BSMPT - Beyond the Standard Model Phase Transitions -A Tool for the Electroweak Phase Transition in Extended Higgs Sectors

TL;DR

The paper introduces BSMPT, a C++ tool for analyzing electroweak phase transitions in extended Higgs models, incorporating loop corrections and enabling parameter scans relevant for cosmology and collider studies.

Contribution

It provides a flexible, efficient computational framework for evaluating phase transition strength and Higgs self-couplings in extended Higgs sectors, including CP-violating models.

Findings

Enables calculation of critical VEV and temperature for phase transitions.

Supports models like 2HDM and N2HDM with on-shell renormalization.

Facilitates studies linking collider phenomenology and cosmology.

Abstract

We provide the C++ tool BSMPT for calculating the strength of the electroweak phase transition in extended Higgs sectors. This relies on the loop-corrected effective potential at finite temperature including daisy resummation of the bosonic masses. The program allows to compute the vacuum expectation value (VEV) $v$ of the potential as a function of the temperature, and in particular the critical VEV $v_c$ at the temperature $T_c$ where the phase transition takes place. In addition, the loop-corrected trilinear Higgs self-couplings are provided. We apply an 'on-shell' renormalization scheme in the sense that the loop-corrected masses and mixing angles are required to be equal to their tree-level input values. This allows for efficient scans in the parameter space of the models. The models implemented so far are the CP-conserving and the CP-violating 2-Higgs-Doublet Models (2HDM) and the Next-to-Minimal 2HDM (N2HDM). The program structure is such that the user can easily implement further models. Our tool can be used for the investigation of electroweak baryogenesis in models with extended Higgs sectors and the related Higgs self-couplings. The combination with parameter scans in the respective models allows to study the impact on collider phenomenology and to make a link between collider phenomenology and cosmology. The program package can be downloaded at: https://github.com/phbasler/BSMPT.