Measurement of Event-By-Event Transverse Momentum and Multiplicity Fluctuations Using Strongly Intensive Measures Delta[P-T, N] and Sigma[P-T, N] in Nucleus-Nucleus Collisions at the Cern Super Proton Synchrotron

Results from the NA49 experiment at the CERN Super Proton Synchrotron (SPS) are presented on event-by-event transverse momentum and multiplicity fluctuations of charged particles, produced at forward rapidities in central Pb + Pb interactions at beam momenta 20A, 30A, 40A, 80A, and 158A GeV/c, as well as in systems of different sizes (p + p, C + C, Si + Si, and Pb Pb) at 158A GeV/c. This publication extends the previous NA49 measurements of the strongly intensive measure Phi(PT) by a study of the recently proposed strongly intensive measures of fluctuations Delta [P-T, N] and Sigma[P-T, N]. In the explored kinematic region transverse momentum and multiplicity fluctuations show no significant energy dependence in the SPS energy range. However, a remarkable system size dependence is observed for both Delta[P-T,N] and Sigma[P-T, N], with the largest values measured in peripheral Pb + Pb interactions. The results are compared with NA61/SHINE (SPS Heavy Ion and Neutrino Experiment) measurements in p + p collisions, as well as with predictions of The Ultrarelativistic Quantum Molecular Dynamics and EPOS models.