

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.
Savas Dimopoulos Perimeter Institute for Theoretical Physics
Sam Dolan University of Southampton
Avery Broderick University of Waterloo
James Steiner Massachusetts Institute of Technology (MIT)
Frans Pretorius Princeton University
Salvatore Vitale Massachusetts Institute of Technology (MIT)
keith Riles University of Michigan–Ann Arbor
Sylvia Zhu Albert Einstein Institute
Asimina Arvanitaki Perimeter Institute for Theoretical Physics
Asimina Arvanitaki Perimeter Institute for Theoretical Physics
Edward Marti University of Colorado Boulder
Holger Mueller University of California System
Ho Jung Paik University of Maryland, College Park
Andrew Geraci University of Nevada Reno
Giorgio Gratta Stanford University
Yannis Semertzidis Institute for Basic Science - Center for Axion and Precision Physics Research
Federica Petricca Max Planck Institute
Rafael Lang Columbia University
Josef Pradler Institut für Hochenergiephysik (HEPHY) - Institut für Hochenergie Physik
Doug Bryman TRIUMF (Canada's National Laboratory for Particle and Nuclear Physics)
Andrzej Czarnecki University of Alberta
Thomas Becher Universität Bern
Kevin Mcfarland University of Rochester
Andre de Gouvea Northwestern University
Kendall Mahn TRIUMF (Canada's National Laboratory for Particle and Nuclear Physics)
Gabriel Perdue Fermi National Accelerator Laboratory (Fermilab)
Michael Peskin SLAC National Accelerator Laboratory
Miriangela Lisanti Princeton University
Michael Peskin SLAC National Accelerator Laboratory
Miriangela Lisanti Princeton University
Michael Peskin SLAC National Accelerator Laboratory
Miriangela Lisanti Princeton University
Michael Peskin SLAC National Accelerator Laboratory
Miriangela Lisanti Princeton University
Zach Weiner University of Washington
Zachary Bogorad Stanford University
This event is meant to study the connections between quantum fields in curved spacetimes with horizons and the effective field theory methods as applied to open systems (Open EFTs). In particular the hope is to exploit the existence of tools (from areas like optics) for dealing with hierarchies of scale in open systems and adapt the to see if they can inform our understanding of controlling late-time predictions in gravitational environments. Please note that this meeting is by invitation only.
Black hole superradiance is a fascinating process in general relativity and a unique window on ultralight particles beyond the standard model. Bosons -- such as axions and dark photons -- with Compton wavelengths comparable to size of astrophysical black holes grow exponentially to form large clouds spinning down the black hole in the process and produce monochromatic continuous gravitational wave radiation. In the era of gravitational wave astronomy and increasingly sensitive observations of astrophysical black holes and their properties superradiance of new light particles is a promising avenue to search for new physics in regimes inaccessible to terrestrial experiments. This workshop will bring together theorists data analysts and observers in particle physics gravitational wave astronomy strong gravity and high energy astrophysics to explore the signatures of black hole superradiance and to study the current and future possibilities of searching for new particles with black holes.
In the last few years there has been a resurgence of interest in small scale high sensitivity experiments that look for new forces and new particles beyond the Standard Model. They promise to expand our understanding of the Cosmos and possibly explain mysteries such as Dark matter in a way that is complementary to colliders and other large scale experiments. There is a number of different physics motivations and approaches currently being explored in many on-going and newly proposed experiments and they often share common experimental techniques.Many workshops in this field focus on the theory motivations behind these experiments without emphasis on the details of the experimental techniques that enable precision measurements. There is also substantial experimental expertise across many fields, often outside of fundamental physics community, that can be relevant to ongoing and proposed experiments.Thus, we decided to organize the workshop around some of the common experimental techniques. We hope it will be educational for both experimentalists and theorists and lead to discussions on the best way forward. We would like to bring together experimentalists with different expertise in the hope that it will lead to new ideas through interdisciplinary interactions. For theorists, we expect it to provide better appreciation of the challenges and opportunities in improving the sensitivity of precision measurement experiments.
Continuing investment in fundamental weakly-coupled science, primarily through neutrino experiments and dark matter searches, prompts the question: is the maximum possible scientific information going to be extracted from these experiments? Are there new creative uses of the existing and planned facilities that would advance our knowledge of fundamental physics? Are there physics targets that have been overlooked by the current approach? This workshop will attempt to advance discussion of these topics, and concentrate on non-traditional ideas and alternative methods of probing new physics, both at underground laboratories and at high-intensity accelerators. The workshop aims to complement the large international conference, Topics in Astroparticle and Underground Physics 2017, to be held in Sudbury ON July 24-28, by directly preceding that meeting.
Radiative Corrections at the Intensity Frontier of Particle Physics
Zach Weiner University of Washington
The cosmic microwave background is a sensitive probe of early-Universe physics, and yet fundamental constants at recombination can differ from their present-day values due to degeneracies in the standard cosmological model. Such scenarios have been invoked to reconcile discrepant measurements of the present-day expansion rate, but even absent such motivation they raise the intriguing possibility of yet-undiscovered physics coupled directly to Standard Model particles. I will discuss theories in which a new scalar field shifts the electron's mass at early times; viable models are already stringently constrained by measurements of quasar absorption lines, the abundances of light elements, and the universality of free fall. I will show that the remaining parameter space is exactly that which allows not only the primary cosmic microwave background but also low-redshift distances to be consistent with observations. After presenting the results of parameter inference I will discuss additional cosmological and laboratory signatures of the model.
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Zoom link https://pitp.zoom.us/j/99705853481?pwd=MTZRWC9hREkvOXpiZkxCM3UvdnRNQT09
Zachary Bogorad Stanford University
Significant effort has been devoted to searching for new fundamental forces of nature. At short length scales (below approximately 10 nm), many of the strongest experimental constraints come from neutron scattering from individual nuclei in gases. The leading experiments at longer length scales instead measure forces between macroscopic test masses. I will present a proposal that combines these two approaches: scattering neutrons off of a target that has spatial structure at nanoscopic length scales. Such structures will give a coherent enhancement to small-angle scattering, where the new force is most significant. This can considerably improve the sensitivity of neutron scattering experiments for new forces in the 0.1 - 100 nm range. I will discuss the backgrounds due to Standard Model interactions and a variety of potential target structures that could be used, estimating the resulting sensitivities. I will show that, using only one day of beam time at a modern neutron scattering facility, our proposal has the potential to detect new forces as much as four orders of magnitude beyond current laboratory constraints at the appropriate length scales.
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Zoom link https://pitp.zoom.us/j/98201041537?pwd=MS9weFpNcHVFTVIwMTVoYmpxeTd6Zz09
Antonio Iovino Sapienza University of Rome
The recent data releases by multiple pulsar timing array (PTA) experiments show evidence for Hellings-Downs angular correlations indicating that the observed stochastic common spectrum can be interpreted as a stochastic gravitational wave background. We study whether the signal may originate from gravitational waves induced by high-amplitude primordial curvature perturbations. Such large perturbations may be accompanied by the generation of a sizable primordial black hole (PBH) abundance. We discuss in which scenarios the inclusion of non-Gaussianities in the computation of the abundance can lead to a signal compatible with the PTA experiments without overproducing PBHs.
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Zoom link https://pitp.zoom.us/j/95261778825?pwd=QndRd0xQVFpNVzk0VXpRUkNqR1JXZz09