A trailblazing physicist who gave up her PhD 75 years ago to have a family has received an honorary doctorate from her former university. Rosemary Fowler, 98, discovered the kaon particle during her doctoral research under Cecil Powell at the University of Bristol in 1948, which contributed to his Nobel prize for physics in 1950. Fowler’s discovery helped lead to a revolution in the theory of particle physics, and it continues to be proven correct – predicting particles such as the Higgs boson, discovered at Cern in Geneva, Switzerland. But she left university without completing her PhD to marry fellow physicist Peter Fowler in 1949, a decision she later described as pragmatic after she went on to have three children in a time of postwar food rationing. She has now been awarded an honorary doctor of science by the University of Bristol chancellor, Sir Paul Nurse, in a private graduation ceremony close to her Cambridge home. Fowler said she felt “very honoured” but added: “I haven’t done anything since to deserve special respect.” Nurse praised Fowler’s “intellectual rigour and curiosity”, which “paved the way for critical discoveries that continue to shape the work of today’s physicists, and our understanding of the universe”. At 22, Fowler spotted something when viewing unusual particle tracks – a particle that decayed into three pions, a type of subatomic particle. She said: “I knew at once that it was new and would be very important. We were seeing things that hadn’t been seen before – that’s what research in particle physics was. It was very exciting.” The track, later labelled K, was evidence of an unknown particle, now known as the kaon or K meson. The K track was the mirror image of a particle seen before by colleagues in Manchester, but their track decayed into two pions, not three. Trying to understand how these images were the same, yet behaved differently, helped lead to a revolution in the theory of particle physics. The year after the discovery, Fowler left university having published her discovery in three academic papers. Fowler was born in Suffolk in 1926, and excelled in maths and science as a child but found writing a challenge. She was the only girl in her year to go to university. She became one of the first women to be awarded a first in physics, and her three children went on to study science. Her daughter, Mary Fowler, studied maths and then geophysics at Cambridge and had an academic career in Switzerland, Canada, London and finally Cambridge, where she was the master of Darwin College from 2012-20.