Why is there more matter than antimatter? Calculational methods for leptogenesis and electroweak baryogenesis

Garbrecht, Björn

doi:10.1016/j.ppnp.2019.103727

Cited by 62 publications

(65 citation statements)

References 159 publications

(383 reference statements)

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“…It is of particular interest to compare our approach with several other transport theory formulations that also employ the closed time path (CTP) methods, such as those presented in refs. [35][36][37][38][39][40][41][42].…”

Section: A Numerical Examplementioning

confidence: 99%

Quantum transport and the phase space structure of the Wightman functions

Jukkala

Kainulainen

Koskivaara

2020

J. High Energ. Phys.

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We study the phase space structure of exact quantum Wightman functions in spatially homogeneous, temporally varying systems. In addition to the usual mass shells, the Wightman functions display additional coherence shells around zero frequency k 0 = 0, which carry the information of the local quantum coherence of particle-antiparticle pairs. We find also other structures, which encode non-local correlations in time, and discuss their role and decoherence. We give a simple derivation of the cQPA formalism, a set of quantum transport equations, that can be used to study interacting systems including the local quantum coherence. We compute quantum currents created by a temporal change in a particle's mass, comparing the exact Wightman function approach, the cQPA and the semiclassical methods. We find that the semiclassical approximation, which is fully encompassed by the cQPA, works surprisingly well even for very sharp temporal features. This is encouraging for the application of semiclassical methods in electroweak baryogenesis with strong phase transitions.

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Section: A Numerical Examplementioning

confidence: 99%

Quantum transport and the phase space structure of the Wightman functions

Jukkala

Kainulainen

Koskivaara

2020

J. High Energ. Phys.

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“…In extensions of the Standard Model where electroweak symmetry breaking in the early universe occurs through such a first-order transition, bubbles may turn out to be pivotal for generating the cosmic matter-antimatter asymmetry [13][14][15] (for a recent review, see Ref. [16]).…”

Section: Contentsmentioning

confidence: 99%

“…τ ))) χ a n (τ ) = κ a n χ a n (τ ) (A. 16) with Dirichlet boundary conditions χ a n (τ = ±T 2) = 0. We refer Eq.…”

Section: A2 Contour Integration In Field Space and Flow Equationsmentioning

confidence: 99%

“…For λ a n > 0, we simply have χ a n (τ ) = f a n (τ ) and κ a n = λ a n . For the negative mode f B 0 (τ ), 16 we have χ B 0 (τ ) = if B 0 (τ ) in order to have positive κ B 0 . Now let us look at the integrand exp(I[z]) in the path integral by substituting z(τ ; u) = z a (τ ) + ∑ n g a n (u)χ a n (τ ) into I[z].…”

Section: A2 Contour Integration In Field Space and Flow Equationsmentioning

confidence: 99%

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Functional methods for false-vacuum decay in real time

Garbrecht

Tamarit

2019

J. High Energ. Phys.

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We present the calculation of the Feynman path integral in real time for tunneling in quantum mechanics and field theory, including the first quantum corrections. For this purpose, we use the well-known fact that Euclidean saddle points in terms of real fields can be analytically continued to complex saddles of the action in Minkowski space. We also use Picard-Lefschetz theory in order to determine the middle-dimensional steepest-descent surface in the complex field space, constructed from Lefschetz thimbles, on which the path integral is to be performed. As an alternative to extracting the decay rate from the imaginary part of the ground-state energy of the false vacuum, we use the optical theorem in order to derive it from the real-time amplitude for forward scattering. While this amplitude may in principle be obtained by analytic continuation of its Euclidean counterpart, we work out in detail how it can be computed to one-loop order at the level of the path integral, i.e. evaluating the Gaußian integrals of fluctuations about the relevant complex saddle points. To that effect, we show how the eigenvalues and eigenfunctions on a thimble can be obtained by analytic continuation of the Euclidean eigensystem, and we determine the path-integral measure on thimbles. This way, using real-time methods, we recover the one-loop result by Callan and Coleman for the decay rate. As a byproduct of our derivation, we note that the optical theorem suggests an interpretation of the false-vacuum energy in flat space in terms of the normalization of the position or field eigenstate associated with the false vacuum, with unit norm corresponding to zero energy up to volume-suppressed effects. We finally demonstrate our real-time methods explicitly, including the construction of the eigensystem of the complex saddle, on the archetypical example of tunneling in a quasi-degenerate quartic potential. arXiv:1905.04236v1 [hep-th]

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“…The departure from thermal equilibrium can occur due to phase transitions and the expansion of the Universe. Furthermore, the baryon and the lepton numbers are violated due to the weak sphaleron processes and the hypercharge Abelian anomaly at finite temperature [10,11]. In fact, the matter-antimatter asymmetry generation and the magnetogenesis, which is the generation of long range magnetic fields in the Universe, are strongly intertwined via these hypercharge Abelian anomalous effects.…”

Section: Introductionmentioning

confidence: 99%

Contribution of the chiral vortical effect to the evolution of the hypermagnetic field and the matter-antimatter asymmetry in the early Universe

2019

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In this paper, we study the contribution of the chiral vortical effect, in addition to that of the chiral magnetic effect, to the evolution of the hypermagnetic field and the matter-antimatter asymmetry in the symmetric phase of the early Universe in the temperature range 100GeV ≤ T ≤ 10TeV. We choose a fully helical Chern-Simons wave configuration for the velocity and the hypermagnetic vector potential fields. The latter makes the plasma force-free in the absence of viscosity. We show that the most pronounced effect of the chiral vorticity is the production and initial growth of the hypermagnetic field. In particular, we show that in the presence of a non-zero matter asymmetry, the hypermagnetic field can grow from zero initial value only in the presence of a non-zero vorticity field. Moreover, we show that this initial growth not only increases the maximum value of the hypermagnetic field, but also causes the saturation of the hypermagnetic field and the conversion of the lepton-baryon asymmetry to occur more quickly, i.e., at a higher temperature. We show that the damping of the vorticity due to the presence of viscosity, which typically occurs extremely rapidly, does not significantly affect the evolution. * s − abbasluo@sbu.ac.ir

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Why is there more matter than antimatter? Calculational methods for leptogenesis and electroweak baryogenesis

Cited by 62 publications

References 159 publications

Quantum transport and the phase space structure of the Wightman functions

Quantum transport and the phase space structure of the Wightman functions

Functional methods for false-vacuum decay in real time

Contribution of the chiral vortical effect to the evolution of the hypermagnetic field and the matter-antimatter asymmetry in the early Universe

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