# 1st year PG student talksP

Speakers today:
• Oliver
• Shane
• Jonathan
• Ibles
• Sophie
• Matt

## Navigating the hidden sector: The design of the SHiP experiment

by Oliver Lantwin

The SHiP experiment will study weakly coupled and long lived neutral particles, which are motivated by numerous physics models and virtually undetectable by conventional experiments. The resulting extreme experimental requirements require careful design and optimisation. After setting this scene, I will go on to describe the basic idea behind the active muon shield and explain why its detailed design is critical for the experimental performance. Finally I will summarise which avenues we will explore to optimise it and thus maximise the SHiP sensitivity.

## Dark Matter searches at CMS

by Shane Breeze

The existence of dark matter is strongly motivated by astrophysical and cosmological observations with a weakly interacting massive particle (WIMP) as a candidate. The true nature of dark matter is probed by production from energetic proton-proton collisions at the LHC leaving a key signature detectable by the CMS experiment. Low dark matter cross-sections and large QCD backgrounds make this a challenging search. The motivation for dark matter and searches for WIMPs at colliders will be presented.

## Global Fits of Supersymmetric Models

by Jonathan Costa

In this talk global fits will be presented of four benchmark models within the R-parity conserving Minimal Supersymmetric extension of the Standard Model (MSSM): the constrained MSSM (CMSSM) and two Non-Universal Higgs Mass (NUHM) models as well as a 10-parameter phenomenological MSSM model (pMSSM10). These global fits take into account experimental constraints from flavour physics, electroweak precision observables, the anomalous magnetic dipole moment of the muon, cosmological constraints on the dark matter relic density, direct detection experiments for dark matter, properties of the Higgs boson, and searches for supersymmetric particles from Run 1 of the LHC. We will also outline a new MasterCode project in which the SUSY SU(5) parameter space will be sampled.

## Direct dark matter searches with the LZ experiment: an overview

by Ibles Olcina

One of the major challenges of modern physics is to discover the nature of dark matter, an invisible and dominant mass component of the observable universe that is indirectly revealed through its gravitational effects on ordinary matter. Assuming that dark matter is made of new elementary particles, a well-motivated and generic class of dark matter candidates are weakly interacting massive particles (WIMPs), which arise naturally in several extensions to the Standard Model and have a mass ranging from a few GeV to a few hundreds of TeV. WIMPs could be directly detected via their scattering off atomic nuclei in underground, ultra low-background detectors. In this report, an overview of the dark matter direct detection LZ experiment is given, which originates from the merging of the successful ZEPLIN experiments in the UK and LUX experiment in the US. With its 7 tonnes of active liquid xenon, it is expected that the LZ experiment will probe WIMP interactions practically as far as it is allowed by new backgrounds from astrophysical neutrinos.

## Anti-deuterons as a Signature in Dark Matter Searches

by Sophie Baker

Antideuterons are a possible signal of dark matter annihilation or decay in our galaxy, with low astrophysical background. Using this signal to discover dark matter relies on first having a sound under- standing of antideuteron production, but our existing models cannot consistently explain all experimental data. The LHCb detector is ideal for measuring (anti)deuteron production and these results can be used to develop more accurate production models.

## Lepton non-universality and the decay $B \to p \bar{p} \tau \nu$

by Matthew Tilley

There has been a possible glimpse at beyond standard model physics in measurements such as the branching ratio of $B \to D^{*} \tau \nu$ with $B \to D^{*} \mu \nu$ ( R(D*) ). The principle that all leptons have universal couplings is challenged by such observations. The Heavy Flavour Averaging Group quote a 3.9$\sigma$ deviation from the standard model with combined results from R(D*) and R(D). This forms the motivation to study similar decays involving couplings to tau leptons such as the ratio of $B \to p \bar{p} \tau \nu$ with $B \to p \bar{p} \mu \nu$ . I will talk about the progress I have made so far in studying this decay.