Science - Berkeley Axion Works

Experiments

People

News

Team awarded $3.7M to build a next generation haloscope to search for the post-inflation axion

In Fall 2022, a consortium of the Simons Foundation, the Alfred P. Sloan Foundation, the John Templeton Foundation and the Gordon and Betty Moore Foundation published a solicitation seeking to make profound advancements in physics by means of Small-Experiments of “table-top” size. The proposal “A Plasma Haloscope for the Post-Inflation Axion” (Karl van Bibber, P.I.) has been announced as one of the 11 awardees among hundreds of initial proposals, for which a total of $30M over five years has been pledged by the foundations. The proposal is to build a metamaterial resonator-based experiment, to be sited at Yale, in an existing 16 Tesla magnet (see above), called ALPHA. The overall collaboration comprises eleven institutions, additionally including Yale, Colorado, MIT, Johns Hopkins, Wellesley, Arizona State, Stockholm, ITMO, Cambridge universities, and Oak Ridge National Laboratory. Further information is found here.

The search is motivated by increasingly sharp predictions for the mass of the axion by the group of Berkeley Professor Ben Safdi. In the scenario where Peccei-Quinn symmetry breaking occurs after Inflation; in this situation the axion mass corresponding to the dark matter density of the Universe can be determined by supercomputer simulations of the evolution of the network of axion strings over cosmic history. For further information, see UC Berkeley news articles here and here.

“Tunable wire metamaterials for an axion haloscope” N. Kowitt et al., published in Physical Review Applied.

This paper reports a study of how wire array metamaterials may be tuned by modifying their unit cell. Extensive measurements were carried out by our group at Berkeley, and compared with both simulations and a semianalytical theory by our collaborators at ITMO St. Petersburg. The first author is Nolan Kowitt, one of our own undergraduates. Congratulations, Nolan!

Alexander Leder joins the LEGEND experiment at LANL

After five years with the van Bibber group, Alexander Sebastian Leder has accepted a staff scientist position at Los Alamos National Lab. He will be working on the LEGEND experiment searching for neutrinoless double-beta decay. Congratulations Sebastian! Left to right: Pablo Castano, Dillon Goulart, Andrei Dones, Alexander Sebastian Leder.

Karl van Bibber Group Awarded 5-Year U.S. Department of Energy Grant

“New Trends in Axion Searches and ALPHA”

Karl van Bibber presents lecture “New Trends in Axion Searches and ALPHA” at the Galileo Galilei Institute for Theoretical Physics conference ‘Axions across boundaries between Particle Physics, Astrophysics, Cosmology and forefront Detection Technologies’, June 5-9, 2023, Arcetri, Florence.

Berkeley axion group well represented at UCLA Dark Matter 2023

The biennial UCLA Dark Matter meeting had its first in-person meeting since 2018, the hiatus owing to the pandemic, but interest was as strong as ever, with over 200 attendees from around the world. Aya Keller gave a well-received plenary talk “An L- and S-Band Search for Ultralight Dark Matter Using Green Bank Telescope Data”; and posters prepared by Nolan Kowitt “Exploration of Wire-Array Metamaterials for the Plasma Axion Cavity”, and Alex Leder “DMRadio-50 Experiment Status and Overview” attracted much interest at the opening reception.

Aya Keller presenting “An L- and S-Band Search for Ultralight Dark Matter Using Green Bank Telescope Data”.

Nolan Kowitt presenting “Exploration of Wire-Array Metamaterials for the Plasma Axion Cavity”.

ALPHA collaboration white paper on a metamaterial-based axion haloscope published in Physical Review D.

The paper by Mackenzie Wooten et al. “Exploration of Wire Array Metamaterials for the Plasma Axion Haloscope” has been published in Annalen der Physik (January 15, 2023) 2200479.

Precision measurement of In-115 Spectra sets world leading limit on half-life and picked as DOE Research Highlight

We commissioned a LiInSe2 crystal, between MIT, University of Jyvasklya, Universite Paris-Saclay, and the RMD corporation (funding provided by a Phase II SBIR grant) to explore the possibility of high-quality, low-background bolometric detectors for use in nuclear decay model verification. Data was collected at near absolute zero allowing us to detect and record even the very smallest spikes in temperature due to particle interactions, such as those from internally generated In-115 beta decays, via highly sensitive thermometers. Background events, such as external gamma rays, are rejected via a combination of particle simulations and careful examination of individual recorded events, to produce an isolated internal In-115 beta decay spectrum. We compare this spectrum to a library of model predictions generated at the University of Jyvaskyla and reduce the library to a small subset of preferred spectra/interaction constants. At the same time, we were able to extract the most precise measurement of the In-115 half-life to date. This measurement opens the door for a larger experimental campaign on other long-lived beta decay isotopes such as V-50 taking advantage of faster quantum sensors currently in development in order to reduce backgrounds due to pile-up and improve the threshold and resolution of the spectrum even further. These additional measurements would give nuclear theory calculation frameworks experimentally verified handles by which they can then fine tune their calculations. We can then use these verified frameworks to confidently model larger more complex systems such as those found in double beta decay isotopes, such as Te-130, whose measurement and characterization represent a high priority in the DOE nuclear physics program.

Alumna Samantha Lewis Appointed Assistant Professor at Wellesley College

Former group member Samantha Lewis (BS MIT 2015, PhD Berkeley 2020) has just accepted a position as Assistant Professor of Physics at Wellesley College, to begin July 1, 2023. Sami joined our group in 2015 to perform a microwave cavity upgrade and characterization for HAYSTAC, and develop a tunable photonic band gap resonator. She subsequently designed and built a compact THz-driven electron gun for Ultrafast Electron Diffraction at SLAC. Currently she is a postdoc at FNAL, where her research involves qubit-based quantum sensing and microwave cavity development for axion searches. We look forward to continued collaboration with her in the future. Congratulations, Sami!

Dr. Johny Echevers joins our group as a postdoc

Johny joins us from the University of Illinois, where he completed his Ph.D. thesis on the EXO experiment “A Search for Lorentz and CPT Violations in Double-Beta Decay with the Complete EXO-200 Dataset” under Professor Liang Yang. Welcome Johny!

Inaugural ALPHA collaboration meeting at ORNL

A large contingent of our group attended the inaugural meeting of the ALPHA collaboration at Oak Ridge National Laboratory, October 21-22, 2022, and made presentations on our R&D on metamaterial resonators to be used in this experiment. The meeting, which attracted 50 attendees from around the world, kicked off planning a very high mass (> 10 GHz) dark matter axion search with the large 13 T magnet to be shipped to ORNL from the Helmholtz Zentrum Berlin in 2023. Wire-array metamaterials are a promising technology as resonators for the Sikivie-type axion search at frequencies above where microwave cavities are no longer practical.

DM Radio papers published

Two publications have recently appeared in Physical Review D, one on the cubic-meter version of DM Radio, in advanced design stage and currently under review by the Department of Energy, and the other on the design of a future much larger scale experiment to search down to neV mass axions.

DMRadio-m³: A Search for the QCD Axion Below 1 μeV, L. Brouwer, et al., Physical Review D 106 (2022) 103008, arXiv:2204.13781
Proposal for a definitive search for GUT-scale QCD axions, L. Brouwer, et al., Physical Review D 106 (2022) 112003, arXiv:2203:11246

Graduate Textbook on Ultralight Dark Matter published

A graduate textbook on axions and other ultralight dark matter candidates, “The Search for Ultralight Bosonic Dark Matter” (editors Derek F. Jackson Kimball and Karl van Bibber) has recently been published by Springer. Group alumna Maria Simanovskaia, along with Gianpaolo Carosi and Karl van Bibber also contributed a chapter “Microwave Cavity Searches”.

Group alum Nicholas Rapidis wins a Best Presentation award at IDM 2022

Nicholas Rapidis (UC Berkeley B.S. 2019) and former group member was awarded one of three Best Presentation awards at the 14th International Conference on the Identification of Dark Matter in Vienna. The title of his talk was “Status of DM Radio 50 L and Cubic Meter”.

Nicholas is currently entering fourth year of graduate work at Stanford University under Prof. Kent Irwin, Project Director of the DM Radio project, which will search for very low mass axions, and we are privileged to have continued collaborating with Nicholas since his graduation.

“A Model-independent Radio Telescope Dark Matter Search” published in the Astrophysical Journal – 03/01/22

Congratulations to Aya for her paper in the Astrophysical Journal!

“A quantum enhanced search for dark matter axions” in Nature – 02/11/21

On February 10, 2021, “A quantum enhanced search for dark matter axions” was published by the journal Nature, along with accompanying articles from UC Berkeley, Yale University, and JILA.

Experiments

ALPHA

HAYSTAC

HAYSTAC (Haloscope At Yale Sensitive To Axion Cold dark matter) is a Yale-Berkeley-Colorado-Johns Hopkins collaboration, and represents the latest... read more

DM Radio

DM Radio is a Stanford-SLAC-Berkeley-MIT-North Carolina-Princeton collaboration to search for dark matter... read more

GBT

GBT Data Mining is the third major activity of the group. Utilizing... read more

Dark matter

What is the universe made of? Observations of gravitationally-bound systems (such as galaxies and clusters of galaxies) hint at there being much more matter than we can see. For example, we can measure the velocity of spiral cavities at different points from their centers. When we construct their rotation curves, we see they remain constant as far out as we can measure. This is inconsistent with the fall-off one would expect if all of the gravitating mass was solely visible stars.

In fact, atoms that make up everything we can see only account for about 16% of matter in the universe. We refer to the rest as the dark matter. Together, atoms and dark matter make up about a third of the total energy density of the universe (the rest is called dark energy).

No one knows for certain what the dark matter is made of. Many theories have been proposed, including axions. Axions are a candidate for cold dark matter (CDM). This is dark matter which is at the same temperature as the background in the universe. Find out more about axions.

Axions

The axion is a hypothetical elementary particle, arising from our best theoretical solution to the strong CP problem. The axion can be thought of as a very light cousin of the neutral pion, importantly possessing a two-photon coupling. It is believed to be very light, between 1–1000 micro-eV in mass (about 10^-42 to 10^-39 kg). A very light axion represents an excellent dark matter candidate. Pierre Sikivie’s article “The Pool-Table Analogy for Axion Physics” [1] presents an intuitive picture for how the axion arises in physics, and how we might be able to find it. A practitioner’s discussion of the theory and experimental avenues to the axion is presented in Ref. [2]

[1] P. Sikivie, “The Pool-Table Analogy to Axion Physics“, Physics Today 49 (1996) 22-27.

[2] P. Graham, I. Irastorza, S. Lamoreaux, A. Lindner, K. A. van Bibber, “Experimental Searches for the Axion and Axion-Like Particles”, Annual Review of Nuclear and Particle Science 65 (2015) 485-514.

People

Faculty

Berkeley Axion Works is led by Dr. Karl van Bibber, professor and executive associate dean for the College of Engineering at UC Berkeley. Photo by Brittany Hosea-Small.