February 20, 2004  


PEP-II Sets New Luminosity Record

By Kate Metropolis

On January 26, PEP-II delivered and BABAR recorded the highest number of electron-positron collisions in a 24-hour period to date. Both the accelerator and the detector exceeded 500 inverse picobarns that day, approximately 500,000 events in which a B meson and an anti-B meson were produced. This number is more than three times higher than PEP-II was designed to deliver.

Although the total is large, BABAR physicists are interested in some very rare events, and the number of those collected on the record-setting day could be small enough to be counted on the fingers of a single graduate student. "That’s why we have to work so hard," said accelerator physicist Mike Sullivan.

The BABAR collaboration sent congratulatory pizzas to the accelerator control room.

The next pizza challenge, according to Bill Wisniewski, BABAR technical coordinator, is to achieve 500 inverse picobarns a day for five days in a row.


The Stanford Linear Accelerator Center is managed by Stanford University for the US Department of Energy

Last update Tuesday February 17, 2004 by Emily Ball