The Standard Model has been an incredibly successful theory of fundamental physics for several decades. With a limited set of free parameters, a cornucopia of observable phenomena have been predicted and found to agree well with experimental data. Nevertheless, we know there must be physics beyond that in the Standard Model. The problem is we do not know where it is yet. In this seminar I will discuss indirect measurements as a tool for discovery, where we look for the imprints of heavy particles in low energy phenomena. In particular I will pay attention to some recent results from LHCb, in the area of electroweak penguin decays, that provide tantalising hints for physics beyond the Standard Model. I will conclude by discussing the prospects for such measurements in the near future and what new experimental avenues we can pursue to keep the field moving forward as the next generation of large high energy physics projects come into view.

Understanding lattice vibrations in two-dimensional (2D) materials is essential for controlling thermal transport, mechanical response, and energy dissipation in nanoscale devices. However, several low-energy phonon modes in hexagonal boron nitride (hBN) remain inaccessible using conventional probes. Here we use helium-3 spin-echo spectroscopy to directly resolve the low-energy phonons at the surface of hBN. We measure the dispersions of the flexural and hybrid Rayleigh wave modes and extract the mechanical properties of a quasi-freestanding hBN monolayer. We simultaneously observe multiple surface-confined interlayer shear modes whose frequencies agree closely with theoretical predictions, and determine their intrinsic linewidths, revealing an order-of-magnitude reduction in phonon lifetimes with few-layer confinement. Finally, we show that the amplitudes of the observed phonon modes can be used to perform non-perturbative thermometry based on their equilibrium (Bose-Einstein) occupations. These results demonstrate the ability of helium atom scattering to access optically silent vibrational modes and provide a direct route to measuring intrinsic phonon dynamics in two-dimensional materials.