This press release describes a very novel way of looking for a possible spin-spin force, using the entire earth (?) and invoking a multidisciplinary knowledge.
Hunter -- along with emeritus Amherst physics professor Joel Gordon; postdoctoral fellow Stephen Peck; student researcher Daniel Ang '15; and Jung-Fu "Afu" Lin, associate professor of geosciences at UT Austin -- co-authored a paper about their work that appears in this week's issue of the journal Science. The highly interdisciplinary research relies on geophysics, atomic physics, particle physics, mineral physics, solid-state physics and nuclear physics to reach its conclusions.
The way this has been titled, and the way it sounds, it makes it sounds as if there is a 5th force, and that we're just trying to hunt it down. All this experiment has done is put a severe limit on such a thing because of a non-detection at the level of accuracy that the experiment has. In other words, they didn't find any!
But what I found unbelievable is the comment from one of the authors.
Lin had his own take: "The most rewarding and surprising thing about this project was realizing that particle physics could actually be used to study the deep Earth."
Whoa! Is this really that surprising? We already have studies on geoneutrinos, among other things. It all came out of our knowledge from high energy physics.
Oh well, I guess we can add this to a GROWING list of practical applications of high energy physics.