An Introduction to Cosmology Lecture 2. (University of Wisconsin Madison)

Transcription

1 An Introduction to Cosmology Lecture 2 Daniel Chung (University of Wisconsin Madison)

2 Outline of lecture 2 Quantitative elements of EW bgenesis number Explain transport eqs. for electroweak baryogenesis Introduction to in-in formalism for out of equilibrium computations

3 Quantitative Elements of EW Baryogenesis

4 BSM ingredients (blue = not generic without singlets; red = tuned): 1) High T; 2) bubbles nucleate; 3) bubble coupling to CPV; 4) efficient diffusion; 5) CP charge quarks + leptons; 6) B-violating sphaleron suppression in broken phase Not much room: 1 3 4, 5 2, 6 In MSSM Maybe enhanced through extra dim? coupled. transport/source calc problem suppression can be unsuppressed by Sometimes suppressed also by mixing change e.g.

5 BSM ingredients (blue = not generic without singlets; red = tuned): 1) High T; 2) bubbles nucleate; 3) bubble coupling to CPV; 4) efficient diffusion; 5) CP charge quarks + leptons; 6) B-violating sphaleron suppression in broken phase 1 3 4, 5 2, 6 In MSSM coupled. transport/source calc problem Light for cubic coupling corners parameter spaces. Higgs mass lower bd large decouple chargino sector

6 BSM ingredients (blue = not generic without singlets; red = tuned): 1) High T; 2) bubbles nucleate; 3) bubble coupling to CPV; 4) efficient diffusion; 5) CP charge quarks + leptons; 6) B-violating sphaleron suppression in broken phase 1 3 4, 5 2, 6 coupled. transport/source calc problem Enlarge param space with singlets [ Anderson and Hall 92; Pietroni 93; many others since then] Nonrenormalizable ops [e.g. Zhang 93; Grojean, Servant, Wells 04; ; Blum, Nir 08]

7 BSM ingredients (blue = not generic without singlets; red = tuned): 1) High T; 2) bubbles nucleate; 3) bubble coupling to CPV; 4) efficient diffusion; 5) CP charge quarks + leptons; 6) B-violating sphaleron suppression in broken phase 1 3 4, 5 2, 6 coupled. transport/source calc problem Where the phase occurs allows weaker EDM bounds either through coupling suppression or sector sequestering and/or spontaneous CP violation. [e.g. in smssm (4 SM singlets + 2 doublets) Kang, Langacker, Li, Liu 09]

8 BSM ingredients (blue = not generic without singlets; red = tuned): 1) High T; 2) bubbles nucleate; 3) bubble coupling to CPV; 4) efficient diffusion; 5) CP charge quarks + leptons; 6) B-violating sphaleron suppression in broken phase 1 3 4, 5 2, 6 Picture that emerges: 1) The scalar sector will be non-minimal in either d.o.f. and/or physics. 2) Either by discrete symmetry or accidental cancellation (0.1 tuning) 3) CP violation sector is either secluded or we will see EDMs if we continue to push experimental sensitivity.

9 1 3 4, 5 2, 6 coupled. transport/source calc problem A popularly discussed source of technical challenges [Riotto 96; Carena, Quiros, Riotto, Vilja, Wagner 97; Carena, Moreno, Quiros, Seco, Wagner 00; Prokopec, Schmidt, Weinstock 01, 03; Kainulainen, Prokopec, Schmidt, Weinstock 01; Konstandin, Prokopec, Schmidt 04; Huber, Konstandin, Prokopec, Schmidt 06; ]

10 Theoretical Uncertainties Transport challenges: 1) spatially inhomogeneous 2) out of equilibrium 3) messy thermal kinematics 4) many order 1 effects 5) BSM can have large number of dof Approximations involve expansions that can be subtle: spacetime dependent VEV Collisions and mixing Ideally, want to begin with above

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12 Charge transport

13 Efficient diff: Scales in Charge Transport

14 CP violation Unsuppressed bubble (i.e. ) coupling to CP violating physics. e.g. one popularly considered source in MSSM Physics: local mass eigenstates do not remain mass eigenstates over VEV insertion approx [Riotto 96; Carena, Quiros, Riotto, Vilja, Wagner 97] CP asymmetry carriers must be thermally populated.

15 Diffusion s Effect Efficient diffusion is useful [Cohen et al 94; Joyce, Prokopec, Turok 94] More charge gets out with less damping Weakly interacting CP asymmetry carrier. (Higgs compared to quarks)

16 CP Asymmetry to B-violating Sector Efficient transfer of CP asymmetry to the B-violating sector e.g. MSSM and similar scenarios: top Yukawa also for even for [DC, Garbrecht, Ramsey-Musolf, Tulin, 08,09]

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20 Quantum transport Eq.

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33 Improvements [Cirigliano, Lee, Tulin 11] [Konstandin, Prokopec, Schmidt, Seco 05]

34 On-off switch Intuition for Boltzmann Eq.

35 EDM Constraints [Baker et al 06; Griffith et al 09; Hudson et al 11] 1.5 improvement e.g.

36 Lec 2 summary 1) Electroweak Bgenesis predictions: a) The scalar sector will be non-minimal either in d.o.f. and/or physics. b) There is likely to be a discrete symmetry or an accidental cancellation in the scalar sector. c) CP violation sector is either secluded or we will see EDMs if we continue to push experimental sensitivity. If secluded, richer spectrum is likely explaining why we do not see EDMs. 2) CPV source/diffusion computation technology is converging, although still incomplete.

37 Big Questions in Cosmology 1) What is the mass and non-gravitational interactions of DM(s)? a recent twist: dark energy discovery dark matter/baryon = O(1) one recent response: asymmetric dark matter relating chemical potentials 2) Why are there more baryons than antibaryons? general wisdom: electroweak scale scenarios are the only ones fully testable in the near future. 3) Is it inflation or are there alternatives? What kind of inflation if inflation? anticipation: Planck data can rule out all single field models; N-point function phenomenology curiosity: anisotropic inflationary models, vector fields driving inflation 4) What solves the classical singularities of general relativity? The answer can change much of our view of inflation. 5) Cosmological constant problem. It is curious that we talk about effective field theories and naturalness to guide inflation (= ds physics) when CC (ds curvature problem) is considered unnatural indicating a possible failure of EFT regarding questions of ds space.