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Physics and Astronomy Colloquium

The Second Results from the Fermilab Muon g-2 Experiment

Dr. Alec Tewsley-Booth

Postdoctoral Research Associate

Department of Physics and Astronomy

University of Kentucky

Host: Renee Fatemi and Tim Gorringe

Title: The Second Results from the Fermilab Muon g-2 Experiment

Abstract: On August 10th, 2023, the Muon g-2 Collaboration presented a new experimental value of the positive muon magnetic anomaly, aμ = (gμ - 2)/2. From this data set, the first analyzed since our release in 2021, we determine aμ = 116592057(25) x 10-11. This result dominates the new experimental world average, aμ = 116592059(22) x 10-11, which includes the 2021 result and the final result from Brookhaven in 2006. This talk will cover the experimental apparatus and analysis techniques used to produce the newest result, especially the improvements made that led to the factor of two improvement over the 2021 result. Additionally, we will cover the state of the theory and its tension with experiment, as well as the contributions from the University of Kentucky.

 

Date:
Location:
CP-155

Studying galaxy clusters in multiwavelength, multiscale, and multidisciplinary

Yuanyuan Su

Assistant Professor

Department of Physics and Astronomy

University of Kentucky

Host: Gary Ferland and Tom Troland

Title: Studying galaxy clusters in multiwavelength, multiscale, and multidisciplinary

Abstract: As the largest gravitational bound systems in the Universe, galaxy clusters are one of the most important probes for testing the standard cosmological models. A typical galaxy cluster contains hundreds to thousands of member galaxies. The space between these galaxies is filled with hot and diffuse plasma -- the intracluster medium (ICM), which constitutes 90% of the baryonic mass and emits strongly in X-rays primarily through bremsstrahlung. ICM provides unique laboratories to study many astrophysical processes, such as the interaction between the hot baryons and the supermassive black hole, the growth of large scale structure, and the enrichment processes of the Universe. In this talk, I will present our recent discovery on galaxy clusters from its centers to the outskirts including the multiphase gas at the brightest cluster galaxies, bow shock in merging clusters, and the chemical composition of the ICM. Our work on active galactic nuclei in cluster member galaxies and machine learning applications will also be discussed. 

 

Date:
Location:
CP-155

QCD for New Physics Searches at the Sensitivity Frontier

Prof. Susan Gardner

Department of Physics and Astronomy

University of Kentucky

Host: Brad Plaster

Title: QCD for New Physics Searches at the Sensitivity Frontier 

Abstract: 

Questions that drive searches for physics beyond the Standard Model  include the physical origin of the cosmic baryon asymmetry and of dark matter. Quark dynamics, as realized through the theory of quantum chromodynamics (QCD), can appear in these studies in very different ways. In this talk, I develop these possibilities explicitly, first describing the role of QCD in ultra-sensitive searches for new physics, particularly at low energies, and then turning to how its features could be exploited in describing the undiscovered universe, along with the essential observational and experimental tests that could confirm them.

 

Date:
Location:
CP-155

The entropy of black holes: The 2023 Andrew Chamblin Memorial Colloquium

 

 

The 2023 Andrew Chamblin Memorial Colloquium

http://andrewchamblin.org/lecture.html

 

Speaker:  Dr. Vijay Balasubramanian

Professor

University of Pennsylvania

 

Title:  The entropy of black holes

Abstract:  One of the most famous results of twentieth-century physics states that black holes carry an entropy proportional to the area of their horizons. This entropy formula is universal in general relativity: it applies to black holes with any mass, charge, or rotation, and in any spacetime dimension.  I will describe a recent proposal explaining the microscopic origin and universality of this formula.  The proposal exploits new developments in the study of many-body chaos, thermalization, and quantum dynamics, along with concepts of complexity and information from theoretical computer science, communications theory, and cryptography.  These developments also suggest that the interior of a black hole is causally accessible to external observers, but only if they can perform egregiously complex measurements that are inaccessible under normal conditions.

Date:
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Location:
CP-155

Physics is Fun! Everyone should do it

Speaker: Patricia Rankin

Professor and Department Chair

Arizona State University

Department of Physics

Host: Plaster

Title: Physics is Fun! Everyone should do it

Abstract: Patricia Rankin became a physicist because she enjoyed it. She still enjoys it. She remembers being asked as a student why more women didn’t study physics. She can now give a much better answer to that question. This talk looks at how physicists solve problems, and why how we think impacts the demographics of our field. She will discuss how our understanding of what makes people leave physics has evolved and why the focus is now on a process driven approach. She will argue that while the field would benefit from more diversity, what matters to an individual is that they get to do what they enjoy and feel welcome.

Date:
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Location:
CP-155

Fractionalized excitations in Quantum Spin Liquids and their Detection

Dr. NandiniTrivedi

Professor

Ohio State University

Host: Murthy

 

Title: Fractionalized excitations in Quantum Spin Liquids and their Detection

Abstract: The 2022 Nobel prize celebrates the detection of entanglement between two photons. Quantum spin liquids (QSLs) are long-range entangled states of matter of billions of interacting qubits or spins that develop in a Mott insulator. The fate of the interacting spins can progress along two paths as the temperature is lowered: the spins can undergo long range ordering, spontaneously breaking the continuous symmetries, leading to a magnetic phase; or the spins can remain disordered but get quantum mechanically entangled with long range patterns of many-body entanglement in the resultant QSL. The possibility of obtaining QSL phases is enhanced by having a low spin and enhanced quantum fluctuations, and frustration arising from the lattice geometry and/or competing spin-spin interactions. Remarkably QSLs harbor fractionalized excitations rather than the conventional spin waves of ordered magnets that carry integer units of angular momentum. In my talk I will identify detectable signatures of these fractionalized excitations in experiments using light and neutrons. These fractionalized excitations are promising candidates to create logical qubits for quantum computation. 

 

Date:
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Location:
CP-155

Probing Cosmic Acceleration with Galaxy Clusters

Dr. Heidi Wu

Assistant Professor

Boise State University

Host: Su

 

Title: Probing Cosmic Acceleration with Galaxy Clusters

Abstract: The accelerated expansion of the Universe is one of the biggest puzzles in physics: Why is gravity repulsive rather than attractive on distance scales larger than a few million lightyears? Cosmic acceleration slows down the growth of structure, and we can use galaxy clusters — the largest gravitationally bound objects in the Universe — to probe the nature of cosmic acceleration.  In this talk, I will first introduce our current understanding of the Universe.  I will then discuss how we use sky surveys of galaxy clusters to measure cosmic acceleration and how several ambitious ground- and space-based missions will revolutionize our understanding of the Universe.

Date:
-
Location:
CP-155

The Life and Death of the Free Neutron

Speaker: Geoff Greene

Professor Emeritus

University of Tennessee

Host: Crawford

Title: The Life and Death of the Free Neutron

Abstract:  The decay of the free neutron is the simplest example of nuclear beta decay and, as such, is the archetype for a wide variety of Weak Interaction processes. These include radioactivity, Big Bang Nucleosynthesis, and energy production in the sun. Additionally, The precise value of the free neutron lifetime, can, along with other data, be used to test the consistency of the Standard Model. Remarkably, the value of neutron lifetime can also help determine the atmospheric composition of Venus. Given the breadth of physics involved, it is  disconcerting to note that, at present, measurements of the neutron lifetime by different methods are inconsistent. In this talk, I will discuss the physics of neutron decay and will review the strategies for the experimental determination of the neutron lifetime. I will discuss some of the experimental challenges and will attempt to provide some illumination of the current discrepant situation. 

Date:
-
Location:
CP-155

Electrify Everything!

Title: Electrify Everything!

 

Abstract: Making everything run on electricity is a necessary step in the transition from fossil fuels.    Starting that process immediately  is also necessary, and  helpful both to the process and the environment.

Date:
-
Location:
Chem-Phys 155
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