Over a century ago, Ernest Rutherford discovered the proton by splitting the atom in a laboratory in Manchester. Today, researchers based in Manchester have discovered a new particle that Rutherford would never have imagined: a “heavier” version of the proton that had been theorized but never clearly observed until now, thanks to recent data from CERN’s particle accelerator, which is the world’s most powerful particle accelerator. The University of Manchester researchers have played a leading role in the discovery of the subatomic particle that was recently announced at the Rencontres de Moriond Electroweak Conference. It is called the Ξcc⁺ (pronounced “xi double-plus”) particle. The Ξcc⁺ particle has a different structure than the proton. Instead of requiring two up quarks and one down quark to make its basic unit, the Ξcc⁺ is made up of two charm quarks and one down quark. As a result, it weighs more than the ordinary proton and is much less stable. It will only survive a fraction of a second before disintegrating into smaller pieces. The short-lived nature of this …