LOWELL, MA — A discovery by a team of researchers led by University of Massachusetts Lowell nuclear physicists could change how atoms are understood by scientists and help explain extreme phenomena in outer space.
The breakthrough by the researchers revealed that a symmetry that exists within the core of the atom is not as fundamental as scientists have believed. The discovery sheds light on the forces at work within the atoms’ nucleus, opening the door to a greater understanding of the universe. The findings were published Apr. 1 in Nature, one of the world’s premier scientific journals.
The discovery was made when the UMass Lowell-led team was working to determine how atomic nuclei are created in X-ray bursts—explosions that happen on the surface of neutron stars, which are the remnants of massive stars at the end of their life.
UMass Lowell Physics assistant professor Andrew Rogers.
Photo courtesy of UMass Lowell
“We are studying what happens inside the nuclei of these atoms to better understand these cosmic phenomena and, ultimately, to answer one of the biggest questions in science—how the chemical elements are created in the universe,” said Andrew Rogers, UMass Lowell assistant professor of physics, who heads the research team.
The research is supported by a $1.2 million grant from the US Department of Energy to UMass Lowell and was conducted at the National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University. At the lab, scientists create exotic atomic nuclei to measure their properties in order to understand their role as the building blocks of matter, the cosmos, and of life itself.
Atoms are some of the smallest units of matter. Each atom includes electrons orbiting around a tiny nucleus deep within its core, which contains almost all its mass and energy. Atomic nuclei are composed of two nearly identical particles: charged protons and uncharged neutrons. The number of protons in a nucleus determines which element the atom belongs to on the periodic table and thus its chemistry. Isotopes of an element have the same number of protons but a different number of neutrons.
At the NSCL, nuclei were accelerated to near the speed of light and smashed apart into fragments creating strontium-73—a rare isotope that is not found naturally on Earth but can exist for short periods of time during violent thermonuclear X-ray bursts on the surface of neutron stars. This isotope of strontium contains 38 protons and 35 neutrons and only lives for a fraction of a second.
Working around the clock over eight days, the team created more than 400 strontium-73 nuclei and compared them to the known properties of bromine-73, an isotope that contains 35 protons and 38 neutrons. With interchanged number of protons and neutrons, bromine-73 nuclei are considered “mirror partners” to strontium-73 nuclei. Mirror symmetry in nuclei exists because of the similarities between protons and neutrons and underlies scientists’ understanding of nuclear physics.
Roughly every half-hour, the researchers created one strontium-73 nucleus, transported it through the NSCL’s isotope separator and then brought the nucleus to a stop at the center of a complex detector array where they could observe its behavior. By studying the radioactive decay of these nuclei, the scientists found that strontium-73 behaved entirely differently from bromine-73. The discovery raises new questions about nuclear forces, according to Rogers.
“Strontium-73 and bromine-73 should appear identical in structure, but surprisingly do not, we found. Probing symmetries that exist in nature is a very powerful tool for physicists. When symmetries break down, that tells us something’s wrong in our understanding, and we need to take a closer look,” Rogers said.
What the scientists saw will challenge nuclear theory, according to Daniel Hoff, a UMass Lowell research associate who was the lead author of the article published in Nature.
“Comparing strontium-73 and bromine-73 nuclei was like looking in a mirror and not recognizing yourself. Once we convinced ourselves that what we were seeing was real, we were very excited,” Hoff said.
Along with Rogers, a Somerville resident, and Hoff of Medford, the UMass Lowell team included Physics Department faculty members Peter Bender, C.J. Lister and former UMass Lowell research associate Chris Morse. Physics graduate students Emery Doucet of Mason, N.H., and Sanjanee Waniganeththi of Lowell also contributed to the project.
As part of the team’s study, state-of-the-art theoretical calculations were carried out by Simin Wang, a research associate at Michigan State, and directed by Witold Nazarewicz, MSU’s John A. Hannah Distinguished Professor of Physics and chief scientist at the Facility for Rare Isotope Beams (FRIB), which will open next year.
The researchers’ work “offers unique insights into the structure of rare isotopes,” Nazarewicz said. “But much still remains to be done. New facilities coming online, such as FRIB at MSU, will provide missing clues into a deeper understanding of the mirror symmetry puzzle. I am glad that the exotic beams delivered by our facility, unique instrumentation and theoretical calculations could contribute to this magnificent work.”
Plans for more experiments are already underway, as the researchers seek to refine and confirm their observations and study these isotopes further.
NAIROBI, Kenya (AP) — The body of Ugandan Olympic athlete Rebecca Cheptegei — who died after being set on fire by her partner in Kenya — was received Friday by family and anti-femicide crusaders, ahead of her burial a day later.
Cheptegei’s family met with dozens of activists Friday who had marched to the Moi Teaching and Referral Hospital’s morgue in the western city of Eldoret while chanting anti-femicide slogans.
She is the fourth female athlete to have been killed by her partner in Kenya in yet another case of gender-based violence in recent years.
Viola Cheptoo, the founder of Tirop Angels – an organization that was formed in honor of athlete Agnes Tirop, who was stabbed to death in 2021, said stakeholders need to ensure this is the last death of an athlete due to gender-based violence.
“We are here to say that enough is enough, we are tired of burying our sisters due to GBV,” she said.
It was a somber mood at the morgue as athletes and family members viewed Cheptegei’s body which sustained 80% of burns after she was doused with gasoline by her partner Dickson Ndiema. Ndiema sustained 30% burns on his body and later succumbed.
Ndiema and Cheptegei were said to have quarreled over a piece of land that the athlete bought in Kenya, according to a report filed by the local chief.
Cheptegei competed in the women’s marathon at the Paris Olympics less than a month before the attack. She finished in 44th place.
Cheptegei’s father, Joseph, said that the body will make a brief stop at their home in the Endebess area before proceeding to Bukwo in eastern Uganda for a night vigil and burial on Saturday.
“We are in the final part of giving my daughter the last respect,” a visibly distraught Joseph said.
He told reporters last week that Ndiema was stalking and threatening Cheptegei and the family had informed police.
Four in 10 women or an estimated 41% of dating or married Kenyan women have experienced physical or sexual violence perpetrated by their current or most recent partner, according to the Kenya Demographic and Health Survey 2022.
TEL AVIV, Israel (AP) — A rare Bronze-Era jar accidentally smashed by a 4-year-old visiting a museum was back on display Wednesday after restoration experts were able to carefully piece the artifact back together.
Last month, a family from northern Israel was visiting the museum when their youngest son tipped over the jar, which smashed into pieces.
Alex Geller, the boy’s father, said his son — the youngest of three — is exceptionally curious, and that the moment he heard the crash, “please let that not be my child” was the first thought that raced through his head.
The jar has been on display at the Hecht Museum in Haifa for 35 years. It was one of the only containers of its size and from that period still complete when it was discovered.
The Bronze Age jar is one of many artifacts exhibited out in the open, part of the Hecht Museum’s vision of letting visitors explore history without glass barriers, said Inbal Rivlin, the director of the museum, which is associated with Haifa University in northern Israel.
It was likely used to hold wine or oil, and dates back to between 2200 and 1500 B.C.
Rivlin and the museum decided to turn the moment, which captured international attention, into a teaching moment, inviting the Geller family back for a special visit and hands-on activity to illustrate the restoration process.
Rivlin added that the incident provided a welcome distraction from the ongoing war in Gaza. “Well, he’s just a kid. So I think that somehow it touches the heart of the people in Israel and around the world,“ said Rivlin.
Roee Shafir, a restoration expert at the museum, said the repairs would be fairly simple, as the pieces were from a single, complete jar. Archaeologists often face the more daunting task of sifting through piles of shards from multiple objects and trying to piece them together.
Experts used 3D technology, hi-resolution videos, and special glue to painstakingly reconstruct the large jar.
Less than two weeks after it broke, the jar went back on display at the museum. The gluing process left small hairline cracks, and a few pieces are missing, but the jar’s impressive size remains.
The only noticeable difference in the exhibit was a new sign reading “please don’t touch.”
VICTORIA – The British Columbia government is partnering with a bear welfare group to reduce the number of bears being euthanized in the province.
Nicholas Scapillati, executive director of Grizzly Bear Foundation, said Monday that it comes after months-long discussions with the province on how to protect bears, with the goal to give the animals a “better and second chance at life in the wild.”
Scapillati said what’s exciting about the project is that the government is open to working with outside experts and the public.
“So, they’ll be working through Indigenous knowledge and scientific understanding, bringing in the latest techniques and training expertise from leading experts,” he said in an interview.
B.C. government data show conservation officers destroyed 603 black bears and 23 grizzly bears in 2023, while 154 black bears were killed by officers in the first six months of this year.
Scapillati said the group will publish a report with recommendations by next spring, while an independent oversight committee will be set up to review all bear encounters with conservation officers to provide advice to the government.
Environment Minister George Heyman said in a statement that they are looking for new ways to ensure conservation officers “have the trust of the communities they serve,” and the panel will make recommendations to enhance officer training and improve policies.
Lesley Fox, with the wildlife protection group The Fur-Bearers, said they’ve been calling for such a committee for decades.
“This move demonstrates the government is listening,” said Fox. “I suspect, because of the impending election, their listening skills are potentially a little sharper than they normally are.”
Fox said the partnership came from “a place of long frustration” as provincial conservation officers kill more than 500 black bears every year on average, and the public is “no longer tolerating this kind of approach.”
“I think that the conservation officer service and the B.C. government are aware they need to change, and certainly the public has been asking for it,” said Fox.
Fox said there’s a lot of optimism about the new partnership, but, as with any government, there will likely be a lot of red tape to get through.
“I think speed is going to be important, whether or not the committee has the ability to make change and make change relatively quickly without having to study an issue to death, ” said Fox.
This report by The Canadian Press was first published Sept. 9, 2024.
