Charged Λc production in pp collisions at √s = 13 TeV as a function of multiplicity.
Summary
The quark gluon plasma (QGP) is a deconfined state of matter that is created during collisions between heavy ions. It was thought that the QGP can only be created in these heavy ion collisions but recent studies show that the results of pp-collisions show some of the same characteristics. One of these characteristics to test for the creation of a QGP is the production of heavy charm particles, in this case $\Lambda_c^+$. A recent trend in physics is to look at observables as a function of multiplicity. In this analysis data obtained from the ALICE detector from pp collisions at $\sqrt{s}=13 \text{ TeV}$ is used and we look at $\Lambda_c^+$ production as a function of multiplicity. To enhance the signal a machine learning technique, Multivariate Analysis, is used. The results will be compared to results from Monte Carlo simulations.\\
The results between two different decay channels show a systematic deviation which is $p_T$ dependent. When comparing the low multiplicity results with the minimum bias results a downward $p_T$ dependent trend was found. None of the tunes used for the simulations correctly describe the results of our analysis. In all cases the $\Lambda_c^+$ production was severely underestimated. Looking at the simulations themselves the difference between different tunes, colour reconnection turned on and off, is smaller than expected based on previous research. For both the measurements and the simulations there is a high statistical uncertainty that stops us from drawing conclusions about whether or not there are similar characteristics as in heavy ion collisions.