Particle Physics

Particle physics is the science which identifies nature's constituents and interactions at the most fundamental level, with an emphasis on comparing theoretical ideas with both terrestrial experiments and astrophysical observations. This mandate gives it a strong overlap with string theory, quantum gravity and cosmology. Particle physicists at Perimeter Institute are currently involved in identifying how cosmological observations and terrestrial accelerator and underground experiments constrain the theoretical possibilities for physics beyond the Standard Model.

Displaying 409 - 420 of 1434

Solving the Hierarchy Problem Discretely
August 14, 2018

PIRSA:18080081
Particle Physics
Roadmap Discussion
June 07, 2018

PIRSA:18060017
Cosmology

Particle Physics
Asymptotically safe gravity and electroweak scalegenesis

Masatoshi Yamada Universität Heidelberg
June 07, 2018

PIRSA:18060016
Cosmology

Particle Physics
Quantum Loops in de Sitter space and Scale Dependent Galaxy Bias at Small Wave-Vectors

Mark Wise California Institute of Technology (Caltech)
June 07, 2018

PIRSA:18060063
Particle Physics
Discussion 4
June 07, 2018

PIRSA:18060019
Cosmology

Particle Physics
Asymptotically Safe Grand Unified Theories

Zhi-Wei Wang University of Waterloo
June 07, 2018

PIRSA:18060021
Cosmology

Particle Physics
Keeping the Standard Model Safe

Robert Mann University of Waterloo
June 07, 2018

PIRSA:18060020
Condensed Matter

Particle Physics
Discussion 3
June 06, 2018

PIRSA:18060018
Cosmology

Particle Physics
Constraining Asymptotic Safety using central charges

Nicola Dondi CP3-Origins
June 06, 2018

PIRSA:18060024
Cosmology

Particle Physics
Beta functions at large N_f

Anders Eller Thomsen CP3-Origins
June 06, 2018

PIRSA:18060025
Cosmology

Particle Physics
Shedding light on dark matter in asymptotic safety

Astrid Eichhorn Universität Heidelberg
June 06, 2018

PIRSA:18060023
Cosmology

Particle Physics
Asymptotic safety of gravity-matter systems and effective universality

Manuel Reichert University of Southern Denmark
June 06, 2018

PIRSA:18060022
Cosmology

Particle Physics

Solving the Hierarchy Problem Discretely
August 14, 2018

PIRSA:18080081
Particle Physics
We present a new solution to the Hierarchy Problem utilizing non-linearly realized discrete symmetries. The cancelations occur due to a discrete symmetry that is realized as a shift symmetry on the scalar and as an exchange symmetry on the particles with which the scalar interacts. We show how this mechanism can be used to solve the Little Hierarchy Problem as well as give rise to light axions.
Roadmap Discussion
June 07, 2018

PIRSA:18060017
Cosmology

Particle Physics
Asymptotically safe gravity and electroweak scalegenesis

Masatoshi Yamada Universität Heidelberg
June 07, 2018

PIRSA:18060016
Cosmology

Particle Physics
We discuss the impact of quantum gravity fluctuations on a scalar mass. In case that the scalar mass becomes irrelevant above the Planck scale, there could be solutions to the gauge hierarchy problem. In this talk, we consider the so-called classically scale invariant extension of the standard model, where non-abelian scalar-gauge theory in a dark sector is introduced to explain the origin of the electroweak scale. We discuss its phenomenological implications towards probing new physics.
Quantum Loops in de Sitter space and Scale Dependent Galaxy Bias at Small Wave-Vectors

Mark Wise California Institute of Technology (Caltech)
June 07, 2018

PIRSA:18060063
Particle Physics
The power spectrum for fluctuations in the number density of galaxies can be very different in shape from the power spectrum for fluctuations in the mass density at very small wave vectors (i.e., large length scales) if the primordial density fluctuations are non-Gaussian. I review this phenomena. (It is fairly well known in the more astrophysical part of the cosmology community but less so in the particle physics part of the field.) Then I show that primordial non-Gaussianities that arise from quantum loop diagrams in de-Sitter space can give rise to this phenomena. I also discuss if it is observable given constraints on primordial non-Gaussianity that arise from the Cosmic Microwave Background
Discussion 4
June 07, 2018

PIRSA:18060019
Cosmology

Particle Physics
Asymptotically Safe Grand Unified Theories

Zhi-Wei Wang University of Waterloo
June 07, 2018

PIRSA:18060021
Cosmology

Particle Physics
Keeping the Standard Model Safe

Robert Mann University of Waterloo
June 07, 2018

PIRSA:18060020
Condensed Matter

Particle Physics
An increasing number of researchers are considering the possibility that the Standard Model, appropriately extended, can attain an interacting ultraviolet fixed point. Such a theory could, in the Wilsonian sense, be regarded as a fundamental theory. I will describe recent work that shows this goal is attainable in principle by adding gauged vector-like fermions to the Standard Model, in the limit of a large number of fermion fields. With this proof-of-principle demonstration, the challenge now to find realistic asymptotically safe extensions of the Standard Model with interesting and falsifiable phenomenological signatures
Discussion 3
June 06, 2018

PIRSA:18060018
Cosmology

Particle Physics
Constraining Asymptotic Safety using central charges

Nicola Dondi CP3-Origins
June 06, 2018

PIRSA:18060024
Cosmology

Particle Physics
I will present constraints from central charges and gradient flow relations on UV and IR interacting fixed points under perturbative control. It is possible to extend this methodology beyond perturbation theory for supersymmetric theories where the central charges are calculated to all orders. In this case, these constraints draw a complex map of possible RG flows, some of them compatible with Asymptotic Safety. Examples of such SUSY theories are discussed
Beta functions at large N_f

Anders Eller Thomsen CP3-Origins
June 06, 2018

PIRSA:18060025
Cosmology

Particle Physics
Including a large number of vector-like fermions can be used to generate fixed points for the RG flows of gauge theories. Recently this has been used as a foundation for constructing UV safe models. The talk will focus on the machinery behind the large N_f computations extended to generic gauge-Yukawa theories. For semi-simple gauge theories the phase diagram shows the persistence that the UV fixed point of simple gauge theories.
Shedding light on dark matter in asymptotic safety

Astrid Eichhorn Universität Heidelberg
June 06, 2018

PIRSA:18060023
Cosmology

Particle Physics
The nature of dark matter is one of the outstanding riddles of fundamental physics. Here, I will discuss first steps to explore dark matter in the asymptotic safety paradigm. As a first example, I will show indications for an asymptotically safe fixed point in the Higgs portal to fermionic dark matter, leading to a relation between the Higgs portal coupling and the dark matter mass. This model also serves as an example for different mechanisms that generate asymptotic safety. I will then review some properties of an extended Higgs sector under the coupling to asymptotically safe quantum gravity and discuss how quantum gravity fluctuations flatten the Higgs potential and thus lead to a decoupling of scalar singlets which are subject to experimental searches for dark matter.
Asymptotic safety of gravity-matter systems and effective universality

Manuel Reichert University of Southern Denmark
June 06, 2018

PIRSA:18060022
Cosmology

Particle Physics
We review the status of asymptotically safe gravity-matter systems. The existence of a UV fixed point in such systems is guaranteed if the matter-self couplings are weak and if higher-derivative gravity terms are neglected. We show how this can manifest itself in a functional renormalisation group computation. Such gravity-matter systems contain various avatars of the dynamical Newton's coupling, e.g. gravitational self-couplings or matter-graviton couplings. We uncover an effective universality for the dynamical Newton's coupling on the quantum level: its momentum-dependent avatars are in remarkable quantitative agreement in the scaling regime of the UV fixed point. This emergence of effective universality is a strong indication for the physical nature of the UV fixed point and it provides a guiding principle for setting up future truncations.

Title	Speaker(s)	Date	Talk Type	Info link
Solving the Hierarchy Problem Discretely		2018-08-14	Scientific Series	View details
Roadmap Discussion		2018-06-07	Conference	View details
Asymptotically safe gravity and electroweak scalegenesis	Masatoshi Yamada	2018-06-07	Conference	View details
Quantum Loops in de Sitter space and Scale Dependent Galaxy Bias at Small Wave-Vectors	Mark Wise	2018-06-07	Scientific Series	View details
Discussion 4		2018-06-07	Conference	View details
Asymptotically Safe Grand Unified Theories	Zhi-Wei Wang	2018-06-07	Conference	View details
Keeping the Standard Model Safe	Robert Mann	2018-06-07	Conference	View details
Discussion 3		2018-06-06	Conference	View details
Constraining Asymptotic Safety using central charges	Nicola Dondi	2018-06-06	Conference	View details
Beta functions at large N_f	Anders Eller Thomsen	2018-06-06	Conference	View details
Shedding light on dark matter in asymptotic safety	Astrid Eichhorn	2018-06-06	Conference	View details
Asymptotic safety of gravity-matter systems and effective universality	Manuel Reichert	2018-06-06	Conference	View details

Particle Physics

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