Current Affairs 2017 - March

Scientists discover five new sub-atomic particles at CERN

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.

Key Facts
  • 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.

About Baryon

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.


Scientists develop new Wi-Fi system to offer super-fast connectivity

Scientists from Eindhoven University of Technology in Netherlands have developed a new wireless Internet network based on infrared rays that is reportedly 100 times faster than existing Wi-Fi (Wireless Fidelity) networks.

It has a huge capacity, more than 40 Gigabits per second (Gbit/s). It also does away with the need of sharing Wi-Fi, as every device gets its own ray of light.

How it works?
  • The wireless data in this network comes from a few central ‘light antennas’, that are able to precisely direct the rays of light supplied by an optical fibre.
  • These antennas contain a pair of gratings that radiate light rays of different wavelengths at different angles (passive diffraction gratings).
  • If a user is walking and his smartphone or tablet is moving out of the light antenna’s direction, then another light antenna takes over.
  • In this system, changing the light wavelengths also changes the direction of the ray of light. It uses safe infrared wavelength that does not reach the retina in the eye.
Key Features of the new system
  • The network tracks the precise location of every wireless device using its radio signal transmitted in the return direction.
  • Different devices are assigned different wavelengths by the same light antenna and so do not have to share capacity.
  • It uses infrared light with wavelengths of 1,500 nanometres and higher. Current, Wi-Fi uses radio signals with a frequency of 2.5 or five gigahertz.
  • On this network, researchers have managed to achieve a speed of 42.8 Gbit/s over a distance of 2.5 metres.
  • It is hundred times fast than best Wi-Fi systems currently available that can provide users maximum 300 mbps speed.
  • The new system so far has used the light rays only to download. Uploads are still done using radio signals since in most applications much less capacity is needed for uploading.