Dr Alexander Mitov
Reader in Theoretical Physics, Fellow of Emmanuel College, University of Cambridge
Awarded ERF 2013
Title of Research: Center for precision LHC studies
To unravel the workings of the Universe one needs to understand the fundamental forces and constituents of matter. This is achieved with the help of particle accelerators: the higher the accelerator energy the smaller the distances that are being probed. The current highest energy collider - the LHC, near Geneva in Switzerland - has the unprecedented ability to produce possible, yet-undiscovered heavy particles and probe their interactions down to extremely small distances.
At colliders, we do not directly observe the particles we hope to study. This is especially the case for possible as-of-yet undetected beyond the Standard Model particles since, due to their expected large mass, they would immediately decay to other known particles. The decay process will typically undergo several stages and will produce hundreds of particles which eventually will be registered in our detectors.
At this point, one may be surprised to hear that the real problem is not with the description of states with very large number of particles; we have the ability to describe those! The real problem particle physicists face is that the Standard Model almost always has a number of ways to produce such final states without the need for extra intermediate heavy particles. Therefore, the ultimate question to address is: how can we tell from the observation of a particular final state if a new particle that was not directly seen may have been present or not?
The work of Dr. Mitov aims at resolving precisely the above ambiguity by deriving with the highest achieved precision the predictions of the Standard Model for complex yet ubiquitous final states. Such precise predictions allow the LHC experimental collaborations to search for signals from New Physics by observing final states a little bit more (or less) often than what is predicted by the Standard Model. His interests cover many collider processes at all high-energy particle colliders. His current focus is on top quark physics. He is also keenly interested in the development of novel theoretical methods that would allow us to tackle even more challenging collider processes.
Dr Pat Scott
Lecturer in Fundamental Physics and STFC Ernest Rutherford Fellow, Imperial College London
Awarded ERF March 2014
Title of Research: The astroparticle road to new physics
Imagine living your life in a 5-person household where you don't know the names or faces of your 4 housemates. This is the situation that astronomers and particle physicists find themselves in right now with the matter in our own Galaxy. Dark matter makes up over 80% of the Milky Way, and the Universe as a whole, but we still don't know what it actually is.
Many theories predict that this mystery is in some way associated with the Higgs boson, the origin of mass, and the existence of an as-yet-undiscovered symmetry about to be unveiled at the Large Hadron Collider (LHC). My research aims to uncover the identity of dark matter, and the broader particle theory responsible for it.
To do this, I put together the results of many different experimental searches for dark matter and other new particles. These range from the LHC to smaller accelerators, gamma-ray telescopes, cosmic antimatter probes, ultra-clean experiments in the world's deepest mines, and a neutrino telescope embedded in the Antarctic ice. I make detailed theoretical predictions of each experimental result in range of different theories, and then compare them to the actual observations, in order to determine which theories provide the best simultaneous fit to all the available data. To make this sort of large-scale evaluation of theories possible, I lead the work of a collaboration of 30 other theorists and experimentalists from across astronomy and particle physics. Together we have developed GAMBIT (The Global and Modular Beyond-the-Standard-Model Inference Tool), a computational framework for carrying out such large-scale analyses across a wide range of different theories and experiments.
Dr Mikako Matsuura. The background is a Herschel Space Observatory image of the Galactic plane.
(Credit: Dr Francisco Diego, UCL)
Dr Mikako Matsuura
STFC Ernest Rutherford Fellow, Cardiff University
Awarded ERF in 2014
Title: Dust formation by supernovae and asymptotic giant branch stars
The supernova explosions of massive stars lead to synthesis of heavy elements. These newly synthesized elements are ejected from the stars into the interstellar medium of galaxies. Many generations of star-formation and subsequent death of stars enrich the interstellar medium with heavy elements. Recent models suggest that supernovae are responsible for enriching interstellar medium not only with heavy elements but also dust grains. My fellowship aims to test the hypothesis if supernovae could be a really important source of dust.
Dust grains are small particles, with a typical size of 100 Angstrom to 1 micron. Their compositions include silicon, oxygen, carbon, which are typically synthesized in supernovae or their progenitor stars. While the supernova explosion itself is one of the biggest energetic explosions in space, the gas left behind the explosion eventually cools down. If the gas temperature drops sufficiently cold enough for the elements to sublimate into dust grains, supernovae and supernova remnants can be important sites of dust formation.
In the last decade, infrared observations began to detect dust in supernovae. Typically, astronomers reported dust masses of 10-6 to 10-4 solar mass per supernovae, but this is insufficient to account for the large amount of dust found in the interstellar medium of galaxies. Theoretical models predict about 0.1 to 1 solar mass of dust per supernova is needed for supernovae to be important source of dust. A breakthrough came with our Herschel Space Observatory’s detection of dust in supernova 1987A, the youngest supernova explosion detected in the last 400 years. Our inferred dust mass was about half a solar mass, which is exactly what theoretical models have been predicted. Now, my research aims have developed into investigating how dust grains have been formed in the first place, using the Atacama Millimetre/Submillimetre Array (ALMA), NASA’s airborne telescope, SOFIA, and European’s eight-meter telescope, Very Large Telescope, with anticipated future observations of NASA and ESA’s space mission, JWST.
Dr Carolyn Devereux
STFC funded Daphne Jackson Research Fellow, University of Hertfordshire
Awarded DJF March 2016
Title of research: Tracing the Dark Matter Cosmic Web
The standard model of cosmology is the Lambda Cold Dark Matter (LCDM) model. It is based on the hot Big Bang followed by expansion which is now accelerating due to dark energy (L), and the existence of cold dark matter (CDM) that provides the framework for the formation of galaxies. We have yet to discover what dark energy is and, although we see the effects of dark matter (for example on the rotation speed of galaxies), we have yet to determine what dark matter consists of. Therefore, there are some big questions still to be answered in cosmology.
My research maps visible galaxies (the baryonic matter) to the distribution of dark matter. Knowing how these overlap provides insight into the large-scale structure of the Universe known as the Cosmic Web, consisting of clusters, voids and filaments, and develops our understanding of the role dark matter plays in the evolution of galaxies.
The Cosmic Microwave Background (CMB) is the remnant light from the Big Bang. The CMB radiation is gravitationally deflected by large masses it encounters on its way to Earth. By measuring the deflection (gravitational lensing) we can determine the projected matter distribution over the sky. The research uses the map of this distribution from the CMB lensing map provided by the Planck project and correlates it to the position of radio galaxies (from FIRST and LOFAR galaxy surveys) to investigate how these luminous galaxies trace the Cosmic Web. This research will help us understand the complex relationship between galaxy growth and dark matter.
Associate Professor of Space Physics, University of Southampton
Awarded ERF in 2014.
Title: Mass transport and loss in planetary and astrophysical plasmas.
The aim of my fellowship is to understand how charged material (plasma) is transported in the space around the planets Mercury, Jupiter and Saturn, and around stars in our galaxy and beyond. The solar wind is a stream of plasma that comes off the Sun and blows out into interplanetary space. Some planets have their own invisible magnetic field which stretches huge distances out into space and acts like a "shield", holding off this solar wind flow so that much of it is deflected around the planet. Behind this shield lies the planet's magnetosphere, like a giant magnetic bubble. Outside of our solar system, there are similar "winds", blowing near stars and creating stellar magnetospheres. Both planetary and stellar magnetospheres are full of plasma. Plasma parcels are "tied" to magnetic field lines, like beads on a string. My work will involve examining the “mass budget” of magnetospheres: deciphering how much material enters, how it moves around, and how much leaves. This will involve using a range of instruments on spacecraft to explore processes including plasma interchange and magnetic reconnection, as well as using telescopes to image these systems from afar.
We know quite a lot about processes such as interchange and reconnection in Earth's magnetosphere because there are many satellites flying around in space near Earth measuring these plasma motions. However, we can learn much more by applying this knowledge further afield and exploring how the situation may be different in other environments. Saturn and Jupiter are huge planets which rotate very rapidly and have a lot of plasma inside their magnetospheres due to exotic volcanic moons and rings. Mercury on the other hand is a much smaller planet and is much more vulnerable to the effects of the solar wind blowing at it as it is so close to the Sun. Stellar magnetospheres are the most dramatic of all due to their enormous size. It is fascinating to think that energy release processes at stars many millions of kilometres away can be so dramatic that we can observe them with telescopes here on Earth! Every planet and every star has a unique character, which is why I find studying similar physics in these exotic and diverse environments so challenging. The rewards for studying a range of environments for me are much greater than studying one place only.
STFC Ernest Rutherford Fellow and Data Scientist, University of Edinburgh
Awarded ERF in 2014.
Title: The Roles of the Mid-infrared and Surveys in the Life and Times of Quasars
Black holes are intriguing objects. These regions of the Universe where mass is so dense, and gravity so strong, that even light cannot escape, were once thought mere oddities due to their extreme properties. Today, however, black holes are now thought to be vital in the formation and lives of galaxies, including our own Milky Way. Observations, including those from the Hubble Space Telescope, have discovered black holes with masses a million or more times that of the Sun lurking at the centres of nearby galaxies. However, upon analysing these data further, there are two very surprising findings. First, these aptly named "Supermassive Black Holes" are ubiquitous at the centres of galaxies, and second, there is a relationship between the mass of the black hole and the properties of the galaxy. Thus, the question arises, do black holes have an intimate relationship with their host galaxy? Do they inform, limit and influence how a galaxy - including its constituent stars and gas - forms and evolves?
One possible line of evidence supporting the idea that black holes "regulate" their host galaxies is when one considers the energy liberated by mass falling into the black holes potential well. As gas and dust fall towards a black hole, but before it gets "swallowed", an accretion disk can form which swirls around the black hole, feeding it. However, due to the intense gravitational fields, the large amounts of angular momentum and friction between the in falling layers of gas, the accretion disk can heat-up to tremendous temperatures, in the process emitting optical, ultra-violet and X-ray light. If a supermassive black hole at the centre of a galaxy is actively accreting, then this "active galactic nucleus" is termed a quasar.
The broad aim of my research is to discover and study quasars; to find out how they are fuelled, how they generate their energy and how they can influence the host galaxies they live in. I use several telescopes across a range of wavelengths, including data from the Sloan Digital Sky Survey and the Hubble Space Telescope in the optical, and the Spitzer Space Telescope and the WISE satellite in the infrared. The infrared is important since quasars emit a considerable amount of their energy at these wavelengths, and one goal is to make sure we account fully for the entire energy production from supermassive black holes. It is with the data from these great observatories that I will discover and examine quasars, test theoretical and computer models of how quasars are fuelled, and gain new insights into how the galaxy-quasar symbiosis is achieved.
This research has potential impact and wider benefits to society in two flavours. First, the direct technological spin-offs that are associated with e.g. space-based telescopes and infrared detector technology. Second, and less immediate, this research, keeps the “awe factor” high. And it is from this, that we understand our environment, home planet and Universe that little bit more.
Dr Simon Badger
STFC Ernest Rutherford Fellow, Durham University
Awarded ERF in 2014
Title: Hard Processes for Hadron Colliders
The Large Hadron Collider (LHC) at CERN is currently taking data at an unprecedented rate and at higher energies than has ever been produced in laboratory conditions before. The aim is to probe into the smallest scales of the matter that make up our universe and to understand their interactions.
In 2012 the LHC experiments discovered an elusive missing piece in our understanding of the fundamental forces of nature - the Higgs boson. This has opened up new opportunities to study the properties of the new fundamental particle and attempt to dig deeper into the long established Standard Model of particle physics. The Standard Model has made some of the most precise predictions describing our universe. Despite its success, Astrophysical and Cosmological measurements have been shown to be incompatible with the Standard Model; leaving many great puzzles about how Dark Matter, Dark Energy and Gravity might fit into the tiny world of high energy collisions. While many theories have been postulated new physics to explain these phenomena, the Standard Model continues to hold up to the increasingly stringent tests performed at the LHC.
This new physics is extremely hard to pin down - the enormous backgrounds of Standard model interactions can hide the rare events that could explain the inadequacies of our current high energy theories. Precise theoretical predictions are also required to match the precision of the experiments and due to the extreme conditions created by the LHC intensive computer simulations are required. Keeping the precision of theoretical predictions in line with the experiments is a constant challenge that tests our knowledge and understanding of the mathematical framework of quantum field theory which underlies the Standard Model. Precision in this context means the computation of quantum corrections to scattering probabilities using perturbation theory. These objects have an incredibly complex structure which means many important quantities still remain unknown.
My research looks at both aspects of this problem - both in understanding the mathematical structure of the underlying theory and in applying new techniques to make precision predictions for the experiments at the LHC. Better understanding of scattering probabilities in quantum field theory can be used to make fast and efficient computer codes to describe the highest energy collisions (known has hard interactions) needed in experimental analyses. Our current computational abilities are often restricted to simple final states and I work on new techniques to extend the range of precision processes and maximise the search potential of the LHC in the future.
STFC Ernest Rutherford Fellow, University of Edinburgh
Awarded ERF in 2014
Title: Six quarks for Muster Mark!
ERF Title: Hunt for Exotic Particles: Dibaryons
The coming decade promises a revolution in our understanding of the fundamental nature of strongly interacting matter - pushed by the step changes in the quality and precision of terrestrial experiments and new vistas to observe hadronic matter in the cosmos, (e.g. neutron stars).
The fundamental theory thought to describe the strong interaction is QuantumChromoDynamics (QCD). QCD permits a large variety of bound states of quarks. Quark-anti-quark systems (mesons) and baryons (3 quarks) are the simplest options. Tetraquarks, pentaquarks, hexaquarks, hadronic molecules - are the new objects only recently starting to reveal themselves. The advance has been made possible by cutting edge experiments using beams at the frontiers of intensity coupled with large acceptance particle detectors.
Recent work led at Edinburgh established a completely new type of matter - the d*(2380) hexaquark. It is predicted to be a highly compact 6-quark state, having a volume similar to a single nucleon. As well as being a unique constraint on QCD the d* hexaquark would have a profound effect on the equation of state for nuclear matter at high densities revealing itself in catastrophic events of neutron star collisions, black hole collapses etc…
The d* also is the only multiquark state which can be produced copiously at current facilities, offering unique access to information beyond its basic quantum numbers, particularly its physical size and internal structure.
The current importance of the d* has analogy with the importance of the deuteron to nuclear physics – detailed measurement of the deuteron’s properties still provides key constraints for models of nuclei and the basic nucleon-nucleon interaction. If we want to achieve a similar predictive framework in the area of the multiquark systems, one needs to find a similar “deuteron” to fix the currently unconstrained physics parameters. The discovery of the d*(2380) hexaquark gives us such an opportunity.
A focussed programme of measurements at two of the world’s leading electromagnetic beam facilities (MAMI and JLAB) allow us to push forward the entire emerging research field of multiquark states.
|Dr Matthew Auger||University of Cambridge|
|Dr Simon Badger||Durham University|
|Dr Sarah Badman||Lancaster University|
|Dr Manda Banerji||University of Cambridge|
|Dr Mikhail Bashkanov||University of Edinburgh|
|Dr Florian Beutler||University of Portsmouth|
|Dr Robert Burston||University of Bath|
|Dr Erminia Calabrese||Cardiff University|
|Dr Christopher Chen||Imperial College London|
|Dr Greig Cowan||University of Edinburgh|
|Dr Timothy Davis||Cardiff University|
|Dr Oscar Dias||University of Southampton|
|Dr Simon Dye||University of Nottingham|
|Dr Gabriel Facini||University College London|
|Dr Jay Farihi||University College London|
|Dr Robert Fear||University of Southampton|
|Dr Andreu Font-Ribera||University College London|
|Dr Poshak Gandhi||University of Southampton|
|Dr Marco Gersabeck||The University of Manchester|
|Dr Scott Gregory||University of St Andrews|
|Dr Roxanne Guenette||University of Oxford|
|Dr Nina Hatch||University of Nottingham|
|Dr Andrew Hillier||University of Exeter|
|Dr Robert Izzard||University of Cambridge|
|Dr Caitriona Jackman||University of Southampton|
|Dr David Jess||Queen’s University of Belfast|
|Dr Izaskun Jimenez-Serra||Queen Mary, University of London|
|Dr Benjamin Joachimi||University College London|
|Dr Andreas Korn||University College London|
|Dr Stefan Kraus||University of Exeter|
|Dr Claudia Lederer||University of Edinburgh|
|Dr Gavin Lotay||University of Surrey|
|Dr Kate Maguire||Queen’s University of Belfast|
|Dr Mikako Matsuura||Cardiff University|
|Dr Christopher McCabe||King’s College London|
|Dr Haixing Miao||University of Birmingham|
|Dr Matthew Middleton||University of Southampton|
|Dr Ryan Milligan||University of Glasgow|
|Dr Alexander Mitov||University of Cambridge|
|Dr Christopher Nixon||University of Leicester|
|Dr Padelis Papadopoulos||Cardiff University|
|Dr Darren Price||The University of Manchester|
|Dr Nicholas Ross||University of Edinburgh|
|Dr Giuseppe Ruggiero||Lancaster University|
|Dr Andreas Schmitt||University of Southampton|
|Dr Pat Scott||Imperial College London|
|Dr Antonino Sergi||University of Birmingham|
|Dr Blake Sherwin||University of Cambridge|
|Dr Rowan Smith||The University of Manchester|
|Dr Colin Snodgrass||Open University|
|Dr Rita Tojeiro||University of St Andrews|
|Dr John Veitch||University of Glasgow|
|Dr Mika Vesterinen||University of Oxford|
|Dr Dominic Walton||University of Cambridge|
|Dr Nicholas Wardle||Imperial College London|
|Dr Nicholas Wright||Keele University|
On the 23rd March 2017 STFC held its first Introductory Workshop for newly appointed Ernest Rutherford Fellows. Thank you to those who participated in the event.
The agenda together with links to the speaker presentations are now available to view.