The production of $\pi^{ \pm}$, $\rm{ K}^{ \pm}$, $\rm{ K}^{ 0}_{ S}$, $\rm{ K}^{ *}(892)^{ 0}$, $\rm{ p}$, $\phi(1020)$, $\Lambda$, $\Xi^{ -}$, $\Omega^{ -}$, and their antiparticles was measured in inelastic proton-proton (pp) collisions at a center-of-mass energy of $\sqrt{ s}$ = 13 TeV at midrapidity ($|y|<0.5$) as a function of transverse momentum ($p_{ \rm{ T}}$) using the ALICE detector at the CERN LHC. Furthermore, the single-particle $p_{ \rm{ T}}$ distributions of $\rm{ K}^{ 0}_{ S}$, $\Lambda$, and $\overline{ \Lambda}$ in inelastic pp collisions at $\sqrt{ s}$ = 7 TeV are reported here for the first time. The $p_{ \rm{ T}}$ distributions are studied at midrapidity within the transverse momentum range $0\leq p_{ \rm{ T}}\leq20$ GeV/$c$, depending on the particle species. The $p_{ \rm{ T}}$ spectra, integrated yields, and particle yield ratios are discussed as a function of collision energy and compared with measurements at lower $\sqrt{ s}$ and with results from various general-purpose QCD-inspired Monte Carlo models. A hardening of the spectra at high $p_{ \rm{ T}}$ with increasing collision energy is observed, which is similar for all particle species under study. The transverse mass and $x_{ \rm{ T}}\equiv2p_{ \rm{ T}}/\sqrt{ s}$ scaling properties of hadron production are also studied. As the collision energy increases from $\sqrt{ s}$ = 7 to 13 TeV, the yields of non- and single-strange hadrons normalized to the pion yields remain approximately constant as a function of $\sqrt{ s}$, while ratios for multi-strange hadrons indicate enhancements. The $p_{ \rm{ T}}$-differential cross sections of $\pi^{ \pm}$, $\rm{ K}^{ \pm}$ and $\rm{ p}$ ($\overline{ \rm{ p}}$) are compared with next-to-leading order perturbative QCD calculations, which are found to overestimate the cross sections for $\pi^{ \pm}$ and $\rm{ p}$ ($\overline{ \rm{ p}}$) at high $p_{ \rm{ T}}$.
Categories: nucl-ex hep-ex