UH Physicist Plays Key Role In Joint U.S. - China Project Studying Origins of the Universe

By Rolando Garcia
Natural Sciences and Mathematics

Deep beneath a mountain in southern China a University of Houston physicist along with a vast international team of researchers is trying to unlock the secrets of a mysterious particle that could shed light on the history of the universe and how existence is possible.

The Daya Bay project, billed as one of the largest scientific collaborations between the U.S. and China, will study a type of subatomic particle known as neutrinos. The project includes researchers from 38 institutions around the world, including UH’s Kwong Lau, a physics professor who plays a key role in designing the 160-ton detectors scientists need to capture and study the elusive particles.

This fall, Lau received a $425,000 grant from the Department of Energy to continue his work to design a detector shield to eliminate cosmic rays that would interfere with the experiments. This award builds on a previous $320,000 DOE grant Lau received at the beginning of the Daya Bay project.

The difficulty of capturing and studying neutrinos free from the static of other particles and cosmic rays is a driving factor behind the size, cost and complexity of the project. Neutrinos are produced in abundance by nuclear reaction, so the project is located near the world’s second largest nuclear power plant.

To keep out cosmic rays, the experiment will take place deep inside an excavated mountain, with detectors placed inside large pools of water, to further protect from radiation that could interfere with measurements. Even then, traces of cosmic rays can still seep into the mountain so Lau’s work on the shield detectors will be crucial.

Neutrinos have become a hot topic in the world of physics after scientists recently discovered that neutrinos do in fact contain a tiny amount of mass, Lau said. Neutrinos – which are uncharged particles – have properties that have long perplexed scientists. For example, they can move through space, rock and even people without interacting with them.

There are three types of neutrinos and the particles morph between types as they travel. Nuclear reactors produce electron-type neutrinos. As these particles are captured and measured in different states by the massive sensor apparatus scientists hope to learn more about how neutrinos transition among the three categories.

Understanding how neutrinos morph could help scientists understand the big questions, Lau said, such as why the universe contains more matter than anti-matter – making existence possible. In theory, the Big Bang should have created equal amounts of matter and anti-matter, cancelling each other out.

The project officially kicked-off in 2007 at a groundbreaking ceremony in the Guangdong province near Hong Kong attended by Lau and UH physics department chair Larry Pinsky. The mountain has been excavated and now the eight massive detectors to be used in the experiments are being built. Each will be placed in pools 20 meters wide and 10 meters deep located at varying distances from the reactor so researchers can measure the neutrinos at different intervals.