Electroweak baryogenesis by axionlike dark matter

Sang Hui Im,Kwang Sik Jeong,Yeseong Lee

doi:10.1103/physrevd.105.035028

Sang Hui Im, Kwang Sik Jeong + Show 1 more

Open Access

https://doi.org/10.1103/physrevd.105.035028

Copy DOI

Abstract

We show that an axionlike particle (ALP) naturally implements spontaneous electroweak baryogenesis through a cosmic evolution strongly tied to the electroweak phase transition (EWPT) if it feebly couples to the Higgs field while giving a small contribution to the Higgs boson mass. The observed baryon asymmetry can be generated successfully if the ALP couples strongly enough to the electroweak anomaly. Also interesting is that the ALP contributes to dark matter, and its coupling to a hidden gauge sector makes the relic abundance insensitive to the cosmic history before the EWPT. The ALP explains both the baryon asymmetry and dark matter in a wide range of the couplings owing to the friction induced by the hidden gauge sector. To be compatible with cosmological and astrophysical observations, the ALP should have a mass in the range between about 0.01 and 30 eV, and is further required to be photophobic if its coupling to the electroweak anomaly is strong, constraining the field content and charge assignment of the UV completion.

Highlights

The observed matter-antimatter asymmetry and the cosmological constraints on dark matter strongly point to the existence of new physics beyond the Standard Model (SM)
We show that an axionlike particle (ALP) naturally implements spontaneous electroweak baryogenesis through a cosmic evolution strongly tied to the electroweak phase transition (EWPT) if it feebly couples to the Higgs field while giving a small contribution to the Higgs boson mass
We have shown that an ALP coupled to the Higgs field can provide the observed dark matter abundance and further relate it with the matter-antimatter asymmetry of the Universe

Summary

INTRODUCTION

The observed matter-antimatter asymmetry and the cosmological constraints on dark matter strongly point to the existence of new physics beyond the Standard Model (SM). We show that an axionlike particle (ALP) coupled to the Higgs field can account for both the baryon asymmetry and dark matter of the Universe. Contribution to the Higgs boson mass is tiny Because it undergoes a cosmic evolution strongly tied to the electroweak phase transition (EWPT), which is a crossover as in the SM, the ALP implements spontaneous electroweak baryogenesis [1,2,3,4,5,6] via its coupling to the electroweak anomaly suppressed by a scale f. ALP should overcome the Hubble and thermal friction at temperatures above the EWPT This puts a lower bound on the ALP mass for F and f fixed to explain both the baryon asymmetry and dark matter.

ALP EVOLUTION

BARYON AND DARK MATTER GENESIS

EXPERIMENTAL CONSTRAINTS

CONCLUSIONS