Neutrinos, The Standard Model, and Beyond
Mikhail Shaposhnikov
June, 2019
Erice, June 2019 – p. 1 Outline
Setting up the scene: the Standard Model and the LHC
Problems of the Standard Model Neutrino masses and oscillations Dark Matter Baryon asymmetry of the Universe
Heavy Neutral Leptons (HNL’s or sterile neutrinos)
Dark matter from HNL
Baryon asymmetry of the Universe from HNL
How to search for HNL
Conclusions
Erice, June 2019 – p. 2 Setting up the scene: the Standard Model and the LHC
Erice, June 2019 – p. 3 The Standard Model was invented back in 1967 and completed with the discovery of the Higgs boson at the LHC 45 year later
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Erice, June 2019 – p. 4 Searches for new physics, SUSY
ATLAS SUSY Searches* - 95% CL Lower Limits ATLAS Preliminary Status: ICHEP 2014 √s =7,8TeV miss 1 e,µ,τ, γ E L dt[fb− ] Model Jets T ! Mass limit Reference
MSUGRA/CMSSM 0 2-6 jets Ye s 20.3 q˜, g˜ 1.7 TeV m(q˜)=m(g˜) 1405.7875 MSUGRA/CMSSM 1 e,µ 3-6 jets Ye s 20.3 g˜ 1.2 TeV any m(q˜) ATLAS-CONF-2013-062 MSUGRA/CMSSM 0 7-10 jets Ye s 20.3 g˜ 1.1 TeV any m(q˜) 1308.1841 0 q˜ χ˜0 st nd q˜q˜, q˜ qχ˜1 0 2-6 jets Ye s 20.3 850 GeV m( 1)=0 GeV, m(1 gen. ˜q )=m(2 gen. ˜q ) 1405.7875 → 0 0 g˜g˜, g˜ qq¯χ˜ 0 2-6 jets Ye s 20.3 g˜ 1.33 TeV m(χ˜1)=0 GeV 1405.7875 ±1 ± → ± 0 g˜ χ˜0 χ˜ χ˜0 g˜g˜, g˜ qqχ˜1 qqW χ˜1 1 e,µ 3-6 jets Ye s 20.3 1.18 TeV m( 1)<200 GeV, m( )=0.5(m( 1)+m(g˜)) ATLAS-CONF-2013-062 → → 0 - g˜ χ˜0 = g˜g˜, g˜ qq(ℓℓ/ℓν/νν)χ˜1 2 e,µ 0-3 jets 20.3 1.12 TeV m( 1) 0GeV ATLAS-CONF-2013-089 GMSB→ (ℓ˜ NLSP) 2 e,µ 2-4 jets Ye s 4 . 7 g˜ 1.24 TeV tanβ<15 1208.4688 GMSB (ℓ˜ NLSP) 1-2 τ +0-1ℓ 0-2 jets Ye s 2 0 . 3 g˜ 1.6 TeV tanβ >20 1407.0603 0 GGM (bino NLSP) 2 γ - Ye s 20.3 g˜ 1.28 TeV m(χ˜1)>50 GeV ATLAS-CONF-2014-001 0 GGM (wino NLSP) 1 e,µ+ γ - Ye s 4 . 8 g˜ 619 GeV m(χ˜ )>50 GeV ATLAS-CONF-2012-144
Inclusive Searches 1 0 GGM (higgsino-bino NLSP) γ 1 b Ye s 4.8 g˜ 900 GeV m(χ˜1)>220 GeV 1211.1167 GGM (higgsino NLSP) 2 e,µ(Z) 0-3 jets Ye s 5 . 8 g˜ 690 GeV m(NLSP)>200 GeV ATLAS-CONF-2012-152 1/2 4 Gravitino LSP 0 mono-jet Ye s 10.5 F scale 645 GeV m(G˜)>10− eV ATLAS-CONF-2012-147 0 g˜ χ˜0 g˜ bb¯χ˜1 03b Ye s 2 0 . 1 1.25 TeV m( 1)<400 GeV 1407.0600 0 0 → ¯χ˜ 0 7-10 jets Ye s 20.3 g˜ 1.1 TeV m(χ˜ ) <350 GeV 1308.1841 gen. g˜ tt 1 1
med. 0 0 → ¯χ˜ 0-1 e,µ 3 b Ye s 2 0 . 1 g˜ 1.34 TeV m(χ˜ )<400 GeV 1407.0600 rd g˜ tt 1 1 ˜ g + 0 3 → ˜ g˜ bt¯χ˜1 0-1 e,µ 3 b Ye s 20.1 g 1.3 TeV m(χ˜1)<300 GeV 1407.0600 → 0 0 ˜ ˜ ˜ χ˜ 0 2 b Ye s 2 0 . 1 b˜ 1 100-620 GeV m(χ˜ )<90 GeV 1308.2631 b1b1, b1 b ±1 1 → ˜ χ± χ0 b˜1b˜1, b˜1 tχ˜1 2 e,µ(SS) 0-3 b Ye s 20.3 b1 275-440 GeV m( ˜1 )=2 m( ˜1) 1404.2500 → ± ˜ 0 t˜1t˜1(light), t˜1 bχ˜1 1-2 e,µ 1-2 b Ye s 4.7 t1 110-167 GeV m(χ˜1)=55 GeV 1208.4305, 1209.2102 → 0 ˜ χ˜0 χ˜± t˜1t˜1(light), t˜1 Wbχ˜1 2 e,µ 0-2 jets Ye s 20.3 t1 130-210 GeV m( 1) =m(t˜1)-m(W)-50 GeV, m(t˜1)< rd 0 → 0 ˜ ˜ ˜ χ˜ 0 mono-jet/c-tag Ye s 20.3 t˜1 90-240 GeV m(t˜ )-m(χ˜ )<85 GeV 1407.0608 3 direct productiont1t1, t1 c 1 1 1 → ˜ 0 t˜1t˜1(natural GMSB) 2 e,µ(Z) 1 b Ye s 2 0 . 3 t1 150-580 GeV m(χ˜1)>150 GeV 1403.5222 0 t˜2t˜2, t˜2 t˜1 + Z 3 e,µ(Z) 1 b Ye s 20.3 t˜2 290-600 GeV m(χ˜ )<200 GeV 1403.5222 → 1 0 0 ℓ˜ ℓ˜ , ℓ˜ ℓχ˜ 2 e,µ 0Yes20.3ℓ˜ 90-325 GeV m(χ˜ )=0 GeV 1403.5294 L+,R L,R+ 1 1 → χ˜ ± 0 ± 0 χ˜ χ˜−, χ˜ ℓν˜ (ℓν˜) 2 e,µ 0 Ye s 20.3 1 140-465 GeV m(χ˜1)=0 GeV, m(ℓ˜, ν˜)=0.5(m(χ˜1 )+m(χ˜1)) 1403.5294 +1 1 +1 ± → - χ˜ χ0 χ± χ0 χ˜ 1 χ˜1−, χ˜1 τν˜ (τν˜) 2 τ Ye s 2 0 . 3 1 100-350 GeV m( ˜1)=0 GeV, m(τ˜, ν˜)=0.5(m( ˜1 )+m( ˜1)) 1407.0350 ± 0 → ˜ ± ˜ 0 ± 0 0 ± 0 χ˜ χ˜ ℓ˜ νℓ˜ ℓ(˜νν), ℓν˜ℓ˜ ℓ(˜νν) 3 e,µ 0 Ye s 20.3 χ , χ 700 GeV m(χ˜1 )=m(χ˜2), m(χ˜1)=0, m(ℓ˜, ν˜)=0.5(m(χ˜1 )+m(χ˜1)) 1402.7029 EW 1 2 L L L 1 2 ± ± 0 ± 0 0 direct 0→ 0 0 χ˜ χ˜ χ˜ χ˜ χ˜ 1403.5294, 1402.7029 χ˜ 1 χ˜2 Wχ˜1Zχ˜ 1 2-3 e,µ 0Yes20.31 , 2 420 GeV m( 1 )=m( 2), m( 1)=0, sleptons decoupled ± 0→ 0 0 χ˜ ± χ˜ 0 χ˜± χ˜0 χ˜0 χ˜ 1 χ˜2 Wχ˜1h χ˜ 1 1 e,µ 2 b Ye s 20.3 1 , 2 285 GeV m( 1 )=m( 2), m( 1)=0, sleptons decoupled ATLAS-CONF-2013-093 0 0 →0 ˜ χ˜ 0 χ˜0 χ˜0 χ˜0 ˜ χ˜0 χ˜0 χ˜ 2χ˜ 3, χ˜ 2,3 ℓRℓ 4 e,µ 0Yes20.32,3 620 GeV m( 2)=m( 3), m( 1)=0, m(ℓ, ν˜)=0.5(m( 2)+m( 1)) 1405.5086 + → ± χ˜ ± χ± χ0 = χ± = Direct χ˜1 χ˜ 1− prod., long-lived χ˜ 1 Disapp. trk 1 jet Ye s 20.3 1 270 GeV m( ˜1 )-m( ˜1) 160 MeV, τ( ˜1 ) 0.2 ns ATLAS-CONF-2013-069 0 Stable, stopped g˜ R-hadron 0 1-5 jets Ye s 2 7 . 9 g˜ 832 GeV m(χ˜1)=100 GeV, 10 µs<τ(˜g)<1000 s 1310.6584 0 -- χ˜ 0 10 Long-lived → q˜q˜, χ˜ qqµ (RPV) 1 µ, displ. vtx --20.3 q˜ 1.0 TeV 1.5 Erice, June 2019 – p. 5 Searches for new physics, exotics LQ1(ej) x2 stopped gluino (cloud) LQ1(ej)+LQ1(νj) stopped stop (cloud) LQ2(μj) x2 HSCP gluino (cloud) Long-Lived LQ2(μj)+LQ2(νj) Leptoquarks HSCP stop (cloud) LQ3(νb) x2 q=2/3e HSCP Particles LQ3(τb) x2 q=3e HSCP LQ3(τt) x2 neutralino, ctau=25cm, ECAL time LQ3(vt) x2 0 1 2 3 4 0 1 2 3 4 j+MET, SI DM=100 GeV, Λ RS1(γγ), k=0.1 j+MET, SD DM=100 GeV, Λ RS1(ee,uu), k=0.1 RS Gravitons γ+MET, SI DM=100 GeV, Λ RS1(jj), k=0.1 γ+MET, SD DM=100 GeV, Λ Dark Matter RS1(WW→4j), k=0.1 l+MET, ξ=+1, SI DM=100 GeV, Λ l+MET, ξ=+1, SD DM=100 GeV, Λ 0 1 2 3 4 l+MET, ξ=-1, SI DM=100 GeV, Λ CMS Preliminary l+MET, ξ=-1, SD DM=100 GeV, Λ 0 1 2 3 4 Heavy Gauge SSM Z'(ττ) SSM Z'(jj) Bosons ADD (γγ), nED=4, MS SSM Z'(bb) ADD (ee,μμ), nED=4, MS Large Extra SSM Z'(ee)+Z'(µµ) ADD (j+MET), nED=4, MD Dimensions SSM W'(jj) ADD (γ+MET), nED=4, MD SSM W'(lv) QBH, nED=4, MD=4 TeV SSM W'(WZ→lvll) NR BH, nED=4, MD=4 TeV SSM W'(WZ→4j) Jet Extinction Scale String Scale (jj) 0 1 2 3 4 0 2 4 5 7 9 Excited e* (M=Λ) Compositeness Fermions dijets, Λ+ LL/RR μ* (M=Λ) dijets, Λ- LL/RR q* (qg) dimuons, Λ+ LLIM q* (qγ) dimuons, Λ- LLIM b* dielectrons, Λ+ LLIM 0 1 2 3 4 dimuons, Λ- LLIM coloron(jj) x2 single e, Λ HnCM coloron(4j) x2 Multijet single μ, Λ HnCM gluino(3j) x2 inclusive jets, Λ+ gluino(jjb) x2 Resonances inclusive jets, Λ- 0 1 2 3 4 0 4 8 13 17 21 CMS Exotica Physics Group Summary – ICHEP, 2014 Erice, June 2019 – p. 6 Marginal evidence (less than 2σ) for the SM vacuum metastability given uncertainties in relation between Monte-Carlo top mass and the top quark Yukawa coupling V V V M crit metastability stability φ φ φ Fermi Planck Fermi Planck Fermi Planck Vacuum is unstable at ∼ 1.5σ Erice, June 2019 – p. 7 Summary of the LHC findings The Standard Model in now complete: the last particle - Higgs boson, predicted by the SM, has been found Erice, June 2019 – p. 8 Summary of the LHC findings The Standard Model in now complete: the last particle - Higgs boson, predicted by the SM, has been found No significant deviations from the SM have been observed Erice, June 2019 – p. 8 Summary of the LHC findings The Standard Model in now complete: the last particle - Higgs boson, predicted by the SM, has been found No significant deviations from the SM have been observed The masses of the top quark and of the Higgs boson, the Nature has chosen, make the SM a self-consistent effective field theory all the way up to the quantum gravity scale 1019 GeV (15 orders of magnitude larger than the LHC energy!). Erice, June 2019 – p. 8 Summary of the LHC findings The Standard Model in now complete: the last particle - Higgs boson, predicted by the SM, has been found No significant deviations from the SM have been observed The masses of the top quark and of the Higgs boson, the Nature has chosen, make the SM a self-consistent effective field theory all the way up to the quantum gravity scale 1019 GeV (15 orders of magnitude larger than the LHC energy!). End of high energy physics? Erice, June 2019 – p. 8 Theoretical prejudice for new physics beyond the Standard Model: WHY questions Hierarchy problem: Why MW /MPl ≪ 1? Stability of the Higgs mass against radiative corrections. 4 Cosmological constant problem: Why ϵvac/MPl ≪ 1? Strong CP-problem: Why θQCD ≪ 1? Fermion mass matrix: Why me ≪ mt? ... Erice, 25 June 2019 – p. 20 Experimental problems of the Standard Model Erice, June 2019 – p. 9 Neutrino masses and oscillations Erice, June 2019 – p. 10 SM: neutrinos are massless and lepton numbers are conserved! neutrino antineutrino Experiment: neutrinos have masses and lepton numbers are not conserved! Lectures by Alessandro Bettini, Sergio Bertolucci, Harald Fritzsch and Mikko Laine. Solution: neutrinos have masses O(eV ) and SM must be extended. Erice, June 2019 – p. 11 Baryon asymmetry of the Universe and baryogenesis Erice, June 2019 – p. 12 The birth of antimatter Erice, June 2019 – p. 13 The birth of antimatter Before 1930 : The only known elementary particles were protons, neutrons, electrons and photons Erice, June 2019 – p. 13 The birth of antimatter Before 1930 : The only known elementary particles were protons, neutrons, electrons and photons Big theoretical issue: how to unify quantum mechanics and special relativity Erice, June 2019 – p. 13 The birth of antimatter Before 1930 : The only known elementary particles were protons, neutrons, electrons and photons Big theoretical issue: how to unify quantum mechanics and special relativity. 1930, Dirac: construction of relativistic equation describing 1 quantum mechanics of electron (particle with spin 2 ) Skoltech, 14 June 2019 – p. 22 Dirac hypothesis: Nobel Prize Lecture, 1933 “If we accept the view of complete symmetry between positive and negative electric charge so far as concerns the fundamental laws of Nature, we must regards it rather as an accident that the Earth(and presumably the whole solar system), contains a predominanceof electrons and positive protons. It is quite possible that forsomeofthe stars it is the other way about, these stars being built up mainly of positrons and negative protons. In fact, there may be half thestarsof each kind. The two kinds of stars would both show exactly the same spectra, and there would be no way of distinguishing them by present astronomical methods." Erice, June 2019 – p. 14 Baryon asymmetry in the present universe Dirac was perfectly correct that the solar system is con- structed from matter! Erice, June 2019 – p. 15 However, how can we know whether distant stars and galaxies consist of matter or antimatter? Erice, June 2019 – p. 16 However, how can we know whether distant stars and galaxies consist of matter or antimatter? Erice, June 2019 – p. 16 However, how can we know whether distant stars and galaxies consist of matter or antimatter? Erice, June 2019 – p. 16 Baryon asymmetry in the present universe There are several methods for detection of antimatter: The search of antinuclei in cosmic rays: the probability of the process pp → antinuclei + etc is very small! Erice, June 2019 – p. 17 Baryon asymmetry in the present universe There are several methods for detection of antimatter: The search of antinuclei in cosmic rays: the probability of the process pp → antinuclei + etc is very small! Result: no antinuclei in cosmic rays have been found! Erice, June 2019 – p. 17 Detection of antimatter Annihilation: particles and antiparticles annihilate: pp¯ → π+ π− π0 → γγ + ← ← − νµµ µ ν¯µ + ← ← − e νeν¯µ e ν¯eνµ Detection of γ-rays? Erice, June 2019 – p. 18 Detection of antimatter Annihilation: particles and antiparticles annihilate: pp¯ → π+ π− π0 → γγ + ← ← − νµµ µ ν¯µ + ← ← − e νeν¯µ e ν¯eνµ Detection of γ-rays? However, this has not been observed! Erice, June 2019 – p. 18 Our universe is asymmetric! Erice, June 2019 – p. 19 Our universe is asymmetric! Dirac was wrong: cosmological observations do not support the hypothesis that the distant stars and galaxies may consist of antimatter. Erice, June 2019 – p. 19 Our universe is asymmetric! Dirac was wrong: cosmological observations do not support the hypothesis that the distant stars and galaxies may consist of antimatter. The problem Erice, June 2019 – p. 19 Our universe is asymmetric! Dirac was wrong: cosmological observations do not support the hypothesis that the distant stars and galaxies may consist of antimatter. The problem Where is antimatter? Erice, June 2019 – p. 19 Our universe is asymmetric! Dirac was wrong: cosmological observations do not support the hypothesis that the distant stars and galaxies may consist of antimatter. The problem Where is antimatter? Its absence looks really strange, as the properties of matterand antimatter are very similar! Erice, June 2019 – p. 19 Sakharov Proposal: Universe is asymmetric because of Baryon number non-conservation (otherwise symmetric state cannot evolve to asymmetric state) - present in the SM CP-violation (otherwise there is no difference between matter and antimatter) - present in the SM, but very small Substantial deviations from thermal equilibrium (otherwise there is no arrow of time and asymmetry cannot be created) - absent in the SM Skoltech, 14 June 2019 – p. 25 Dark matter in the universe Erice, June 2019 – p. 34 Problem since 1933, F. Zwicky. Most of the matter in the universe is dark Evidence: Rotation curves of galaxies Big Bang nucleosynthesis Structure formation CMB anisotropies Supernovae observations Non-baryonic dark matter: ΩDM ≃ 0.22 Erice, June 2019 – p. 35 Erice, June 2019 – p. 36 Erice, June 2019 – p. 37 Standard Model: no particle physics candidate for Dark Matter The only neutral stable objects - atoms and neutrinos if atoms: contradiction with BBN - so many baryons are not admitted if neutrinos - hot DM: contradiction with structure formation - small scale inhomogeneities are erased Dark Matter : new particle (?) Erice, June 2019 – p. 38 What do we know for sure about DM particles Erice, June 2019 – p. 39 They must have a lifetime exceeding the age of the Universe - otherwise they would have decayed. Relatively light particles (M The DM particles should form the cold or warm DM – they must not be relativistic at the onset of structure formation, Lyman-α data puts λFS < 150 kpc. If they are fermions, their mass should not be below 400 eV – Tremaine-Gunn bound. Erice, June 2019 – p. 40 Hot DM Warm DM Cold DM Ben Moore simulations Erice, June 2019 – p. 41 Number of satellites of the Milky way CDM versus WDM, Carlos Frenk et al. Erice, June 2019 – p. 42 Lower mass bound on fermionic DM ! The smaller is the DM mass the bigger is the number of particles in an object with the mass Mvir ! Average phase-space density of fermion DM particles should be smaller than density of degenerate Fermi gas M 1 2m 4 vir ≤ DM 4π R3 4π v2 π! 3 3 vir 3 ∞ (2 ) ! Objects with highest phase-space density – dwarf spheroidal galaxies – lead to the lower bound on the fermionic DM mass mDM " 400 eV “Tremaine-Gunn bound” Non-WIMP DM candidates – p.5/61 Erice, June 2019 – p. 43 What we do not know about DM particles Erice, June 2019 – p. 44 Mass : the range from 10−33 eV (stringy axions) to 1024 GeV (supersymmetric Q-balls) was considered Spin : both fermions and bosons are OK Interaction strength and interaction type Production mechanism How they are embedded into Big Picture of particle physics Erice, June 2019 – p. 45 How to reconcile the evidence for new physics without spoiling the success of the Standard Model? Erice, 25 June 2019 – p. 26 Where is new physics? Munich, June 18, 2019 – p. 13 Only at the Planck scale? Does not work: neutrino masses from five-dimensional operator 1 ¯ ˜ † c Aαβ !Lαφ"!φ Lβ" MP −5 suppressed by the Planck scale are too small, mν < 10 eV. Munich, June 18, 2019 – p. 14 Below the Planck scale, but where? Neutrino masses and oscillations: the masses of right-handed see-saw neutrinos can vary from O(1) eV to O(1015) GeV Dark matter, absent in the SM: the masses of DM particles can be as small as O(10−22) eV (super-light scalar fields) or as large as O(1020) GeV (wimpzillas, Q-balls). Baryogenesis, absent in the SM: the masses of new particles, responsible for baryogenesis (e.g. right-handed neutrinos), can be as small as O(10) MeV or as large as O(1015) GeV Higgs mass hierarchy : models related to SUSY, composite Higgs, large extra dimensions require the presence of new physics right above the Fermi scale,whereasthemodelsbasedonscale invariance (quantum or classical) may require the absence of new physics between the Fermi and Planck scales Munich, June 18, 2019 – p. 15 Arguments for absence of new heavy particles above the Fermi scale Higgs self coupling λ 0 at the ≈ Planck scale (criticality of the SM Stability of the Higgs -asymptoticsafety? Astrid Eich- mass against radiative horn lectures). This is violated if new particles contribute to the corrections evolution of the SM couplings. Higgs mass Mh$125.3%0.6 GeV 0.06 2 n 2 0.04 δmH ≃ αGUT Mheavy 0.02 Λ No heavy particles - no large 0.00 contributions - no fine tuning !0.02 100 105 108 1011 1014 1017 1020 Scale Μ, GeV Erice, 25 June 2019 – p. 24 Outline of possible answer Right handed neutrinos (other names: Majorana fermions, heavy neutral leptons – HNLs, sterile neutrinos) Minimal physics for neutrino masses Baryogenesis Dark Matter Conclusions Erice, June 2019 – p. 47 the νMSM Erice, June 2019 – p. 48 The missing piece: sterile neutrinos Most general renormalizable (see-saw) Lagrangian µ MI c Lsee−saw = LSM +N¯I i∂µγ NI −FαI L¯αNI Φ− N¯ NI +h.c., 2 I Assumption: all Yukawa couplings with different leptonic generations are allowed. I ≤ N -numberofnewparticles-HNLs-cannotbefixedbythe symmetries of the theory. Let us play with N to see if having some number of HNLs is good for something Erice, June 2019 – p. 49 N =1:Onlyoneoftheactiveneutrinosgetsamass Erice, June 2019 – p. 50 N =1:Onlyoneoftheactiveneutrinosgetsamass N =2:Twooftheactiveneutrinosgetmasses:allneutrinoexperiments, except LSND-like, can be explained. The theory contains 3 new CP-violating phases: baryon asymmetry of the Universe can be understood item N =2:Twooftheactiveneutrinosgetmasses:allneutrinoexperiments, except LSND-like, can be explained. The theory contains 3 newCP-violating phases: baryon asymmetry of the Universe can be understood Erice, June 2019 – p. 50 N =1:Onlyoneoftheactiveneutrinosgetsamass N =2:Twooftheactiveneutrinosgetmasses:allneutrinoexperiments, except LSND-like, can be explained. The theory contains 3 new CP-violating phases: baryon asymmetry of the Universe can be understood item N =2:Twooftheactiveneutrinosgetmasses:allneutrinoexperiments, except LSND-like, can be explained. The theory contains 3 newCP-violating phases: baryon asymmetry of the Universe can be understood N =3:Allactiveneutrinosgetmasses:allneutrinoexperiments,canbe explained (LSND with known tensions). The theory contains 6 new CP-violating phases: baryon asymmetry of the Universe can be understood. If LSND is dropped, dark matter in the Universe can be explained. The quantisation of electric charges follows from the requirement of anomaly cancellations (1-3-3, 1-2-2, 1-1-1, 1-graviton-graviton). Erice, June 2019 – p. 50 N =1:Onlyoneoftheactiveneutrinosgetsamass N =2:Twooftheactiveneutrinosgetmasses:allneutrinoexperiments, except LSND-like, can be explained. The theory contains 3 new CP-violating phases: baryon asymmetry of the Universe can be understood item N =2:Twooftheactiveneutrinosgetmasses:allneutrinoexperiments, except LSND-like, can be explained. The theory contains 3 newCP-violating phases: baryon asymmetry of the Universe can be understood N =3:Allactiveneutrinosgetmasses:allneutrinoexperiments,canbe explained (LSND with known tensions). The theory contains 6 new CP-violating phases: baryon asymmetry of the Universe can be understood. If LSND is dropped, dark matter in the Universe can be explained. The quantisation of electric charges follows from the requirement of anomaly cancellations (1-3-3, 1-2-2, 1-1-1, 1-graviton-graviton). N > 3:Nowyoucandomanythings,dependingonyourtaste-extrarelativistic degrees of freedom in cosmology, neutrino anomalies, dark matter, different scenarios for baryogenesis, and different combinations of the above. Erice, June 2019 – p. 50 New mass scale and Yukawas Y 2 = Trace[F †F ] - - - - - - Erice, June 2019 – p. 51 N =3with MI =$&006>0,0&%(3),.6 =$&006>0,0&%(3),.6 )86?%((0&6@A0&'3),.B6."3,6C )86?%((0&6@A0&'3),.B6."3,6C E EE EEE E EE EEE '%..: !"#$%&' ("!)$*&' ()+"!$*&'$ 46 '%..: !"#$%&' ("!)$*&' ()+"!$*&'$ 46 #$%&/0: ! ! ! 4 #$%&/0: ! ! ! 4 t t t ! t " t # t ( ! " # ( Left Righ Left Righ Left Righ Left Righ Left Righ ,%'0: Left !" Righ #$%&' ()" /2!), ,%'0: !" #$%&' ()" /2!), #",$%&' (-#$%&' #"!$*&' 4 #",$%&' (-#$%&' #"!$*&' 4 -" -" -" 4 -" -" -" 4 t t t $ t % t & t % $ % & % ;!%&7. ;!%&7. Left Righ Left Righ Left Righ Left Righ Left *)+, Righ Left .(&%,/0 Righ 1)(()' "$)(), *)+, .(&%,/0 1)(()' "$)(), $ /("!$*&' * 5F56>0H6 0(-$1&' 0*&' 0*&' /("!$*&' * 5F56>0H6 4 4 # 4 $ 4 4 4 4 # 4 $ 4 4 t t t " t ! t ! t " ! ! ! ) 4 - ! . . . ) 4 - '!), (%! * '!), + (%! , Lef Lef Lef Lef 020#(&),Lef Lef ,0!(&3,) +0%7 #$%%& 020#(&), ,0!(&3,) +0%7 #$%%& ,0!(&3,) ,0!(&3,) 8)� '(&() ,0!(&3,) ,0!(&3,) 8)� '(&() -".(($%&' (-.")$%&' (")))$*&' ,-"#$*&' ."3,64 -".(($%&' (-.")$%&' (")))$*&' ,-"#$*&' ."3,64 , , -5 -5 -5 9 5 -5 -5 -5 9 5 t t t ' t # t $ t + ' # $ + Left Righ Left Righ Left Righ Left Righ Left Righ Left Righ <0"(),. <0"(),. D).),.6@A)�.B6."3,65 D).),.6@A)�.B6."3,65 +0%7 +0%7 020#(&), '!), (%! 8)� 020#(&), '!), (%! 8)� N = Heavy Neutral Lepton - HNL Role of N1 with mass in keV region: dark matter Role of N2,N3 with mass in 100 MeV – GeV region: “give” masses to neutrinos and produce baryon asymmetry of the Universe Erice, June 2019 – p. 52 What should be the properties of N1,2,3 in the minimal setup - no any type of new physics between the Fermi and Planck scales ? How to search for them experimentally? Erice, June 2019 – p. 53 Baryon asymmetry Sakharov conditions: Baryon number violation - OK due co complex vacuum structure in the SM and chiral anomaly CP-violation - OK due to new complex phases in Yukawa couplings Deviations from thermal equilibrium - OK as HNL are out of thermal equilibrium for T>O(100) GeV More in lecture by Mikko Laine Erice, June 2019 – p. 54 Baryon asymmetry Creation of baryon asymmetry - a complicated process involving creation of HNLs in the early universe and their coherent CP-violating oscillations, interaction of HNLs with SM fermions, sphaleron processes with lepton and baryon number non-conservation Akhmedov, Rubakov, Smirnov; Asaka, MS Resummation, hard thermal loops, Landau-Pomeranchuk-Migdal effect, etc. Ghiglieri, Laine.Howtodescribetheseprocessesisstillunder debate, but the consensus is that it works and is testable. Erice, June 2019 – p. 55 Baryon asymmetry: HNLs N2,3 NuTeV CHARM ! ! 10 6 NuTeV 10 6 CHARM PS191 PS191 BAU BBN BAU 2 2 !8 !8 BBN U U 10 10 BAU BAU 10!10 10!10 Seesaw Seesaw 10!12 10!12 0.2 0.5 1.0 2.0 5.0 10.0 0.2 0.5 1.0 2.0 5.0 10.0 M !GeV" M !GeV" Constraints on U 2 coming from the baryon asymmetry of the Universe, from the see-saw formula, from the big bang nucleosynthesis and experimental searches. Left panel - normal hierarchy, rightpanel- inverted hierarchy (Canetti, Drewes, Frossard, MS ’12). Similar results: recent works by Abada, Arcadia, Domcke, Lucente ’ 15, Hernández, Kekic, J. López-Pavón, Racker, J. Salvado ’16,Drewes, Garbrech, Guetera, Klaric’16,Hambye,Teresi’17,Ghiglieri,Laine’18,’19,´ Eijima, Timiryasov, MS ’18 Erice, June 2019 – p. 56 Experimental challenges: HNL production and decays are highly suppressed – dedicated experiments are needed: Production via intermediate (hadronic) state p + target → mesons + ...,andthenhadron→ N + .... via Z-boson decays: e+e− → Z → νN Detection Subsequent decay of N to SM particles Erice, June 2019 – p. 57 Dedicated experiments Common features of all relatively light feebly interacting particles : Can be produced in decays of different mesons (π,K,charm,beauty) Can decay to SM particles (l+l−, γγ,lπ,etc) Can be long lived Requirements to experiment: Produce as many mesons as you can Study their decays for a missing energy signal: charm or B-factories, NA62 Search for decays of hidden sector particles - fixed target experiments Have as many pot as you can, with the energy enough to produce charmed (or beauty) mesons Put the detector as close to the target as possible, in order tocatchallhidden particles from meson decays (to evade 1/R2 dilution of the flux) Have the detector as large as possible to increase the probability of hidden particle decay inside the detector Have the detector as empty as possible to decrease neutrino and other backgrounds Erice, June 2019 – p. 58 Energy and Intensity Frontiers Skoltech, 14 June 2019 – p. 4 Most recent dedicated experiment - 1986, Vannucci et al No new particles are found with mass below K-meson, the best constraints are derived Erice, June 2019 – p. 59 NA62 Rencontres de Blois, June 4, 2018 – p. 48 SHiP [ins-det:1504.04956, JINST 14(2019)03 P03025, CERN-SPSC-2019-010] scattering and neutrino detector target and 12 m decay volume ⇠ hadron absorber beam decay spectrometer 120 m muon shield ⇠ I a discovery machine for weakly coupled LLPs, with a complementary detector for ⌫ physics and LDM scattering signatures I large geometrical acceptance: long volume close to dump I zero background with spectrometry, PID and VETO taggers 3 / 12 MATHUSLA MAssive Timing Hodoscope for Ultra-Stable NeutraL PArticles Rencontres de Blois, June 4, 2018 – p. 50 Normal hierarchy 10-6 NuTeV -7 10 PS191 BAU 10-8 2 SHiP -9 |U| 10 10-10 BBN FCC-ee 10-11 Seesaw 1 10 HNL mass (GeV) FCC at 1013 Z0 and decay length 0.01-500 cm Erice, June 2019 – p. 60 Dark Matter candidate: N1 DM particle is not stable. Main decay mode N1 → 3ν is not observable. Subdominant radiative decay channel: N → νγ. e± ν Photon energy: Ns ν W ∓ M W ∓ γ Eγ = 2 Radiative decay width: 2 9 αEM GF 2 5 Γrad = sin (2θ) M 256 · 4π4 s Erice, June 2019 – p. 61 Constraints on DM sterile neutrino N1 Stability. N1 must have a lifetime larger than that of the Universe Production. N1 are created in the early Universe in reactions l¯l → νN1,qq¯ → νN1 etc. We should get correct DM abundance. More in lecture by Mikko Laine Structure formation. If N1 is too light it may have considerable free streaming length and erase fluctuations on small scales.This can be checked by the study of Lyman-α forest spectra of distant quasars and structure of dwarf galaxies X-rays. N1 decays radiatively, N1 → γν,producinganarrowline which can be detected by X-ray telescopes (such as Chandra or XMM-Newton). Erice, June 2019 – p. 62 1029 1028 [sec] ! 1027 XMM, HEAO-1 SPI Chandra Life-time 1026 8 PSD exceeds degenerate Fermi gas ! = Universe life-time x 10 Available X-ray satellites: Suzaku, XMM-Newton, Chandra, 1025 -1 0 1 2 3 4 INTEGRAL, NuStar 10 10 10 10 10 10 MDM [keV] Erice, June 2019 – p. 63 eeto fA ndnie msinLn nteSakdX-r Stacked the in Line Emission Unidentified An of Detection esu aaycutr .Byrk .Rcasi,D Iaku D. Ruchayskiy, O. arXiv:1402.4119 , e-Print: Boyarsky A. Franse. cluster. galaxy galaxy Andromeda the Perseus of spectra X-ray in line unidentified An arXiv:1402. e-Print: Randall. Fo W. A. S. Markevitch, Loewenstein, M. M. Bulbul, Smith, E. Clusters. Galaxy of spectrum 2 Interaction strength [Sin (2θ)] 10 10 10 10 10 10 10 10 10 -14 -13 -12 -11 -10 -9 -8 -7 -6 Phase-space density constraints 1 Non-resonant production Non-resonant BBN limit: L limit: BBN Too muchDarkMatter Not enoughDarkMatter 6 BBN = 2500 = L L L DM mass[keV] 6 6 6 max =25 =70 =700 L 6 =12 5 of darkmatterdecayline Excluded bynon-observation 10 for NRPsterileneutrino Lyman- α bound 2301 50 osy,J. bovskyi, tr .K. R. ster, ay and rc,Jn 09–p 64 p. – 2019 June Erice, Erice, June 2019 – p. 65 Conclusions Heavy neutral leptons can be a key to (almost all)BSMproblems: neutrino masses and oscillations dark matter baryon asymmetry of the universe They can be found in Space and on the Earth X-ray satellites proton fixed target experiment - SHIP, M ! 2 GeV collider experiments at FCC-ee in Z-peak, M " 2 GeV Erice, June 2019 – p. 66 Inflation: Higgs boson Potential in Einstein frame for non-minimally coupled Higgs, ξRh2 U(χ) λM4/ξ2/4 Standard Model λ v4/4 λM4/ξ2/16 0 0 v 0 0 χ χ -canonicallynormalisedscalarfieldinEinsteinframe. Erice, 25 June 2019 – p. 41 MP Stage 1: Higgs inflation, h> √ξ ,slowrolloftheHiggs field U(χ) λM4/ξ2/4 inflation λM4/ξ2/16 0 0 χend χCOBE χ Makes the Universe flat, homogeneous and isotropic Produces fluctuations leading to structure formation: clusters of galaxies, etc Erice, 25 June 2019 – p. 42 CMB parameters - spectrum and tensor modes, ξ ! 1000 ns =0.97,r=0.003 Erice, 25 June 2019 – p. 43 MP MP Stage 2: Big Bang, ξ λM4/ξ2/4 λM4/ξ2/16 Reheating 0 0 χend χCOBE χ All particles of the Standard Model are produced Coherent Higgs field disappears 14 The Universe is heated up to T ∝ MP /ξ ∼ 10 GeV Erice, 25 June 2019 – p. 44