Physicists map rare particle collisions to test fundamental theories
Scientists at the CERN laboratory have made precise measurements of how Z bosons interact with heavy quarks in particle collisions, testing predictions from competing physics models. The findings help validate computational tools that underpin searches for new physics and could refine our understanding of matter's basic building blocks.
Originaltitel: Measurements of the production cross-section for a <em>Z</em> boson in association with <em>b</em>- or <em>c</em>-jets in proton-proton collisions at <em>√s</em>=13 TeV with the ATLAS detector
<p>This paper presents a measurement of the production cross-section of a Z boson in association with b- or c-jets, in proton-proton collisions at √s = 13 TeV with the ATLAS experiment at the Large Hadron Collider using data corresponding to an integrated luminosity of 140 fb<sup>-1</sup>. Inclusive and differential cross-sections are measured for events containing a Z boson decaying into electrons or muons and produced in association with at least one <em>b</em>-jet, at least one <em>c</em>-jet, or at least two <em>b</em>-jets with transverse momentum p<sub>T</sub> > 20 GeV and rapidity |y| < 2.5. Predictions from several Monte Carlo generators based on next-to-leading-order matrix elements interfaced with a parton-shower simulation, with different choices of flavour schemes for initial-state partons, are compared with the measured cross-sections. The results are also compared with novel predictions, based on infrared and collinear safe jet flavour dressing algorithms. Selected Z+ ≥ 1 <em>c</em>-jet observables, optimized for sensitivity to intrinsic-charm, are compared with benchmark models with different intrinsic-charm fractions.</p>