Dataset Instruction

Overview

This repository provides a standardized, continuously updated research software platform for collecting, analyzing, and visualizing experimental constraints on spin-dependent exotic interactions (also known as the spin-dependent fifth force, SDFF).

The platform integrates a curated dataset of experimental limits with an interactive visualization and comparison tool, enabling researchers to:

Access and compare constraints across different experiments and interaction types;
- Generate exclusion plots in a unified and consistent framework;
- Benchmark new theoretical models or experimental results against existing bounds;
- Contribute and update data as part of a growing community resource.

The SDFF arises from the exchange of a hypothetical boson of mass M between fermions X and Y, representing a possible extension beyond the four fundamental forces. Unlike conventional forces, SDFF depends explicitly on the spin degrees of freedom, analogous in some aspects to magnetic interactions.

My Figure — **Figure 1:** An exotic boson carrying a fifth force that depends on the spins of the involved fermions.

We categorize interactions into the following types:

Axial-vector/vector, axial-vector/axial-vector, vector/vector.
Pseudoscalar/scalar, pseudoscalar/pseudoscalar, scalar/scalar.
Tensor/tensor, pseudotensor/tensor, and pseudotensor/pseudotensor.

For notation and operator definitions, see the RMP review: Spin-Dependent Exotic Interactions.

Role as a Community Research Tool

This project is designed as a community-driven scientific software platform, rather than a static dataset. It serves as a reference infrastructure for the field, accompanying recent review work and supporting ongoing theoretical and experimental studies.

The software is actively used within our collaboration and is intended for broader adoption by the community.

For contributions or to include your new results, please feel free to contact Dr. Lei Cong (congllzu@gmail.com), Dr. Wei Ji (weiji001@uni-mainz.de), or Prof. Dmitry Budker (budker@uni-mainz.de).

Citation

Please cite this repository as follows: . One can copy the BibTeX file from here: BibTeX Format.

Datasets

For additional explanations of the constraints, see the Author Notes page.
Download the complete normalized dataset and example plotting code:
📦 Download SDFF normalized dataset
🌐 Interactive Plot Viewer (Test Version) 👉 Spin-Dependent Fifth-Force Interactive Viewer (Test)
⚠️ Note: The viewer webpage may take up to 10 seconds to load all datasets. If no figure appear after that, please try refreshing the page.
The viewer allows users to: a. Select and overlay different coupling types (e.g., g_Ag_A, g_pg_p, etc.); b. Display or hide datasets; c. Upload your own data files (λ [m], gg) for direct comparison.

1. g_Ag_A

Description: Constraints for axial-vector/axial-vector couplings ($g_Ag_A$) are presented across different interaction categories, including lepton-lepton, lepton-nucleon, and nucleon-nucleon interactions.
Data: The data are available in the folder gAgA.

2. g_Ag_V

Description: Constraints for vector/vector couplings ($g_Ag_V$).
Data: The data are available in the folder gAgV.

3. g_Vg_V

Description: Constraints for vector/vector couplings ($g_Vg_V$).
Data: The data are available in the folder gVgV.

4. g_pg_s

Description: Constraints for pseudoscalar/scalar couplings ($g_pg_s$).
Data: The data are available in the folder gpgs.
Ciaran O’Hare’s page: The similar dataset for $g_pg_s$ can be found here.

5. g_pg_p

Description: Constraints for pseudoscalar/pseudoscalar couplings ($g_pg_p$).
Data: The data are available in the folder gpgp.

6. g_sg_s

Description: Constraints for scalar/scalar couplings ($g_sg_s$).
Data: The data are available in the folder gsgs.

7. Tensor and Pseudotensor Interactions

Description: Constraints for tensor and pseudotensor Interactions couplings.
Data: Please find the data in Tab. IV and V of our review

8. V₁ Results

Data: The data are available in the folder V1.

Course

Conference Information

2020 Seminar on Precision Physics and Fundamental Symmetries
17.01 to 20.01, 2025, International Symposium on New Physics Beyond the Standard Model, Sanya, China
17.02 to 21.02, 2025 CAU BSM Workshop, Seoul, Korea
24.03 to 27.03, 2025Criticality and Continuous Measurements in Quantum Sensing: From Theory to Experiments
04.05 to 14.05, 2025 LULBI - Light \& ultralight BSM interactions
11.05 to 16.05, 2025, Frontiers of Quantum Metrology for New Physics Searches, Bad Honnef, Germany
26.05 to 30.05, 2025 10th International Conference on Precision Physics and Fundamental Physical Constants (FFK2025), Warsaw, Poland
23.06 to 11.07, 2025 Axions in Stockholm
04.08 to 15.08, 2025 New ways to discover light new physics, Mainz, Germany
22.09 to 26.09, 2025 20th Patras Workshop on Axions, WIMPs and WISPs, Tenerife, Spain
29.09 to 03.10, 2025 Ultralight Dark Matter and observable phenomena, Trieste, Italy
29.03 to 01.04, 2026 Parity Violation in Molecules, Bad Honnef, Germany
18.05 to 22.05, 2026 International Conference on Precision Physics of Simple Atomic Systems (PSAS 2026)
02.08.2026 to 07.08.2026 Dark Intersections, Bad Honnef, Germany

Job Information

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Acknowledgement

We would like to express our gratitude to Fadeev Pavel, Wei Ji for initiating the idea of this webpage. We sincerely acknowledge Haosen Guan for collecting most of the data. We deeply appreciate Yevgeny Stadnik for supervising the work on astrophysical limits and combined limits. We also extend our heartfelt thanks to Prof. Dmitry Budker for his invaluable support and guidance.

Additionally, we would like to thank all contributors, including Peng-Shun Luo, and [You], who provided data for this repository, enabling its comprehensive and collaborative nature.

Spin-Dependent-5th-Force-Limits

Dataset Instruction