**IPPP Summer Studentships 2018:**

The IPPP will offer again this summer the possibility of working on a project in theoretical particle physics for about three weeks in Summer 2018. The topic and the names of the supervisors are given below. The exact dates can be agreed individually with the supervisor; successful applicants will receive 100 pounds per week from the IPPP. In the previous years this turned out to be a very successful program. Three years ago some of the students managed even to write a publication. Durham students should apply via the Physics department webpage, non-Durham students please contact alexander.lenz@durham.ac.uk.

The deadline for the application is 27th March 2018.

**Simon Badger and Fabrizio Caola - Finding new physics in the Higgs sector**

With no direct sign of new physics at the LHC so far, search for subtle

deviations from the Standard Model is becoming an essential task.

A useful and popular framework to perform these studies is provided by

effective field theory (EFT) techniques, which allow to study many

different beyond the standard model (BSM) scenarios at once, with only

few theoretical assumptions.

The aim of this project is to first understand the EFT theoretical

framework, and then apply it to key Higgs processes at present and

future colliders.

**Silvia Pascoli - Sterile neutrinos: truth or fiction?**

Neutrinos are the most elusive of the fundamental components of the Universe. But they provide us with the only particle physics evidence that the current and very successful picture of particles and their interactions, the Standard Model, is not the ultimate answer. Something is missing and is required to explain why neutrinos have, albeit tiny, masses. Some even more puzzling pieces of information are emerging. Some experiments seem to indicate that there exists a new type of neutrinos, called sterile neutrinos, which do not interact via the four known forces but can manifest themselves in neutrino oscillation experiments. This project will focus on the still-controversial experimental hints in favour and against sterile neutrinos and will try to compose a coherent theoretical picture. Results from the Neutrino 2018 conference, in June 2018, will also be considered as well as the tests at the now-starting programme SBN at Fermilab.

**David Cerdeno - Introduction to the detection of dark matter particles**

Astrophysical and cosmological evidence indicates that the majority of the matter in the Universe takes the form of non-luminous particles known as dark matter. The detection and identification of this new kind of matter constitutes one of the main open problems in modern Astroparticle Physics. In this project we will investigate ways to detect these particles in experiments on Earth, through their collisions with a target material.

**Alexander Lenz, Luca DiLuzio - Introduction to grand unified theories **

Various features of the Standard Model of elementary particles point to a deeper structure in which the strong and electroweak forces are unified. In this project, we shall pass through the motivation for extending the SU(3)xSU(2)xU(1) gauge symmetry of the Standard Model to a simple or semi-simple gauge group, which would eventually leave us with two basic classes of unified frameworks - the SU(5) grand unification and the left-right symmetric models involving namely the Pati-Salam and SO(10) scenarios. We shall consider some of the consequences of embedding the Standard Model into such unified theories, like the unification of gauge and Yukawa couplings at some very high scale, the implications for neutrino masses and baryon stability. While an elementary knowledge of quantum field theory and group theory is welcome, the project will be tuned to the student’s level.

** Michael Spannowsky, Ramona Gröber - The Higgs sector beyond the Standard Model:**

The Higgs boson, discovered in 2012, was the last missing ingredient of the Standard Model.

This now opens up the possibility for a precise understanding of the origin of particle’s masses

and the mechanism of electroweak symmetry breaking. Since the Higgs boson is the only

spin-0 particle of the Standard Model, one can ask the question whether the Higgs sector might be

extended and whether such an extensions can be related to yet unsolved issues of the Standard Model.

In this project we will investigate the Higgs sector of the

Standard Model and extensions and how it can be probed at the LHC.

**Steven Abel, Jakub Scholtz - Constraints on Andromeda DM halo ellipticity from its Plane of Satellites**

It appears that 15 out of ~30 satellite galaxies of the Andromeda lie in a very narrow plane (width ~ 20 kpc, radius ~ 200kpc). If the dark matter halo of Andromeda were sufficiently elliptical, then the spherical symmetry breaking terms would lead to angular momentum non-conservation and randomize the orbits of the satellites that were originally all in one plane. As a result the existence of this plane of satellites can be interpreted as a bound on the ellipticity of the dark matter halo.

A summer student could determine the orbits of these satellites in a non-spherical halo using GalPot -- a scientific software that is designed to integrate the orbits. Once the student is familiar with GalPot, we would scan over a range of ellipticities and orientations of the triaxial halo and determine which configurations lead to significant losses of planarity. These configurations are then ruled out. The creative research element comes from determining a reasonable criterion that determines the loss of planarity. I would think that growth of the standard deviation of unit angular momentum vectors of the satellite population would work, but I would like the student to come up with their own ideas in this regard.

**Frank Krauss, Jonas Lindert - Top-quark reconstruction in ttbb production at the Large Hadron Collider**

Precise measurements of Higgs boson production in association with top-quark pairs

allow for constraints on the top-quark Yukawa coupling, which in turn is crucial to fully

characterise the scalar sector of the Standard Model and could also open a window on

Beyond-the-Standard-Model interactions. At the Large Hadron Collider, searches for

ttH production in the dominant H -> b bar channel are plagued by a large QCD background,

which is dominated by ttbb production. The detailed understanding of this

multi-particle background process is of crucial importance for the sensitivity of ttH(->b bar)

analyses. In this project we will employ state-of-the art simulation software

including higher-orders in perturbation theory for the modeling of ttbb and will

investigate and compare different analyses techniques for the identification of

top-quark candidates in ttbb production. In particular we want to develop a strategy

based on Machine Learning techniques to separate b-quarks originating in the hard process

against b-quarks from top-quark decays.