Oct 2021 - Sept 2022

Internal seminar: Joseph Walker and Robert Heighton

Europe/London
OC218

OC218

Description

Joe Walker: Cornering Charming Higgs decays

Abstract: This talk discusses on how to identify events with fat-jets from charming Higgs decays, $H\to cc$, at the LHC. To reduce the overwhelmingly large backgrounds and to reduce false positives, we consider a combination of jet shape observables and imaging techniques, using a selection of traditional cut flow techniques and neural network architectures. Event shape distributions of the remaining events are profiled with the CLs method under the kappa framework to yield confidence limits with further constrain the Yukawa charm coupling.

Robert Heighton: Probing New Physics with Ultra-High-Energy Cosmic Rays

Abstract: The investigation of ultra-high-energy cosmic rays (UHECR) opens various avenues for the exploration of new physics. Experiments such as IceCube, ANITA, and Auger have set out to detect neutrinos of ultra-high (> PeV) energies, and in particular aspire to measure the so-called GZK flux of cosmogenic neutrinos expected at EeV scales. By considering modifications to the behaviour of Earth-traversing UHE neutrinos, we seek to predict the effects of Beyond the Standard Model (BSM) physics on the observations of such detectors. In particular, we introduce a right-handed Majorana neutrino (RHN) coupled to the Standard Model via a seesaw mechanism. Working with the TauRunner Python package, we simulate the new physics and predict the flux and spectra of Earth-exiting RHNs and tau leptons, in combination with preliminary detector simulations based on POEMMA and, in future, GRAND. In further work, we seek to set constraints on the RHN parameter space.

We find that, with improving detection capabilities and runtimes, the phenomenology discussed will become increasingly relevant for constraining BSM physics. The high and ultra-high energies reached by cosmic rays provide a promising probe for new physics beyond collider scales.

Zoom Meeting ID: 948 7183 3595