Scientists intent on unraveling the mystery of the force that binds the building blocks of visible matter are gathered in Kobe, Japan, this week to present and discuss the latest results from "ultrarelativistic nucleus-nucleus collisions."

Known more colloquially as Quark Matter 2015, the conference convenes scientists studying smashups of nuclei traveling close to the speed of light at the world's premier particle colliders--the Relativistic Heavy Ion Collider (RHIC, https://www.bnl.gov/rhic/) at the U.S. Department of Energy's Brookhaven National Laboratory, and the Large Hadron Collider (LHC) at the European Center for Nuclear Research (CERN).

These collisions momentarily recreate the extreme conditions of the early universe so scientists can study quarks and gluons, the building blocks of ordinary protons and neutrons, as they existed and interacted nearly 14 billion years ago, before becoming bound by the strong nuclear force to form the atoms of the visible universe today.

The last few years have yielded a series of intriguing results that RHIC, in particular, has the unique ability to explore in depth by colliding many different types of nuclei over a wide range of energies.

Members of STAR and PHENIX, the two scientific collaborations conducting nuclear physics research at this DOE Office of Science User Facility--along with theorists analyzing and guiding the research and colleagues working on complementary studies at the LHC--are eager to share the latest insight.

"We're particularly excited about the breadth of new results that PHENIX will be showing in Kobe," said Brookhaven physicist Dave Morrison, a co-spokesperson for the PHENIX collaboration.

"We explain our key analyses in scientific papers that we've recently submitted to peer-reviewed journals."

"STAR will be presenting the first scientific results from recent detector upgrades, which showcase our ability to probe the behavior of distinct types of particles over a wide range of energies," said Brookhaven physicist Zhangbu Xu, spokesperson for the STAR collaboration.

"These data are helping us map out the only phase diagram involving the strong nuclear force and lay the foundation for future experiments at RHIC."