The production of a pair of Higgs bosons via vector-boson fusion is a very rare process that can be influenced by new physics not described by the Standard Model (SM). This study presents a new search strategy for finding this process in proton-proton collision events at the Large Hadron Collider (LHC). Beyond the Standard Model (BSM) extensions introduce new physics in the form of extra Higgs particles, which modify the rate, or cross-section, of Di-Higgs events we would expect to see at the LHC. In order to test these BSM extensions, and search for new physics, we need to measure the cross-section of the Di-Higgs production process for deviations in the SM expectation. Current searches for this process focus on the case where both Higgs decay into 4 b quarks, and have excluded large deviations from the SM. However, because these BSM extensions only slightly modify this production rate, we need a more sensitive search strategy to probe these small deviations. Our search strategy focuses on the case where both Higgs decay into 2 b quarks and 2 tau leptons, which benefits from having a softer background, at the cost of a lower cross-section. The results of our search strategy will allow physicists at the LHC to experimentally verify that the Di-Higgs process occurs, and whether it happens at the rate predicted by the Standard Model.

Reaction-diffusion equations have been used extensively to model phenomena arising in the physical sciences. Examples include modeling the population density of a given species over time and modeling the temperature of reacting fluids. An important part of the study of reaction diffusion equations is understanding the behavior of traveling wave solutions. In this research we explore the properties of a function eta which is closely related to the behavior of traveling waves. The eta function arises from a differential equation, and while it is known that the function exists, many properties of the function are currently unknown. This research focuses on the function’s behavior for a special case of the Fisher-KPP (FKPP) equation. We provide an upper bound for the solution in the case of a specific starting value which allows for the simplification of an important overdetermined system. We also explore the application of numerical approximation techniques to provide a starting point for the further study of this function.

Two-Dimensional materials research has found them to have exotic electronic properties. One of these properties is the appearance of flat band electronic structures. Flat bands are a collection of energy states an electron can take combined into a single band. Near these flat bands, there is high electron correlation which leads to interesting physics such as superconductivity, correlated states and other phenomena due to the high potential energy and lower kinetic energy. These flat bands have been found in twisted bilayer Tungsten Diselenide between a wider range of twist angles than twisted bilayer Graphene. One of the experimental techniques to study these materials and their electronic properties is scanning tunneling microscopy. We make stacked devices of twisted homobilayer Tungsten Diselenide with a Graphene sensing layer to prevent tip effects from affecting the sample. We also fabricated twisted trilayer Graphene for scanning tunneling microscopy measurements.

The CrystaLiZe experiment is a small version of the LUX-Zeplin experiment, both of which aim to detect dark matter. The solid xenon housed in the Time Projection Chamber (TPC) of the CrystaLiZe assembly commonly contains the radon-222 isotope as an impurity. This isotope is part of a decay chain that results in the lead-210 isotope. The alpha decay that creates this lead isotope can cause a false detection of a WIMP (Weakly Interacting Massive Particle) dark matter particle due to the similar kinetic energy and mass of the daughter nucleus. To address this, we have designed a scintillating PTFE (Polytetrafluoroethylene, more commonly known as Teflon) material using ZnO nano-particles for the walls of the detector. A dark box experiment set-up has been designed to test how well the ZnO-PTFE scintillates. Using the same photo-sensors as those in the CrystaLiZe assembly, this dark box will measure the level of scintillation of the PTFE material while surrounded by radon gas. Thus, we aim to use this material in the TPC to help identify false detections of a WIMP when a photon is detected at the same time due to scintillation. This will ultimately allow us to eliminate noise from the detector and have more accurate data.