Program: BSMPT version 3.0.7

Released by: Philipp Basler, Lisa Biermann, Margarete Mühlleitner, Jonas Müller, Rui Santos and João Viana

Manual: version 3.0

BSMPT - Beyond the Standard Model Phase Transitions:

The C++ program package BSMPT allows for the detailed study of (multi-step) phase transitions between temperature-dependent minima in the one-loop daisy-resummed finite-temperature effective potential.

The program tracks temperature-dependent minima, calculates the bounce solution, the characteristic temperatures and gravitational wave signals of first-order phase transitions. The code also allows to derive the loop-corrected trilinear Higgs self-couplings and provides the computation of the baryon asymmetry for the CP-violating 2-Higgs Doublet Model (C2HDM).

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

• Standard Model (SM)
• CP-conserving 2-Higgs-Doublet Model (R2HDM)
• CP-violating 2-Higgs-Doublet Model (C2HDM)
• Next-to-Minimal 2HDM (N2HDM)
• CP in the Dark (arXiv 1807.10322, arXiv 2204.13425)
• Complex Singlet Extension (CxSM)

The code is structured such that users can add their own models.

The program package can be downloaded at: https://github.com/phbasler/BSMPT

The documentation of the code is provided at https://phbasler.github.io/BSMPT/documentation.

Sample input and output files are provided in the directory 'example'.

Modifications and corrected bugs are reported in the file 'Changelog.md'.

For additional information, comments, complaints or suggestions open a corresponding issue or start a discussion. For non-public matters please send an e-mail to bsmpt@lists.kit.edu.

---

Citation:

If you use this program for your work, please cite

• 1803.02846
• 2007.01725
• 2404.19037

Installation:

BSMPT uses cmake and conan 2 for its installation which can be installed through pip with pip3 install cmake conan. In addition, you need a C and C++ compiler installed.

build - simple

If you want the default installation of BSMPT, you can then use the Build.py script. The script Build.py installs the necessary conan profiles for your operating system, handles the dependencies and compiles BSMPT with its default settings in release mode. You can execute it with

python3 Build.py

Dependencies

BSMPT uses cmake and conan 2 for dependencies. The used dependencies are:

1. GSL library.
2. Eigen3
3. libcmaes: Additionally to GSL you should either use libcmaes or NLopt. For more details on the libcmaes installation, e.g. possible dependencies, visit their wiki. If you don't want to install or use it, you can set --options UseLibCMAES=False when using the detailed build, as described below.
4. NLopt: If you do not want to use NLopt, you can set --options UseNLopt=False when using the detailed build, as described below.
5. Boost : This is optional and only required for the Baryogenesis calculations. In order to compile the Baryogenesis calculation, set --options CompileBaryo=True when using the detailed build, as described below.

build - detailed

We provide the script Setup.py which installs conan profiles for your operating system and runs conan install to download the dependencies. If you want to use other profiles feel free to execute conan install with your profile manually or add it to the script.

You can build the code with

python3 Setup.py  
cmake --preset ${profile}  
cmake --build --preset ${profile} -j  
cmake --build --preset ${profile} -j -t doc

The -t doc will use doxygen to create the online help in build/html which can be opened locally. The ${profile} parameter depends on your operating system. After running the Setup script you can call cmake --list-presets to show the found presets.

The script Setup.py can take several optional arguments, run python3 Setup.py -h or python3 Setup.py --help to display them.

Unit tests

After compiling the code call ctest --preset ${profile} -j in the root folder to run some checks. Here the NLO VEV and EWPT for the R2HDM, C2HDM and N2HDM example points will be calculated and compared to the expected results.

Development

Most modern IDEs support cmake profiles. After running the Setup.py script you can open the root folder in an IDE of your choice (e.g. VSCode with cmake extension) and it will recognise the cmake profile.

Code from the following repositories is used in BSMPT:

• ttk592::spline by Tino Kluge, a C++ cubic spline interpolation library
• AsciiPlotter by Joe Hood, for ASCII plots in the terminal

---

How to add a new model:

To add a new model, you have to modify/create five files (for further details, also consult the manual):

1. Go to include/BSMPT/models and copy ClassTemplate.h to YourModel.h. Adjust the name of the class Class_Template to Class_YourModel.

2. Go to src/models and copy ClassTemplate.cpp to YourModel.cpp, and again change Class_Template to Class_YourModel. Also, follow the instructions in this file and in the manual to set up your new model.

3. For your model to compile, you have to open src/models/CMakeLists.txt and add ${header_path}/YourModel.h as well as YourModel.cpp to the listed headers and source files.

4. In include/BSMPT/models/IncludeAllModels.h you need to add a new entry in the enum class ModelIDs above the stop entry which is different from the already defined ModelIDs, e.g. YourModel. Additionally, you have to create a new entry in the const std::unordered_map<std::string, ModelIDs> ModelNames map in the same file and add a new line with {"YourModelName",ModelIDs::YourModel}.

5. In src/models/IncludeAllModels.cpp you have to add #include <BSMPT/models/YourModel.h> to the include list. Also, to be able to call your model, you have to extend the FChoose function. For this you add a new case to the switch statement, which reads

    case ModelIDs::YourModel: return std::make_unique<Class_YourModel>(); break;
   

Generate the C++ code for a model

We provide currently two methods to generate the tensors and calculate the counter terms for a new model.

1. At tools/ModelGeneration/Maple we provide the maple Worksheet CreateModel.mw which you can use to implement your model and get the tensors.
2. At tools/ModelGeneration/sympy we provide a setup using only python3 with sympy (at least version 1.10!, if your packet manager only has an older installed, e.g. ubuntu 20.04 only has v1.6, then you have to install v1.10 or up with pip). Here we provide two examples, SM.py and G2HDM.py (generic 2HDM) which both use the ModelGenerator.py module to calculate the tensors and CT. You can get the CT using python3 SM.py --show ct and the tensors by calling python3 SM.py --show tensors. If your counterterms don't have a unique solution, then the solution space will be shown to you and you have to add additional equations until you have a unique solution (e.g. in the G2HDM example).
3. To show the simplified tree-level and counterterm potentials, you can use python3 SM.py --show treeSimpl and python3 SM.py --show CTSimpl.

You can use the Test executable to detect possible errors in your implementation. If the Test executable does not show you an error, but something is still wrong, contact us at bsmpt@lists.kit.edu

Also contact us if you have a custom model for BSMPT v1.x and you have trouble converting it to the new notation.

Executables

BSMPT provides multiple executables. Here we give a quick overview of them. Every executable can be called with the --help option to see how it can be run and to get an overview of all its required and optional arguments. Also, consult the manuals (BSMPTv1, BSMPTv2, BSMPTv3) for more details on the executables and their input parameters.

Note, that every executable has the option to set the --json=/path/to/your/file.json which contains a json string with the parameters you can set through the CLI. This can be useful if you want to store the parameters you used for a given call. Please beware that all paths in the json file are considered relative to the current working directory and not to the location of the json file. Examples can be found in example/JSON. If you want to be sure to have the correct output file we recommend using absolute paths.

In BSMPTv3, the following four executables are added:

MinimaTracer

MinimaTracer tracks temperature-dependent local minima in a user-defined temperature interval.

CalcTemps

CalcTemps identifies regions of coexisting minima, calculates the bounce solutions and characteristic temperature scales (critical, nucleation, percolation and completion temperature) of first-order phase transitions. Based on that, we report a transition history for the point.

CalcGW

CalcGW expands CalcTemps by the additional calculation of the gravitational waves spectra sourced by first-order phase transitions.

PotPlotter

PotPlotter calculates user-defined data grids that can be used for the visualization of multi-dimensional potential contours.

The following executables were released with BSMPTv1 and BSMPTv2:

Test

Test checks the model implementation for a provided parameter point. Some of the performed tests are e.g.: matching fermion masses and tree-level electroweak minimum with SM, tadpole relations, matching scalar masses between tree-level and NLO and symmetries of the coupling-tensors. The number of passed/failed tests is reported.

BSMPT

BSMPT calculates the strength of a single-step electroweak phase transition (EWPT), defined as the ratio of the vacuum expectation value (VEV) at the critical temperature \f$v_c\f$ over the critical temperature \f$T_c\f$, based on finding a discontinuity in the electroweak VEV of the temperature-dependent global minimum.

CalcCT

CalcCT calculates the (finite) counterterms for the 'on-shell' renormalization scheme.

NLOVEV

NLOVEV calculates the zero-temperature VEV at one-loop order. This can be used to investigate the vacuum stability of the model.

VEVEVO

VEVEVO calculates the evolution of the global minimum of a given point in a user-specified temperature range.

TripleHiggsCouplingNLO

TripleHiggsCouplingNLO calculates the trilinear Higgs self-couplings at NLO at zero temperature.

CalculateEWBG

CalculateEWBG calculates the difference between baryons and anti-baryons normalized to the photon density generated through the EWPT. Please beware that this is only tested for the C2HDM so far and the general implementation is future work.

PlotEWBG_vw

PlotEWBG_vw varies the wall velocity of a given parameter point and calculates the baryon asymmetry for each velocity.

PlotEWBG_nL

PlotEWBG_nL calculates the left-handed fermion density in front of the wall as a function of the distance to the bubble wall.