Hosted by: Janet Conrad
Dr. Gonzalo Herrera Moreno
Low-Energy Neutrino Signatures at Dark Matter Direct Detection Experiments
Abstract:
Dark matter direct detection experiments have become excellent low-energy neutrino detectors. In this talk I will present several opportunities to learn new physics from neutrinos at low-energy recoils in these experiments. New physics can arise from processes such as elastic neutrino-electron scatterings, Coherent Elastic Neutrino-Nucleus Scatterings, and the yet unobserved Migdal effect. I will also discuss the challenge that the so-called neutrino floor or fog constitutes for dark matter direct detection searches, and the degeneracy of new physics signatures with uncertainties arising from the quenching factor in certain materials.
Hosted by: Ronald Ruiz
Xing Fan, Professor – Harvard University
Probing Physics Beyond the Standard Model Using
Radioactive Molecular Ions
Abstract:
We present a new experiment to measure the Schiff Moment of 229ThF+ molecular ions. We particularly focus on the advantages of using ions. Th-229 has a potentially large Schiff Moment from octupole deformation and is efficiently available by α-recoil from U-233. ThF+’s electronic structure has also been measured by the JILA electron EDM experiment. By combining the efficient ion manipulation techniques, we hope to overcome the difficulty of rare radioactive species.
Hosted by: Brooke Russell
Lars Bathe-Peters, Graduate Student - University of Oxford
Quantum Decoherence in the DUNE and
T2K Neutrino Oscillation Experiments
Abstract:
Neutrinos can change flavour as they propagate, a phenomenon known as neutrino oscillations. Long-baseline neutrino oscillation experiments such as DUNE and T2K aim to precisely measure the neutrino oscillation parameters that govern this effect. In addition to these standard (3×3-PMNS) neutrino oscillation parameters measurements, accelerator-neutrino beams also provide a powerful probe of new physics beyond the Standard Model such as quantum decoherence, which may arise from quantum gravitational effects, stochastic fluctuations of spacetime or other neutrino interactions with the environment. In this talk, I will discuss ongoing studies on the sensitivity of DUNE to quantum decoherence signatures and on constraining the strength of this effect using T2K data.
Hosted by: Ronald Ruiz
Jose Munoz, Graduate Student - MIT
Global Emulators for Ab Initio Nuclear Calculations
Abstract:
Understanding how complex nuclear phenomena arise from the fundamental forces and particles of nature remains a long-standing problem of modern physics. In recent years, significant progress has been achieved through the development of lattice QCD, chiral effective field theory, advanced computational methods, and steadily increasing computational power. These advances have enabled ab initio calculations of nuclear properties starting from effective interactions between nucleons and pions. However, it is still a challenge to understand the connection between these effective interactions and the underlying theory of the strong force, and how the details of the interactions impact bulk nuclear properties such as radii, binding energies, and electromagnetic observables.
In this talk, I will present how ab initio calculations of many-body nuclei can be combined with statistical and machine learning methods to construct robust "nuclear emulators". These emulators can predict nuclear properties with a reduction of computational cost by orders of magnitude. This approach allows us to explore how the fine details of the nuclear force shape the bulk properties of nuclei and provides essential guidance for the design and interpretation of future experiments.
Hosted by: Ronald Ruiz
Washington Taylor
Atmospheric Carbon Dioxide Removal (CDR) -- a Physical Science Perspective
Abstract:
As atmospheric carbon dioxide levels continue to rise, there has been increasing interest from both the public and private sectors in methods and technologies for directly removing carbon dioxide from the atmosphere (CDR). Large-scale CDR may be a useful complement to emissions reductions in achieving specific carbon or climate goals. The American Physical Society's Panel on Public Affairs (POPA) has recently released a report that focuses on the physical constraints and requirements of large-scale CDR efforts. This talk will present the main aspects of the science analysis and policy conclusions of the report. In particular the talk will describe the energy, land area, and materials requirements for a variety of CDR approaches, as well as uncertainties in effectiveness and impact. These basic scientific observations can help inform sensible carbon management policies.
Hosted by: Philip Harris
Garyfallia Paspalaki - CERN
Probing Higher-Dimensional Wilson Operators in the VVV Production and Opportunities for Run3 using the Scouting Dataset
Abstract:
The study of multi-boson production at the LHC provides a powerful way to probe the self-interactions of the electroweak gauge bosons and to search for signs of physics beyond the Standard Model (BSM). In this seminar, I will present a search for the production of three massive vector bosons (VVV, where V=W,Z) in final states with boosted kinematics, in which each boson has transverse momentum above 200 GeV. Hadronically decaying W or Z bosons are reconstructed as large-radius, V-tagged jets using jet substructure and dedicated tagging techniques. The results are interpreted in the framework of the Standard Model Effective Field Theory (SMEFT), setting limits on Wilson coefficients of relevant dimension-6 and dimension-8 operators.
I will also discuss the Run3 opportunities in the VVV search, which includes the use of alternative data streams (scouting data) with the use of a global particle transformer (scouting GloParT) classifier.
Hosted by: Janet Conrad
Darcy Newman
Scintillation and Cherenkov Light Separation in a Liquid Argon Detector
Abstract:
This talk will present the first event-by-event observation of Cherenkov radiation from sub-MeV electrons in a high-yield scintillator (liquid argon) detector, representing a milestone in low-energy particle detector development and one of the major goals of 2021 Snowmass Process. This work utilizes the Coherent CAPTAIN-Mills (CCM) experiment, a 10-ton liquid argon light collection detector located at the Los Alamos National Lab pion decays at rest source. The detector is instrumented with 200 8-inch PMTs, 80% of which are coated in a wavelength shifter and 20% are uncoated. Using gamma-rays from a sodium-22 radioactive source, we have isolated prompt Cherenkov light with >5 sigma confidence, possible through the unique combination of coated and uncoated PMTs. Cherenkov light identification allows for a highly pure selection of electromagnetic events, enabling exciting beyond Standard Model physics searches that I will review.
Hosted by: Michael Williams
Nate Grieser - University of Cincinnati
Probing the Electroweak Sector and Partonic Structure in the Forward Region with LHCb
Abstract:
The LHCb experiment's design as a single-arm forward spectrometer offers a distinctive window into electroweak processes at the LHC. Its acceptance allows for the study of W and Z boson production in a kinematic regime that is highly complementary to ATLAS and CMS, providing LHC-unique access to extreme values of Bjorken-x. This seminar will focus on recent precision measurements of electroweak boson properties using the full LHC Run 2 dataset. I will highlight how these results serve as powerful tests of the Standard Model and, crucially, provide key inputs for reducing uncertainties in global determinations of parton distribution functions (PDFs). The talk will conclude by discussing the promising prospects for these measurements in Run 3, leveraging the enhanced capabilities of the newly upgraded LHCb detector.
Hosted by: Richard Milner
Noah Wuerfel
Realizing a Polarized 3He++ Ion Source at Brookhaven National Lab with Metastability Exchange Optical Pumping
Abstract:
A high intensity (2 x 10ˆ11 ions per pulse) polarized 3He++ ion source is being developed at BNL for use at the future Electron Ion Collider (EIC). The helium gas will be polarized using a novel technique based on metastability-exchange optical pumping (MEOP) in the 5T field of the existing Electron Beam Ion Source (EBIS), where it can be ionized and prepared for injection into the Booster. An infrared laser system has been developed for optical pumping and measuring the polarization of the gas inside of the EBIS field. Previous results in a test setup have shown up to 80% polarization for ultra-pure 3He in an “open” cell configuration, with isolation valve and refilling tubes closed. Now, the setup has been moved into an exact copy of the EBIS magnet to prepare for final integration and injection into the Booster. An absolute nuclear polarimeter and spin-rotator has been constructed to measure the 3He polarization near 6 MeV in the EBIS to Booster transit line. The ion source will be an essential component of future polarized neutron studies at the planned Electron Ion Collider (EIC).
In this seminar, I will provide a brief introduction to the theory behind the MEOP process and a discussion of relevant technical challenges in implementing the source at BNL. The status of the project and plans for integration and polarization measurements inside of EBIS during the 2026 RHIC shutdown will be presented. I will also provide an overview to the absolute nuclear polarimeter in the EBIS transport line to Booster and future polarimetry plans for AGS and EIC.
Hosted by: Prajwal MohanMurthy
William Milner
Experimental Scheme for Polarizing the Boron Nuclei
Abstract:
Unravelling the internal structure of nuclei in terms of the quarks and gluons of Quantum Chromodynamics is a central focus of current nuclear physics research. Directly observing gluonic states in the nucleus would be groundbreaking and is an objective of the future Electron-Ion Collider (EIC). Over thirty years ago, Jaffe and Manohar identified a new structure function, directly sensitive to exotic gluons, that could be measured via electron scattering from a target with spin I ≥ 1. Here, we identify the spin-3 nucleus boron-10 as a particularly interesting system to search for exotic gluons. Leveraging technical advances in atomic physics over the past decade, we outline an experimental scheme to directly optically pump a beam of stable boron atoms to polarize the nuclear spin.
Hosted by: Ronald Ruiz
Alyssa Gaiser
Isotope Harvesting at FRIB and Exploring Promethium
Abstract:
The Facility for Rare Isotope Beams (FRIB) is a world-class research and training center with the most powerful rare-isotope accelerator. During routine operation at FRIB, there are many isotopes that may be harvested from the unused primary beam through a program called isotope harvesting. The Gaiser research group is working toward isolating and studying isotopes and elements, predominantly in the f-block, of relevance to isotope harvesting, fundamental symmetries measurements, and those with applications in nuclear medicine, stockpile stewardship, and nuclear energy.
Promethium is the only exclusive radioactive lanthanide element and has applications in both nuclear medicine and energy. The Gaiser group is investigating the fundamental chemistry of promethium to improve separations from its lanthanide neighbors—samarium and neodymium—in addition to elucidating the similarities and differences with the trivalent actinides. Adjacent lanthanide separations are critical to modern technologies and technological advancement. The Gaiser group employs highly customizable ligands to bind f-elements probing their fundamental chemistries for future separations.
Hosted by: Phiala Shanahan and T. William Donnelly
Yang Fu
Collins-Soper Kernel from Lattice QCD
Abstract:
The Collins-Soper (CS) kernel relates transverse momentum distributions (TMDs) at different energy scales and is a critical component of TMD factorization. At small parton transverse momentum, this kernel is inherently nonperturbative. The quark kernel is only weakly constrained by experiments with recent global analysis show some discrepancies, while the gluon kernel remains largely unknown due to the lack of experimental data. In this talk, I'll present our lattice QCD calculations of the CS kernel using large momentum effective theory (LaMET) framework. Our study of the quark CS kernel has progressed from early quenched calculation to fully dynamical simulation at the physical pion mass with controlled systematics, achieving precision sufficient to discriminate between different phenomenological models. I will also discuss our ongoing efforts in the gluon sector, where future facilities such as EIC will open new opportunities to probe the gluon TMDs.
Hosted by: Ronald Ruiz
Sven Sturm
Precision tests of QED and CPT with cryogenic Penning traps
Abstract:
Experiments with single ions confined in a cryogenic Penning trap enable access to a broad range of observables that are of fundamental importance for our understanding of fundamental physics. At MPIK, a large electron-beam ion trap (EBIT) allows the production of highly charged ions (HCI), which we can capture and trap in the ALPHATRAP cryogenic trap setup. There, we can determine the cyclotron rotation frequency as well as the spin precession frequency non-destructively and with high precision. Recently, we have determined the g-factor of hydrogenic tin 118Sn49+, where the single remaining electron is exposed to electric fields of 3*10^15 V/cm. Consequently, the comparison of our experimental result with the prediction from quantum electrodynamics yields a very stringent test of the validity of QED in strong fields. Further, the continuous Stern-Gerlach effect, which we utilize to determine the spin projection non-destructively, also enables us to perform laser spectroscopy of otherwise hard-to-access systems such as molecular hydrogen ions HD+, H2+ or even in the future the antimatter equivalent Hbar2-.
Currently, we are building a new trap system, LSym, that will be cooled to below 300mK, which allows ground-state cooling of the motion of a single positron. By co-trapping that positron with a single He+ ion (as proxy for a free electron) we plan to coherently determine the difference of the spin precession frequencies of electron and positron and so probe the validity of matter/antimatter (CPT) symmetry with order-of-magnitude higher precision than previously possible in the lepton sector.
