Large Hadron Collider: World's biggest physics experiment restarts

By Monica Sarkar, CNN

Updated 1911 GMT (0311 HKT) April 5, 2015

The Large Hadron Collider is located at CERN, the European Organization for Nuclear Research, near Geneva, Switzerland. This is CERN's Globe of Science and Innovation, which hosts a small museum about particle physics inside. The ATLAS experiment is housed underground nearby.
Photos: Exploring the universe at CERN
The Large Hadron Collider is located at CERN, the European Organization for Nuclear Research, near Geneva, Switzerland. This is CERN's Globe of Science and Innovation, which hosts a small museum about particle physics inside. The ATLAS experiment is housed underground nearby.
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The Higgs boson, the elusive particle that scientists had hoped to find for decades, was detected by two general-purpose experiments at the Large Hadron Collider, as scientists announced in 2012. The Compact Muon Solenoid (CMS) experiment, pictured, is one of them.
Photos: Exploring the universe at CERN
The Higgs boson, the elusive particle that scientists had hoped to find for decades, was detected by two general-purpose experiments at the Large Hadron Collider, as scientists announced in 2012. The Compact Muon Solenoid (CMS) experiment, pictured, is one of them.
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The ATLAS experiment, seen here in 2011, also detected the Higgs boson, a particle that helps explain why matter has mass. It has been called the "God particle" because of a book by that title, but scientists hate the name.
Photos: Exploring the universe at CERN
The ATLAS experiment, seen here in 2011, also detected the Higgs boson, a particle that helps explain why matter has mass. It has been called the "God particle" because of a book by that title, but scientists hate the name.
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Much of three stories of electronics at CMS are involved in making split-second decisions about what data to keep and what to discard. This is one of those areas.
Photos: Exploring the universe at CERN
Much of three stories of electronics at CMS are involved in making split-second decisions about what data to keep and what to discard. This is one of those areas.
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A technician works on the CMS experiment. Technicians are adding new cooling lines for CMS for a system that will be put in place in two or three years.
Photos: Exploring the universe at CERN
A technician works on the CMS experiment. Technicians are adding new cooling lines for CMS for a system that will be put in place in two or three years.
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CMS is adding this layer for the next run of particle collisions to improve the detection of muons, which are fundamental particles.
Photos: Exploring the universe at CERN
CMS is adding this layer for the next run of particle collisions to improve the detection of muons, which are fundamental particles.
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