Journal Club

Seminar Room

Tuesday 31st of May, 2022

Hour: 10:00

Title: dE/dx from boosted long-lived particles

Presented by: Pablo Olgoso

Ref: https://arxiv.org/abs/2205.04473v2

Abstract:

At colliders massive long-lived charged particles could be revealed through their anomalously large ionisation energy loss $dE/dx$. In this paper we explore a class of scenarios in which the LLPs are particularly boosted, owing to production from the decay of a heavy parent resonance. Such scenarios give rise to unique signatures as compared to traditionally considered $dE/dx$ new-physics benchmarks. We demonstrate that this class of models, unlike traditional new-physics theories, can explain the recently reported excess of events in the $dE/dx$ search by the ATLAS collaboration without conflicting with the determination of $\beta$ from ionisation and time-of-flight measurements.

Hour: 10:00

Title: Impact of the recent measurements of the top-quark and W-boson masses on electroweak precision fits

Presented by: Jorge de Blas Mateo

Ref: https://arxiv.org/abs/2204.04204v2

Abstract:

We assess the impact of the very recent measurement of the top-quark mass by the CMS Collaboration on the fit of electroweak data in the Standard Model and beyond, with particular emphasis on the prediction for the mass of the W boson. We then compare this prediction with the average of the corresponding experimental measurements including the new measurement by the CDF Collaboration, and discuss its compatibility in the Standard Model, in new physics models with oblique corrections, and in the dimension-six Standard Model Effective Field Theory. Finally, we present the updated global fit to electroweak precision data in these models.