David L.-J. Ho
A5047112391- High-Energy Particle Collisions Research
- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- Particle Detector Development and Performance
- Physics of Superconductivity and Magnetism
- Cosmology and Gravitation Theories
- Magnetic Field Sensors Techniques
- Superconducting Materials and Applications
- Particle Accelerators and Free-Electron Lasers
- Quantum, superfluid, helium dynamics
- Computational Physics and Python Applications
- Particle accelerators and beam dynamics
- Electromagnetic Effects on Materials
Imperial College London
2019-2025
This search for magnetic monopoles (MMs) and high electric charge objects (HECOs) with spins 0, 1/2, 1, uses the first time full MoEDAL detector, exposed to 6.46 fb^{-1} proton-proton collisions at 13 TeV. The results are interpreted in terms of Drell-Yan photon-fusion pair production. Mass limits on direct production MMs up 10 Dirac charges HECOs range 10e 400e, were achieved. placed MM HECO currently strongest world. is only LHC experiment capable being directly calibrated highly ionizing...
Magnetic monopoles may be produced by the Schwinger effect in strong magnetic fields of peripheral heavy-ion collisions. We review form electromagnetic such collisions and calculate from first principles cross section for monopole pair production. Using worldline instanton method, we work to all orders charge, hence are not hampered breakdown perturbation theory. Our result depends on spacetime inhomogeneity through a single dimensionless parameter, Keldysh which is independent collision...
We report on a search for magnetic monopoles (MMs) produced in ultraperipheral Pb-Pb collisions during Run 1 of the LHC. The beam pipe surrounding interaction region CMS experiment was exposed to <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:mn>184.07</a:mn><a:mtext> </a:mtext><a:mtext> </a:mtext><a:mi mathvariant="normal">μ</a:mi><a:msup><a:mrow><a:mi...
Magnetic monopoles may be produced by the dual Schwinger effect in strong magnetic fields. Today, strongest known fields Universe are fleetingly heavy-ion collisions. We use complex worldline instanton method to calculate momentum distribution of collisions, an approximation that includes field all orders but neglects monopole self-interactions. The result saturates preparation time-energy uncertainty principle, and yields a necessary ingredient for experimental searches
We show that in the SU(2) Georgi-Glashow model, 't Hooft-Polyakov monopoles are produced by a classical instability magnetic fields above Ambjorn-Olesen critical field, which coincides approximately with field at Schwinger pair production becomes unsuppressed. Below it, can be thermally, and we rate is higher than for pointlike calculating sphaleron energy as function of field. The results applied to heavy-ion collisions or early Universe.
We present the results of an explicit numerical computation a novel instanton in Georgi-Glashow SU(2) theory. The is physically relevant as mediator Schwinger production 't Hooft--Polyakov magnetic monopoles from strong fields. In weak fields, pair rate has previously been computed using worldline approximation, which breaks down fields due to effects finite monopole size. Using lattice field theory we have overcome this limit, including size all orders. demonstrate that full consideration...
In an external magnetic field, the energy of electroweak sphaleron---representing barrier to baryon and lepton number violation---decreases but remains nonzero until upper Ambj\o{}rn--Olesen critical field strength set by Higgs mass electric charge. At this point sphaleron vanishes. We demonstrate numerically computing configuration in presence over full range strengths discuss implications for baryogenesis early universe possibility observing violation heavy-ion collisions.
We report on a search for magnetic monopoles (MMs) produced in ultraperipheral Pb--Pb collisions during Run-1 of the LHC. The beam pipe surrounding interaction region CMS experiment was exposed to 174.29 $\mathrm{\mu}$b$^{-1}$ at 2.76 TeV center-of-mass energy per collision December 2011. It scanned by MoEDAL using SQUID magnetometer trapped MMs. No MM signal observed. two distinctive features this are use trapping volume very close point and ultra-high fields generated heavy-ion run that...