Before travelling, we had to ask ourselves many questions: Can I travel with only one dose? Will two doses be compulsory? Will I need vaccination certificates? What will they ask me to enter a shop, a supermarket, or a plane? Will I need a QR code? How many people can I travel with or eat in a restaurant? etc., even: Will there be quotas for people to access beaches? Will quarantines be necessary? There were so many questions to answer that, in many cases, we were reluctant to decide to travel beyond, once again, places already known and close to us.Īt the start of the summer of 2022, many of the restrictions are behind us. But there were still many restrictions and rules for travelling, even within the EU, and many more for travelling to EU external countries. We already knew that one dose of the vaccine could prevent us from contracting COVID-19, or at least from becoming seriously ill. We just had to be well informed about the precautions we would have to take when going to certain places. In 2021, with access to vaccines and, indeed, the security they provide, both as a perception and a reality, Europeans began to ask: Can we consider travelling during the pandemic? Many of us already saw it as more possible. We all had fresh figures on cumulative incidence, deaths, people hospitalised, ICUs overcrowded. Even within each country, and sometimes within regions, there were a large number of restrictions: capacity limits in supermarkets, restaurants, shops, etc., physical distancing, use of masks, hydroalcoholic gels, etc. There were border restrictions or closures, making travel beyond our own country quite complex. At that time, we still did not know if and when vaccines would arrive. But experiments show B-mesons decay into electrons about 15 percent more often than they decay into muons, said particle physicist Chris Parkes, who leads the Large Hadron Collider Beauty (LHCb) experiment.At the beginning of the summer of 2020, and after having spent weeks or even months all over Europe either confined to our homes or with severe restrictions on mobility, very few people were thinking about their summer holidays beyond nearby and familiar places. One of the most puzzling is a discrepancy in the decay of the B-meson, a transient particle composed of two types of quarks - the subatomic particles that make up protons and neutrons.Īccording to theory, B-mesons should decay into electrons and muons - a related class of subatomic particles - with equal rarity. The results are incorporated into the Standard Model, which describes all the known particles (there are currently 31, including the Higgs boson) and three of the four known fundamental forces: the electromagnetic force, the strong nuclear force and the weak nuclear force, but not gravity.Īs well as allowing even more precise measurements of the particles that make up all the matter we see, scientists think the upgraded LHC can help resolve several anomalies in the Standard Model that have recently been reported. The LHC is the most advanced particle accelerator built so far, and was designed to look for those particles and measure them. It’s now being tested at low-power, and the first experimental collisions of the third run will begin on July 5. The LHC has been dormant for more than three years while it’s been upgraded with tens of millions of dollars worth of improvements - the upgraded facility will achieve energies of up to 13.6 trillion electron volts (TeV), compared to just 13 TeV in the previous run - and advanced detecting equipment to better examine the chaotic explosions inside the giant atom smasher. “We’re now ready for Run 3,” said Rende Steerenberg, who heads beam operations for CERN, the international organization that runs the LHC - a vast hidden ring of tunnels and detector caverns built deep underground beneath fields, trees and towns on the border of France and Switzerland, over 5 miles across and more than 16 miles around. But scientists hope the latest LHC run will explain even greater mysteries of existence - including the invisible particles that make up dark matter, and just why there is anything here at all. The Higgs discovery in July 2012 affirmed the Standard Model of Particle Physics, which still holds sway as the best explanation of how matter works. The collider’s reopening (it’s been closed since 2018) is an important event for global science, as what is generally considered one of the biggest science experiments ever conducted has already helped reveal important details about the fabric of reality.
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