Analysis: Science & Technology — 03 November 2026
LHC finds quark-gluon plasma in oxygen and neon collisions
All four major Large Hadron Collider experiments—ALICE, ATLAS, CMS and LHCb—have now reported signs that quark-gluon plasma can form when oxygen and neon nuclei collide. The results, released a year after the LHC’s first oxygen runs, include jet energy imbalance, suppressed high-energy particle yields, and differential suppression of bound heavy-quark states. The plasma is the deconfined state of quarks and gluons thought to have filled the universe in the first millionths of a second after the Big Bang, at temperatures more than 100,000 times hotter than the Sun’s core.
For decades, experimenters treated lead–lead collisions as the practical route to that state, because only the largest nuclei seemed able to produce enough volume and energy density. Hints had already appeared in proton–proton, proton–lead and oxygen–oxygen data. The new oxygen and neon analyses add parton energy loss that grows with collision centrality, stronger suppression in neon than in oxygen, and baryon-versus-meson anisotropic flow of the kind expected if quarks inherit collective motion from a small plasma droplet.
The open question is whether these signatures prove a true quark-gluon liquid or can be reproduced by other dense-matter effects. Reduced particle production alone is not unique to energy loss; ALICE’s pion comparison between oxygen–oxygen and proton–oxygen collisions is the cleanest current check. The High-Luminosity LHC upgrade will increase statistics, but it will not by itself settle how small a system can still thermalize.
Sources: ScienceDaily; CERN.
Near-maximal spin may open a window for black holes to split
A theoretical study in Physical Review D, “When Black Holes Admit Pair-of-pants Topologies,” argues that the usual thermodynamic ban on black-hole fission is not absolute. For a non-rotating hole, splitting would lower total entropy and is therefore forbidden. The authors—Francesco Sannino and colleagues at the University of Southern Denmark, Naples and CNRS—find that extreme spin can reverse that entropy balance, at least on paper.
Even then, the two daughter holes must recede far enough not to fall back together. Once that kinematic requirement is imposed, the allowed window shrinks to objects rotating close to the maximum rate. In extra-dimension models, fragmentation can become thermodynamically favored, especially if one fragment is much smaller than the other. The spacetime history of such a split would look like a pair of trousers: one horizon branching into two.
No observation exists. The authors give no single probability, because the rate depends on gravity beyond Einstein’s theory. They expect primordial micro-holes, if any exist, to be more susceptible than stellar-mass objects, and they point to Fermi-LAT gamma-ray searches for tiny fragments as a possible indirect test.
Sources: ScienceDaily; Physical Review D; University of Southern Denmark.
Topological insulator Josephson junctions match Fu-Kane Andreev states
University of Cologne physicists have used tunneling spectroscopy on a topological-insulator Josephson junction and found highly transmissive Andreev states that track the Fu–Kane 2008 model. The device joins two superconductors across a topological insulator, whose interior is insulating while its surface conducts. Theory predicts that this geometry can host topological superconductivity and, potentially, Majorana modes of interest for error-resistant qubits.
The Andreev states persisted across a range of charge-carrier densities, as expected for surface electrons, and concentrated in specific regions of the junction under magnetic field, matching RWTH Aachen simulations. The result is experimental support for how conventional superconductivity couples to topological surface states, not a working topological qubit.
The decisive signature—an energy gap that closes and reopens, marking a topological transition—has not been seen. The Cologne group says that step needs better energy and time resolution.
Sources: Phys.org; Science Advances; University of Cologne.