MEYRIN, Switzerland ? Vivek Sharma missed his daughter. A professor at the University of California, San Diego, Dr. Sharma had to spend months at a time away from home, coordinating a team of physicists at the Large Hadron Collider, here just outside Geneva. But on April 15, 2011, Meera Sharma?s 7th birthday, he flew to California for some much-needed family time. ?We had a fine birthday, a beautiful day,? he recalled.