Physicists at the Large Hadron Collider (LHC) have discovered two never-before-seen subatomic particles. These subatomic particles were projected by the quark model and expected to have masses approximately six times that of the proton, but earlier experiments have not run at high enough energy to yield these massive particles. The findings offer new exact measurements of the Ξb masses, which will place tauter limitations on particle physics theories. Quarks come in three categories: up/down, strange/charm, and bottom/top. In 2007, physicists detected the first particle with one quark from each category: Ξ−b, containing one bottom, one strange, and one down quark, provinding it a negative charge of −1. Though, this is just the lowermost mass type of this three-category quark grouping. Quark theory forecasts the presence of two higher mass companions of Ξ−b, called Ξ′−b and Ξ∗−b, which are described by their spin of 1/2 and 3/2, correspondingly. To approve the presence of these short-lived Ξ−b particles, the LHCb experiment at CERN observed for indication of Ξ−b decays in data from proton-proton smashes at energies of 7 and 8 tera-electron-volts. Specially, they examined decays into a neutral Ξ0b and a negatively charged pion (π−). They detected signatures for two particles at masses of 5935 and 5955 mega-electron-volts, conforming Ξ′−b and Ξ∗−b.
The outcomes came as a surprise, as numerous models projected that the Ξ′−b was not massive enough to decay through this course, and a hunt at additional CERN experiment had not found the corresponding decay of a closely connected particle Ξ′0b. By means of the new, very accurate mass measurements, theorists will be able to advance their models—especially those that forecast the mass of other quark-based particles.
The discovery of two new subatomic particles were published in Physical Review Letters recently.
Learn more here http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.114.062004