The standard model of particle physics works really well, but it can’t explain why the universe exists. Something is missing, and this trapped particle might hold a clue to the answer

October 23, 2026 2:59 p.m.

The positron is held inside a tank beneath ground level. Northwestern University

How do you contain a fast-moving particle that disappears as soon as it touches almost anything? You build a very special trap.

For the first time, researchers have used electric and magnetic fields to capture and maintain an elusive kind of particle known as a positron —the antimatter cousin of an electron. In a study published October 21 in Physical Review Letters , the team describes how they have kept the particle trapped for months, where they can control and study it.…