arXiv subjects

C. Bird

Publications and source records attributed to C. Bird.

3 recordsLinked to original sources

arXiv2022

A Strategic Approach to Advance Magnet Technology for Next Generation Colliders

Colliders are built on a foundation of superconducting magnet technology that provides strong dipole magnets to maintain the beam orbit and strong focusing magnets to enable the extraordinary luminosity required to probe physics at the energy frontier. The dipole magnet strength plays a critical role in dictating the energy reach of a collider, and the superconducting magnets are arguably the dominant cost driver for future collider facilities. As the community considers opportunities to explore new energy frontiers, the importance of advanced magnet technology - both in terms of magnet performance and in the magnet technology's potential for cost reduction - is evident, as the technology status is essential for informed decisions on targets for physics reach and facility feasibility.

physics.acc-ph↗

arXiv2008

Galactic Positrons as a Probe of Large Extra Dimensions

In the last decade, there has been increased interest in the possibility that the Universe contains large additional dimensions. In this article it is proposed that the Kaluza-Klein modes which are predicted to exist in such models will be trapped in the galactic halo, and that the subsequent decays of these modes in the present will generate an observable flux of positrons and $γ$-rays from the galactic core. In particular, by restricting the rate of production 511 keV photons to be below that observed by the INTEGRAL satellite, a new set of constraints are imposed on the ADD model.

hep-ph↗

arXiv2006

Dark matter pair-production in b -> s transitions

The flavour-changing neutral current transition b \to s can serve as a sensitive probe of WIMP dark matter models, if the WIMP mass is under 2 GeV. In this work we extend our earlier analysis to a generic class of models where the interaction between the dark matter sector and the Standard Model matter sector is mediated by the Higgs boson(s). We show that experimental limits on the decays of B-mesons to K(K^*) and missing energy provide stringent constraints on the parameter space of such models, but do not rule out sub-GeV WIMPs in a model-independent way. We find that in the context of the NMSSM with light pseudoscalar Higgs, the WIMP masses under a few hundred MeV are generically excluded with the exception of few highly tuned points in the parameter space.

hep-ph↗