STAR sees a magnetic imprint on deconfined nuclear matter

Data from heavy ion collisions give new insight into the electromagnetic properties of quark-gluon plasma “deconfined” from protons and neutrons

2024-05-17

(Press-News.org) The Science Scientists have the first direct evidence that the powerful magnetic fields created in off-center collisions of atomic nuclei induce an electric current in “deconfined” nuclear matter. This is a plasma “soup” of quarks and gluons that have been set free, or “deconfined,” from nuclear matter—protons and neutrons—in the particle collisions. The magnetic fields in deconfined nuclear matter are a billion times stronger than a typical refrigerator magnet, but their effects can be hard to detect. This new study’s evidence is from measuring the way particles with an electric charge are deflected when they emerge from the collisions. The study provides proof that the powerful magnetic fields exist. It also offers a new way to measure the electrical conductivity in the quark-gluon plasma (QGP).

The Impact Scientists can infer the value of the QGP’s electrical conductivity from how much the electromagnetic field deflects charged particles such as electrons, quarks, and protons. The stronger a particular type of deflection is, the stronger the conductivity. Conductivity is an important property of matter, but scientists have not been able to measure it in QGP before. Understanding the electromagnetic properties of the QGP may help physicists unravel the mysteries of the phase transition between QGP and ordinary nuclear matter made of protons and neutrons. The work will also aid in explorations of other magnetic effects in the QGP.

Summary Off-center collisions of atomic nuclei at the Relativistic Heavy Ion Collider (RHIC), a Department of Energy particle accelerator user facility at Brookhaven National Laboratory, should generate powerful magnetic fields. That’s because some of the non-colliding positively charged protons are set swirling as the nuclei sideswipe one another at close to the speed of light. The fields are expected to be stronger than those of neutrons stars and much more powerful than Earth’s. But measuring magnetic fields in the QGP is challenging because this deconfined nuclear matter doesn’t last very long. So, instead, scientists measure the QGP’s properties indirectly, for example by using RHIC’s STAR detector to track the impact of the magnetic field on charged particles streaming from the collisions.

The STAR physicists saw a pattern of charged-particle deflection that could only be caused by an electromagnetic field and current induced in the QGP. This was clear evidence that the magnetic fields exist. The degree of deflection is directly related to the strength of the induced current. Scientists will now use this method to measure the conductivity of the QGP. That, in turn, may help them unravel mysteries of the phase transition between deconfined quarks and gluons and composite particles such as protons and neutrons.

Funding This research was funded by the Department of Energy Office of Science, the National Science Foundation, and a range of international organizations and agencies listed in the scientific paper. The STAR team used computing resources at the Scientific Data and Computing Center at Brookhaven National Laboratory, the National Energy Research Scientific Computing Center (NERSC) at Lawrence Berkeley National Laboratory, and the Open Science Grid consortium.

END

[Attachments] See images for this press release:

ELSE PRESS RELEASES FROM THIS DATE:

CU faculty member receives prestigious award for health equity work

2024-05-17

In recognition of her exceptional work in advancing health equity, the Society of General Internal Medicine (SGIM) bestowed its 2024 Herbert W. Nickens Award to Rita Lee, MD, a University of Colorado Department of Medicine faculty member, at a May 17 meeting in Boston. “The committee has chosen to honor you as an exemplary SGIM member who has made prioritizing minority health and diversity the primary focus of your career,” Alana Biggers, MD, MPH, the chair of the award selection committee, said in a congratulatory letter to Lee. The ...

Better medical record-keeping needed to fight antibiotic overuse, studies suggest

2024-05-17

A lack of detailed record-keeping in clinics and emergency departments may be getting in the way of reducing the inappropriate use of antibiotics, a pair of new studies by a pair of University of Michigan physicians and their colleagues suggests. In one of the studies, about 10% of children and 35% of adults who got an antibiotic prescription during an office visit had no specific reason for the antibiotic in their record. The rate of this type of prescribing is especially high in adults treated seen in emergency departments and in adults seen in clinics who have Medicaid coverage or no insurance, the ...

Clinicians report success with first test of drug in a patient with life-threatening blood clotting disorder

2024-05-17

Key Takeaways Immune thrombotic thrombocytopenic purpura, a rare blood clotting disorder, results from an autoimmune attack against an enzyme called ADAMTS13 A recombinant form of human ADAMTS13 approved for a different condition helped to save the life of a young mother with immune thrombotic thrombocytopenic purpura Results from this first use of the drug for this condition—by a team led by researchers from Massachusetts General Hospital—warrants testing the drug in a clinical trial A team led by investigators from Massachusetts General Hospital, a founding member of the Mass General Brigham healthcare system, used a new drug to save the life of a patient ...

NIH study shows chronic wasting disease unlikely to move from animals to people

2024-05-17

WHAT: A new study of prion diseases, using a human cerebral organoid model, suggests there is a substantial species barrier preventing transmission of chronic wasting disease (CWD) from cervids—deer, elk and moose—to people. The findings, from National Institutes of Health scientists and published in Emerging Infectious Diseases, are consistent with decades of similar research in animal models at the NIH’s National Institute of Allergy and Infectious Diseases (NIAID). Prion diseases are degenerative diseases found in some mammals. These diseases primarily involve deterioration of the brain but also can affect the eyes and other organs. ...

Scientists discover mechanism of sugar signaling in plants

2024-05-17

UPTON, N.Y. — Proteins are molecular machines, with flexible pieces and moving parts. Understanding how these parts move helps scientists unravel the function a protein plays in living things — and potentially how to change its effects. Biochemists at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory and colleagues at DOE’s Pacific Northwest National Laboratory (PNNL) have just published a new example of how one such molecular machine works. Their paper in the journal Science Advances describes how the moving parts of ...

Cleveland Clinic research finds VISTA directly blocks T-cells from functioning in immunotherapy

2024-05-17

A Cleveland Clinic-led team of scientists and physicians have discovered that the immune checkpoint protein VISTA can directly turn off tumor-fighting T-cells during immunotherapy and resist treatment. The study, published in Science Immunology, explains that VISTA can bind to a protein called LRIG1 in T cells, which was previously only thought to promote bone and fat development. When VISTA binds to LRIG1, the researchers found, LRIG1 sends signals that suppress T cell replication, survival ...

Pagan-Christian trade networks supplied horses from overseas for the last horse sacrifices in Europe

2024-05-17

Horses crossed the Baltic Sea in ships during the Late Viking Age and were sacrificed for funeral rituals, according to research from Cardiff University. Published in the journal Science Advances, studies on the remains of horses found at ancient burial sites in Russia and Lithuania show that they were brought overseas from Scandinavia utilising expansive trade networks connecting the Viking world with the Byzantine and Arab Empires. Up to now, researchers had believed sacrificial horses were always locally-sourced stallions. ...

University of Bristol researchers develop world’s smallest quantum light detector on a silicon chip

2024-05-17

Researchers at the University of Bristol have made an important breakthrough in scaling quantum technology by integrating the world’s tiniest quantum light detector onto a silicon chip. A critical moment in unlocking the information age was when scientists and engineers were first able to miniaturise transistors onto cheap micro-chips in the 1960s. Now, for the first time, University of Bristol academics have demonstrated the integration of a quantum light detector – smaller than a human hair – onto a silicon chip, moving us one step closer to the age of quantum technologies using light. Making high performance electronics ...

Gut bacteria boost immune response to fight tumors

2024-05-17

Roughly one in five cancer patients benefits from immunotherapy – a treatment that harnesses the immune system to fight cancer. Such an approach to beating cancer has seen significant success in lung cancer and melanoma, among others. Optimistic about its potential, researchers are exploring strategies to improve immunotherapy for cancers that don’t respond well to the treatment, with the hope of benefiting more patients. Now, researchers at Washington University School of Medicine in St. Louis have found, in ...

How heatwaves are affecting Arctic phytoplankton

2024-05-17

The basis of the marine food web in the Arctic, the phytoplankton, responds to heatwaves much differently than to constantly elevated temperatures. This has been found by the first targeted experiments on the topic, which were recently conducted at the Alfred Wegener Institute’s AWIPEV Station. The phytoplankton’s behaviour primarily depends on the cooling phases after or between heatwaves, as shown in a study just released in the journal Science Advances. Heatwaves, which we’ve increasingly seen around the globe in recent years, are also becoming more and ...