Baryogenesis and Particle Antiparticle Oscillations

Transcription

1 Baryogenesis and Particle Antiparticle Oscillations Seyda Ipek UC Irvine SI, John March-Russell, arxiv:

2 Sneak peek There is more matter than antimatter - baryogenesis SM cannot explain this There is baryon number violation Not enough CP violation No out-of-equilibrium processes CP violation is enhanced in particle antiparticle oscillations Can these oscillations play a role in baryogenesis? Seyda Ipek (UCI) 2

3 There is more matter than antimatter 0.69 DM 0.27 B 0.04 number of baryons: = n B n n B ' CMB PDG Seyda Ipek (UCI) 3

4 How Fermilab produces its baryons Seyda Ipek (UCI) 4

5 How the Universe would do Need to produce 1 extra quark for every 10 billion antiquarks! Sakharov Conditions Three conditions must be satisfied: Sakharov, JETP Lett. 5, 24 (1967) 1) Baryon number (B) must be violated can t have a baryon asymmetry w/o violating baryon number! 2) C and CP must be violated a way to differentiate matter from antimatter 3) B and CP violating processes must happen out of equilibrium equilibrium destroys the produced baryon number Seyda Ipek (UCI) 5

6 We need New Physics Couple to the SM Extra CP violation Some out-of-equilibrium process Seyda Ipek (UCI) 6

7 Old New Physics Extra scalar fields First-order phase transition CP violation in the scalar sector 2HDM, MSSM, NMSSM, Out-of-equilibrium decays Leptogenesis CP violation from interference of tree-level and loop processes Heavy right-handed neutrinos, Asymmetry in the dark sector Asymmetry in the visible sector asymmetric dark matter + Affleck-Dine Seyda Ipek (UCI) 7

8 We need New Physics Couple to the SM Let s re-visit SM CP violation Extra CP violation Some out-of-equilibrium process Seyda Ipek (UCI) 8

9 CP Violation in Neutral Meson Mixing We see SM CP violation through neutral meson mixing B d B d K K B s B s D D A few Nobel prizes CKM matrix Top quark Are particle antiparticle oscillations special for CP violation? Seyda Ipek (UCI) 9

10 Particle Antiparticle Oscillations Take a Dirac fermion with an approximately broken U(1) charge L mass = M + m 2 ( c + c ) Dirac mass Majorana mass with interactions L int = g 1 XY + g 2 c XY +h.c. : pseudo-dirac fermion We will want the final state XY to carry either baryon or lepton number Seyda Ipek (UCI) 10

11 Particle Antiparticle Oscillations Hamiltonian: H = M i 2 M = ' M m m M 1 2re i 2 re i 1 eigenvalues: H,L i = p i ± q c i r = g 2 g 1 1 mass states interaction states OSCILLATIONS! Seyda Ipek (UCI) 11

12 Particle Antiparticle 1.0 Oscillations 0.8 1/ important parameter: Probability x m 1/ m 0.2 m = M H M L ' 2m time Goldilocks principle for oscillations x 1 x 1 x 1 Too fast Just right Too slow Seyda Ipek (UCI) 12

13 CP Violation in Oscillations = Z 1 0 dt ( / c! f) ( / c! f) ( / c! f)+ ( / c! f) 10-1 r =0.1 For r = g 2 g 1 1 ϵ sin =0.5 ' 2xrsin 1+x exact approximation CP violation is maximized for x ~ 1 x = 2m / Γ Seyda Ipek (UCI) 13

14 CP Violation ' 2xrsin 1+x 2 Baryon Number Violation Say the final state f has baryon number +1 e.g. RPV SUSY gudd Baryon asymmetry is produced due to oscillations and decays: n B n B = n Seyda Ipek (UCI) 14

15 How to decay out of thermal equilibrium? Oscillations in the early Universe? Seyda Ipek (UCI) 15

16 Oscillations in the early Universe are complicated M 300 GeV Rates (ev) 10-4 Hubble rate Big Bang? 10-6 Time z = M/T Seyda Ipek (UCI) 16

17 Oscillations in the early Universe are complicated M 300 GeV Rates (ev) 10-4 Hubble rate Big Bang? 10-6 Decay rate Time z = M/T Out-of-equilibrium decay:. H(T M) Seyda Ipek (UCI) 17

18 Oscillations in the early Universe are complicated M 300 GeV Oscillations start when! osc >H Rates (ev) 10-4 Hubble rate ω osc = 2m Big Bang? 10-6 Decay rate Time z = M/T Out-of-equilibrium decay:. H(T M) Seyda Ipek (UCI) 18

19 Oscillations in the early Universe are complicated Particles/antiparticles are in a hot/dense plasma with interactions L scat = 1 2 a f a f Seyda Ipek (UCI) 19

20 Oscillations in the early Universe are complicated What if interactions can tell the difference between a particle and antiparticle? Quantum Zeno effect Oscillations delayed till! osc > ann, scat Seyda Ipek (UCI) 20

21 Oscillations in the early Universe are complicated M 300 GeV Rates (ev) 10-4 Hubble rate Annihilation rate ω osc = 2m Elastic scattering rate Big Bang? 10-6 Decay rate Time z = M/T oscillations are further delayed Seyda Ipek (UCI) 21

22 Oscillations in the early Universe are complicated Described by the time evolution of the density matrix H : Hamiltonian Y: Density matrix O ± = diag(1, ±1) Oscillations zh dy dz = i HY YH ± 2 [O ±, [O ±, Y]] 1 sh vi ± 2 {Y,O ±ȲO ±} Yeq 2 z = M/T Vanishes if scatterings are flavor blind Annihilations not redshift! Seyda Ipek (UCI) 22

23 Oscillations + Decays (z) Y Y c : particle asymmetry M = 300 GeV, = 10 6 ev Δ(z) m = 5 x 10-6 ev, x = 10 m = 2 x 10-6 ev, x = 4 m = 0.25 x 10-6 ev, x = 0.5 r =0.1 sin =0.5 Symmetric initial conditions: (0) = 0 Oscillations are delayed for smaller m (z) = Y eq (1) exp z = M/T z 2H(z) sin 2 m 2H(z) Smaller asymmetry Seyda Ipek (UCI) 23

24 Oscillations + Decays + Annihilations/Scatterings Two types of interactions flavor-blind flavor-sensitive! c : e.g. scalar L! L L! L e.g. vector L = 1 2 ff L = 1 2 µ f µ f f : (massless) fermion : interaction scale Seyda Ipek (UCI) 24

25 Elastic scatterings/annihilations delay oscillations Ignoring decays, particle asymmetry is given by y = z 2 z = M/T d 2 (y) d (y) dy 2 +2! 0 dy (z) Y Y c +! 2 0 (y) =0! 0 m S yh, ann / V scat 2m 1 < 1 overdamped, no oscillations underdamped, system oscillates Seyda Ipek (UCI) 25

26 Elastic scatterings/annihilations delay oscillations flavor-sensitive interactions! osc = scat (z osc ) flavor-blind interactions! osc = ann (z osc ) when oscillations start zosc 10 0 =1fb 0 = 1 ab z = M/T mass difference m (ev) (ev) Seyda Ipek (UCI) 26

27 Oscillations + Decays + Annihilations/Scatterings (z) Y + Y c : total number of particles 10-3 M = 300 GeV m ev Σ(z) 10-6 No annihilation <σv> =10-2 ab <σv> =1 ab = 10 6 ev sin =0.5 r = z = zm/t flavor-sensitive Seyda Ipek (UCI) 27

28 Oscillations + Decays + Annihilations/Scatterings (z) ' Y eq (z osc )exp 2H(z) sin 2 m 2H(z) Δ(z) No annihilation <σv> =10-2 ab <σv> =1 ab M = 300 GeV m ev = 10 6 ev sin =0.5 r = Oscillations are delayed z = M/T Smaller asymmetry z Seyda Ipek (UCI) 28

29 How about baryon asymmetry? Annihilations freeze-out Hubble rate Annihilation rate z f ' 20 Rates (ev) 10-4 ω osc 10-6 Decay rate z = M/T Seyda Ipek (UCI) 29

30 How about baryon asymmetry? Annihilations freeze-out Hubble rate Decay rate Annihilation rate ω osc Elastic scattering rate z f ' 20 Rates (ev) Oscillations start z osc ' z = M/T Seyda Ipek (UCI) 30

31 How about baryon asymmetry? Annihilation rate Elastic scattering rate Annihilations freeze-out z f ' 20 Rates (ev) Hubble rate Decay rate ω osc z = M/T Oscillations start z osc ' 60 Annihilations are Boltzmann suppressed ann Oscillate a few times Produce the baryon asymmetry ' (z osc ) Seyda Ipek (UCI) 31

32 Let there be baryons! For z>z osc baryon asymmetry is given by: d B (z) dz ' zh (z) 10-3 (z) Flavor-sensitive Abundancies M = 300 GeV m = ev = 10 6 ev = /6 (z) 0 = 10 2 ab 0 = 1 ab BARYONS!!! B(z) z = M/T z B = Y B Y B : baryon asymmetry Seyda Ipek (UCI) 32

33 My history of the Universe hot K K K 3,000 K Temperature p n n p Big Bang Time Inflation Equal number of particles and antiparticles Antiparticles turn into particles n p n p p p n n n p n Particles decay into protons and neutrons Atoms, stars, galaxies are formed 1 ns 10 ns 1 s 300, billion years years Seyda Ipek (UCI) 33

34 What kind of model? Oscillations Pseudo-Dirac fermions Approximately broken U(1) symmetry DM theories with a global U(1)? global symmetries are broken by gravity Seyda Ipek (UCI) 34

35 Hall, Randall, Nuc.Phys.B Kribs, Poppitz, Weiner, arxiv: Frugiuele, Gregoire, arxiv: SI, McKeen, Nelson, arxiv: SI, John March-Russell, arxiv: Pilar Coloma, SI, arxiv: My favorite model for everything! U(1)R -symmetric SUSY Has Dirac gauginos Dirac gauginos are awesome - less tuning for heavier stops Solves SUSY CP and flavor problems, Seyda Ipek (UCI) 35

36 U(1)R symmetric SUSY Sfermions have +1 R-charge Fields SU(3) c SU(2) L U(1) Y U(1) R Q = q + q 3 2 1/6 1 Ū = ū + ū 3 1-2/3 1 D = d + d 3 1 1/3 1 D = D + D 3 1 1/3 1 D = D + D 3 1-1/3 1 W B, B S = s + S Bino has +1 R-charge Singlino (S) has -1 R-charge (pseudo)-dirac gauginos! Seyda Ipek (UCI) 36

37 U(1)R symmetric SUSY Fields SU(3) c SU(2) L U(1) Y U(1) R Q = q + q 3 2 1/6 1 Ū = ū + ū 3 1-2/3 1 D = d + d 3 1 1/3 1 D = D + D 3 1 1/3 1 D = D + D 3 1-1/3 1 W B, B S = s + S New superfields non-gauge couplings for Dirac partners Seyda Ipek (UCI) 37

38 Pseudo-Dirac gauginos Take the bino and the singlino: B (1, 1, 0) +1 S (1, 1, 0) 1 Fox, Nelson, Weiner, hep-ph/ L mass M D BS + M D B S U(1)R must be broken because (anomaly mediation) (Small) Majorana mass for the bino m B = (g) g m 3 3/ M 2 Pl F some conformal parameter. F. m 3/2 Arkani-Hamed, et al, hep-ph/ Seyda Ipek (UCI) 38

39 SUSY CP Problem Electron electric dipole moment: de 0.87x10-28 e cm ACME, Science 343 (2014) What we have in the SM: γ What SUSY has: γ e EW loop de e cm e e L ẽ L ẽ R e R SUSY CP problem Seyda Ipek (UCI) 39

40 SUSY CP Problem: Solved Due to the UR(1) symmetry: No (very small) Majorana gaugino masses No left-right mixing for sfermions γ (similar story for the flavour problem) e L ẽ L ẽ R e R We can have large CP violating parameters w/o affecting EDMs Seyda Ipek (UCI) 40

41 Pseudo-Dirac bino oscillations Mass terms: L mass! M D BS m B B B + ms SS +h.c. Let s also consider R-parity violation L e = G B B ū d d + GS S ū d d +h.c. G B g Y m 2 sf 00 G S g S 00 m 2 Remember from before: L mass = M + m 2 ( c + c ) with interactions bino antibino L int = g 1 XY + g c 2 XY +h.c. udd udd Seyda Ipek (UCI) 41

42 Pseudo-Dirac bino oscillations Oscillation Hamiltonian: H = MD m m M D i 2 1 2re i 2re i 1 with annihilations + elastic scatterings: g V,A = Y 2 R ± Y 2 L 2 L scat = g2 Y m 2 sf F = fl f R ' M 5 (32 ) 3 G B 2 r = G S G B 1 µp L F µ (g V + g A 5 )F flavor sensitive, oscillations are delayed, etc etc Seyda Ipek (UCI) 42

43 Let there be baryons! 10-3 (z) Abundancies M = 300 Σ(z) GeV m ev Δ(z) = 10 6 ev Δ B (z) = /6, r =0.1 (z) m sf = 20 TeV m sf = 10 TeV z = M/T z B(z) BARYONS!!! Seyda Ipek (UCI) 43

44 Outlook Sfermions are a few TeV (no lighter than ~ 3 TeV) O(100 GeV - TeV) particles Decay rate < 10-4 ev Colliders! travels > mm displaced vertices! How about lepton number violation? same-sign lepton asymmetry? Connection to asymmetric DM? Seyda Ipek (UCI) 44

45 backup slides Seyda Ipek (UCI) 45

46 Time dependent oscillations (t)i = g + (t) i c (t)i = g + (t) c i q p g (t) c i, p q g (t) i g ± (t) = 1 2 e im Ht 1 2 Ht ± e im Lt 1 2 L t Seyda Ipek (UCI) 46

47 Oscillations+Decays d 2 (y) d (y) dy 2 +2! 0 dy +! 2 0 (y) =! 2 0 (y) For: (z) =2Y eq (1) exp 2H(z) for z>1 Solution is (z) ' A Y eq (1) exp 2H(z) sin 2 m 2H(z) + Seyda Ipek (UCI) 47

48 Different mass difference 10-6 M = 300 GeV = /6, r =0.1 0 = 1 ab = 10 4 ev Δ B 10-8 = 10 5 ev = 10 6 ev m (ev) = 10 7 ev Seyda Ipek (UCI) 48

49 Oscillation start times Hubble z osc 6 r ev m M 300 GeV Flavor-blind "10 7 z osc ln M 300 GeV ev m 0 1fb # Flavor-sensitive z osc ' 80 M 300 GeV 3/ ev m 1/5 0 1fb 1/5 Seyda Ipek (UCI) 49

50 Elastic scatterings delay oscillations M 300 GeV 1 h vi =1fb 10-2 annihilation rate scattering rate Rates (ev) 10-4 Hubble rate ωosc = 2m Big Bang? Time 10-6 Decay rate z = M/T Seyda Ipek (UCI) 50