Events at Physics
Events During the Week of October 29th through November 5th, 2023
- Graduate Program Event
- Innovative Approaches in Neutrino Telescope Research and Analysis
- Time: 12:00 pm - 2:00 pm
- Place: 4274 Chamberlin Hall
- Speaker: Jeffrey Lazar, Department of Physics Graduate Student
- Abstract: Despite it’s immense success, the Standard Model of particle physics is unable to provide an explanation of the nature of dark matter and the origin of neutrino masses. A desire to jointly explain these two mysteries motivates careful studies of neutrino properties. The goal of this thesis is to highlight efforts to explore possible connections of neutrinos to beyond Standard Model physics. In particular, we will focus on searches for high-energy, astrophysical neutrinos, and describe new tools that have enabled or will soon enable new searches.
First, we will describe the χaroν package, which simulates the neutrino yields from dark matter annihilation and decay. This will lead us into an analysis looking for an excess of neutrinos from the direction of the Sun using data from the IceCube Neutrino Observatory. Such an excess would be a signature of dark matter captured by scattering on solar nuclei and annihilating to Standard Model particles. In addition, we will describe using this same analysis framework to search for the predicted, but yet-unobserved flux of solar atmospheric neutrinos created when cosmic rays interact and produce meson in the thin solar atmosphere. Next, we will turn our attention to flavor physics, and discuss how new physics may manifest in the ratio of neutrino flavors at Earth. In particular, we will discuss the importance of tau neutrino identification in understanding the flavor triangle. Then we will introduce the TauRunner package which simulates the passage of the highest energy neutrinos through the arbitrary media, including previously neglected effects. This new simulation framework will then be applied to simulating ultra- high-mass dark matter in the solar core, in an attempt to evade the solar opacity limit. Finally, we will describe the simulation framework that has been developed for the Tau Air-Shower Mountain-Based Observatory. This proposed, next-generation detector in the Colca Valley of Peru could provide a tau-pure flux of neutrinos in the 1 PeV–100 PeV energy range.
Finally, we will describe the Prometheus simulation package, an open-source framework for simulating neutrino telescopes with arbitrary geometries in water and ice. For the first time, this allows for a consistent simulation framework between the global network of neutrino telescopes that is currently being constructed. Furthermore, this allows for the rapid prototyping of new reconstruction and data storage techniques with easy, cross-detector application. We provide three examples of such techniques: a machine-learning-based reconstruction capable of running faster than the trigger rate of neutrino telescopes; a machine-learning-based reconstruction of dimuon events in an ice-based detector; and a demonstration of efficiently storing event-level data from neutrino telescopes in quantum memory.
- Network in Neutrinos, Nuclear Astrophysics, and Symmetries (N3AS) Seminar
- Consistent inference of neutron star bulk and crust properties and nuclear observables.
- Time: 2:00 pm
- Place: Join Zoom Meeting Meeting ID: 912 3071 4547
- Speaker: Will Newton , Texas A&M
- Abstract: We have entered the era of multi-messenger nuclear astrophysics,
bringing a host of astrophysical observations and nuclear experimental
data to collectively measure the properties of neutron star matter and
the nuclear force in neutron-rich systems. In order to combine disparate
data sets with meaningful uncertainty quantification, over the past
decade statistical inference techniques employing ensembles of
models of each observable have been increasingly employed. In order to
minimize systematic model uncertainty, where possible the same
underlying model should be used to construct neutron star and nuclear
models. We present an example of such an approach, using an
Energy-Density Functional to model bulk properties of neutron stars such
as the maximum mass, radii, tidal deformabilities and moments of
inertia, crust properties of neutron stars, and nuclear properties
including nuclear masses, neutron skins and dipole polarizabilities. In
particular, we argue that crust observables can help constrain both core
properties and nuclear observables when consistent ensembles of crust
models are used.
NOTE: All participants and hosts are now required to sign into a Zoom account prior to joining meetings hosted by UC Berkeley.
- GREAT IDEAS DEI Reading Group
- GREAT IDEAS Coffee Hour
- Time: 12:00 pm - 1:00 pm
- Place: Sterling B343
- Abstract: We will be discussing the paper "Examining the effect of counternarratives about physics on women’s physics career intentions" by Potvin et al (open access). We will also discuss a summary at the beginning of the session, and welcome attendees who have not had a chance to read the article.
GREAT IDEAS stands for Group for Reading, Educating, And Talking about Inclusion, Diversity, Equity, & Advocacy in Science. It is a multimedia reading group dedicated to amplifying the experiences of underrepresented groups in science and academia in order to become better advocates for our peers. GREAT IDEAS is open to everyone (students/ faculty/ staff/ etc), and all are welcome and encouraged to engage with the material and contribute to the discussions. To keep a welcoming and safe environment for everyone, we ask that everyone understand and adhere to our community guidelines for the discussions.
- Host: GMaWiP (contact Faizah with questions)
- Theory Seminar (High Energy/Cosmology)
- Anomalies and bordism of non-supersymmetric heterotic strings
- Time: 12:00 pm - 1:15 pm
- Place: Van Vleck B223 (Note Special Room)
- Speaker: Miguel Montero, Instituto de Física Teórica, Madrid
- Abstract: There are three tachyon-free non-supersymmetric string theories in ten dimensions where anomalies cancel by a non-supersymmetric version of the Green-Schwarz mechanism. However, these theories have not been shown to be free of global anomalies. I will fill this gap by studying these anomalies with cobordism theory; as a byproduct we will compute bordism groups of these non-susy strings, which may be useful to the construction of new charged branes in this theory using the cobordism conjecture.
- Host: Gary Shiu
- NPAC (Nuclear/Particle/Astro/Cosmo) Forum
- How to do particle physics in a climate emergency?
- Time: 3:30 pm - 6:00 pm
- Place: 5310 Chamberlin Hall
- Speaker: Ken Bloom , University of Nebraska-Lincoln
- Abstract: The pursuit of particle physics, or any kind of discovery-driven research, requires a stable and prosperous society. Today, our society is increasingly threatened by global climate change. Human-influenced climate change has already impacted weather patterns, and global warming will only increase unless deep reductions in emissions of CO2 and other greenhouse gases are achieved. Current and future activities in particle physics need to be considered in this context, either on the moral ground that we have a responsibility to leave a habitable planet to future generations, or on the more practical ground that, because of their scale, particle physics projects and activities will be under scrutiny for their impact on the climate. I will discuss several contexts in which particle physics has an impact on greenhouse gas emissions, and how our field can contribute to a more sustainable future.
- Host: Kevin Black
- R. G. Herb Condensed Matter Seminar
- Theory of Pines' demon in multiband metals
- Time: 10:00 am - 6:00 pm
- Place: 5310 Chamberlin
- Speaker: Edwin Huang, Notre Dame
- Abstract: In 1956, David Pines predicted the existence of an acoustic plasmon, dubbed a "demon", in metals with multiple and sufficiently distinct charge carrier species. Despite extensive searches, demons have not been observed directly until recent momentum-resolved electron energy-loss spectroscopy (M-EELS) experiments on Sr2RuO4. Here, we discuss the theoretical conditions for the existence of demons as a stable collective excitation in multiband metals. We find, without any fitting or tuning of parameters, agreement between experimental M-EELS spectra and multi-orbital random phase approximation (RPA) calculations of the charge susceptibility. A decomposition of the calculation of the susceptibility into intra- and inter-band components provides direct evidence of the out-of-phase character of the demon. Our findings thus demonstrate the utility of numerical calculations for the microscopic interpretation of experimental spectroscopy. Nature 621, 66–70 (2023)
- Host: Ilya Esterlis
- NPAC (Nuclear/Particle/Astro/Cosmo) Forum
- Looking inside the Earth with neutrinos
- Time: 2:30 pm - 3:30 pm
- Place: CH5310 /
- Speaker: Sergio Palomares Ruiz, IFIC (CSIC - University of Valencia)
- Abstract: Looking at the Earth's interior with neutrinos is a realistic possibility with current and future neutrino detectors, which is complementary to geophysics methods, but it is based purely on weak interactions. In this talk, I will give an overview of the two main approaches to perform Earth tomography with neutrinos: (i) neutrino absorption tomography, based on partial absorption of a neutrino flux as it propagates through the Earth (at energies about a few TeV) and (ii) neutrino oscillation tomography, based on coherent Earth matter effects on the neutrino oscillatory pattern (at energies below a few tens of GeV). I will first discuss (i) and present the first neutrino tomography of Earth using IceCube data. Then, I will discuss (ii) and, in particular, I will focus on supernova neutrinos with tens of MeV.
- Host: Francis Halzen
- Astronomy Colloquium
- Electromagnetic Transients in the Disks of Active Galactic Nuclei
- Time: 3:30 pm - 4:30 pm
- Place: 4421 Sterling Hall
- Speaker: Rosalba Perna, Stony Brook University
- Abstract: The disks of Active Galactic Nuclei (AGNs) have emerged as interesting
environments for the evolution of stars and the compact objects they leave
behind. The very high density of the medium, combined with torques from the
gas, yield evolutionary paths for main sequence stars which
differ from those in typical galaxies.
Well known transient phenomena such as long and short GRBs may have
a different-than-usual appearance when emerging from AGN disks, and
new astrophysical phenomena, such as the accretion induced collapse
of neutron stars to black holes, may be commonplace in AGN disks.
- Host: Ke Zhang
- Physics Department Colloquium
- Multimessenger View of High-Energy Cosmic Neutrino Sources
- Time: 3:30 pm - 5:00 pm
- Place: Chamberlin 2241
- Speaker: Kohta Murase, Penn State
- Abstract: The discovery of high-energy cosmic neutrinos opened a new window of astroparticle physics. Revealing the sources is also relevant for solving the long-standing puzzle about the origin of cosmic rays. I will discuss theoretical implications of the latest results on high-energy neutrino observations, and demonstrate the power of multi-messenger approaches. In particular, I will highlight our recent developments about astrophysical neutrino emission from extragalactic gamma-ray dark sources and the Galactic plane. I will explore the potential of utilizing high-energy neutrinos as a probe of physics beyond the Standard Model.
- Host: Lu Lu