News

Dark Matter Day is an international event dedicated to outreach activities focused on the research and exploration of dark matter and its many enigmas. And of course it’s celebrated on Halloween 🎃, because it’s some spooky stuff 😉!

The Dark Matter and Neutrinos group, together with colleagues from the IGC and physics department, hosted an information booth at the HUB (the main student center in the university), to talk to people about Dark Matter, Cosmology, and Physics in general! We had a lot of students stopping to ask about it, and some lively discussions! In the spirit of Halloween, we also gave out some dark chocolate!

Below are some pictures. The booth was hosted by: Luiz de Viveiros, Carmen Carmona, Donghui Jeong (Faculty); Sarah Schon (Postdoc); Wei Zha, Katie Wild, Joshua Black (Grad Students); Amber Krape, Gus Eberlein (Undergraduate Students).

Congratulations Dr. Ziegler!

Andrew has successfully defended his PhD thesis, titled “Development of Scalable Approaches to Neutrino Mass Measurement with the Project 8 Experiment”! It was a very well written dissertation and masterfully delivered presentation! The only bad thing is that he will be leaving us after this! We will miss you Andrew! Congrats!

Our paper with the Project 8 “Phase-II” results has been published! This is the first measurement of the tritium beta decay and consequently the first limit on the neutrino mass using the new technique we developed, Cyclotron Radiation Emission Spectroscopy (CRES)! Although we were not able to measure the mass of the neutrino, due to limited stats, this result proves that the technique works and is opens a promising path to make a definitive measurement of the neutrino mass!

There were a number of press releases and article following the paper publication, including a video we produced summarizing how the experiment works – see links below:

https://www.sciencealert.com/wild-new-technique-could-finally-measure-the-elusive-neutrino

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.131.102502

Congratulations Dr. Dan Kodroff!!!

Dan has successfully defended his PhD thesis, titled “Background Modeling and First Searches for Low Energy Signals in the LUX-ZEPLIN Dark Matter Experiment”! It was an impressive presentation, the culmination of years of excellent work and dedication!

The Penn State group was at the April APS Meeting 2023 in Minneapolis, MN, representing both the LZ dark matter and Project 8 neutrino mass experiments!

LZ had a huge showing, with 9 talks, plus a number of collaborators presenting talks on adjacent topics. Our grad student Dan Kodroff was at the meeting giving the talk detailing the backgrounds present in the LZ detector, with an emphasis on the background model used in LZ’s first results and how these backgrounds were constrained in situ.

We also saw our former undergraduate student, Jacob McLaughlin, now a grad student at Northwestern and still working on LZ, presenting with a great talk on the use of Rn chain pair tagging to help mitigate Pb backgrounds!

Luiz de Viveiros presented a talk giving an overview of the Project 8 experimental program, and highlighting the latest results including our first tritium endpoint measurement and neutrino mass limit.

We have written a companion paper to the First Tritium Results Paper (posted earlier in this blog), which was submitted to PRL. This is a longer paper, being submitted to PRC, and it gives a detailed description of the experiment, focusing on the systematic effects and analysis techniques used in the PRL:

https://arxiv.org/abs/2303.12055

 

The whole LZ group from Penn State went to the LZ Collaboration Meeting at the University of Maryland (UMD) on January 5-7! It has been a long time since we met in person, due to the pandemic, and it was good seeing everyone! We met to discuss the latest results, and make plans for the year ahead. It was a good time, celebrating the incredible year we have had, with lots of good science done in 2022, and lots more to come!

Andrew Ziegler, our grad student here at Penn State, has authored a paper on his groundbreaking research for the Project 8 neutrino mass experiment.

He developed an antenna called SYNCA that can mimic the cyclotron radiation emitted by a single electron in a magnetic trap (which we call CRES) – the type of signal that we want to acquire with the Project 8 detector! We have recently proved that CRES works at small scale, but now we need to scale it up to get more stats. The original plan was to build a large trap, and acquire the electron signals using large antenna arrays. The transmitter antenna would allow us to develop the receiver antenna array without building a full detector to trap electrons. Andrew built a small antenna array at Penn State to demonstrate the use of his SYNCA antenna, and the paper also reports on the first case of CRES acquired with antenna arrays and reconstructed via digital beamforming!

The paper is on arXiv and will be submitted to publication on JINST soon. You can read it here: https://arxiv.org/abs/2212.08026.

At the end of 5 long years, we have completed the “Phase-II” of the Project 8 experiment! We have posted to Arxiv the paper with our final results from this phase of the experiment, and will be submitting it for publication to PRL.

The goal of Project 8 is to measure the neutrino using an entirely new technique we invented called “Cyclotron Radiation Emission Spectroscopy” (CRES). Due to the complexity and ambition of this goal, we have split our scientific program into phases. Phase-I was proving that the CRES technique worked at all, and this was shown in 2016. Phase-II was the demonstration that we could use CRES to measure the beta decay spectrum of tritium, a crucial step in measuring the mass of electron-neutrinos. In this paper, we report our measurement of the tritium spectrum, and use it to set a limit on the neutrino mass! It’s not a competitive limit (compared to, say, KATRIN), but it serves to demonstrate that everything works as planned! Now the next step is to grow the experiment, so that we can have enough stats to make an actual measurement!

“Tritium Beta Spectrum and Neutrino Mass Limit from Cyclotron Radiation Emission Spectroscopy” – https://arxiv.org/abs/2212.05048

This week, our group had a couple of invited talks highlighting the results from the LZ first science run (SR1), as we reported earlier. Our SR1 resulted in a world-leading sensitivity to dark matter, and there has been a lot of interest!

Prof. Carmen Carmona-Benitez gave a virtual seminar at the University of Kentucky on Thursday December 8, and Prof. Luiz de Viveiros gave an in-person presentation at Rutgers University on Friday December 9. We had a lot of questions, and interesting discussions about the LZ detector and future plans!