LNS Lunchtime Seminars | Laboratory for Nuclear Science

Tuesdays 12:00 PM

Please note indication on each talk IN-PERSON or VIRTUAL

Committee: Joseph Formaggio ~ Ronald Garcia Ruiz ~ Afroditi Papadopoulou

VIRTUAL

Evan Rule

Nuclear Effective Theory of μ→e Conversion

Abstract:
The Mu2e and COMET μ→e collaborations plan to advance branching ratio sensitivities by four orders of magnitude, further constraining new sources of charged lepton flavor violation (CLFV). We formulate a non-relativistic nucleon-level effective theory for this process, in order to clarify what can and cannot be learned about CLFV operator coefficients from elastic μ→e conversion. We employ a treatment of the lepton Coulomb physics that is very accurate, yet yields transparent results and preserves connections to standard-model processes like β decay and μ capture. The formulation provides a bridge between the nuclear physics needed in form factor evaluations and the particle physics needed to relate low-energy constraints from μ→e conversion to UV sources of CLFV. Using state-of-the-art shell model methods we evaluate the nuclear responses, deriving bounds on operator coefficients from existing and anticipated μ→e conversion limits. Finally, we discuss the relation of μ→e conversion to μ→e+γ and μ→3e, illustrating how MEG-II and Mu3e results will complement those of Mu2e and COMET.

time: Noon
place: Virtual (26-)

Will also be broadcast via Zoom: https://mit.zoom.us/j/99836328643

IN-PERSON

Jeff Lazar

Solar Neutrinos: From MeV to EeV

Abstract:
While the Sun has already proved a fruitful laboratory for neutrino physics, high-energy solar neutrinos may continue to provide insight. For example, current-generation neutrino telescopes have searched for an excess of neutrinos from the Sun's direction as evidence of annihilating weakly interacting massive particles (WIMPs) at energies from ~0.1 GeV to 10^4 GeV. Detection of these neutrinos would be a smoking-gun signature of WIMPs since backgrounds from the Sun are well-understood. Furthermore, there is a well-predicted but unmeasured flux of neutrinos created in cosmic-ray interactions with the solar atmosphere. Detecting this flux may shed light on the unexpected dip observed in the solar ring γ-ray spectrum. The IceCube Neutrino Telescope is a gigaton-scale neutrino telescope located between 1450m and 2450m beneath the geographic South Pole. The detector geometry makes it well-suited to carrying out such solar neutrino searches. In this seminar, I will present the status of IceCube's ongoing solar WIMP and solar atmospherics searches and describe theoretical efforts to extend these searches.

time: Noon
place: Kolker Room (26-414)

Will also be broadcast via Zoom: https://mit.zoom.us/j/99836328643

No Talk - Spring Break

No Speaker Scheduled

VIRTUAL

Samuel Hedges

Low Energy Neutrino-Nucleus Interactions at the Spallation Neutron Source

Abstract:
Using the low energy neutrinos produced by the Spallation Neutron Source (SNS), the COHERENT collaboration is studying the physics of low energy neutrino-nucleus interactions, including coherent elastic neutrino-nucleus scattering (CEvNS). CEvNS is a neutral-current process in which an entire nucleus recoils as a result of a neutrino interaction, leading to a cross section potentially orders of magnitude greater than those of other low energy neutrino interactions. However, the experimental signature of the CEvNS process, a low energy nuclear recoil, can be difficult to detect. COHERENT reported the first successful observation of CEvNS in 2017, and has been deploying a suite of detectors to the SNS to study the physics of CEvNS with different targets. The collaboration has also deployed several detectors to measure inelastic neutrino-nucleus scattering on a variety of nuclei. An overview of the COHERENT experiment and latest results will be presented.

time: Noon
place: Virtual (26-)

Will also be broadcast via Zoom: https://mit.zoom.us/j/99836328643

VIRTUAL

Steven Gardener

Detecting low-energy astrophysical neutrinos with DUNE

Abstract:
In the coming decade, the Deep Underground Neutrino Experiment (DUNE) will leverage a suite of liquid argon time projection chamber (LArTPC) detectors to pursue a broad science program in neutrino physics and beyond. One of DUNE's primary goals is to obtain a high-statistics measurement of electron neutrinos produced by a galactic core-collapse supernova if one should occur during the lifetime of the experiment. While challenging, other related measurements may be possible as well, including studies of solar neutrinos. In this talk, I present an overview of the physics opportunities and technical challenges involved in detecting these low-energy (MeV to tens-of-MeV) neutrinos in DUNE and successfully interpreting the results. Particular attention will be paid to (1) capabilities and challenges that make DUNE unique in the anticipated low-energy experimental landscape, and (2) the state of the art in simulating the relevant neutrino interaction physics.

time: Noon
place: Kolker Room (26-)

Will also be broadcast via Zoom: https://mit.zoom.us/j/99836328643

VIRTUAL

Julie He

ANNIE Deploys Its First LAPPD

Abstract:
The Accelerator Neutrino Neutron Interaction Experiment (ANNIE) is a 26-ton gadolinium-doped water Cherenkov detector situated 100-m downstream in Fermilab's Booster Neutrino Beam. ANNIE’s main physics goal is to measure the final state neutron multiplicity of neutrino-nucleus interactions as a function of momentum transfer. This measurement will improve our understanding of these complex interactions and help reduce the associated systematic uncertainties, thus benefiting the next generation of long-baseline neutrino experiments. ANNIE will achieve its physics goals with the use of a new type of photodetector, the Large Area Picosecond PhotoDetector (LAPPD). The experiment is the first physics experiment to deploy an array of LAPPDs. Significant progress has been made on the characterization and development of this system. This progress is met with success: ANNIE recently deployed its first LAPPD. In this talk, I present the status of ANNIE experiment and the work that went into getting the LAPPD deployment-ready.

time: Noon
place: Kolker Room (26-)

Will also be broadcast via Zoom: https://mit.zoom.us/j/99836328643

VIRTUAL

Pedro Machado

Dark neutrinos and other BSM searches in SBN

Abstract:
In this informal, blackboard-style talk, I will discuss some exciting BSM scenarios that can be probed in SBN. I will discuss their motivation, such as solving the MiniBooNE anomaly, or connections to the origin of neutrino masses; their signatures in LArTPCs; and the main challenges for these searches. Most of the discussion will be open-ended, so please feel free to bring questions and comments with you.

time: Noon
place: Kolker Room (26-)