The analysis of azimuthal correlations in multiparticle production can be useful to uncover the existence of new physics beyond the Standard Model, e.g., Hidden Valley, in <math><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>−</mo></msup></math> annihilation at high energies. In this paper, based on previous theoretical studies and using the pythia8 event generator, it is found that both azimuthal and rapidity long-range correlations are enhanced due to the presence of a new stage of matter on top of the QCD partonic cascade. Ridge structures, similar to those observed in hadronic collisions at the LHC, show up providing a possible signature of new physics at future <math><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>−</mo></msup></math> colliders.

France

Redamy Pérez-Ramos

Spain

Miguel-Angel Sanchis-Lozano

CERN

United States

Edward K. Sarkisyan-Grinbaum

Searching for hidden matter with long-range angular correlations at <math><mrow><msup><mrow><mi>e</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>e</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow></math> colliders

The moments of the single inclusive momentum distribution of hadrons in QCD jets, are studied in the next-to-modified-leading-log approximation (NMLLA) including next-to-leading-order (NLO) corrections to the α s strong coupling. The evolution equations are solved using a distorted Gaussian parametrisation, which successfully reproduces the spectrum of charged hadrons of jets measured in e + e − collisions. The energy dependencies of the maximum peak, multiplicity, width, kurtosis and skewness of the jet hadron distribution are computed analytically. Comparisons of all the existing jet data measured in e + e − collisions in the range s ≈ 2 − 200 $$ \sqrt{\mathrm{s}}\approx 2-200 $$ GeV to the NMLLA + NLO * predictions allow one to extract a value of the QCD parameter Λ QCD , and associated two-loop coupling constant at the Z resonance α s (m Z 2 ) = 0.1195 ± 0.0022, in excellent numerical agreement with the current world average obtained using other methods.

Finland

David d’Enterria

Energy evolution of the moments of the hadron distribution in QCD jets including NNLL resummation and NLO running-coupling corrections