Tiny Particle Collisions Behave the Same Way in Two Different Systems
Physicists at CERN discovered that high-energy particles behave identically whether they're produced in proton-lead or lead-lead collisions—a finding that challenges existing models of how matter behaves under extreme conditions. The result could reshape understanding of fundamental physics and has implications for materials science and energy research.
Originaltitel: Evidence for Similar Collectivity of High Transverse-Momentum Particles in 𝑝-Pb and Pb-Pb Collisions
<p>Charged hadron elliptic anisotropies (𝑣2) are presented over a wide transverse momentum (𝑝T) range for proton-lead (𝑝Pb) and lead-lead (PbPb) collisions at nucleon-nucleon center-of-mass energies of 8.16 and 5.02 TeV, respectively. The data were recorded by the CMS experiment and correspond to integrated luminosities of 186 and 0.607 nb<sup>−1</sup> for the 𝑝Pb and PbPb systems, respectively. A four-particle cumulant analysis is performed using subevents separated in pseudorapidity to effectively suppress noncollective effects. At high 𝑝T (𝑝T>8 GeV), significant positive 𝑣<sub>2</sub> values that are similar between 𝑝Pb and PbPb collisions at comparable charged particle multiplicities are observed. This observation suggests a common origin for the multiparticle collectivity for high-𝑝T particles in the two systems.</p>