"Interferometric techniques to improve vibration isolation in gravitational wave detectors" by Alexandra Mitchell (Nikhef, VU)
Current gravitational wave detectors have a detection bandwidth of around 20Hz to a few kHz, allowing them to detect black hole mergers of 7-80 solar masses. To be able to detect higher mass systems and coalescing objects from larger redshifts this detection bandwidth needs to extend to lower frequencies. New detectors, such as the Einstein Telescope, aim to extend the bandwidth down to around 3Hz. For this to be realised, the vibration of the detector optics at low frequencies, even below 3Hz, must be vastly reduced. I will present design solutions that can improve the seismic isolation in current and future detectors, and that are based on a new compact interferometric sensor.
"Looking for the missing CP-violation" by Valeriia Lukashenko (Nikhef, VU)
The amount of matter and anti-matter in the Universe should be the same. However, we live in a world that predominantly consists of matter. The observed difference can be generated if a few conditions, known as Sakharov conditions, are satisfied. One of these conditions is charge and parity (CP) violation. Unfortunately, the amount of Standard model CP-violation is insufficient to explain the difference in the amounts of matter and anti-matter observed. Therefore, beyond-the-Standard model (or ’new’) sources of CP violation must exist. Within the quark sector, one of the strong probes for the new contributions to CP-violation is the CP-violating phase φₛ. If a deviation in the measured value from the Standard Model prediction is observed, it will indicate new contributions to CP violation. In this talk, I present an updated measurement of CP-violating phase φₛ with Bₛ⁰ to J/ψ and φ(1020) using the 2015-2018 LHCb dataset.