arXiv subjects

Anna Mullin

Publications and source records attributed to Anna Mullin.

6 recordsLinked to original sources

arXiv2026

SET-ANUBIS: a modular pipeline for ANUBIS long-lived particle sensitivity studies

The proposed ANUBIS detector has been designed to search for Long-Lived Particle (LLP) signatures, which have become a focus for a variety of experiments within recent years. Due to the variety of possible LLP models and the need for directly comparable sensitivity results highlighting the potential coverage of ANUBIS, the SET-ANUBIS (Simulation, accEptance and sensiTivity studies framework for ANUBIS) framework has been developed. SET-ANUBIS is a flexible open-source Python framework that can perform full sensitivity studies of LLP signatures for the ANUBIS detector, allowing others to directly produce ANUBIS-like limits or even implement other geometries and detectors. It starts from a Universal FeynRules Output model or user-supplied rates; it exposes model parameters and particle content for user modification, and evaluates decay widths, branching ratios and lifetimes. MARTY can also be used to compute matrix elements, decay widths, branching ratios, and cross-sections. Then the framework prepares or runs event generation through Pythia8 or MadGraph, ingests HepMC event records, models the geometry of the ATLAS cavern and ANUBIS tracking stations, and applies a configurable sequence of geometric, kinematic and isolation requirements to select a set of surviving LLP candidates for evaluation. The implementation follows a ports-and-adapters architecture so that the core logic remains separate from external generators, persistent storage and visualisation. A scan-aware SQLite catalogue and content-addressed store preserve cards, metadata and compact selection-ready event bundles while avoiding duplicate artifacts. A pre-release version of the SET-ANUBIS framework has already been used to successfully derive the sensitivity of ANUBIS to three LLP benchmark models involving a Higgs portal and a Heavy Neutral Lepton model.

hep-ph↗

arXiv2026

Projected sensitivity of the ANUBIS detector to heavy neutral leptons

Long-Lived Particles (LLPs) are a common feature in various extensions to the Standard Model (SM) that seek to address known limitations. The ANUBIS detector has been proposed to extend the sensitivity of the ATLAS experiment at the LHC to LLPs by instrumenting the ceiling of the ATLAS detector cavern. This article presents the projected sensitivity of ANUBIS to Heavy Neutral Leptons (HNLs). For a minimal Majorana HNL model that only couples to a single flavour of lepton ($e$ or $\mu$) ANUBIS reaches a maximum sensitivity of $|V_{1e}|^2=1.8\times10^{-8}$ and $|V_{1\mu}|^2=1.9\times10^{-8}$ for a HNL mass of $m_{N_1}=6.4$ GeV and 6.3 GeV respectively. This provides complementary coverage to other proposed LLP experiments in the HNL parameter-space, with potential for significant improvement during ANUBIS data-taking through advances in analysis strategies. The results are obtained with SET-ANUBIS, a flexible framework to evaluate the sensitivity of ANUBIS to a variety of LLP models.

hep-ex↗

arXiv2025

ANUBIS: Projected Sensitivities and Initial Results from the proANUBIS demonstrator with Run 3 LHC data

Despite the success of the Standard Model (SM) there remains behaviour it cannot describe, in particular the presence of non-interacting Dark Matter. Many models that describe dark matter can generically introduce exotic Long-Lived Particles (LLPs). The proposed ANUBIS experiment is designed to search for these LLPs within the ATLAS detector cavern, located approximately 20-30 m from the Interaction Point (IP). A prototype detector, proANUBIS, has taken data within the ATLAS detector cavern since 2024, corresponding to 104 $fb^{-1}$ of pp data. We report on the potential sensitivity of ANUBIS to a selection of LLP models, i.e. Higgs Portal and Heavy Neutral Leptons, as well as future planned studies. Additionally, we will show the first results of the proANUBIS demonstrator, and how it will be used to study the expected backgrounds for the ANUBIS detector.

hep-ex↗

arXiv2025

Distorted Sounds: Unlocking the Physics of Modern Music

In the production of modern music, the musical characteristics of the guitar or keyboard amplifier play an integral role in the creative process. This article explores the physics of music with an emphasis on the role of distortion in the amplification. In particular, we derive and illustrate how a distorted amplifier creates new musical notes that are not played by the musician, greatly simplifying the playing technique. In providing a comprehensive understanding, we commence with a discussion of the physics of music, highlighting the harmonic series and its relation to pleasing harmonies. This is placed in the context of the standard music notation of intervals and their relation to note frequency ratios. We then discuss the problems of tuning an instrument and why the equal temperament of standard guitar tuners is incompatible with good sounding music when amplifier distortion is involved. Drawing on the basic trigonometric identities for angle sums and differences, we show how the nonlinear amplification of a distorted amplifier, generates new notes not played by the musician. Here the importance of setting your guitar tuner aside and using your ear to tune is emphasised. We close with a discussion of how humans decipher musical notes and why some highly distorted guitar chords give the impression of low notes that are not actually there. This article will be of assistance to students interested in the physics of music and lecturers seeking fascinating and relevant applications of mathematical trigonometric relations and physics to capture the attention of their students.

physics.pop-ph↗

arXiv2023

Plan B: New ${Z^\prime}$ models for $b\rightarrow sl^+l^-$ anomalies

Measurements of $b \rightarrow s \mu^+ \mu^-$ transitions indicate that there may be a new physics field coupling to di-muon pairs associated with the $b$ to $s$ flavour transition. Including the 2022 LHCb reanalysis of $R_K$ and $R_{K^\ast}$, one infers that there may also be associated new physics in $b\rightarrow e^+ e^-$ transitions. Here, we examine the extent of the statistical preference for $Z^\prime$ models coupling to di-electron pairs taking into account the relevant constraints, in particular from experiments at LEP-2. We identify an anomaly-free set of models which interpolates between the $Z^\prime$ not coupling to electrons at all, to one in which there is an equal $Z^\prime$ coupling to muons and electrons (but where in all models in the set, the $Z^\prime$ boson can mediate $b\rightarrow \mu^+ \mu^-$ transitions). A $3B_3-L_e-2L_\mu$ model provides a close-to-optimal fit to the pertinent measurements along the line of interpolation. We have (re-)calculated predictions for the relevant LEP-2 observables in terms of dimension-6 SMEFT operators and put them into the ${\tt flavio}$ computer program, so that they are available for global fits.

hep-ph↗

arXiv2021

Does SUSY have friends? A new approach for LHC event analysis

We present a novel technique for the analysis of proton-proton collision events from the ATLAS and CMS experiments at the Large Hadron Collider. For a given final state and choice of kinematic variables, we build a graph network in which the individual events appear as weighted nodes, with edges between events defined by their distance in kinematic space. We then show that it is possible to calculate local metrics of the network that serve as event-by-event variables for separating signal and background processes, and we evaluate these for a number of different networks that are derived from different distance metrics. Using a supersymmetric electroweakino and stop production as examples, we construct prototype analyses that take account of the fact that the number of simulated Monte Carlo events used in an LHC analysis may differ from the number of events expected in the LHC dataset, allowing an accurate background estimate for a particle search at the LHC to be derived. For the electroweakino example, we show that the use of network variables outperforms both cut-and-count analyses that use the original variables and a boosted decision tree trained on the original variables. The stop example, deliberately chosen to be difficult to exclude due its kinematic similarity with the top background, demonstrates that network variables are not automatically sensitive to BSM physics. Nevertheless, we identify local network metrics that show promise if their robustness under certain assumptions of node-weighted networks can be confirmed.

hep-ph↗