My research to tries to answer one of the Big Questions in science: what is the universe made of? My research focuses on neutrinos, the most abundant known massive particle in the universe, and the search for dark matter, the unknown stuff that makes up more than 80% of the matter in the universe!
I have a long history of working on dark matter experiments, having been part of CMDS-II, XENON10, ZEPLIN-III, and the Large Underground Xenon (LUX); and I am currently working on the LUX-ZEPLIN (LZ) experiment, a next-generation dark-matter detector that will be the most sensitive search over the next decade. More recently, I have been working on the Project 8 Neutrino Mass experiment. Although the neutrino was discovered almost 60 years ago, it’s one of nature’s most elusive particles, and we still don’t know one of its most fundamental properties, its mass. The Project 8 experiment seeks to determine the neutrino mass by precisely measuring the energy spectrum of Tritium beta decay, using a technique that allows the measurement of individual electrons in a magnetic trap, called Cyclotron Radiation Emission Spectroscopy (CRES).
I am originally from São Luís in Brasil, but I did both my undergraduate and graduate studies in the US. I have a Bachelors Degree from Clark University in Massachusetts, where I majored in Physics and Philosophy, and worked in the Organic Superconductors Lab. I got my PhD in Physics at Brown University, where I was part of the Particle Astrophysics Group, and my advisor was Prof. Richard Gaitskell. During my graduate studies, I worked on the XENON, LUZ and LZ experiments. XENON10 was located at the Gran Sasso Underground Labs, about 1 hour northeast of Rome, so I got to spend a year living in Italy. I also spent 4 years living in Portugal, where I did a Postdoc at Laboratório de Instrumentação e Física Experimental de Partícula (LIP) in Coimbra; and 3 years in Santa Barbara, California (USA), where I did another postdoc at the University of California, Santa Barbara (undoubtedly the most beautifully located campus ever!).
Publications
Luiz de Viveiros's research group
| Name | Role | Affiliation | Phone | Office Address | Affiliated Center(s) | Research Topics(s) | ||
|---|---|---|---|---|---|---|---|---|
 | Srinikitha Bhagvati | Graduate Student | Physics | skb6413@psu.edu | - | 108 Osmond Laboratory | CMA | Dark Matter |
 | Yen-Ting Chin | Graduate Student | Physics | ypc5402@psu.edu | 18144248968 | - Osmond Laboratory | CMA | Dark Matter |
 | Gus Eberlein | Undergraduate Student | Physics | goe5044@psu.edu | 7175859863 | NA Whitmore Laboratory | IGC | Dark Matter |
 | Reagen Garcia | Graduate Student | Physics | rgarcia@psu.edu | --- | 114 Osmond Laboratory | CMA | Neutrinos |
 | Amber Krape | Undergraduate Student | Physics | ark5916@psu.edu | -- | -- NONE | IGC | Dark Matter |
 | Richard Mueller | Graduate Student | Physics | rjm6826@psu.edu | +1 814 865 7533 | 6E Osmond Laboratory | IGC | Neutrinos |
 | Katherine Wild | Graduate Student | Physics | kvw5673@psu.edu | (954) 225-1854 | 108 Osmond Laboratory | IGC | Dark Matter |
 | Wei Zha | Graduate Student | Physics | wpz5141@psu.edu | 114 Whitmore Laboratory | IGC | Dark Matter | |
 | Andrew Ziegler | Graduate Student | Physics | ziegler@psu.edu | -- | 6E Osmond Laboratory | CMA | Neutrinos |
Luiz de Viveiros's former research group members
| Name | Role | Affiliation | Phone | Office Address | Affiliated Center(s) | Research Topics(s) | ||
|---|---|---|---|---|---|---|---|---|
 | Daniel Kodroff | Graduate Student | Physics | dsk192@psu.edu | 0000000000 | Basement Osmond Laboratory | CMA | Neutrinos, Dark Matter |
Luiz de Viveiros's research group news
International LZ collaboration sets a world’s best in the hunt for dark matter
2025-12-08
Largest dataset ever collected by dark matter detector offers insight into dark matter candidate and provides new look at neutrinos from the Sun’s core 8 December 2025 Dark matter is an invisible substance that accounts for 85 percent of the mass in the universe, but determining exactly what it is remains one of the biggest questions about how the universe works. The newest results from the international LUX-ZEPLIN (LZ) collaboration, which includes Penn State researchers, extend the experiment’s search for low-mass dark matter, and setting world-leading constraints on the properties of one of the prime dark matter candidates: weakly interacting massive particles, or WIMPs. The experiment also detected signals from tiny, elusive particles called neutrinos from the sun, marking a milestone in the detector’s sensitivity and providing a window into the behavior of fundamental particles and stars.
The results were presented today in a scientific talk at the Sanford Underground Research Facility and will be released on the online repository arXiv. The paper will also be submitted to the journal Physical Review Letters.
“Although dark matter has never been directly detected, our continued searches help us set limits on the potential characteristics of WIMPs,” said Carmen Carmona, Norman and Trygve Freed Early Career Professor of Physics and leader of the LZ group at Penn State. “Even failure to detect certain events can provide important information about what these particles are, or what they aren’t, which gives us new insights into the mysterious yet ubiquitous dark matter.”
The LZ detector is managed by the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) and operates nearly one mile below ground at the Sanford Underground Research Facility (SURF) in South Dakota. Researchers at Penn State made key contributions to the construction of the LZ detector, specifically on the cryogenics and liquid xenon systems, and have led several key analyses, including background modeling, detector calibrations, and dark matter sensitivity projections.
The LZ collaboration, which includes more than 250 researchers from 37 institutions worldwide, used the largest dataset ever collected by a dark matter detector, which has unmatched sensitivity. The analysis, based on 417 live days of data that were taken from March 2023 to April 2025, found no sign of lower mass WIMPs with a mass between 3 GeV/c2 (gigaelectronvolts/c2) — roughly the mass of three protons— and 9 GeV/c2. This was the first time LZ researchers have looked for WIMPs below 9 GeV/c2. The world-leading results further narrow down possibilities of what dark matter might be and how it might interact with ordinary matter.
“We have been able to further increase the incredible sensitivity of the LUX-ZEPLIN detector with this new run and extended analysis,” said Rick Gaitskell, a professor at Brown University and the spokesperson for LZ. “While we don’t see any direct evidence of dark matter events at this time, our detector continues to perform well, and we will continue to push its sensitivity to explore new models of dark matter. As with so much of science, it can take many deliberate steps before you reach a discovery, and it’s remarkable to realize how far we’ve come. Our latest detector is over 3 million times more sensitive than the ones I used when I started working in this field.”
Dark matter has never been directly detected, but its gravitational influence shapes how galaxies form and stay together; without it, the universe as we know it wouldn’t exist. Because dark matter doesn’t emit, absorb, or reflect light, researchers must find a different way to “see” it.
LZ uses 10 tonnes of ultrapure, ultracold liquid xenon. If a WIMP hits a xenon nucleus, it deposits energy, causing the xenon to recoil and emit light and electrons that the sensors record. Deep underground, the detector is shielded from cosmic rays and built from low-radioactivity materials, with multiple layers to block or tag other particle interactions – letting the rare dark matter interactions stand out.
“Reducing and modeling backgrounds is essential to LZ because any unaccounted-for signal can mimic or obscure the rare interactions expected from dark matter,” said Luiz de Viveiros, associate professor of physics at Penn State and member of the LZ experiment. “By carefully understanding and predicting all background sources, LZ can distinguish potential dark matter events from radioactive or instrumental noise, improving both its sensitivity and the reliability of its results.”
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International LZ experiment sees new results in search for dark matter
2024-08-26
Using the world’s most sensitive dark matter detector, an international collaboration puts the best-ever limits on particles called WIMPs, a leading candidate for what makes up the universe’s invisible mass.
The nature of dark matter, the invisible substance thought to make up most of the mass in our universe, is one of the greatest mysteries in physics. Using new results from the world’s most sensitive dark matter detector, LUX-ZEPLIN (LZ), an international collaboration that includes Penn State researchers has narrowed down the possible properties of one of the leading candidates for the particles that compose dark matter: weakly interacting massive particles, or WIMPs.
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