Every Thursday, Laboratory Equipment features a Scientist of the Week, chosen from the science industry’s latest headlines. This week’s scientist is Xavier Calmet from Univ. of Sussex. He and a team studied how the Higgs boson interacts with gravity and took a small step toward fulfilling Einstein’s dream of proving there is only one fundamental force in nature.

**Q: What made you interested in studying how the Higgs field interacts with gravity?**

**A:** The existence of the Higgs particle implies that there is one new constant of nature that fixes the strength of the interactions between the Higgs boson and the gravitational field. In technical terms, this new fundamental parameter of nature is called the non-minimal coupling. It is a dimensionless coupling constant and a unique feature of the Higgs field. We have derived the first bound ever on the value of this fundamental parameter.

**Q: What are the future implications of your research and findings?**

**A:** Our results are important for models, which use the Higgs boson as the field responsible for the very early expansion of the universe. Knowing how the Higgs boson interacts with gravity is important to check whether the Higgs is indeed responsible for this early expansion. These models need to be reconsidered in details in the light of our result. The interactions of the Higgs boson with gravity could also be the key to understand the unification of all forces of nature.

**Q: What was the most surprising thing you found in your research?**

**A:** It was surprising to me that the tightest bound came from data produced at the Large Hadron Collider. We first thought of trying to use data from neutron stars or supernovae. The magnitude of the bound was also surprising. Naively one would have expected a bound of the order of 10^{32} instead of 10^{15}.

**Q: What is the take home message of your research and results?**

**A:** It is amazing that the Large Hadron Collider could teach us something about the gravitational interactions of the Higgs boson.

**Q: What is next for you and your research?**

**A:** We will probably try to find a smart way to improve the bound on this new fundamental constant which will not be easy. I am also planning on looking again at models using the Higgs boson to explain the early universe expansion.