arXiv subjects

James Pinfold

Publications and source records attributed to James Pinfold.

9 recordsLinked to original sources

arXiv2026

Analysis of Mixed Radiation Fields at the MoEDAL Experiment Based on Real-Time Data from a Timepix Detector Network

The primary objective of this work is the determination of fluences and characteristics of fast neutrons, other hadrons, and highly ionizing particles (HIPs) in the environment of the MoEDAL experiment at the Large Hadron Collider. These particles may constitute an experimental background for the passive Nuclear Track Detectors (NTDs) used by MoEDAL to search for tracks potentially produced by magnetic monopoles, in particular by particles indistinguishable in NTD from monopoles. The study is based on data acquired by the Timepix hybrid silicon pixel detector network, which represents the first and only active detector system installed and operated as part of the MoEDAL experiment from 2013 to 2018. The Timepix detector network enables real-time measurements of mixed radiation fields, including the composition, spectral properties, and directional characteristics of individual radiation components across different regions of the MoEDAL experimental area. The paper presents detailed results of the radiation field analysis with emphasis on neutrons and highly ionizing particles, including their directional distributions. The first results demonstrating the spatial tracking capabilities of the Timepix detectors are also reported, illustrating the reconstruction of particle direction and energy-loss profiles from individual detector frames.

physics.ins-det↗

arXiv2025

Searching for Dark Pions with the MoEDAL-MAPP Detector at the LHC

We investigate the potential for detecting pion-like dark matter within the framework of a Strongly Interacting Massive Particle (SIMP) model using the MoEDAL Apparatus for Penetrating Particles (MAPP) at the LHC. The model, motivated by Chiral Perturbation Theory, features milli-charged dark pions that couple to Standard Model particles via kinetic mixing with a dark photon. Production channels considered include Drell--Yan pair production and photon fusion via the Wess--Zumino--Witten term, the latter providing a distinctive three-body final state signature. Cross-sections are computed using MadGraph and WHIZARD for a range of dark pion masses, decay constants, and dark $Z$ boson masses. Sensitivity projections for MAPP-1 during the High-Luminosity LHC phase are presented under a background-free assumption, showing competitive reach into previously unexplored parameter space for milli-charged dark pseudoscalars. These results highlight the complementary role of MoEDAL-MAPP in probing dark sector models and motivate further detector-level simulations to refine exclusion limits.

hep-ph↗

arXiv2025

Minicharged Particle Sensitivity of the MAPP Outrigger Detector

We present a detailed study of the projected background-free sensitivity of the MAPP Outrigger Detector (OD) to minicharged particles (mCPs) at the High-Luminosity Large Hadron Collider (HL-LHC). As the first upgrade to the MAPP Experiment, the MAPP OD is a standalone detector designed to offer enhanced sensitivity to high-mass mCPs with intermediate effective charges. The MAPP OD is planned for installation in a duct adjacent to the MAPP-1 detector, located between the LHC's UA83 gallery and the beamline. Considering mCP production via the Drell-Yan mechanism and various meson decays, the results show that, at the 95% confidence level, the MAPP OD can extend the experiment's upper mass reach to mCP masses of approximately 200 GeV at the HL-LHC.

hep-ph↗

arXiv2023

Searching for Minicharged Particles at the Energy Frontier with the MoEDAL-MAPP Experiment at the LHC

MoEDAL's Apparatus for Penetrating Particles (MAPP) Experiment is designed to expand the search for new physics at the LHC, significantly extending the physics program of the baseline MoEDAL Experiment. The Phase-1 MAPP detector (MAPP-1) is currently undergoing installation at the LHC's UA83 gallery adjacent to the LHCb/MoEDAL region at Interaction Point 8 and will begin data-taking in early 2024. The focus of the MAPP experiment is on the quest for new feebly interacting particles$\unicode{x2014}$avatars of new physics with extremely small Standard Model couplings, such as minicharged particles (mCPs). In this study, we present the results of a comprehensive analysis of MAPP-1's sensitivity to mCPs arising in the canonical model involving the kinetic mixing of a massless dark $U(1)$ gauge field with the Standard Model hypercharge gauge field. We focus on several dominant production mechanisms of mCPs at the LHC across the mass$\unicode{x2013}$mixing parameter space of interest to MAPP: Drell$\unicode{x2013}$Yan pair production, direct decays of heavy quarkonia and light vector mesons, and single Dalitz decays of pseudoscalar mesons. The $95\%$ confidence level background-free sensitivity of MAPP-1 for mCPs produced at the LHC's Run 3 and the HL-LHC through these mechanisms, along with projected constraints on the minicharged strongly interacting dark matter window, are reported. Our results indicate that MAPP-1 exhibits sensitivity to sizable regions of unconstrained parameter space and can probe effective charges as low as $8 \times 10^{-4}\:e$ and $6 \times 10^{-4}\:e$ for Run 3 and the HL-LHC, respectively.

hep-ph↗

arXiv2023

Minicharged Particles at Accelerators: Progress and Prospects

Minicharged particles (mCPs), hypothetical free particles with effective electric charges much smaller than the elementary charge, $e$, offer a valuable probe of dark sectors and fundamental physics through several clear experimental signatures. Various models of physics beyond the Standard Model predict such particles, the existence of which could help elucidate the ongoing mysteries regarding electric charge quantization and the nature of dark matter. Moreover, a hypothetical scenario involving a small minicharged subcomponent of dark matter has recently been demonstrated as a viable explanation of the anomaly in the 21 cm hydrogen absorption signal reported by the EDGES collaboration. Although several decades of indirect observations and direct experimental searches for mCPs at particle accelerators have led to severe constraints, a substantial window of the mCP mass$\unicode{x2013}$mixing parameter space remains unexplored at the energy frontier accessible to current state-of-the-art accelerators, such as the Large Hadron Collider (LHC). Consequently, mCPs have remained topical over the years, and new experimental searches at accelerators have been gaining interest. In this article, we review the theoretical frameworks in which mCPs emerge and their phenomenological implications, the current direct and indirect constraints on mCPs, and the present state of the ongoing and upcoming searches for mCPs at particle accelerators.

hep-ph↗

arXiv2022

MoEDAL-MAPP, an LHC Dedicated Detector Search Facility

During LHC's Run-2 the MoEDAL experiment, the LHC's first dedicated search experiment, took over 6 fb^-1 of data at IP8, with p-p and Pb-Pb collisions, operating with 100% efficiency. The LHCC has endorsed the LoI of the MoEDAL Collaboration describing an exciting program to expand the search for Highly Ionizing Particles (HIPs) in p-p and heavy-ion collisions to include feebly ionizing and Long Lived Particle (LLP) messengers of new physics (NP) at LHC's RUN-3 and eventually HL-LHC. In 2021, as part of Phase-1 of the program, the baseline MoEDAL detector was approved by CERN for reinstallation for Run-3 with increased efficiency, lower threshold, a factor of 5 increase in instantaneous luminosity, and, a higher Ecm. MoEDAL will continue the search for HIP avatars of NP with an emphasis on the search for massive, single and multiply electrically charged avatars of BSM physics arising from, eg, supersymmetry, neutrino mass models, L-R symmetry, etc. As part of Phase-1 of the MoEDAL-MAPP project CERN also approved in 2021 the installation of the MoEDAL Apparatus for Penetrating Particles (MAPP) in the UA83 tunnel 100m away from IP8. The MAPP detector has sensitivity to feebly-interacting particles with charge, or effective charge, as low as 10^-3e. Additionally, the MAPP detector, in conjunction with MoEDAL's trapping detector, gives us a unique sensitivity to charged LLPs. MAPP also has some sensitivity to neutral LLPs. In Phase-2 of the project we will instal the MAPP-2 upgrade for the HL-LHC. We envisage that this detector will be deployed in the UGC1 gallery near to IP8. This phase of the experiment is designed to ensure that MoEDAL-MAPP's sensitivity to neutral LLP messengers of BSM physics is competitive and complementary to other planned projects in this arena. Initial MoEDAL plans for the MEDICI facility at the 100 TeV FCC-hh machine will also be briefly presented.

hep-ph↗

arXiv2020

Searching for Heavy Neutrinos with the MoEDAL-MAPP Detector at the LHC

We present a strategy for searching for heavy neutrinos at the Large Hadron Collider using the MoEDAL Experiment's MAPP detector. We hypothesize the heavy neutrino to be a member of a fourth generation lepton doublet, with the electric dipole moment (EDM) introduced within a dimension-five operator. In this model the heavy neutrino is produced in association with a heavy lepton. According to our current experimental and theoretical understanding, the electric dipole moment of this heavy neutrino may be as high as $10^{-15}$ $e$ cm. Taking advantage of the sensitivity of MoEDAL detector, we examine the possibility of detecting such a heavy neutrino in the MAPP as an apparently fractionally charged particle, via ionization due to the neutrino's EDM.

hep-ph↗

arXiv2014

Solid state breakdown counter for magnetic monopole and other highly ionizing particles searches

Solid state breakdown counters combine threshold properties of nuclear track detectors with the convenience of electronic event registration in real time. Here we discuss the principle of operation of the breakdown counters and their potential applicability to the existing (MoEDAL) and foreseen (CosmicMoEDAL) searches of magnetic monopoles and other highly ionizing rare particles. Avenues of R\&D that may lead to an increased appeal of the technology are also described

physics.ins-det↗

arXiv2014

Non-collider searches for stable massive particles

The theoretical motivation for exotic stable massive particles (SMPs) and the results of SMP searches at non-collider facilities are reviewed. SMPs are defined such that they would be sufficiently long-lived so as to still exist in the cosmos either as Big Bang relics or secondary collision products, and sufficiently massive to be beyond the reach of any conceivable accelerator-based experiment. The discovery of SMPs would address a number of important questions in modern physics, such as the origin and composition of dark matter in the Universe and the unification of the fundamental forces. This review outlines the scenarios predicting SMPs and the techniques used at non-collider experiments to look for SMPs, eg in cosmic rays and bound in matter. The limits so far obtained on the fluxes and matter densities of SMPs which possess various detection-relevant properties such as electric and magnetic charge are given.

hep-ph↗