# The Lancaster, Manchester, Sheffield Consortium for Fundamental Physics: Particle Physics, From the Universe to the LHC

Lead Research Organisation:
University of Manchester

Department Name: Physics and Astronomy

### Abstract

Particle physics is all about understanding the elementary building blocks of nature and their interactions. Over the years, physicists have developed the Standard Model of particle physics, which is extremely successful in describing a very wide range of natural phenomena from things as basic as how light works and why atoms form through to the complicated workings inside stars and the synthesis of nuclei in the first few minutes after the Big Bang. However, we know that the Standard Model is not the whole story for it leaves many questions unanswered. Our proposal focuses on these unanswered questions and the way that scientists hope to address them in the coming years using experiments like the Large Hadron Collider (LHC) or observations like those that will be made using the Planck satellite.

The discovery at the LHC of a Higgs boson is a major milestone in our quest to understand the origin of mass. It is certainly not, however, the whole story. The LHC experiments are working hard to measure the properties of the particle they have discovered. They are also searching for new particles such as those predicted by supersymmetry. If supersymmetry is discovered then it offers the hope to explain the origin of the Dark Matter that makes up a large fraction of the material that is known to exist in the Universe. The scientists in our consortium will explore the theory of supersymmetry and dark matter. We will use data from experiments like the LHC to identify which of the many possible variants of supersymmetry are allowed by the data and to suggest new ways to explore those models in experiments. Any "new physics" produced at the LHC will be produced as a result of smashing two protons into each other, a very complicated environment, usually in association with "jets" of other particles. Members of our consortium will explore how we can make use of these jets to learn more about the associated new physics: the better we understand the environment in which new physics occurs, the more we are able to learn about the new physics itself. This is a complicated business that often necessitates computer simulations of particle collisions. Our members are experts in these simulations and have plans on how the make them more accurate, which is necessary if we are to make the most of the exciting data from the LHC.

The Standard Model of particle physics is also insufficient when it comes to explaining the early history of the Universe, when it was hot and dense. The evidence is now very strong that the history began with an era of accelerating expansion, called inflation. We are experts on inflation and its consequences. Inflation makes the Universe featureless, except for tiny quantum fluctuations that cause the density of matter and energy in the Universe to vary with position. These initially small variations grow to become observable effects. One effect is the formation of the billions of galaxies that populate the night sky. Another is to leave a tiny imprint on the cosmic microwave background radiation (CMB), a faint hum of microwave radiation in which the Universe is bathed. The CMB is being studied in exquisite detail by the Planck satellite, which was launched in 2009. We are at the forefront of interpreting the Planck data in the hope of pinning down which of the various theories of the early universe are ruled out and which remain viable. The deficiencies of the Standard Model extend still further for it does not explain the amount nor even the existence of ordinary matter. Our scientists will use this to constrain possible physics beyond the Standard Model and to do that they need to master the dynamics of the Universe shortly after the end of inflation. Last but not least, we hope to understand better the mysterious "Dark Energy" that drives the current and future acceleration of the Universe: one possibility is that it is because Einstein's theory of gravity is not quite right and that is something we will explore.

The discovery at the LHC of a Higgs boson is a major milestone in our quest to understand the origin of mass. It is certainly not, however, the whole story. The LHC experiments are working hard to measure the properties of the particle they have discovered. They are also searching for new particles such as those predicted by supersymmetry. If supersymmetry is discovered then it offers the hope to explain the origin of the Dark Matter that makes up a large fraction of the material that is known to exist in the Universe. The scientists in our consortium will explore the theory of supersymmetry and dark matter. We will use data from experiments like the LHC to identify which of the many possible variants of supersymmetry are allowed by the data and to suggest new ways to explore those models in experiments. Any "new physics" produced at the LHC will be produced as a result of smashing two protons into each other, a very complicated environment, usually in association with "jets" of other particles. Members of our consortium will explore how we can make use of these jets to learn more about the associated new physics: the better we understand the environment in which new physics occurs, the more we are able to learn about the new physics itself. This is a complicated business that often necessitates computer simulations of particle collisions. Our members are experts in these simulations and have plans on how the make them more accurate, which is necessary if we are to make the most of the exciting data from the LHC.

The Standard Model of particle physics is also insufficient when it comes to explaining the early history of the Universe, when it was hot and dense. The evidence is now very strong that the history began with an era of accelerating expansion, called inflation. We are experts on inflation and its consequences. Inflation makes the Universe featureless, except for tiny quantum fluctuations that cause the density of matter and energy in the Universe to vary with position. These initially small variations grow to become observable effects. One effect is the formation of the billions of galaxies that populate the night sky. Another is to leave a tiny imprint on the cosmic microwave background radiation (CMB), a faint hum of microwave radiation in which the Universe is bathed. The CMB is being studied in exquisite detail by the Planck satellite, which was launched in 2009. We are at the forefront of interpreting the Planck data in the hope of pinning down which of the various theories of the early universe are ruled out and which remain viable. The deficiencies of the Standard Model extend still further for it does not explain the amount nor even the existence of ordinary matter. Our scientists will use this to constrain possible physics beyond the Standard Model and to do that they need to master the dynamics of the Universe shortly after the end of inflation. Last but not least, we hope to understand better the mysterious "Dark Energy" that drives the current and future acceleration of the Universe: one possibility is that it is because Einstein's theory of gravity is not quite right and that is something we will explore.

### Planned Impact

See the attached "Pathways to Impact" document for details.

This project has impact beyond the international scientific community mainly through the training of highly skilled graduate students and postdoctoral researchers and through extensive "outreach" activities of various kinds aimed at engaging directly with the general public, school children, teachers, policy makers and the media. Undergraduate teaching is also impacted beneficially by our research.

This project has impact beyond the international scientific community mainly through the training of highly skilled graduate students and postdoctoral researchers and through extensive "outreach" activities of various kinds aimed at engaging directly with the general public, school children, teachers, policy makers and the media. Undergraduate teaching is also impacted beneficially by our research.

### Publications

Arnaud Q
(2018)

*First results from the NEWS-G direct dark matter search experiment at the LSM*in Astroparticle Physics
Dimopoulos K
(2016)

*Active galaxies can make axionic dark energy*in Astroparticle Physics
Dimopoulos K
(2017)

*Initial conditions for inflation*in Astroparticle Physics
Nolan B
(2016)

*On the stability of dyons and dyonic black holes in Einsteinâ??Yangâ??Mills theory*in Classical and Quantum Gravity
Biswas T
(2014)

*Generalized ghost-free quadratic curvature gravity*in Classical and Quantum Gravity
Talaganis S
(2016)

*High-energy scatterings in infinite-derivative field theory and ghost-free gravity*in Classical and Quantum Gravity
Talaganis S
(2015)

*Towards understanding the ultraviolet behavior of quantum loops in infinite-derivative theories of gravity*in Classical and Quantum Gravity
Conroy A
(2015)

*Generalized quadratic curvature, non-local infrared modifications of gravity and Newtonian potentials*in Classical and Quantum Gravity
Shipley J
(2016)

*Binary black hole shadows, chaotic scattering and the Cantor set*in Classical and Quantum Gravity
Akcay S
(2017)

*Spin-orbit precession for eccentric black hole binaries at first order in the mass ratio*in Classical and Quantum Gravity
Ashoorioon A
(2014)

*Black holes as beads on cosmic strings*in Classical and Quantum Gravity
Ambru? V
(2017)

*Thermal expectation values of fermions on anti-de Sitter space-time*in Classical and Quantum Gravity
Biswas T
(2014)

*Super-inflation, non-singular bounce, and low multipoles*in Classical and Quantum Gravity
Dolan S
(2015)

*Bound states of the Dirac equation on Kerr spacetime*in Classical and Quantum Gravity
Bezrukov F
(2015)

*Inflation, LHC and the Higgs boson*in Comptes Rendus Physique
Dulat S
(2016)

*Impact of the HERA I+II combined data on the CT14 QCD global analysis*in EPJ Web of Conferences
Dulat S
(2016)

*The structure of the proton: The CT14 QCD global analysis*in EPJ Web of Conferences
Dev P
(2014)

*Constraining non-thermal and thermal properties of Dark Matter*in Frontiers in Physics
Abel P
(2016)

*Vacuum for a massless quantum scalar field outside a collapsing shell in anti-de Sitter space-time*in General Relativity and Gravitation
Donnachie A
(2014)

*Central soft production of hadrons in pp collisions*in International Journal of Modern Physics A
Dempsey D
(2016)

*Waves and null congruences in a draining bathtub*in International Journal of Modern Physics D
Van De Bruck C
(2017)

*Reheating and preheating in the simplest extension of Starobinsky inflation*in International Journal of Modern Physics D
McDonald J
(2015)

*A minimal sub-Planckian axion inflation model with large tensor-to-scalar ratio*in Journal of Cosmology and Astroparticle Physics
Ashoorioon A
(2014)

*Reconciliation of high energy scale models of inflation with Planck*in Journal of Cosmology and Astroparticle Physics
McDonald J
(2014)

*Sub-Planckian two-field inflation consistent with the Lyth bound*in Journal of Cosmology and Astroparticle Physics
Mazumdar A
(2016)

*Constraints on variations in inflaton decay rate from modulated preheating*in Journal of Cosmology and Astroparticle Physics
Dimopoulos K
(2017)

*Quintessential inflation with a-attractors*in Journal of Cosmology and Astroparticle Physics
Kahlhoefer F
(2015)

*WIMP dark matter and unitarity-conserving inflation via a gauge singlet scalar*in Journal of Cosmology and Astroparticle Physics
McDonald J
(2016)

*Warm dark matter via ultra-violet freeze-in: reheating temperature and non-thermal distribution for fermionic Higgs portal dark matter*in Journal of Cosmology and Astroparticle Physics
Roszkowski L
(2017)

*Towards understanding thermal history of the Universe through direct and indirect detection of dark matter*in Journal of Cosmology and Astroparticle Physics
McDonald J
(2014)

*Negative running of the spectral index, hemispherical asymmetry and the consistency of Planck with large*in Journal of Cosmology and Astroparticle Physics
Dimopoulos K
(2016)

*How thermal inflation can save minimal hybrid inflation in supergravity*in Journal of Cosmology and Astroparticle Physics
De Bruck C
(2015)

*The variation of the fine-structure constant from disformal couplings*in Journal of Cosmology and Astroparticle Physics
Lyth D
(2015)

*Generating at l ? 60*in Journal of Cosmology and Astroparticle Physics
Bezrukov F
(2017)

*Hiding an elephant: heavy sterile neutrino with large mixing angle does not contradict cosmology*in Journal of Cosmology and Astroparticle Physics
Sanchez J
(2014)

*Inflationary buildup of a vector field condensate and its cosmological consequences*in Journal of Cosmology and Astroparticle Physics
De Bruck C
(2017)

*Non-Gaussianity in multi-sound-speed disformally coupled inflation*in Journal of Cosmology and Astroparticle Physics
Chatterjee A
(2015)

*Bound on largest ? 0.1 from sub-Planckian excursions of inflaton*in Journal of Cosmology and Astroparticle Physics
McDonald J
(2015)

*Signatures of Planck corrections in a spiralling axion inflation model*in Journal of Cosmology and Astroparticle Physics
De Bruck C
(2015)

*Disformal couplings and the dark sector of the universe*in Journal of Cosmology and Astroparticle Physics
Conroy A
(2017)

*Defocusing of null rays in infinite derivative gravity*in Journal of Cosmology and Astroparticle Physics
Mifsud J
(2017)

*Probing the imprints of generalized interacting dark energy on the growth of perturbations*in Journal of Cosmology and Astroparticle Physics
Ashoorioon A
(2014)

*Gravitational waves from preheating in M-flation*in Journal of Cosmology and Astroparticle Physics
Adhikari R
(2017)

*A White Paper on keV sterile neutrino Dark Matter*in Journal of Cosmology and Astroparticle Physics
Lyth D
(2014)

*BICEP2, the curvature perturbation and supersymmetry*in Journal of Cosmology and Astroparticle Physics
Bezrukov F
(2018)

*On the robustness of the primordial power spectrum in renormalized Higgs inflation*in Journal of Cosmology and Astroparticle Physics
Bélanger G
(2015)

*Limits on dark matter proton scattering from neutrino telescopes using micrOMEGAs*in Journal of Cosmology and Astroparticle Physics
De Bruck C
(2014)

*Power spectra beyond the slow roll approximation in theories with non-canonical kinetic terms*in Journal of Cosmology and Astroparticle Physics
De Bruck C
(2016)

*Disformally coupled inflation*in Journal of Cosmology and Astroparticle Physics
Bezrukov F
(2015)

*Why should we care about the top quark Yukawa coupling?*in Journal of Experimental and Theoretical PhysicsDescription | Progress on many fronts towards a better understanding of the universe, by developing theoretical models constrained by data from the LHC and cosmology experiments such as Planck. |

Exploitation Route | By continued research. |

Sectors | Education |

Description | Researchers supported by this award have been very active in outreach activities for the general public, schools and scientists from other fields. |

First Year Of Impact | 2014 |

Sector | Education |

Impact Types | Cultural,Societal |