Minimal Extension of the Standard Model of Particle Physics. Dmitry Gorbunov

Transcription

1 Minimal Extension of the Standard Model of Particle Physics Dmitry Gorbunov Institute for Nuclear Research, Moscow, Russia 14th Lomonosov Conference on Elementary Paticle Physics, Moscow, MSU, Dmitry Gorbunov (INR) Minimal Extension of the SM , Moscow 1 / 18

2 Outline Outline 1 Motivation: Phenomena Observed but Unexplained within the SM 2 The νmsm Model: Content and Lagrangian 3 The νmsm Model: Numbers in Sterile Neutrino Sector 4 Conclusions Dmitry Gorbunov (INR) Minimal Extension of the SM , Moscow 2 / 18

3 Motivation: Phenomena Observed but Unexplained within the SM Outline 1 Motivation: Phenomena Observed but Unexplained within the SM 2 The νmsm Model: Content and Lagrangian 3 The νmsm Model: Numbers in Sterile Neutrino Sector 4 Conclusions Dmitry Gorbunov (INR) Minimal Extension of the SM , Moscow 3 / 18

4 Motivation: Phenomena Observed but Unexplained within the SM Neutrino Oscillations: Masses and Mixing Dmitry Gorbunov (INR) Minimal Extension of the SM , Moscow 4 / 18

5 Motivation: Phenomena Observed but Unexplained within the SM Baryons and Dark Matter in Astrophysics Rotation curves Gravitational lensing Bullet cluster Dmitry Gorbunov (INR) Minimal Extension of the SM , Moscow 5 / 18

6 Motivation: Phenomena Observed but Unexplained within the SM Baryons and Dark Matter in Cosmology Rotation curves Structures Dmitry Gorbunov (INR) BBN Gravitational lensing CMB fluctuations Minimal Extension of the SM Bullet cluster , Moscow 6 / 18

7 Motivation: Phenomena Observed but Unexplained within the SM Standard Model: Success and Problems Gauge fields (interactions) γ, W ±, Z, g Three generations of matter: L = ( ν L e L ), er ; Q = ( ul d L ), d R, u R Describes all experiments dealing with electroweak and strong interactions Does not describe Neutrino oscillations Dark matter (Ω DM ) sterile neutrino as DM Baryon asymmetry leptogenesis via sterile neutrino oscillations Dark energy (ΩΛ ) Inflation Strong CP Gauge hierarchy Quantum gravity νmsm explains these but does not address those Dmitry Gorbunov (INR) Minimal Extension of the SM , Moscow 7 / 18

8 Motivation: Phenomena Observed but Unexplained within the SM Standard Model: Success and Problems Gauge fields (interactions) γ, W ±, Z, g Three generations of matter: L = ( ν L e L ), er ; Q = ( ul d L ), d R, u R Describes all experiments dealing with electroweak and strong interactions Does not describe Neutrino oscillations Dark matter (Ω DM ) sterile neutrino as DM Baryon asymmetry leptogenesis via sterile neutrino oscillations Dark energy (ΩΛ ) Inflation Strong CP Gauge hierarchy Quantum gravity νmsm explains these but does not address those Dmitry Gorbunov (INR) Minimal Extension of the SM , Moscow 7 / 18

9 Motivation: Phenomena Observed but Unexplained within the SM Standard Model: Success and Problems Gauge fields (interactions) γ, W ±, Z, g Three generations of matter: L = ( ν L e L ), er ; Q = ( ul d L ), d R, u R Describes all experiments dealing with electroweak and strong interactions Does not describe Neutrino oscillations Dark matter (Ω DM ) sterile neutrino as DM Baryon asymmetry leptogenesis via sterile neutrino oscillations Dark energy (ΩΛ ) Inflation Strong CP Gauge hierarchy Quantum gravity νmsm explains these but does not address those Dmitry Gorbunov (INR) Minimal Extension of the SM , Moscow 7 / 18

10 Motivation: Phenomena Observed but Unexplained within the SM Standard Model: Success and Problems Gauge fields (interactions) γ, W ±, Z, g Three generations of matter: L = ( ν L e L ), er ; Q = ( ul d L ), d R, u R Describes all experiments dealing with electroweak and strong interactions Does not describe Neutrino oscillations Dark matter (Ω DM ) sterile neutrino as DM Baryon asymmetry leptogenesis via sterile neutrino oscillations Dark energy (ΩΛ ) Inflation R 2, RH H,... Strong CP changing topology,... Gauge hierarchy No scales! Quantum gravity νmsm explains these explained by Plank-scale physics? Dmitry Gorbunov (INR) Minimal Extension of the SM , Moscow 8 / 18

11 Outline The νmsm Model: Content and Lagrangian 1 Motivation: Phenomena Observed but Unexplained within the SM 2 The νmsm Model: Content and Lagrangian 3 The νmsm Model: Numbers in Sterile Neutrino Sector 4 Conclusions Dmitry Gorbunov (INR) Minimal Extension of the SM , Moscow 9 / 18

12 The νmsm Model: Content and Lagrangian νmsm Particle Content 36 quark states: (u,d) L, (c,s) L, (t,b) L and u R, d R, c R, s R, t R, b R (u,d) L, (c,s) L, (t,b) L and u R, d R, c R, s R, t R, b R (u,d) L, (c,s) L, (t,b) L and u R, d R, c R, s R, t R, b R 9+3 leptonic states: (ν e,e) L, (ν µ, µ) L, (ν τ,τ) L and N 1, e R, N 2, µ R, N 3, τ R SU(3) SU(2) L U(1) 12 gauge bosons (8+3+1) one Higgs doublet Leptonic sector has similar structure as the quark sector Dmitry Gorbunov (INR) Minimal Extension of the SM , Moscow 10 / 18

13 The νmsm Model: Content and Lagrangian νmsm Particle Content 36 quark states: (u,d) L, (c,s) L, (t,b) L and u R, d R, c R, s R, t R, b R (u,d) L, (c,s) L, (t,b) L and u R, d R, c R, s R, t R, b R (u,d) L, (c,s) L, (t,b) L and u R, d R, c R, s R, t R, b R 9+3 leptonic states: (ν e,e) L, (ν µ, µ) L, (ν τ,τ) L and N 1, e R, N 2, µ R, N 3, τ R SU(3) SU(2) L U(1) 12 gauge bosons (8+3+1) one Higgs doublet Leptonic sector has similar structure as the quark sector Dmitry Gorbunov (INR) Minimal Extension of the SM , Moscow 10 / 18

14 The νmsm Model: Content and Lagrangian νmsm Lagrangian Let us try to use as little new physics as possible Require to get the correct neutrino oscillations Explain DM and baryon asymmetry of the Universe Lagrangian Most general renormalizable with 3 right-handed neutrinos N I L νmsm = L MSM + N I i/ N I f Iα HN I L α M I 2 Nc I N I + h.c. Extra coupling constants: 3 Majorana masses M i 15 new Yukawa couplings (Dirac mass matrix M D = f H has 3 Dirac masses, 6 mixing angles and 6 CP-violating phases) Asaka, Blanchet, Shaposhnikov, 2005 Asaka, Shaposhnikov, 2005 Dmitry Gorbunov (INR) Minimal Extension of the SM , Moscow 11 / 18

15 The νmsm Model: Content and Lagrangian ν Masses and Mixings: seesaw from f Iα HN I L α M I M D = f v says nothing about M I! dangerous: δm 2 h M2 I 3 heavy neutrinos with masses M I similar to quark masses Light neutrino masses M ν = (M D ) T 1 M I M D f 2 v 2 m U T M ν U = 0 m m 3 M I Mixings: flavor state ν α = U αi ν i + θ αi N c I Active-sterile mixings θ αi = (MD ) αi M I f v M I 1 Dmitry Gorbunov (INR) Minimal Extension of the SM , Moscow 12 / 18

16 The νmsm Model: Numbers in Sterile Neutrino Sector Outline 1 Motivation: Phenomena Observed but Unexplained within the SM 2 The νmsm Model: Content and Lagrangian 3 The νmsm Model: Numbers in Sterile Neutrino Sector 4 Conclusions Dmitry Gorbunov (INR) Minimal Extension of the SM , Moscow 13 / 18

17 The νmsm Model: Numbers in Sterile Neutrino Sector Spectrum of νmsm ev t c u quarks b s d τ µ νn 2 e N 1 leptons νn νn 3 1 N 2 N 3 ν ν ν Dirac masses Majorana masses Dmitry Gorbunov (INR) Minimal Extension of the SM , Moscow 14 / 18

18 The νmsm Model: Numbers in Sterile Neutrino Sector DM lightest sterile neutrino N Ω N1 > Ω DM NRP 10-8 X-ray constraints sin 2 (2θ 1 ) Phase-space density constraints L 6 =25 L 6 =70 L 6 max =700 BBN limit: L 6 BBN = Ω N1 < Ω DM M 1 [kev] Dmitry Gorbunov (INR) Minimal Extension of the SM , Moscow 15 / 18

19 The νmsm Model: Numbers in Sterile Neutrino Sector BAU heaviest sterile neutrinos N 2,3 Dmitry Gorbunov (INR) Minimal Extension of the SM , Moscow 16 / 18

20 Outline Conclusions 1 Motivation: Phenomena Observed but Unexplained within the SM 2 The νmsm Model: Content and Lagrangian 3 The νmsm Model: Numbers in Sterile Neutrino Sector 4 Conclusions Dmitry Gorbunov (INR) Minimal Extension of the SM , Moscow 17 / 18

21 Conclusions Conclusions νmsm the simplest Standard Model extension with right handed neutrinos provides active neutrino masses and mixing angles 1-50 kev neutrino as DM mechanism for baryon asymmetry generation Possible searches for Dark Matter kev sterile neutrino X-ray observations indirect evidence 0νββ decay very small rate, m ν 10 5 ev Full kinematics measurement of beta decay in the laboratory? Possible searches for heavy sterile neutrinos responsible for baryogenesis sterile neutrino from K, D, B, τ decays with Br sterile neutrino decays searches: CNGS, T2K, etc. Model with M N < M K can be fully explored experimentally Dmitry Gorbunov (INR) Minimal Extension of the SM , Moscow 18 / 18