Sep 15, 2026 04:56 PM
(This post was last modified: Sep 15, 2026 05:56 PM by C C.)
https://www.sciencealert.com/cern-detect...iggs-boson
EXCERPTS: Scientists have been producing and measuring entangled particles such as atoms and photons for decades, more recently hoping to exploit them for quantum communications and quantum computing. In 2024, the ATLAS Collaboration reported the first observation of quantum entanglement between pairs of top quarks produced at the LHC.
Z bosons do things a little differently. Unlike top quarks, which have two possible spin states, Z bosons have three – a distinction that, in the language of quantum information, makes a Z boson a qutrit, rather than a two-state qubit.
"And that makes another important difference, because this is the first time entanglement has been measured with elementary particles that are qutrits," Aguilar-Saavedra explained.
[...] There's a catch, though. A Higgs boson has a mass of around 125 GeV, while a Z boson weighs in at around 91 GeV. There simply isn't enough energy available for the Higgs to produce two ordinary Z bosons at once. So at least one of them has to be virtual.
Virtual particles are strange even by quantum-physics standards. They emerge fleetingly during collider interactions, but can't be observed as free particles in the way their "real" counterparts can. That raises an intriguing question: if one of the Z bosons in the pair is virtual, can it still participate in something as fundamentally quantum as entanglement? The new result suggests that it can.
[...] But the experiment also raises another, more intriguing question about the virtual Z itself. Physicists don't entirely agree on what it means to say a virtual particle "exists". Unlike ordinary particles, virtual particles can't be directly observed; some physicists regard them primarily as mathematical ingredients used to describe interactions.
Yet here, a virtual Z appears to behave in a strikingly particle-like way – it carries spin information that can become entangled with another Z. "One can ask: do virtual particles exist, or are they a construct of our minds that we use to calculate things?" Aguilar-Saavedra said.
He cautioned that the result doesn't settle that philosophical question, but said it could "shed a little light on whether virtual particles are particles or not."
"If it walks like a duck and quacks like a duck, then what we're looking at must be a duck," he said. "In this case, a virtual duck." The results have been published in Physical Review Letters...... (MORE - missing details)
RELATED (eurekalert): Oxford physicists help uncover ‘spooky’ quantum effect in the Large Hadron Collider
EXCERPTS: Scientists have been producing and measuring entangled particles such as atoms and photons for decades, more recently hoping to exploit them for quantum communications and quantum computing. In 2024, the ATLAS Collaboration reported the first observation of quantum entanglement between pairs of top quarks produced at the LHC.
Z bosons do things a little differently. Unlike top quarks, which have two possible spin states, Z bosons have three – a distinction that, in the language of quantum information, makes a Z boson a qutrit, rather than a two-state qubit.
"And that makes another important difference, because this is the first time entanglement has been measured with elementary particles that are qutrits," Aguilar-Saavedra explained.
[...] There's a catch, though. A Higgs boson has a mass of around 125 GeV, while a Z boson weighs in at around 91 GeV. There simply isn't enough energy available for the Higgs to produce two ordinary Z bosons at once. So at least one of them has to be virtual.
Virtual particles are strange even by quantum-physics standards. They emerge fleetingly during collider interactions, but can't be observed as free particles in the way their "real" counterparts can. That raises an intriguing question: if one of the Z bosons in the pair is virtual, can it still participate in something as fundamentally quantum as entanglement? The new result suggests that it can.
[...] But the experiment also raises another, more intriguing question about the virtual Z itself. Physicists don't entirely agree on what it means to say a virtual particle "exists". Unlike ordinary particles, virtual particles can't be directly observed; some physicists regard them primarily as mathematical ingredients used to describe interactions.
Yet here, a virtual Z appears to behave in a strikingly particle-like way – it carries spin information that can become entangled with another Z. "One can ask: do virtual particles exist, or are they a construct of our minds that we use to calculate things?" Aguilar-Saavedra said.
He cautioned that the result doesn't settle that philosophical question, but said it could "shed a little light on whether virtual particles are particles or not."
"If it walks like a duck and quacks like a duck, then what we're looking at must be a duck," he said. "In this case, a virtual duck." The results have been published in Physical Review Letters...... (MORE - missing details)
RELATED (eurekalert): Oxford physicists help uncover ‘spooky’ quantum effect in the Large Hadron Collider