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Related papers: Upper Bound on the Cosmic Baryon Chemical Potentia…

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A chiral chemical potential present in the early universe can source helical hypermagnetic fields through the chiral plasma instability. If these hypermagnetic fields survive until the electroweak phase transition, they source a…

High Energy Physics - Phenomenology · Physics 2023-07-12 Valerie Domcke , Kohei Kamada , Kyohei Mukaida , Kai Schmitz , Masaki Yamada

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 investigate how a lepton asymmetry impacts the cosmic trajectory in the QCD phase diagram. We study the evolution of chemical potentials during the QCD epoch of the early Universe using susceptibilities from lattice QCD to interpolate…

High Energy Physics - Phenomenology · Physics 2018-11-20 Mandy M. Wygas , Isabel M. Oldengott , Dietrich Bodeker , 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

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

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

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

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

We report on the first searches for lepton flavour violating $\tau^-$ decays at a hadron collider. These include searches for the lepton flavour violating decay $\tau^-\to \mu^+\mu^-\mu^-$ and the lepton flavour and baryon number violating…

High Energy Physics - Experiment · Physics 2015-09-08 Jonathan Harrison

The thermal restoration of chiral symmetry in QCD is known to proceed by an analytic crossover, which is widely expected to turn into a phase transition with a critical endpoint as the baryon density is increased. In the absence of a…

High Energy Physics - Lattice · Physics 2021-11-08 Owe Philipsen

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

We investigate the Taylor expansion of the baryon number susceptibility, and hence, pressure, in a series in the baryon chemical potential (mu_B) through a lattice simulation with light dynamical staggered quarks at a finer lattice cutoff…

High Energy Physics - Lattice · Physics 2008-12-30 R. V. Gavai , Sourendu Gupta

We present a phase diagram study of the O(4) model as an effective theory for 2-flavor QCD. In the chiral limit, both theories perform spontaneous symmetry breaking with isomorphic groups, which suggests that they belong to the same…

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 map out the QCD crossover line $\frac{T_c(\mu_B)}{T_c(0)} = 1 - \kappa_2 \left( \frac{\mu_B}{T_c(0)} \right)^2 - \kappa_4 \left( \frac{\mu_B}{T_c(0)} \right)^4 + \mathcal{O}(\mu_B^6)$ for the first time up to $\mathcal{O}(\mu_B^4)$ for a…

High Energy Physics - Lattice · Physics 2019-02-20 Patrick Steinbrecher

Despite intense experimental and theoretical research, the QCD phase diagram at finite baryon density remains to a large extent unexplored. From the theoretical side, the obvious non-perturbative approach is lattice QCD simulations, which…

This is a review of the cosmological bounds on $B-L$ violating interactions, and the loopholes in the argument that gives these constraints. If one assumes that the baryon asymmetry we observe today was present above the electroweak phase…

High Energy Physics - Phenomenology · Physics 2007-05-23 Sacha Davidson

Previously, it was found that pion superfluidity could be realized in the QCD epoch of the early universe, when lepton flavor asymmetry $|l_{\rm e}+l_\mu|$ is large enough to generate a charge chemical potential $|\mu_{\rm Q}|$ larger than…

High Energy Physics - Phenomenology · Physics 2024-05-14 Gaoqing Cao

We propose a scenario to produce large primordial lepton flavor asymmetries with vanishing total lepton asymmetry, based on the Affleck-Dine mechanism with Q-ball formation. This scenario can produce large lepton flavor asymmetries while…

High Energy Physics - Phenomenology · Physics 2026-02-17 Kensuke Akita , Koichi Hamaguchi , Maksym Ovchynnikov

We show that the nonlocal two-flavor Nambu--Jona-Lasinio model predicts the enhancement of both chiral and axial symmetry breaking as the chiral imbalance of hot QCD matter, regulated by a chiral chemical potential $\mu_5$, increases. The…

High Energy Physics - Phenomenology · Physics 2020-07-22 Marco Ruggieri , Maxim N. Chernodub , Zhen-Yan Lu
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