arXiv subjects

Evelyn Thomson

Publications and source records attributed to Evelyn Thomson.

3 recordsLinked to original sources

arXiv2025

The ABC of RPV II: Classification of R-parity Violating Signatures from UDD Couplings and their Coverage at the LHC

We perform a detailed study of the current phenomenological status of baryon number violating operators within the framework of the $R$-parity violating Minimal Supersymmetric Standard Model (RPV-MSSM). This study aims to identify any gaps in the experimental coverage of the RPV landscape. We identify the unique final states for all possible LSPs decaying via four different benchmark UDD operators. Both the direct production of the LSP and its production via gauge-cascades are considered. For each LSP, we assume that only one UDD coupling is non-zero at a time and confront the signals with existing ATLAS and CMS searches implemented in the recasting framework \texttt{CheckMATE\;2}. We find that the UDD colored LSP sector is well covered with the mass bounds on the gluino LSP being the strongest, and with possible improvements for some of the right-handed squark LSPs. We also point out that there is limited coverage for electroweakino and slepton LSPs with UDD decays. This limitation may be due to the lack of targeted experimental searches for these specific final states or the appropriate recasting of existing searches.

hep-ph↗

arXiv2024

Optimizing $\tilde{X}^{\pm}_{W} \rightarrow h^0\ell^{\pm}_{i}$ Reconstruction Efficiency with Small-R (R = 0.4) and Large-R (R = 1.0) Jets

Many Beyond the Standard Model searches at ATLAS employ jets to simplify event reconstruction. These jets cluster particle shower products into calculable objects, which are then used to obtain information about parent particles. Large-R (R = 1.0) jets combine these products into one jet that spans 2 radians, while small-R (R = 0.4) jets are used to further refine individual b-quark trajectories. Optimizing the use of jets is crucial for making precision measurements of Higgs bosons with high transverse momenta, and this paper uses b-quarks produced in the Wino chargino LSP decay to identify parameters that best do so. Monte Carlo simulation found that parameters such as the distance between Higgs bosons and the distance between b-jets were relevant in selecting the most accurate small-R reconstructions. Truth data analysis corroborated the paper's findings, especially for charginos with higher mass. These parameters were then used to refine small-R jet selection, increasing reconstruction efficiency across chargino masses. Further analysis into large-R jet selection would enhance these results, especially at higher chargino masses. A neural network would also prove useful for exploring the effects of combinations of parameters across chargino masses.

hep-ex↗

arXiv2022

On Baryon and Lepton Number Violation

In this report we discuss the main theories to understand the origin of baryon and lepton number violation in physics beyond the Standard Model. We present the theoretical predictions for rare processes such as neutrinoless double beta decay, proton decay, and neutron-antineutron oscillation, and overview the prospects to discover these rare processes in the near future. The possibility to observe baryon and lepton violating signatures at current and future colliders and through precision studies of other rare processes, and the testability of different baryogenesis mechanisms is discussed in detail. A healthy and broad experimental program looking for proton decay, neutrinoless double beta decay and neutron-antineutron oscillations is essential to make new discoveries in this field. These searches are carried out at various experimental facilities in the US and abroad, and use instrumentation arching across traditional HEP/NP boundaries. In addition, experiments such as those at the Large Hadron Collider could discover exotic baryon and/or lepton number violating signatures connected to low energy scale theories for neutrino masses, supersymmetric models with R-parity violation, new gauge theories or other mechanisms for physics beyond the Standard Model. The landscape presented in this report could be crucial to discover the underlying mechanism for neutrino masses and the matter-antimatter asymmetry in the universe.

hep-ph↗