20 March 2017 Current Affairs: Scientists using Large Hadron Collider accelerator (LHC) at CERN (European Organisation for Nuclear Research) have discovered a new system of five particles all in a single analysis. This discovery is unique as observing five new states all at once is very rare. According to the standard convention, these particle states were named Oc(3000)0, Oc(3050)0, Oc(3066)0, Oc(3090)0 b Oc(3119)0. The numbers indicate their masses in megaelectronvolts (MeV), measured by LHCb experiment, one of seven particle physics detector experiments collecting data at LHC, world’s largest and most powerful particle accelerator.
The new particles were found to be in excited states (a particle state that has a higher energy than the ground state or absolute minimum configuration) of a particle called Omega-c-zero. Omega-c-zero is a baryon.
It is a particle with three quarks, containing two strange and one charm quark. It decays via the strong force into another baryon, called Xi-c-plus (containing a “charm”, a “strange” and an “up” quark) and a kaon K-. Xi-c-plusparticle further decays in turn into a proton p, a kaon K- and a pion p+. LHCb collaboration by analysing trajectories and energy left in the detector by all the particles in this final configuration were able to trace back the initial event he decay of the Omega-c-zeroand its excited states.
Now quantum numbers of these new particles, characteristic numbers used to identify the properties of a specific particle and their theoretical significance will be determined. Significance of the Discovery: It will contribute to understanding how the three constituent quarks are bound inside a baryon.
It will also help to probe the correlation between quarks, which plays a key role in describing multi-quark states, such as tetraquarks and pentaquarks.
Baryon is a composite subatomic particle made up of three quarks (a triquark, as distinct from mesons, which are composed of one quark and one antiquark). Baryons and mesons belong to the hadron family of particles, which are the quark-based particles. The most familiar baryons are the protons and neutrons that make up most of the mass of the visible matter in the universe.