LHCb observes two new baryon particles

Today the collaboration for the LHCb experiment at CERN's Large Hadron Colliderannounced the discovery of two new particles in the baryon family. The particles, known as the Xi_b'- and Xi_b*-, were predicted to exist by the quark model but had never been seen before. A related particle, the Xi_b*0, was found by the CMS experiment at CERN in 2012. The LHCb collaboration submitted a paper reporting the finding to Physical Review Letters.

Like the well-known protons that the LHC accelerates, the new particles are baryons made from three quarks bound together by the strong force. The types of quarks are different, though: the new X_ib particles both contain one beauty (b), one strange (s), and one down (d) quark. Thanks to the heavyweight b quarks, they are more than six times as massive as the proton. But the particles are more than just the sum of their parts: their mass also depends on how they are configured. Each of the quarks has an attribute called "spin". In the Xi_b'- state, the spins of the two lighter quarks point in the opposite direction to the b quark, whereas in the Xi_b*- state they are aligned.

GPS satellites have atomic clocks on board to keep accurate time

General and Special Relativity however predict that differences will appear between these clocks and an identical clock on Earth. General Relativity predicts that time will appear to run slower under stronger gravitational pull – the clocks on board the satellites will therefore seem to run faster than a clock on Earth. Furthermore, Special Relativity predicts that because the satellites' clocks are moving relative to a clock on Earth, they will appear to run slower. The whole GPS network has to make allowances for these effects – proof that Relativity has a real impact.

'Frighteningly easy' for criminals to get Visa card details, study claims

It is "frighteningly easy" for criminals to get security details for a Visa debit or credit cards, according to research from Newcastle University.

Fraudsters are able to work out expiry dates and security code numbers by making multiple invalid attempts on different websites, the team claims.
It is thought a similar method was used in the recent Tesco Bank fraud hack.
Visa said the research did not take into account other layers of security such as its Verified by Visa system.
According to the research, which has been published in the journal IEEE Security & Privacy, fraudsters use a so-called Distributed Guessing Attack to get around security features put in place to stop online fraud.