E.J. Salumbides, J.C.J. Koelemeij, J. Komasa, K. Pachucki, K.S.E. Eikema, W. Ubachs
Highly accurate results from frequency measurements on neutral hydrogen molecules H2, HD, and D2 as well as the HD+ ion can be interpreted in terms of constraints on possible fifth-force interactions. Where the hydrogen atom is a probe for yet unknown lepton-hadron interactions, and the helium atom is sensitive for lepton-lepton interactions, molecules open the domain to search for additional long-range hadron-hadron forces. First principles calculations in the framework of quantum electrodynamics have now advanced to the level that hydrogen molecules and hydrogen molecular ions have become calculable systems, making them a search ground for fifth forces. Following a phenomenological treatment of unknown hadron-hadron interactions written in terms of a Yukawa potential of the form V5(r)=βexpâ¡(-r/λ)/r, current precision measurements on hydrogenic molecules yield a constraint β<1. 4×10-8 eV·Å for long-range hadron-hadron interactions at typical force ranges commensurate with separations of a chemical bond, i.e., λ≈1 Å and beyond. This corresponds to a constraint of β/α<10-9, where α represents the strength of the electromagnetic interaction, i.e., the fine-structure constant. © 2013 American Physical Society.
Department of Physics and Astronomy, LaserLaB, VU University, 1081 HV Amsterdam, De Boelelaan 1081, Netherlands; Department of Physics, University of San Carlos, Cebu City 6000, Philippines; Faculty of Chemistry, A. Mickiewicz University, 60-780 Poznań, Grunwaldzka 6, Poland; Faculty of Physics, University of Warsaw, 00-681 Warsaw, Hoza 69, Poland
