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Justice Department Announces Results From Operation Not Forgotten 2026
WASHINGTON, Oct. 21 -- The U.S. Department of Justice issued the following news release:
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Justice Department Announces Results from Operation Not Forgotten 2026
October 20, 2026
In Its Fourth Year, ONF Surge to Indian country Supported 548 Case Investigations, a 59% increase from 2025
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The Department of Justice and FBI announced today results of the personnel surge in support of Operation Not Forgotten 2026, which focuses on unresolved cases in Indian country with a priority on cases involving violence against women and children, including those who are missing or murdered.
In its
... Show Full Article
WASHINGTON, Oct. 21 -- The U.S. Department of Justice issued the following news release:
* * *
Justice Department Announces Results from Operation Not Forgotten 2026
October 20, 2026
In Its Fourth Year, ONF Surge to Indian country Supported 548 Case Investigations, a 59% increase from 2025
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The Department of Justice and FBI announced today results of the personnel surge in support of Operation Not Forgotten 2026, which focuses on unresolved cases in Indian country with a priority on cases involving violence against women and children, including those who are missing or murdered.
In itsfourth year, Operation Not Forgotten surged personnel and investigative resources across the country from April 1 through September 30, resulting in 118 arrests, 41 individuals charged federally, 25 child victims identified or located, and 72 weapons recovered. FBI agents conducted 990 interviews and 232 search operations. Arrests increased by 123% and subjects charged by 52% over 2025.
"The Department of Justice will always work to deliver justice for the victims of violent crime in Indian country," said Attorney General Todd Blanche. "Thanks to the hard work of the FBI, our U.S. Attorneys, and other federal and tribal partners, Operation Not Forgotten and Operation Steadfast Promise are helping make communities safer and providing comfort for victims and families."
"This year's Operation Not Forgotten continued this FBI's largest commitment to Indian Country in the history of the Bureau," said FBI Director Kash Patel. "The results were outstanding - from April 1 through September 30, this FBI worked more than 500 cases, a 59% increase from last year's operation; 118 arrests, a 123% increase; and 41 subjects charged federally, a 52% increase. This is in addition to 25 child victims identified or located and 72 weapons recovered. These involved life-saving operations, with cases including child sexual abuse, physical assault and abuse, domestic violence, CSAM cases, and more.
"Operation Not Forgotten sends a loud and clear message that our long-forgotten partners in Indian Country are forgotten no more," said Director Patel. "When I assumed the position of FBI Director a year and a half ago, this FBI promised we would be there for our tribal partners. We have and will continue to be - through our 400 agents dedicated to Indian country, 30 Safe Trails Task Forces, and increased awareness with our Voices Not Forgotten program, where the FBI quadrupled the rewards to at least $25,000 for information associated with homicides, kidnappings and missing persons in Indian country. Thank you to our federal, state, and local partners who continue to work with us to ensure these unsolved crimes and cases receive the surge in resources they deserve."
"Operation Not Forgotten demonstrates the Trump Administration's commitment to protecting tribal communities, strengthening public safety, and ensuring that victims and their families have access to justice," said Billy Kirkland, Assistant Secretary for Indian Affairs, U.S. Department of the Interior. "Through close collaboration across the federal government and in partnership with tribal, state, and local law enforcement, we are bringing additional resources and investigative support to Indian Country to address violent crime, advance unresolved cases, and help families find answers. The Department of the Interior, through the Bureau of Indian Affairs, remains committed to working alongside our partners to deliver meaningful results and build safer communities for generations to come."
Examples of cases charged during this period include:
In the District of Wyoming, the surge resulted in the federal indictment of 18 individuals for an array of violent crimes, and child abuse offenses on the Wind River Indian Reservation, including U.S. v. Jose Benito Ocon: This prosecution arises from an August 2025 incident near Riverton, where the defendant allegedly executed a male passenger with a gunshot to the head inside a moving vehicle before turning the firearm on two female witnesses. Leveraging the surge's enhanced investigative assets, a grand jury returned an indictment charging the defendant with five felony counts, including first-degree murder, discharging a firearm during a crime of violence, and two distinct counts of assault with a dangerous weapon. He faces a mandatory sentence of life imprisonment if convicted. In U.S. v. Darlynn Sheree Seminole, federal prosecutors filed charges following a June 2026 domestic violence intervention by the Bureau of Indian Affairs (BIA) Wind River Police Department, involving allegations of severe physical trauma inflicted on a 10-year-old.
In the District of Nevada, in July a federal grand jury returned a superseding indictment charging Delshay Astor with the alleged murder of Anna Scott, a member of the Pyramid Lake Paiute Tribe, on the Reno-Sparks Indian Colony in February 2022, and also charged Joel Christy for assisting Astor to avoid apprehension.
In the District of Minnesota, Operation Not Forgotten has resulted in four cases charged during the surge period with violent and sexual offenses in Indian Country, including sexual abuse of minors, domestic assault causing substantial bodily injury, assault by strangulation, and assault with intent to commit kidnapping. One recent case includes U.S. v. Courtney John Barrett Sr. indicted on September 22, 2026, on two counts of sexual abuse of a minor.
In the District of Montana, Michael Plentybuffalo was charged in the death of Shann Nomee, who went missing during an extreme cold snap in January 2024 and whose frozen body was found in a field north of Lodge Grass, Montana after a community led search and a tip to the Bureau of Indian Affairs that pointed to Plentybuffalo. His case is pending trial.
Also in Montana, Lance Crookedarm was charged with the May 2026 violent assault and non-fatal strangulation of a female victim.
In the District of Arizona, at least four cases were charged including two violent assaults, an arson, and the aggravated sexual abuse of a minor under 12, all of which occurred on the Navajo Nation, as well as an additional assault that was committed on the Fort Apache Indian Reservation.
FBI's Operation Steadfast Promise
Operation Steadfast Promise, first announced in 2026, is a continuing comprehensive surge of resources to address a wide range of violent criminal threats impacting Indian country. Operation Steadfast Promise builds on the successes of Operation Not Forgotten with the addition of multiple new initiatives to improve public safety in Tribal communities. The FBI, in coordination with U.S. Attorneys' Offices, the Bureau of Indian Affairs Missing and Murdered Unit, Alcohol, Tobacco, Firearms and Explosives and Tribal and other federal law enforcement partners, is working across multiple territories to bring investigative aid to cases and resolution for victims and their families. Since Operation Steadfast Promise began in April, the FBI opened over 1,200 new investigations in Indian country, obtained criminal charges on 678 subjects, made over 700 arrests, recovered 2,260 weapons, and made 140 drug seizures.
This year, Operation Not Forgotten continued to address the over 4,000 open investigations in Indian country including death investigations, child abuse cases, domestic violence, and adult sexual abuse investigations, underscoring the persistent and urgent need for sustained resource investment in these communities.
During Operation Not Forgotten, the FBI surged personnel, including investigative, intelligence, and other support personnel, on rotating temporary duty assignments across Indian country in twelve FBI field offices, in Albuquerque, Billings, Detroit, Denver, Jackson, Las Vegas, Minneapolis, Oklahoma City, Omaha, Portland, Phoenix and Salt Lake City. Working in close coordination with Tribal law enforcement agencies, the BIA Missing and Murdered Unit, and U.S. Attorneys' Offices, together law enforcement worked to advance open investigations and pursue accountability for victims and their families.
Additionally, the FBI has brought focus to a new FBI's Voices Not Forgotten webpage that includes a searchable and interactive map that brings attention to FBI investigations in Indian country where the FBI, in coordination with state, local and Tribal law enforcement are seeking the public's assistance. In August 2026, the FBI announced the establishment of a new protocol which created a minimum reward of up to $25,000 for all publicly advertised cases involving homicides, kidnappings and missing persons in Indian country where the FBI has assumed jurisdiction.
The FBI remains committed to standing alongside Tribal communities, federal partners, and local law enforcement to address the violent crime threats that continue to impact Indian country. To learn more, visit www.fbi.gov/investigate/violent-crime/indian-country-crime.
The FBI encourages anyone with information related to unresolved violent crimes in Indian country to contact their local FBI field office or submit a tip at https://tips.fbi.gov.
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Original text here: https://www.justice.gov/opa/pr/justice-department-announces-results-operation-not-forgotten-2026
IDB Launches Regional Network to Attract More Foreign Direct Investment to Latin America and the Caribbean
WASHINGTON, Oct. 21 -- The Inter-American Development Bank issued the following news release:
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IDB Launches Regional Network to Attract More Foreign Direct Investment to Latin America and the Caribbean
October 20, 2026
The platform will bring together the region's investment promotion agencies to strengthen cooperation among countries.
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PANAMA CITY - The Inter-American Development Bank (IDB) today launched the Latin America and the Caribbean Investment Promotion and Facilitation Network, a new platform aimed at facilitating the exchange of information and experiences among countries
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WASHINGTON, Oct. 21 -- The Inter-American Development Bank issued the following news release:
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IDB Launches Regional Network to Attract More Foreign Direct Investment to Latin America and the Caribbean
October 20, 2026
The platform will bring together the region's investment promotion agencies to strengthen cooperation among countries.
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PANAMA CITY - The Inter-American Development Bank (IDB) today launched the Latin America and the Caribbean Investment Promotion and Facilitation Network, a new platform aimed at facilitating the exchange of information and experiences among countriesand strengthening cooperation and promotion efforts to attract more foreign investment to the region.
The Network will bring together government entities responsible for investment facilitation and promotion in the region's countries.
The initiative responds to growing demand among IDB member countries seeking to promote foreign investment, a key driver of growth, to advance development. Every dollar invested in investment promotion can generate up to an additional US$56 in foreign direct investment, according to an IDB study.
"This Network brings together those who attract and facilitate investment in each country, so they can learn from one another and investors can find a more predictable region. The Network focuses above all on implementation, not only to attract more investment, but also quality investment that translates into development for people and businesses," said Anabel Gonzalez, IDB Vice President for Countries and Regional Integration.
"Latin America and the Caribbean needs to attract more foreign direct investment to achieve its development goals. This Network will enable countries to share experiences and good practices and strengthen cooperation to reinforce their investment attraction strategies," said Fabrizio Opertti, Manager of the IDB's Productivity, Trade and Innovation Sector. "It will be a permanent space to work together and make better use of investment opportunities in the region," he added.
As part of its work to strengthen productivity, promote trade and investment, and foster innovation in Latin America and the Caribbean, the IDB, through its Productivity, Trade and Innovation Sector, will serve as the Network's technical secretariat during its initial phase.
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About the IDB
The Inter-American Development Bank (IDB), a member of the IDB Group, is devoted to improving lives across Latin America and the Caribbean. Founded in 1959, the Bank works with the region's public sector to design and enable impactful, innovative solutions for sustainable and inclusive development. Leveraging financing, technical expertise, and knowledge, it promotes growth and well-being in 26 countries. Visit: www.iadb.org/en.
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Original text here: https://www.iadb.org/en/news/idb-launches-regional-network-attract-more-foreign-direct-investment-latin-america-and-caribbean
Homeland Security IG: CBP and ICE Had Effective Processes for Issuing and Acting Upon Immigration Enforcement-Related Detainers in Del Rio, Texas
WASHINGTON, Oct. 21 (TNSLrpt) -- The Homeland Security Inspector General issued the following report (No. 26-35) on September 25, 2026, entitled "CBP and ICE Had Effective Processes for Issuing and Acting Upon Immigration Enforcement-Related Detainers in Del Rio, Texas."
Here are excerpts:
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Why We Did This Review
For aliens charged with violations, DHS may issue a detainer when it transfers them to Federal law enforcement custody for prosecution. We conducted this review to determine whether CBP and ICE have effective processes for issuing, acting upon, or lifting detainers placed on aliens
... Show Full Article
WASHINGTON, Oct. 21 (TNSLrpt) -- The Homeland Security Inspector General issued the following report (No. 26-35) on September 25, 2026, entitled "CBP and ICE Had Effective Processes for Issuing and Acting Upon Immigration Enforcement-Related Detainers in Del Rio, Texas."
Here are excerpts:
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Why We Did This Review
For aliens charged with violations, DHS may issue a detainer when it transfers them to Federal law enforcement custody for prosecution. We conducted this review to determine whether CBP and ICE have effective processes for issuing, acting upon, or lifting detainers placed on aliensfor immigration enforcement-related Federal criminal proceedings in Del Rio, Texas.
What We Recommend
We made no recommendations in this report.
OIG Access
CBP and ICE provided timely responses and did not delay or deny access to our requests for information.
What We Found
From fiscal years 2021 to 2024, U.S. Customs and Border Protection (CBP) and U.S. Immigration and Enforcement (ICE) in Del Rio, Texas, had effective processes for issuing and acting upon detainers placed on aliens for immigration enforcementrelated Federal criminal proceedings. CBP and ICE prioritized detaining and removing aliens sent for prosecution and had clear, established processes for DHS to take custody following prosecution. We did not identify any instances in which CBP or ICE lifted a detainer.
CBP and ICE in Del Rio followed the relevant enforcement priorities and issued detainers on all individuals referred for Federal prosecution for improper entry and reentry after removal. Additionally, CBP and ICE established coordinated processes and procedures for acting upon those detainers. CBP and ICE used U.S Marshals Service's email notifications on the release of aliens with detainers to determine which component would act upon the detainer.
In Del Rio, CBP Border Patrol took custody of Mexican nationals who did not claim asylum; CBP Office of Field Operations (OFO) took custody of its own referrals. ICE Enforcement and Removal (ERO) took custody of its own referrals as well as individuals apprehended by Border Patrol or OFO who claimed asylum or were not Mexican nationals and transferred them to a detention facility.
DHS' Response
CBP and ICE declined to submit management comments.
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The report is posted at: https://www.oig.dhs.gov/sites/default/files/assets/2026-09/OIG-26-35-Sep26.pdf
FCC Removes Convicted Fraudster From USF Programs
WASHINGTON, Oct. 21 -- The Federal Communications Commission issued the following news release:
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FCC Removes Convicted Fraudster from USF Programs
Long Island-Based Consultant Took Kickbacks as Part of Scheme to Defraud E-Rate Program and a COVID-Era Connectivity Program
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WASHINGTON, October 20, 2026--The Federal Communications Commission today suspended Long Island-based school consultant Richard Bernstein from participating in federal universal service fund-supported programs. It also set in motion the process to debar him from the programs. Mr. Bernstein pled guilty earlier this year
... Show Full Article
WASHINGTON, Oct. 21 -- The Federal Communications Commission issued the following news release:
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FCC Removes Convicted Fraudster from USF Programs
Long Island-Based Consultant Took Kickbacks as Part of Scheme to Defraud E-Rate Program and a COVID-Era Connectivity Program
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WASHINGTON, October 20, 2026--The Federal Communications Commission today suspended Long Island-based school consultant Richard Bernstein from participating in federal universal service fund-supported programs. It also set in motion the process to debar him from the programs. Mr. Bernstein pled guilty earlier this yearto conspiracy to defraud the United States in connection with his scheme to steer federal funds to school vendors in exchange for a share of their profits. Specifically, his scheme involved more than $100,000 in kickbacks to his consulting company for advising schools in the E-Rate program and the since-expired, COVID-era Emergency Connectivity Fund program to vendors with which he had agreements.
Hunter Deeley, Chief of the Enforcement Bureau, issued the following statement:
"Getting kickbacks under the guise of helping schools navigate federal programs is an egregious level of corruption. Unfortunately, this corrupt behavior is not unique to this case. Today's action reflects the Enforcement Bureau's ongoing effort to protect the integrity of federally funded programs. We are making progress, but the job is far from over."
Additional Background Information:
In today's action, the FCC's Enforcement Bureau formally suspended Mr. Bernstein from the E-Rate program and all federal universal service support mechanisms. The Bureau also began a proceeding to debar him from future participation in these programs. The suspension bans him from participating in the programs and the proposed debarment would remove him from the programs going forward.
In January, as announced by the Department of Justice and FCC Office of Inspector General, Mr. Bernstein pled guilty to devising a scheme and conspiracy to defraud the E-Rate and Emergency Connectivity Fund programs. In 2021 and 2022, he conspired with others to use his position as an active agent of schools seeking benefits under the ECF and E-Rate programs to solicit kickback payments from vendors of those programs. In exchange for these kickbacks, he agreed to steer the schools to select those vendors, ensuring that the vendors would receive federal funds for the services and equipment they provided to the schools through the ECF and E-Rate programs.
The FCC is committed to fighting waste, fraud, and abuse in federal programs. To that end, it launched a top-to-bottom evaluation of the E-Rate program, including proposals to strengthen E-Rate program integrity by increasing oversight of consultants, streamlining administrative processes, and eliminating certain rules for the COVID-era Emergency Connectivity Fund program. The agency also recently barred seven convicted criminals from the E-Rate program. Separately, the FCC recently adopted rules to bolster its tools for quickly and lawfully removing bad actors from federal programs. The FCC has also adopted major reforms to its USF-supported Lifeline program.
The FCC's Notice of Suspension and Initiation of Debarment Proceeding of Mr. Bernstein is available at: https://docs.fcc.gov/public/attachments/DA-26-1123A1.pdf.
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Original text here: https://docs.fcc.gov/public/attachments/DOC-426063A1.pdf
Energy Department Announces New Investments to Strengthen America's Power Grid and Lower Electricity Costs
WASHINGTON, Oct. 21 -- The U.S. Department of Energy issued the following news release:
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Energy Department Announces New Investments to Strengthen America's Power Grid and Lower Electricity Costs
Additional funding will help states, territories, and tribes modernize critical energy infrastructure, improve grid reliability, and deliver more affordable electricity to American families and businesses.
October 20, 2026
WASHINGTON-- The U.S. Department of Energy (DOE) today announced approximately $967 million in additional funding through its Grid Resilience State and Tribal Formula Grant
... Show Full Article
WASHINGTON, Oct. 21 -- The U.S. Department of Energy issued the following news release:
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Energy Department Announces New Investments to Strengthen America's Power Grid and Lower Electricity Costs
Additional funding will help states, territories, and tribes modernize critical energy infrastructure, improve grid reliability, and deliver more affordable electricity to American families and businesses.
October 20, 2026
WASHINGTON-- The U.S. Department of Energy (DOE) today announced approximately $967 million in additional funding through its Grid Resilience State and Tribal Formula Grantprogram to modernize critical energy infrastructure, lower electricity costs and strengthen America's power grid. The funding will support locally driven projects across states, territories, and tribes to upgrade critical infrastructure, prevent power disruptions, and meet growing electricity demand while helping lower costs for American families and businesses.
The investment advances President Trump's American energy dominance agenda. Projects funded through the program will help states, territories, and tribes invest in infrastructure improvements that protect against disruptive events, improve system performance, and ensure communities and businesses have dependable power when they need it most.
"Lowering costs and unleashing prosperity are top priorities for President Trump," said U.S. Secretary of Energy Chris Wright. "These commonsense investments provide resources directly to states, territories, and tribes to lower electricity costs and strengthen grid reliability for American businesses and families."
"A strong and dependable grid is the backbone of American economic prosperity," said Office of Electricity Assistant Secretary Katie Jereza. "This funding will help Americans across the country, including our tribal partners, optimize their electricity systems and prepare for future growth while strengthening energy security and deploying technologies that can lower the long-term cost of delivering reliable power."
States, tribes, and U.S. territories can view their funding allocations and application instructions here (https://www.fedconnect.net/FedConnect/default.aspx?doc=DE-FOA-0002736&agency=DOE).
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Original text here: https://www.energy.gov/articles/energy-department-announces-new-investments-strengthen-americas-power-grid-and-lower
Chiricahua National Monument Becomes America's Newest National Park
WASHINGTON, Oct. 21 -- The U.S. Department of the Interior National Park Service issued the following news release:
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Chiricahua National Monument Becomes America's Newest National Park
Redesignation recognizes one of nation's most extraordinary landscapes and cultural treasures
October 20, 2026
WILLCOX, Ariz. - Chiricahua National Monument is now Chiricahua National Park, following President Donald J. Trump's signing of the Chiricahua National Park Act into law on Oct. 20, 2026. The redesignation recognizes the national significance of the area's extraordinary natural and cultural resources
... Show Full Article
WASHINGTON, Oct. 21 -- The U.S. Department of the Interior National Park Service issued the following news release:
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Chiricahua National Monument Becomes America's Newest National Park
Redesignation recognizes one of nation's most extraordinary landscapes and cultural treasures
October 20, 2026
WILLCOX, Ariz. - Chiricahua National Monument is now Chiricahua National Park, following President Donald J. Trump's signing of the Chiricahua National Park Act into law on Oct. 20, 2026. The redesignation recognizes the national significance of the area's extraordinary natural and cultural resourcesand marks a new chapter for one of Arizona's most distinctive landscapes.
"Chiricahua's towering rock spires, rich Apache heritage and remarkable biodiversity make it one of America's most extraordinary landscapes," said Secretary of the Interior Doug Burgum. "This new designation will shine a national spotlight on one of Arizona's hidden gems, creating opportunities to welcome more visitors, strengthen local economies and share this incredible landscape with more Americans."
Located in the southeastern corner of Arizona, the park protects a landscape of towering rhyolite rock spires and balanced rocks formed by an ancient volcanic eruption roughly 27 million years ago. Rising from the "sky island" of the Chiricahua Mountains, where desert, grassland, and forest ecosystems meet, the area supports remarkable biodiversity and provides opportunities for hiking, wildlife viewing, birding and stargazing.
"Chiricahua has been part of the National Park System for more than a century, and this new designation marks an exciting chapter in its history," said Jessica Bowron, Comptroller Exercising the Delegated Authority of the Director of the National Park Service. "While its name is changing, our commitment remains the same: protecting this remarkable landscape and its cultural heritage while providing opportunities for visitors to experience and enjoy it for generations to come."
First protected as a national monument in 1924, Chiricahua preserves thousands of years of human history, including its importance as the homeland of the Chiricahua Apache and its legacy of early homesteading families at Faraway Ranch. The redesignation reflects the national significance of the area's natural and cultural resources and the longstanding efforts to conserve them.
The park will continue to offer its hiking, camping, scenic drives, wildlife viewing and other opportunities. Visitors can find current information at nps.gov/chir.
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About Chiricahua National Park: Located near Willcox, Arizona, the park protects approximately 12,000 acres of rugged volcanic landscape, diverse wildlife, and cultural history. Learn more at nps.gov/chir.
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About the National Park Service. Since 1916, the National Park Service has been entrusted with the care of America's national parks. With the help of volunteers and partners, we safeguard these special places and share their stories with millions of people every year. Learn more at nps.gov.
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Original text here: https://www.nps.gov/chir/learn/news/chiricahua-national-monument-becomes-america-s-newest-national-park.htm
Brookhaven National Laboratory: Oxygen Collisions Quench Jets' Energy at RHIC
UPTON, New York, Oct. 21 (TNSjou) -- The U.S. Department of Energy Brookhaven National Laboratory issued the following news release:
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Oxygen Collisions Quench Jets' Energy at RHIC
Strong evidence for jet quenching in oxygen-oxygen smashups offers clear sign of a quark-gluon plasma in a small nuclear system at lowest collision energy yet
October 20, 2026
UPTON, N.Y. -- New results from the STAR experiment at the Relativistic Heavy Ion Collider (RHIC) provide strong evidence that smashing oxygen nuclei together at nearly the speed of light generates a quark-gluon plasma (QGP), a type of
... Show Full Article
UPTON, New York, Oct. 21 (TNSjou) -- The U.S. Department of Energy Brookhaven National Laboratory issued the following news release:
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Oxygen Collisions Quench Jets' Energy at RHIC
Strong evidence for jet quenching in oxygen-oxygen smashups offers clear sign of a quark-gluon plasma in a small nuclear system at lowest collision energy yet
October 20, 2026
UPTON, N.Y. -- New results from the STAR experiment at the Relativistic Heavy Ion Collider (RHIC) provide strong evidence that smashing oxygen nuclei together at nearly the speed of light generates a quark-gluon plasma (QGP), a type ofmatter that existed just after the birth of the universe. The data, just published in Physical Review Letters, show that energetic jets of particles lose energy as they traverse the hot, dense matter left in the collision's wake.
This energy loss phenomenon, known as jet quenching, has been one of the "smoking gun" signatures of QGP formation in collisions of larger atomic nuclei at RHIC, a U.S. Department of Energy (DOE) Office of Science User Facility that operated at DOE's Brookhaven National Laboratory from 2000 until earlier this year. This signature has also been observed in oxygen-oxygen collisions at the Large Hadron Collider (LHC), located at CERN, the European Particle Physics Laboratory. The analysis from RHIC at significantly lower collision energy sets a new lower boundary for the conditions capable of producing the primordial QGP in this small collision system.
"The QGP is believed to be the form of matter that filled the early universe -- before the protons and neutrons that make up today's atoms formed. Understanding its properties is essential for uncovering how the early universe evolved in its first microseconds," said Li Yi, a professor of physics at Shandong University who oversaw the STAR analysis. "One of the most powerful ways scientists study the QGP is by identifying where its signatures appear -- and just as importantly, where these signatures turn off," she said.
Rongrong Ma, a STAR physicist from Brookhaven Lab, said, "This analysis is pushing the boundaries to an extreme case to help us learn something about this jet quenching phenomenon and the conditions needed to generate a QGP."
Tracking jets
RHIC was built to create and study the QGP. Its collisions of gold nuclei, each packed with 79 protons and 118 neutrons, effectively melt the boundaries of these atoms' protons and neutrons, thus setting free their constituent quarks and gluons. The collisions also deposit enough energy to be transformed via Einstein's famous equation, E=mc2, into thousands of new quarks and gluons. But because the resulting QGP is a speck smaller than a single atomic nucleus and lasts less than a billionth of a billionth of a second before the quarks and gluons join up to form more ordinary particles, the only way to know if a QGP has formed is to study particles flying out of the collisions using giant detectors like STAR.
Seeing signs that some particles emerge with less energy than expected implies that they've gotten "stuck," or quenched, by interacting with the soup of quarks and gluons on the way out. Energy loss by collimated sprays of very energetic particles known as jets has been a particular interest. These jets are typically produced when a single quark or gluon in one nucleus interacts with a quark or gluon in the other, shooting out two sprays of energetic particles back-to-back from the point of that interaction. When these "di-jets" are produced near the edge of the collision zone, they give physicists a built-in way to study the plasma by tracking how each half of the jet gets affected as it moves different distances through the blob of hot nuclear matter.
"You can think of it like shooting a bullet through, say, water," Yi said. "Because of the resistance, the bullet will slow down. It's the same thing with these high-energy particles. When they go through the QGP, they will lose energy."
For many years, RHIC physicists have seen definitive evidence of quenching in gold-gold collisions, particularly in jet particles that traverse a relatively long distance through the matter generated in the collisions. Presumably these long-distance travelers interact with more quarks and gluons along their longer escape path than jets escaping from closer to the edge of the QGP blob. These observations were among the evidence RHIC scientists presented as part of the case for having created the QGP in gold-gold collisions, backed by a trove of other QGP signature measurements from multiple RHIC experiments.
Among those other measurements was the observation that lower-energy particles emerging from gold-gold smashups move in a coordinated way. These observations of collective behavior led physicists to declare that the matter created in RHIC's collisions flows like a nearly perfect liquid with nearly zero viscosity or resistance. This was a major RHIC discovery that, at the time, was completely unexpected, but has since become another "smoking gun" signature of the QGP.
QGP in small systems?
Years after the definitive flow and jet-quenching results from RHIC emerged, physicists at the LHC and then later at RHIC began to see signs of collective flow in much smaller collision systems, including collisions of tiny protons, deuterons, and helium-3 nuclei with large gold or lead nuclei. Experiments at the LHC even observed flow patterns in data from proton-proton collisions. These observations in small collision systems at both facilities raised the intriguing question of whether the flow signature is sufficient to say that these systems are creating a QGP.
"The next natural question is: Can you see jet quenching, the other key signature that QGP is formed, in these very small collision systems?" asked Brookhaven's Ma. "We haven't seen any unambiguous signal, so it's still kind of under debate in these small systems. We want to search for the smallest system where we can still see an unambiguous jet-quenching signal," he said.
Enter the oxygen-oxygen smashups.
Oxygen collisions offer a small system with just 8 protons and 8 neutrons in each colliding nucleus. Also, the oxygen nuclei are symmetrically spherical.
"That means we can more easily look for signs of asymmetric quenching of di-jets produced close to the edge of the circular interaction region in head-on collisions," said Maowu Nie, an associate professor at Shandong University who was also involved in the analysis.
"We can also compare how jets behave in head-on central collisions -- those that produce the most particles and therefore have the highest likelihood of making a QGP -- with collisions where the two oxygen nuclei barely strike each other, which aren't expected to generate a QGP." The latter can be distinguished because they produce many fewer particles, he said.
The oxygen-oxygen results
"Our measurements are essentially counting experiments," said Sijie Zhang, who worked on this project for her master's thesis under Yi and Nie's guidance at Shandong University and is now pursuing a Ph.D. at Yale University. "We have an algorithm that finds the collimated groups of high energy particles, the jets, and we count how many of these particles above a certain energy threshold come out."
Yang He, another former Ph.D. student at Shandong University who set up the analysis framework and now analyzes oxygen-oxygen collisions at the LHC, added, "We compare what we see in back-to-back jets produced near the edge of the system, and we compare what we see in head-on collisions with the counts in non-central collisions where we don't expect to see quenching."
The analysis, based on STAR data collected from oxygen-oxygen collisions at 200 billion electron volts (GeV) at RHIC in 2021, revealed a 20% suppression in high-energy particles due to jet quenching. That's lower than the level seen in RHIC's gold-gold smashups, which is what the scientists would expect from this much smaller system, but it's still a clear sign that these collisions are creating a QGP.
In addition, because oxygen is the only nuclear species -- aside from proton-proton collisions -- that has been studied at both RHIC and the LHC, physicists are able to do an "apples-to-apples" comparison of the results from the two facilities.
The LHC collided oxygen atoms for the first time in 2025. A recent CERN article summarizes their results to date, including observations of collective flow and jet quenching in oxygen-oxygen collisions.
Importantly, the LHC jet-quenching data come from collisions at much higher energies than at RHIC -- more than 5,000 GeV.
"With a higher energy collision, it's more likely to create more and more quarks and gluons and a hotter, denser QGP system," Yi said. "That means the jet quenching signal, if it's there, should be bigger at LHC compared to RHIC."
But when physicists are trying to see where a QGP signature turns off, turning down the collision energy may get them closer to that limit.
"We are pushing the boundaries in two ways to explore the minimal conditions for creating a QGP, both in terms of the nucleus size by looking at these small oxygen-oxygen collisions, but also by looking at data from lower collision energies -- and we still see this crucial QGP signature. That's a unique feature of our measurement," Ma said.
There will be much more to come in the oxygen-oxygen story from RHIC, using data collected by STAR and sPHENIX, RHIC's newest detector, during the collider's final run. Indeed, that final run ended with oxygen-oxygen smashups at both detectors on Feb. 6, 2026. What that data show and what it means in the quest for understanding the conditions needed to generate the QGP offer an exciting opportunity for new insights.
This research was supported by the DOE Office of Science, the U.S. National Science Foundation (NSF), and a range of international agencies and organizations listed in the scientific paper. In addition to using the Open Science Grid, supported directly by NSF, the researchers made use of computing resources in the Scientific Data and Computing Facilities at Brookhaven Lab and the National Energy Research Scientific Computing Center (NERSC), which is another DOE Office of Science User Facility at DOE's Lawrence Berkeley National Laboratory.
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Brookhaven National Laboratory is supported by the Office of Science of the U.S. Department of Energy. The Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, visit science.energy.gov.
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View journal here: https://journals.aps.org/prl/accepted/10.1103/9w2y-bz9n
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Original text here: https://www.bnl.gov/newsroom/news.php?a=123196
