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Nobel Prize to F. Englert and P. Higgs

October 21, 2013

The Royal Swedish Academy of Science awarded the Nobel Prize in Physics to two theorists, François Englert of Université Libre de Bruxelles, Belgium, and Peter W. Higgs of the University of Edinburgh, UK, “ for the theoretical discovery of a mechanism that contributes to our understanding of the origin of mass of subatomic particles and which was recently confirmed through the discovery of the predicted fundamental particle by the ATLAS and CMS experiments at CERN ’s Large Hadron Collider (LHC).”

KEK congratulates Englert and Higgs on the award. Their work serves as the foundation of the Standard Model (SM) of elementary particle physics, which was recently confirmed by the ATLAS and CMS experiments through their discovery of the predicted new particle from more-than-two-quadrillion (1015) proton –proton collisions at the LHC. The two recent articles of the ATLAS experiment have demonstrated evidence of the scalar nature of the new particle, which is consistent with the Higgs particle predicted by a theory (Figure 1) published nearly 50 years ago.

http://www.sciencedirect.com/science/article/pii/S0370269313006369
http://www.sciencedirect.com/science/article/pii/S0370269313006527

KEK, with the funding support of the Japanese government and in close cooperation with Japanese industries, contributed to the construction of the LHC accelerator. In addition, KEK, along with fifteen universities in Japan, has been playing a significant role in the ATLAS experiment since its early design stage.

The LHC is a large ring accelerator with a circumference of 27 km. In this ring, protons are accelerated to nearly the speed of light in clockwise and counterclockwise directions and are made to collide at four interaction points at a center-of-mass energy of 8 TeV. It is important to squeeze the beam at the interaction points to attain a high rate of proton –proton interactions in these collisions. For this purpose, the KEK team, in collaboration with Fermilab in the US, developed and built superconducting focusing magnets (Figure 2).

The search for Higgs particles in a large amount of proton –proton collisions is a challenging task. A high-performance detector complex, along with large computing resources and sophisticated analyses procedures, is essential for the discovery of the new particle. The Japanese group has contributed to various aspects of the projects, including the detector construction of the muon trigger system, silicon tracker (Figure 3), and superconducting solenoid. Interesting stories related to constructions and operations of the detectors can be found in previous articles.

http://legacy.kek.jp/en/feature/2010/ATLASFirstCollision.html
http://legacy.kek.jp/en/feature/2010/ATLAS_BelleII.html

It is noteworthy that many Japanese companies have been playing indispensable roles in the success of the LHC accelerator and detectors. Two well-known examples are the Furukawa Electric, which manufactured the superconducting cables, and Hamamatsu Photonics, which constructed the photo sensors and silicon detectors; however, they are a part of a long list of contributions made by the Japanese industries. They have worked together with the researchers at the LHC from all over the world and have contributed key technologies. They are essential for the discovery of the Higgs particle that has long been sought after.