# Particle Physics

This series consists of talks in the areas of Particle Physics, High Energy Physics & Quantum Field Theory.

## Seminar Series Events/Videos

Currently there are no upcoming talks in this series.

## Cosmology and Signals of Strongly Interacting Dark Sectors

Tuesday Nov 21, 2017
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Standard Model particles account for a small fraction of the matter content of the universe. If the remaining dark matter (DM) was ever in thermal equilibrium with itself or with the Standard Model (SM) sector, there must exist interactions that allowed its number density to be depleted to its present value. An interesting possibility for achieving this arises in scenarios where the DM is composed of pions'' of a QCD-like dark sector.

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## TBA

Tuesday Nov 14, 2017
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Abstract TBA

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## Baryon-dark matter interactions and the radial acceleration relation

Tuesday Nov 07, 2017
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The radial acceleration relation is an empirical universal scaling relation between the total gravitational field and the Newtonian acceleration generated by baryons at any given radius within spiral galaxies. In this talk, I will discuss the possibility that such a relation arises from interactions between baryons and dark matter (DM), rather than from feedback processes or modifications of gravity. Starting from this premise, I will discuss what we can infer about the nature of baryon-DM interactions.

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## Bounds on new physics from electric dipole moments

Tuesday Oct 31, 2017
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Electric dipole moments are extremely sensitive probes for additional sources of CP violation in new physics models. The multi-scale problem of relating the high precision measurements with neutrons, atoms and molecules to fundamental parameters can be approached model-independently to a large extent; however, care must be taken to include the uncertainties from especially nuclear and QCD calculations properly. The resulting bounds on fundamental parameters are illustrated in the context of Two-Higgs-Doublet models.

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## Observation of a Gravitational Wave Emitting Neutron Star Merger with the Dark Energy Camera

Tuesday Oct 24, 2017

Motivated by the exciting prospect of new wealth of information arising from the first observations of gravitational and electromagnetic radiation from the same astrophysical phenomena, the Dark Energy Survey (DES) has performed a broad range follow-up program for LIGO/Virgo events using the Dark Energy Camera (DECam). In this talk, I present the discovery of the optical transient associated with the neutron star merger GW170817 using DECam and discuss its implications for the emerging field: multi-messenger cosmology with gravitational waves and optical data.

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## Recent results and future plans for the MAJORANA DEMONSTRATOR

Friday Oct 20, 2017
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The MAJORANA DEMONSTRATOR (MJD) is a 44-kg array of low-background germanium detectors of which 30kg is made from detectors enriched to 88% in 76Ge. MJD is operating a mile underground in the Sanford Underground Research Laboratory in Lead, SD. Its main purpose is to search for the neutrinoless double-beta decay of 76Ge and to demonstrate the technical feasibility of a tonne-scale Ge-based neutrinoless double-beta decay experiment. It is also capable of direct searches of a variety of dark matter candidates and other physics beyond the Standard Model.

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## Hunting for WIMPs: How low should we go?

Tuesday Oct 17, 2017
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Direct detection experiments are rapidly improving their sensitivity to weak scale Dark Matter.  A particular interesting (and minimal) possibility is that the Dark matter interacts with ordinary matter via the exchange of weak bosons: the W, Z, and Higgs.  Dark matter with substantial coupling to the Higgs boson is already under significant tension from limits on spin-independent scattering.  We comment on the power of  spin-dependent scattering as a probe of Z-mediated dark matter, both in a simple effective theory, and in the so-called Singlet-Doublet Model, which we argue is a useful be

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## Tunneling in Quantum Field Theory and the Ultimate Fate of our Universe

Tuesday Oct 03, 2017
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One of the most concrete implications of the discovery of the Higgs boson is that, in the absence of physics beyond the standard model, the long term fate of our universe can now be established through precision calculations. Are we in a metastable minimum of the Higgs potential or the true minimum? If we are in a metastable vacuum, what is its lifetime? To answer these questions, we need to understand tunneling in quantum field theory.

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## Searches for ALPs with Current and Future X-ray Satellites

Tuesday Sep 26, 2017

Galaxy clusters represent excellent laboratories to search for Axion-Like Particles (ALPs). They contain magnetic fields which can induce quasi-sinusoidal oscillations in the X-ray spectra of AGNs situated in or behind them. Ultra-deep Chandra observations of the Perseus cluster contain over 5 x 105 counts from the central NGC1275 AGN, and represent an extraordinary dataset for ALP searches. In this talk I will describe how we used these to search for spectral irregularities from the AGN.

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## Secondary Astrophysical Production of Anti-Deuteron and Anti-Helium3 Cosmic Ray

Friday Sep 22, 2017
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Cosmic-ray anti-deuterium and anti-helium have long been suggested as probes of dark matter, as their secondary astrophysical production was thought extremely scarce. But how does one actually predict the secondary flux? Anti-nuclei are dominantly produced in pp collisions, where laboratory cross section data is lacking. We make a new attempt at tackling this problem by appealing to a scaling law of nuclear coalescence with the physical volume of the hadronic emission region. The same volume is probed by Hanbury Brown-Twiss (HBT) two-particle correlations.

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## LECTURES ON-DEMAND

### Gabriela González, Louisiana State University

Speaker: Gabriela Gonzalez