Theory Division

In January 2020 the Department of Energy announced that the US Electron Ion Collider (EIC) had received a CD0 in December 2019, and that it would be located at BNL. The EIC will be built jointly by BNL and Jefferson Lab as partners. The EIC project setup in 2020 has picked up speed and steered... More »

The fine structure constant is this “magic ” number close to 1/137 that appears in several areas of physics. This dimensionless constant characterizes the strength of the electromagnetic interaction between light and charged elementary particles, such as electron or muon. A precise knowledge of its numerical value is crucial to test, even with low-energy experiments,... More »

I argue that in the 21st century no other area of particle physics has seen such a wealth of stimulating results as has the study of quark transitions. I assess the reasons for this progress, before surveying a selection of the most interesting recent results in the field. I conclude by looking forward to the... More »

The LHCb detector is a dedicated flavour physics detector at the LHC, instrumented in the forward region and optimised for the study of B and D hadron decays. However, due to its unique coverage, it has also made important measurements in a number of other sectors including electroweak and top quark physics. It was also... More »

Galaxy surveys are fundamental tools of cosmology allowing us to measure the geometry and growth of structure in the universe. Using weak gravitational lensing and galaxy clustering from these surveys, we can directly trace the dark matter distribution and infer from this the properties of Dark Energy and Dark Matter. Recent measurements of this kind... More »

We report first results from a search for neutrino-induced neutral current (NC) resonant ∆(1232) baryon production followed by ∆ radiative decay. Data corresponding to MicroBooNE’s first three years of operations (6.80×1020 protons on target) are used to select single-photon events with one or zero protons and without charged leptons in the final state. The background... More »