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Related papers: Cosmic QCD Epoch at Nonvanishing Lepton Asymmetry

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We study the influence of lepton asymmetry on the evolution of the early Universe. The lepton asymmetry $l$ is poorly constrained by observations and might be orders of magnitude larger than the baryon asymmetry $b$, $|l|/b \leq 2\times…

High Energy Physics - Phenomenology · Physics 2014-11-20 Dominik J Schwarz , Maik Stuke

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

The lepton flavour asymmetries of the Universe are observationally almost unconstrained before the onset of neutrino oscillations. We calculate the cosmic trajectory during the cosmic QCD epoch in the presence of large lepton flavour…

High Energy Physics - Phenomenology · Physics 2022-05-19 Fei Gao , Isabel M. Oldengott

We compute the full cosmic trajectories of the early Universe across the QCD phase diagram as the plasma cools from $T\simeq500\,$MeV to $30\,$MeV, assuming $\beta$-equilibrated matter. The trajectories are obtained by simultaneously…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-04 Lorenzo Formaggio , Francesco Di Clemente , Geetika Yadav , Alessandro Drago , Claudia Ratti

We study the early Universe trajectory around the QCD transition in lepton-flavor-asymmetric cases with small total lepton asymmetry ($|\ell|\lesssim 10^{-2}$), while allowing large individual lepton asymmetries. For each temperature, we…

High Energy Physics - Phenomenology · Physics 2025-11-18 Francesco Di Clemente , Alessandro Drago , Lorenzo Formaggio , Claudia Ratti , Volodymyr Vovchenko , Geetika Yadav

The lepton asymmetry of order one is not excluded experimentally and, if present, can lead to interesting phenomena in the early Universe. It is shown that, when the temperature is above the quark-hadron transition, the lepton asymmetry…

High Energy Physics - Phenomenology · Physics 2009-10-31 K. Zarembo

We study the impact of large lepton flavour asymmetries on the cosmic QCD transition. Scenarios of unequal lepton flavour asymmetries are observationally almost unconstrained and therefore open up a whole new parameter space for the cosmic…

High Energy Physics - Phenomenology · Physics 2022-06-28 Mandy M. Middeldorf-Wygas , Isabel M. Oldengott , Dietrich Bödeker , Dominik J. Schwarz

The total lepton asymmetry $l=\sum_f l_f$ in our universe is only poorly constrained by theories and experiments. It might be orders of magnitudes larger than the observed baryon asymmetry $b\simeq {\cal O}(10^{-10})$, $|l|/b \leq {\cal…

High Energy Physics - Phenomenology · Physics 2011-03-28 Maik Stuke

A large primordial lepton asymmetry can lead to successful baryogenesis by preventing the restoration of electroweak symmetry at high temperatures, thereby suppressing the sphaleron rate. This asymmetry can also lead to a first-order cosmic…

High Energy Physics - Phenomenology · Physics 2025-08-29 Fei Gao , Julia Harz , Chandan Hati , Yi Lu , Isabel M. Oldengott , Graham White

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 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

A large lepton asymmetry in the Universe is still a viable possibility and leads to many interesting phenomena such as gauge symmetry nonrestoration at high temperature. We show that a large lepton asymmetry changes the predicted cosmic…

High Energy Physics - Phenomenology · Physics 2009-10-31 William H. Kinney , Antonio Riotto

We discuss the cosmological consequences of QCD phase transition(s) on the early universe. We argue that our recent knowledge about the transport properties of quark-gluon plasma (QGP) should throw additional lights on the actual time…

High Energy Physics - Phenomenology · Physics 2010-03-26 A. Tawfik

A QCD phase transition in the early universe could have left inhomogeneities in the baryon to photon ratio and in isospin that might have affected nucleosynthesis later on. At very high temperature QCD plasma can be described by…

Astrophysics · Physics 2007-05-23 Joseph I Kapusta

We propose a new mechanism for late cosmological baryon asymmetry in models with first order electroweak phase transition. Lepton asymmetry arises through the decay of particles produced out of equilbrium in bubble collisions and is…

High Energy Physics - Phenomenology · Physics 2011-07-19 Antonio Masiero , Antonio Riotto

We propose a new scenario to simultaneously explain a large lepton asymmetry and a small baryon asymmetry. We consider a rolling scalar field and its derivative coupling to the lepton number current. The presence of an effective nonzero…

High Energy Physics - Phenomenology · Physics 2009-11-07 Masahide Yamaguchi

A poorly constrained parameter in the Standard Model of Cosmology is the lepton asymmetry l = \sum_f l_f=\sum_f(n_f+n_{\nu_f})/s. Each flavour asymmetry l_f with f=e, \mu, {\tau} is the sum of the net particle density of the charged leptons…

High Energy Physics - Phenomenology · Physics 2015-06-03 Dominik J. Schwarz , Glenn D. Starkman , Maik Stuke

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

We study the possibility of generating baryon asymmetry of the universe from dark matter (DM) annihilations during non-standard cosmological epochs. Considering the DM to be of weakly interacting massive particle (WIMP) type, the generation…

High Energy Physics - Phenomenology · Physics 2023-03-29 Devabrat Mahanta , Debasish Borah

We study lepton asymmetry evolution in plasma of the early Universe before the electroweak phase transition (EWPT) accounting for chirality flip processes via Higgs decays (inverse decays) entering equilibrium at temperatures below T_RL ~…

Cosmology and Nongalactic Astrophysics · Physics 2013-01-23 Maxim Dvornikov , Victor B. Semikoz
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