School of Natural Sciences and Mathematics

U. T. Dallas High Energy Physics Researchers Behind Discovery of Mysterious New Particle

Work Part of BaBar Experiment at Stanford Linear Accelerator Center

RICHARDSON, Texas (July 7, 2005) – Scientists from The University of Texas at Dallas (UTD) High Energy Physics (HEP) Group were instrumental in a discovery disclosed to the scientific community last week of a mysterious new subatomic particle – dubbed Y(4260). The researchers are part of the BaBar experiment, a United States Department of Energy (DOE) particle physics collaborative research program being conducted at the Stanford Linear Accelerator Center (SLAC).

The discovery could ultimately provide scientists with a deeper understanding of the makeup of the universe.

UTD Physics Researchers

From left: UTD physics professors Joseph Izen, Ph.D.; Xinchou Lou, Ph.D., head of the physics department; and researcher Shuwei Ye, Ph.D., helped discover a new particle.

Details of the breakthrough are contained in a paper that was submitted to the journal Physical Review Letters. In addition, the discovery was reported last week at a research conference in Uppsalla, Sweden, and an announcement was made, also last week, by SLAC (

Major contributors to the discovery include four researchers from UTD – HEP Group scientist Dr. Shuwei Ye, Professor and Physics Department head Dr. Xinchou Lou, Physics Professor Dr. Joseph Izen and Ph.D. student Glenn Williams. The group’s research is funded by the DOE.

UTD’s Ye is scheduled to present a seminar tomorrow at SLAC to describe the discovery in detail.

“The Y(4260) was a surprise, and we are just beginning to make sense of its peculiar mass and the unusual way it decays,” said Izen. “It's quite an unusual discovery.”

UTD’s Lou echoed Izen’s assessment, characterizing the new particle as “kind of mysterious to us. We are looking at our data to understand what it is and if it has ‘siblings.’”

The Y(4260) particle was discovered in the collisions of electrons and their anti-matter counterparts, positrons, at the SLAC facility.

The BaBar experiment is an international collaboration of some 600 physicists and engineers designed to investigate the fundamental nature of matter and the laws that govern it.

About UTD

The University of Texas at Dallas, located at the convergence of Richardson, Plano and Dallas in the heart of the complex of major multinational technology corporations known as the Telecom Corridor®, enrolls more than 14,500 students. The school’s freshman class traditionally stands at the forefront of Texas state universities in terms of average SAT scores. The university offers a broad assortment of bachelor’s, master’s and doctoral degree programs. For additional information about UTD, please visit the university’s web site at

UTD News Contact: Steve McGregor (972)883-2293

  • Updated: December 19, 2007