendly minimal freeze-in models 12 Julia Harz

1 Heavy Stable Charged Particles (HSCP)

CMS Coll., Searches for long-lived charged particles in pp collisions at √s=7 and 8 TeV, JHEP 07 (2013) 122, [arXiv:1305.0491] CMS Coll., Search for heavy stable charged particles with 12.9 fb−1 of 2016 data, CMS-PAS-EXO-16-036 (2016).

  • F has smallish life time

→! re-scale the effjciency of particles that surpasses the tracker (L = 3m) / detector (L = 11 m)

  • production cross section computed by using MADGRAPH_aMC@NLO
  • charged particle F is suffjciently long lived such that it decays
  • utside of the detector

→! ionizing tracks or “R-hadrons”

  • comparison with upper limits obtained by production of staus (leptonic model)
  • r stops (hadronic model)
  • decay outside the tracker

→! tracker-only analysis

  • decay outside the muon chamber →! tracker + TOF analysis (cτ > 10m)
  • as heavier than SM particles
  • →! higher ionization energy loss / larger time-of-fmight (TOF) than SM particles
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LHC friendly minimal freeze-in models 13 Julia Harz

1 Heavy Stable Charged Particles (HSCP)

  • 13 TeV data most constraining for large cτ, in particular with TOF
  • 8 TeV data more constraining for smaller cτ, due to more integrated luminosity

Leptonic model:

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LHC friendly minimal freeze-in models 14 Julia Harz

1 Heavy Stable Charged Particles (HSCP)

  • heavy hadrons (R-hadrons) can fmip their charge when traversing the detector
  • tracker-only selection may fail tracker+TOF selection

Hadronic model:

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LHC friendly minimal freeze-in models 15 Julia Harz

2 Disappearing Tracks (DT)

  • isolated track reconstructed in the pixel and strip detectors

without any hit in the outer tracker (CMS) or a track with only pixel hits (ATLAS)

  • ATLAS can reconstruct tracks down to 12 cm (new innermost

tracking layer “IBL”); CMS 25-30 cm

  • CMS has better coverage for longer life times cτ > 1m

13 TeV ATLAS analysis 36.1 fb-1 13 TeV CMS analysis 138.4 fb-1

  • AMSB motivated scenario with mass degenerate

lightest chargino and neutralino

ATLAS Coll., Search for long-lived charginos based on a disappearing-track signature in pp collisions at √s= 13TeV with the ATLAS detector, JHEP06(2018) 022, [arXiv:1712.02118] CMS Coll., Search for disappearing tracks as a signature of new long-lived particles in proton-proton collisions at √s=13 TeV, arXiv:1804.07321

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LHC friendly minimal freeze-in models 16 Julia Harz

2 Disappearing Tracks (DT)

ATLAS Coll., Search for long-lived charginos based on a disappearing-track signature in pp collisions at √s= 13TeV with the ATLAS detector, JHEP06(2018) 022, [arXiv:1712.02118] CMS Coll., Search for disappearing tracks as a signature of new long-lived particles in proton-proton collisions at √s=13 TeV, arXiv:1804.07321

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LHC friendly minimal freeze-in models 17 Julia Harz

2 Disappearing Tracks (DT)

  • isolated track reconstructed in the pixel and strip detectors

without any hit in the outer tracker (CMS) or a track with only pixel hits (ATLAS)

  • ATLAS can reconstruct tracks down to 12 cm (new innermost

tracking layer “IBL”); CMS 25-30 cm

  • CMS has better coverage for longer life times cτ > 1m

13 TeV ATLAS analysis 36.1 fb-1 13 TeV CMS analysis 138.4 fb-1

  • AMSB motivated scenario with mass degenerate

lightest chargino and neutralino

ATLAS Coll., Search for long-lived charginos based on a disappearing-track signature in pp collisions at √s= 13TeV with the ATLAS detector, JHEP06(2018) 022, [arXiv:1712.02118] CMS Coll., Search for disappearing tracks as a signature of new long-lived particles in proton-proton collisions at √s=13 TeV, arXiv:1804.07321

  • Recasting of two analyses of ATLAS and CMS
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LHC friendly minimal freeze-in models 18 Julia Harz

2 Disappearing Tracks (DT)

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LHC friendly minimal freeze-in models 19 Julia Harz

3 Displaced leptons (DL) / Vertices (DV) + MET

  • F can decay into both muon and electron

8 TeV CMS analysis 19.7 fb-1 13 TeV CMS analysis 2.6 fb-1

CMS Coll., Search for Displaced Supersymmetry in events with an electron and a muon with large impact parameters,

  • Phys. Rev. 1240 Lett. 114 (2015), no. 6 061801, [arXiv:1409.4789]

CMS Coll., Search for displaced leptons in the e-mu channel, CMS-PAS-EXO-16-022 (2016).

  • CMS search for non-prompt RPV violating

SUSY decays into e/μ fjnal state

  • search optimized for lifetimes longer than

prompt searches, but shorter than long- lived BSM signatures

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3 Displaced leptons (DL) / Vertices (DV) + MET

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LHC friendly minimal freeze-in models 21 Julia Harz

3 Displaced leptons (DL) / Vertices (DV) + MET

  • F can decay and hadronize into R-hadrons

13 TeV ATLAS analysis 32.8 fb-1

ATLAS Coll., Search for long-lived, massive particles in events with displaced vertices and missing transverse momentum in √s= 13 TeV pp-collisions with the ATLAS detector, Phys. Rev.D97(2018), no. 5 052012, [arXiv:1710.04901]

  • ATLAS search for a simplifjed split-

SUSY model

  • Pythia 8 hadronization + 50k MC

events per given mF-cτ combination

  • prompt multi-jet + MET CMS 13 TeV

35.9 fb-1 analysis weaker

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LHC friendly minimal freeze-in models 22 Julia Harz

3 Displaced leptons (DL) / Vertices (DV) + MET

ATLAS Coll., Search for long-lived, massive particles in events with displaced vertices and missing transverse momentum in √s= 13 TeV pp-collisions with the ATLAS detector, Phys. Rev.D97(2018), no. 5 052012, [arXiv:1710.04901]

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LHC friendly minimal freeze-in models 23 Julia Harz

Combined results – leptonic model

Overlay with DM expectations:

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Combined results – leptonic model

Overlay with DM expectations: high reheating temperature (exact value does not impact result)

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Combined results – leptonic model

Overlay with DM expectations: smallest DM mass in agreement with Lyman-α

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Probing freeze-in dark matter and baryogenesis

Assuming that DM is mostly generated by decays of the parent F, we can relate the relic abundance with the parent particle life time Possibility to falsify baryogenesis / leptogenesis models that rely on efgective sphaleron interactions in case of an observation indicating a too small reheating temperature

  • ms=12keV is the smallest possible mass

from Lyman-α constraints ms > 12 keV would imply even smaller TR

  • If s made up not all of the DM, a smaller TR

would be implied →! most conservative choice

TR=50GeV TR=100GeV TR=160GeV

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LHC friendly minimal freeze-in models 27 Julia Harz

Combined results – hadronic model

Overlay with DM expectations:

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LHC friendly minimal freeze-in models 28 Julia Harz

Conclusions

  • Defjnition of an “LHC friendly” minimal freeze-in model with heavy quarks
  • r leptons
  • Considering all indirect and cosmological constraints
  • Model Lagrangian (FeynRules, UFO, CalcHEP) available

http://feynrules.irmp.ucl.ac.be/wiki/FICPLHC

  • Possible link to baryogenesis
  • Recasting of all relevant LHC searches
  • More accurate studies would need input of experimental collaborations
  • Dedicated studies for proposed set of models highly interesting
  • New: “Searching for long-lived particles beyond the Standard Model at

the Large Hadron Collider” [hep-ph/1903.04497]

  • Neat interplay of collider, cosmological and indirect constraints
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LHC friendly minimal freeze-in models 29 Julia Harz

Thank you for your attention!

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Extrapolation to High Luminosity LHC

High Lumi LHC could almost close the parameter space in which baryogenesis models would be in tension in case of an observation.

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Extrapolation to High Luminosity LHC