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A multigene phylogenetic assessment of North American species of Mallocybe is presented based on analyses of rpb1, rpb2, ITS, and 28S rDNA nucleotide data. This framework enables a systematic revision of the genus for 16 eastern North American species and captures taxonomic and phylogenetic diversity in a global context. A grade of two unusual and poorly known North American species stems from the most recent common ancestor of the genus that gives rise to three core subgroups named here as clades Unicolores, Nothosperma, and Mallocybe. The grade of taxa includes the poorly known Lepista praevillosa from Florida and a new species from the southern Appalachians, M. montana, both of which appear to be narrow-range endemics. Clade Nothosperma is characterized by Australian and New Zealand species, whereas clade Unicolores is composed of six species from eastern North America and East Asia. Clade Mallocybe is dominated by numerous north temperate taxa and constitutes the sister group to clade Nothosperma. These major clades are distinguished by a combination of phylogeny, morphology, geographic distribution, and ecology. In addition, four North American species are described as new: M. leucothrix, M. luteobasis, M. montana, and M. tomentella. Several names originating in North America, long ignored or misunderstood in the literature, are revitalized and established by type comparisons and modern reference material collected from or near type localities. In addition, 11 species were subjected to mass spectrometry muscarine assays, none of which contained detectable amounts of muscarine except for two: M. sabulosa and M. praevillosa. This confirms a diffuse phylogenetic distribution of muscarine within the genus. Taxonomic descriptions are presented for 16 species, several synonymies proposed, and four new combinations made. A key to species of eastern North American Mallocybe is presented, along with illustrations of important diagnostic features. 

A<sc>bstract</sc> The yields of prompt and non-prompt J/ψand the fraction of non-prompt J/ψare measured at midrapidity (|y| < 0.9) via the dielectron decay channel as a function of the midrapidity charged-particle multiplicity (|η| < 0.9) in pp collisions at$$\sqrt{s}=13$$TeV. The J/ψyields and the multiplicity are normalized by their average value in inelastic collisions. The multiplicity-dependent yield ratio between prompt J/ψand D⁰is reported. The multiplicity is further divided into three azimuthal regions with respect to the J/ψmomentum: toward the J/ψemission direction, transverse, or opposite to it. A stronger-than-linear increase of the self-normalized yields is observed for both prompt and non-prompt J/ψproduction, with similar trends. This behaviour is also observed in the toward region, while a weaker increase is observed in the transverse and away regions. 

Abstract Two-particle angular correlations probe particle production mechanisms and the underlying event-wide phenomena present in hadronic collisions. The correlations are examined as a function of rapidity and azimuthal-angle differences ($$\Delta y, \Delta \varphi $$ $\Delta y,\Delta \phi$) for pairs of like- and unlike-sign pions, kaons, and (anti-)protons produced in pp collisions at$$\sqrt{s}$$ $\sqrt{s}$= 13 TeV, measured by the ALICE experiment. Two-particle correlation functions are provided together with$$\Delta y$$ $\Delta y$and$$\Delta \varphi $$ $\Delta \phi$projections and compared to Monte Carlo (MC) model predictions. For the first time, the measurement is performed as a function of the event’s charged-particle density. Previous studies conducted for pp collisions at$$\sqrt{s}$$ $\sqrt{s}$= 7 TeV at ALICE revealed a near-side anticorrelation for baryon–baryon and antibaryon–antibaryon pairs, whose origin remains unresolved. Here, an additional approach is introduced to study the multiplicity dependence and the expected inverse multiplicity scaling of the correlation function. This method highlights qualitative differences in the underlying sources of correlations, such as quantum-statistics effects, final-state interactions, and resonance decays. The puzzling near-side anticorrelation in baryon baryon measurements is observed across all multiplicity classes and continues to challenge current particle-production models. Furthermore, the multiplicity dependence of the correlations between mesons provides an independent probe of the sensitivity of current MC models to soft-QCD effects and hadronization dynamics. The presented measurements, together with the baryon results, enrich the experimental picture of two-particle correlations in pp collisions and serve as valuable input for ongoing theoretical developments. 

A<sc>bstract</sc> Measurements of transverse momentum (p_T) and pseudorapidity (η) dependent flow vector fluctuations in p–Pb collisions at$$\sqrt{{s}_{NN}}=5.02$$TeV at the CERN Large Hadron Collider are presented. By studying long-range two-particle correlations with a template fit method, potential biases from non-flow effects such as jets and resonance decays are effectively suppressed. Significantp_T- andη-dependent fluctuations of the second-harmonic flow vector are observed with more than 5σconfidence in p–Pb collisions, similar to the observations in Pb–Pb collisions. The influence of residual non-flow effects has been evaluated and cannot account for the observed fluctuations, thereby confirming the observation of flow vector fluctuations in small collision systems at the LHC. Comparisons to model calculations from 3DGlauber+MUSIC+UrQMD and the parton transport model from AMPT are also presented. The measurements provide constraints on the theoretical modelling of the three-dimensional initial geometry and its event-by-event fluctuations, offering critical insights into the origin of collective flow in small collision systems at the LHC. 

A<sc>bstract</sc> The probability to observe a specific number of strange and multi-strange hadrons (n_S), denoted as P(n_S), is measured by ALICE at midrapidity (|y|<0.5) in$$\sqrt{s}=5.02$$TeV proton-proton (pp) collisions, dividing events into several multiplicity-density classes. Exploiting, for the first time, a technique based on counting the number of strange-particle candidates event-by-event, this measurement allows one to extend the study of strangeness production beyond the mean of the distribution. This constitutes a new test bench for production mechanisms, probing events with a large imbalance between strange and non-strange content. The analysis of a large-statistics data sample makes it possible to extract P(n_S) up to a maximumn_Sof 7 for$${\text{K}}_{\text{S}}^{0}$$, 5 for Λ and$$\overline{\Lambda }$$, 4 for Ξ⁻and$${\overline{\Xi } }^{+}$$, and 2 for Ω⁻and$${\overline{\Omega } }^{+}$$. From this, the probability of producing strange hadron multiplets per event is calculated, thereby enabling the extension of the study of strangeness enhancement to extreme situations where several strange quarks hadronize in a single event at midrapidity. Moreover, comparing hadron combinations with differentuanddquark compositions and equal overallsquark content, the contribution to the enhancement pattern coming from non-strangeness related mechanisms is isolated. The results are compared with state-of-the-art phenomenological models implemented in commonly used Monte Carlo event generators, including PYTHIA 8 Monash 2013, PYTHIA 8 with QCD-based Color Reconnection and Rope Hadronization (QCD-CR + Ropes), and EPOS LHC, which incorporates both partonic interactions and hydrodynamic evolution. These comparisons show that the new approach dramatically enhances the sensitivity to the different underlying physics mechanisms modeled by each generator. 

Abstract The azimuthal-correlation distributions between electrons from the decays of heavy-flavor hadrons and associated charged particles in Pb–Pb collisions at$$\sqrt{s_{\textrm{NN}}} = 5.02$$ $\sqrt{s_{\text{NN}}}=5.02$TeV are reported for the 0–10% and 30–50% centrality classes. This measurement provides access to the jet-like correlation observables in the heavy-flavor sector in Pb–Pb collisions. The analysis is performed for trigger electrons from heavy-flavor hadron decays with transverse momentum$$4< p_\textrm{T}^\textrm{e} < 16~\textrm{GeV}/c$$ $4<p_{\text{T}}^{\text{e}}<16\text{GeV}/c$, considering associated particles within the transverse-momentum range$$1< p_\textrm{T}^\textrm{assoc} < 7$$ $1<p_{\text{T}}^{\text{assoc}}<7$$$\textrm{GeV}/c$$ $\text{GeV}/c$, and a pseudorapidity difference of$$|\Delta \eta |<1$$ $\left|\Delta \eta \right|<1$between the trigger electron and associated particles. The per-trigger nuclear modification factor ($$I_\textrm{AA}$$ $I_{\text{AA}}$) is calculated to compare the near- and away-side peak yields to those in pp collisions at$$\sqrt{s} = 5.02$$ $\sqrt{s}=5.02$TeV. In 0–10% central collisions, the$$I_\textrm{AA}$$ $I_{\text{AA}}$indicates a hint of enhancement of associated-particle yields with$$p_\textrm{T}<3$$ $p_{\text{T}}<3$GeV/con the near side, and a suppression of yields with$$p_\textrm{T}>4$$ $p_{\text{T}}>4$GeV/con the away side. The$$I_\textrm{AA}$$ $I_{\text{AA}}$for electron triggers from heavy-flavor hadron decays is compared with that for light-flavor and strange-particle triggers to investigate the dependence on different fragmentation processes and parton-medium dynamics, and is found to be the same within uncertainties.