In this work, we propose a methodology to quantify the production of softened hadrons in pp, pA, and AA collisions at LHC energies, as well as their contribution to the $p_T$ spectrum, effective temperature, and mean $p_T$. Within the color string fragmentation framework, we describe the charged particle production through the Tricomi function, resulting from the convolution of the Schwinger mechanism with $q$-Gaussian string tension fluctuations. In particular, the Tricomi function accurately describes the entire $p_T$ spectrum of experimental data from minimum bias and low multiplicity events in pp collisions, as well as peripheral events in AA collisions. This suggests that the fragmentation of color strings is the baseline for particle production. However, by analyzing the experimental $p_T$ spectrum for the most energetic, highest multiplicities, and central AA collisions, the Tricomi function deviates from the data in an intermediate $p_T$ region. This implies that mechanisms beyond color string fragmentation, such as color reconnection, parton recombination, energy loss, and jet quenching, among other collective effects, contribute to the enhancement of particle production at intermediate $p_T$ values. Consequently, the experimental $p_T$ spectrum originates from the combination of color string fragmentation and collective effects.

diana.rosales.herrera@cern.ch

Diana Rosales Herrera