fermilab (2)

Weighty W...


Living on: data taken by the now-defunct CDF experiment has revealed a surprising mass for the W boson. (Courtesy: Fermilab)

Topics: Fermilab, High Energy Physics, Modern Physics, Particle Physics, Steven Weinberg

The most precise measurement to date of the mass of the W boson has yielded a result seven standard deviations away from that predicted by the Standard Model of particle physics. The stunning result was obtained by a painstaking analysis of data taken at the Fermilab Tevatron collider in the US before it closed in 2011. The particle physics community must now study the results carefully to work out whether it is an incredible statistical fluke, an unknown experimental error, a flaw in the Standard Model, or a genuine indication of physics beyond the Standard Model.

The W boson is one of the most intriguing particles described by the Standard Model. Together with the neutral Z boson, the charged W boson mediates the weak interaction, which causes beta decay and several other important processes in particle physics. The weak interaction has long intrigued scientists searching for physics beyond the Standard Model, partly because it is the only force known to violate charge-parity symmetry. If particles in a process are exchanged for their antiparticles and the spatial coordinates are inverted, the weak interaction in this mirror image process is not always identical. This puzzle is not explained in the Standard Model.

W boson mass measurement surprises physicists, Tim Wogan, Physics World

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Image Source: Fermilab, and link below

Topics: Fermilab, High Energy Physics, Modern Physics, Neutrinos, Particle Physics

Solving big mysteries

The Deep Underground Neutrino Experiment is an international flagship experiment to unlock the mysteries of neutrinos. DUNE will be installed in the Long-Baseline Neutrino Facility, under construction in the United States. DUNE scientists will paint a clearer picture of the universe and how it works. Their research may even give us the key to understanding why we live in a matter-dominated universe — in other words, why we are here at all.

DUNE will pursue three major science goals: find out whether neutrinos could be the reason the universe is made of matter; look for subatomic phenomena that could help realize Einstein’s dream of the unification of forces; and watch for neutrinos emerging from an exploding star, perhaps witnessing the birth of a neutron star or a black hole.

DUNE at LBNF, Fermilab

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