18th January 2018 – The production of top quarks in association with vector bosons is a hot topic at the LHC. ATLAS first reported strong evidence for the production of a top quark in association with a Z boson at the EPS 2017 conference. In a paper submitted to the Journal of High-Energy Physics, the ATLAS experiment describes the measurement of top-quark production in association with a W boson in 13 TeV collisions.
5th January 2018 – This past Spring, I had the opportunity to travel to Taos, New Mexico, USA, to work with artist Agnes Chavez, on one of her “Projecting Particles” workshops. Her innovative programme aims to develop STEM (Science, Technology, Engineering, Math) skills in students aged 8 and up, employing a mixture of science education and artistic expression. It is a winning combination for everyone involved.
18th December 2017 – The Standard Model has a number of puzzling features. For instance, why does the Higgs boson have a relatively low mass? Could its mass arise from a hidden symmetry that keeps it from being extremely heavy? And what about dark matter? While the Standard Model has some (almost) invisible particles, like neutrinos, those particles can’t account for all of the dark matter observed by cosmological measurements.
15th December 2017 – Supersymmetry (SUSY) is an extension of the Standard Model that predicts the existence of “superpartners” with slightly different properties compared to their Standard Model counterparts. Physicists have been searching for signs of SUSY for over forty years, so far without success, which makes us think that SUSY particles — should they exist — are also heavier than particles in the Standard Model. However, in order for SUSY to help mitigate some problems with the Higgs boson sector of the Standard Model, SUSY particles should not be too heavy. And if some SUSY particles are relatively light, then they should be produced copiously at CERN’s Large Hadron Collider (LHC). So for SUSY to remain an attractive theory of nature, it must be hiding in plain sight in LHC data.
13th December 2017 – Enter the world of particle physics with the newly-launched ATLAScraft! Players can explore the CERN campus, shrink down to the size of a particle, and even conduct their own “experiments” in educational minigames.
6th November 2017 – A few times a year, the large LHC collaborations such as ATLAS organise an internal overview session. This photo essay will take you to the most recent of these “ATLAS Weeks” – giving you a glimpse behind the curtain, and exploring this essential part of the collaboration structure and life.
31st October 2017 – Take something you think you understand, change it and see what happens. Earlier this month, the ATLAS Experiment put this basic scientific principle to the test during the first Large Hadron Collider (LHC) xenon run.
26th October 2017 – The ATLAS collaboration has presented evidence of “ttH production”, a rare process where a pair of top quarks emits a Higgs boson. Observing this process would provide new insight into the Higgs mechanism and allow for new studies of how unknown physics might (or might not) change the behaviour of this fundamental particle.
23rd October 2017 – Collisions of lead nuclei in the LHC form the hot, dense medium known as the quark-gluon plasma (QGP). Experimentally, the QGP is characterized by the collective flow of emerging quarks and gluons. They fragment into highly collimated “jets” of particles that in turn lose energy through a phenomenon known as “jet quenching”. Studying this effect can help improve our understanding of quantum chromodynamics, the theory of the strong nuclear interaction that governs the behaviour of the QGP.