Two of the major questions facing fundamental physics are:

What are the fundamental constituents of the universe and how do they interact? and How did the Universe begin, and how does it evolve?

Currently our best description of the theory of fundamental interactions of particles, the standard model of particle physics (SM), does not describe the Universe we live in. The SM cannot explain the observed matter-antimatter asymmetry of the Universe. This is before we consider the problem the 95% of the Universe that is made up of "dark" matter and energy of which the SM has nothing to say.

I am currently working on  the ATLAS experiment based at the Large Hadron Collider (LHC) in Geneva. I am searching for phenomena that cannot be explained by the standard model of particle physics. The LHC is running at a centre-of-mass energy of 13 TeV, the highest energy particle collisions ever produced on earth.

I am investigating the creation of high energy jets of particles in these proton-proton collisions. In most proton proton collisions two jets of particles are produced. By measuring the energy of each of the jets, physicists can calculate their mass (using Einstein’s E = mc²), this is called the dijet mass.

The phenomena I will be searching for include excited quarks, quantum black holes and additional bosons that appear as a peak in the mass spectrum or as a deviation from the predictions of the standard model. Some of these particles could interatct with Dark mater. The latest results (from an analysis of data collected in 2015 to 2016) was published in Physical Review D  where we probe masses of the order of 5 TeV. Unfortunatley we have not found anything new yet. 

I am currently working to improve this search by "tagging" the jets as being created by quarks or gluons. The results of this research should be published by the end of 2019.  

Previous Research Areas

I worked on the confirmation, published in Physical Review D, of the X(5568) particle observed by the the DØ experiment using semileptonic decays of the B_s⁰ meson. The X(5568) is an exiotc particle candidate that is composed of two quarks and two anti-quarks, an up quark, a strange anti-quark, a bottom quark and an anti-down quark  (normal matter is made up of baryons with three quarks or mesons made of a quark and an anti-quark).  

I  carried out searches for differences between the behaviour of particles and anti-particles (CP violation) that contain bottom (or b) quarks. The most important of these results is the investigation of the decays of electrically neutral B mesons (particles made up of a quark and an anti-quark, one of them a b-quark) to a muon and other particles: B_s⁰ → D_sμX and B_d⁰ → D^(∗)μX. These processes are especially sensitive to the difference between matter and antimatter.At the time of their publication both of these results were the most precise tests of their kind in the world.

I also made several “standard candle” measurements of CP violation in the decay processes B^± → J/ψK^±, B^± → μ^±D⁰,  Ds^± → φπ^± and D^± → K^∓π^±π^±.

I have also used the measurement of B_s⁰ → D_sμX decays to see if the fabric of space has a preferred direction (known as CPT violation or Lorentz violation).

Unfortunately I have not found any new sources of CP-violation that would be able to explain the matter domination of the Universe. I am continuing the search in the decay of mesons containing charm quarks. 

Experimental Particle Physics Group

 I am teaching the following courses:

• PHYS101 The Physical Universe
• PHYS281 Scientific Programming & Modelling Project
• PHYS389 Computer Modelling
• PHYS451 MPhys Project (Serach for New Particles with the ATLAS experiment at the LHC)