Neutrino Interactions with Transverse Kinematic Imbalance

by Xianguo Lu (University of Oxford)

Wednesday 7 Apr 2021, 15:30 → 16:30 Asia/Shanghai

One of the most surprising properties of neutrinos is that they have mass and oscillate among flavours during propagation. Measuring neutrino and antineutrino oscillations is a crucial step to answer existential questions like why the universe is dominated by matter over antimatter. In the current (future) long-baseline experiments NOvA and T2K (DUNE and Hyper- Kamiokande), neutrinos and antineutrinos of few-GeV energies are produced and their oscillations are compared. GeV-neutrinos can also come from cosmic rays interacting with the Earth’s atmosphere. They can help determine the neutrino mass ordering but they are also an important background of the searches for rare events like the proton decay. In this talk, I will discuss the science case of neutrino-nucleus interactions in the GeV regime, showcased by MINERvA, or Main INjector ExpeRiment for v-A, at Fermilab, an experiment dedicated to the study of neutrino interactions. I will demonstrate how the analysis technique Transverse Kinematic Imbalance can provide in-depth understanding of neutrino interactions. This is a technique to precisely identify intranuclear dynamics, or the absence thereof. Like the missing energy used in collider experiments to probe invisible beyond-the-Standard-Model particles, TKI reveals surgical details of any hidden dynamics inside the nucleus. As selecting zero-TKI events allows us to exclusively single out neutrino interactions on hydrogen from among other nuclei, the concept of a hydrogen-rich high-pressure time projection chamber has been introduced. When combined with TKI, it could provide high statistics neutrino- hydrogen events with superb kinematic determination. In this talk, the basic principle of this concept will also be discussed. About the speaker: Xianguo is an STFC Ernest Rutherford Fellow at the University of Oxford, where he studies neutrinos in accelerator-based experiments located in the US and Japan. He was raised in Shunde, China, received his first degree from Peking University, and his PhD in experimental physics from the University of Heidelberg under Johanna Stachel. He was a postdoc in heavy ion physics at the University of Heidelberg, and then in neutrino physics at the University of Oxford before moving on to become an Ernest Rutherford Fellow. He is also a Senior Research Fellow in Pembroke College Oxford. -------------------- Zoom Meeting Number: 66347157081 Password: 125732 or click: https://weidijia.zoom.com.cn/j/66347157081?pwd=TVdULzg3N3FiR1ZySDE3a0Z4MjhqQT09

Slides xlu_20210407_IHEP.pdf