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Related papers: Lepton asymmetry and the cosmic QCD transition

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A large neutrino asymmetry is an interesting possibility for cosmology, which can have significant observable consequences for nucleosynthesis and the cosmic microwave background. However, although it is a possibility, there is no obvious…

High Energy Physics - Phenomenology · Physics 2009-10-31 John McDonald

A cosmic lepton asymmetry $\eta_{\text{l}}=(n_{\text{l}}-n_{\bar{\text{l}}})/n_{\gamma}$ affects the primordial helium abundance and the expansion rate of the early Universe. Both of these effects have an impact on the anisotropies of the…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-25 Isabel M. Oldengott , Dominik J. Schwarz

The QCD phase diagram might exhibit a first order phase transition for large baryochemical potentials. We explore the cosmological implications of such a QCD phase transition in the early universe. We propose that the large baryon-asymmetry…

Cosmology and Nongalactic Astrophysics · Physics 2011-03-28 Simon Schettler , Tillmann Boeckel , Jurgen Schaffner-Bielich

A large primordial lepton asymmetry is capable of explaining the baryon asymmetry of the Universe (BAU) through suppression of the electroweak sphaleron rates (``sphaleron freeze-in") which can lead to a first-order cosmic QCD transition…

High Energy Physics - Phenomenology · Physics 2023-09-06 Fei Gao , Julia Harz , Chandan Hati , Yi Lu , Isabel M. Oldengott , Graham White

We determine the possible trajectories the universe may have followed in the QCD phase diagram during the QCD epoch. We focus on the roles of chiral symmetry breaking and pion condensation under high imbalances in lepton asymmetry. Adopting…

High Energy Physics - Phenomenology · Physics 2025-11-11 Osvaldo Ferreira , Eduardo S. Fraga , Maurício Hippert , Jürgen Schaffner-Bielich

In this article, we discuss the mechanism for generating the lepton/baryon number and its subsequent conservation based on extradimensional evolution. The internal angular momentum of extra space is related to the lepton/baryon charge.…

High Energy Physics - Phenomenology · Physics 2021-09-14 Valery V. Nikulin , Sergey G. Rubin

A large lepton number asymmetry of $\mathcal{O}(0.1-1)$ at present universe might not only be allowed but also necessary for consistency among cosmological data. We show that, if a sizeable lepton number asymmetry were produced before the…

High Energy Physics - Phenomenology · Physics 2017-05-10 Gabriela Barenboim , Wan-Il Park

We explore the possibility that the observed baryon asymmetry of the universe is the result of an earlier phase transition in which an extended gauge sector breaks down into the $SU(3)_C \times SU(2)_L \times U(1)_Y$ of the Standard Model.…

High Energy Physics - Phenomenology · Physics 2008-11-26 Jing Shu , Tim M. P. Tait , Carlos E. M. Wagner

We discuss the interplay between lepton asymmetry L and neutrino oscillations in the early Universe. Neutrino oscillations may suppress or enhance previously existing L. On the other hand L is capable to suppress or enhance neutrino…

Cosmology and Nongalactic Astrophysics · Physics 2013-02-14 Daniela Kirilova

The formation of baryon asymmetry in the Universe is considered in the left-right asymmetry model of weak interaction. In this model, the nature of CP violation is associated with the presence of a right vector boson admixture, with a…

High Energy Physics - Phenomenology · Physics 2026-05-22 A. P. Serebrov , O. M. Zherebtsov , A. K. Fomin , R. M. Samoilov , N. S. Budanov

The baryon asymmetry of the Universe should have been produced after the inflation era. We consider the possibility that the asymmetry is generated by the flavor oscillations in the reheating process after inflation, so that the baryon…

High Energy Physics - Phenomenology · Physics 2016-11-10 Yuta Hamada , Ryuichiro Kitano

We investigate the issue of how accurately we can constrain the lepton number asymmetry xi_nu = mu_nu/T_nu in the Universe by using future observations of 21 cm line fluctuations and cosmic microwave background (CMB). We find that…

Cosmology and Nongalactic Astrophysics · Physics 2016-02-09 Kazunori Kohri , Yoshihiko Oyama , Toyokazu Sekiguchi , Tomo Takahashi

We investigate the possible formation of a Bose-Einstein condensed phase of pions in the early Universe at nonvanishing values of lepton flavor asymmetries. A hadron resonance gas model with pion interactions, based on first-principle…

High Energy Physics - Phenomenology · Physics 2021-01-08 Volodymyr Vovchenko , Bastian B. Brandt , Francesca Cuteri , Gergely Endrődi , Fazlollah Hajkarim , Jürgen Schaffner-Bielich

Baryogenesis appears to require lepton number violation. This is naturally realized in extensions of the standard model containing right-handed neutrinos. We discuss the generation of a baryon asymmetry by the out-of-equilibrium decay of…

High Energy Physics - Phenomenology · Physics 2007-05-23 W. Buchmuller , M. Plumacher

We analyze the effects of lepton asymmetry on neutrino oscillations and on cosmological nucleosynthesis with active-sterile oscillating neutrinos. It is shown that small lepton asymmetries, L < 0.01, whose direct kinetic effect on…

Astrophysics · Physics 2009-11-06 Daniela Kirilova , Mihail Chizhov

Non-perturbative electroweak effects, in thermal equilibrium in the early universe, have the potential to erase the baryon asymmetry of the universe, unless it is encoded in a B-L asymmetry, or in some "accidentally" conserved quantity. We…

High Energy Physics - Phenomenology · Physics 2009-09-11 B. A. Campbell , S. Davidson , J. Ellis , And K. A. Olive

The Baryon-Lepton difference ($B-L$) is increasingly emerging as a possible new symmetry of the weak interactions of quarks and leptons as a way to understand the small neutrino masses. There is the possibility that current and future…

High Energy Physics - Phenomenology · Physics 2015-06-23 Rabindra N. Mohapatra

We calculate Boltzmann neutrino energy transport with self-consistently coupled nuclear reactions through the weak-decoupling-nucleosynthesis epoch in an early universe with significant lepton numbers. We find that the presence of lepton…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-08 E. Grohs , George M. Fuller , C. T. Kishimoto , Mark W. Paris

A novel mechanism for explaining the matter-antimatter asymmetry of the universe is considered. We assume that the universe starts from completely symmetric state and then, as it cools down, it undergoes a quantum-phase transition which in…

Cosmology and Nongalactic Astrophysics · Physics 2011-05-31 V. R. Shaginyan , G. S. Japaridze , M. Ya. Amusia , A. Z. Msezane , K. G. Popov

Particle decay in leptogenesis provides a simple avenue to explain the baryon asymmetric universe, where the decaying particle can provide the out-of-equilibrium condition to create a net lepton asymmetry. It is widely anticipated that the…

High Energy Physics - Phenomenology · Physics 2025-09-05 Shinya Kanemura , Shao-Ping Li