The LHCb experiment’s forward acceptance offers a unique opportunity to study bulk physics in heavy-ion collisions. Properties of bulk particle production, such as the average transverse momentum of charged particles, are sensitive to both collective phenomena and the initial state of heavy-ion collisions. Bulk physics measurements in small collision systems can reveal the interplay between initial- and final-state effects in heavy-ion collisions, and can provide new insights into the origins of collective phenomena. In this contribution, new bulk physics measurements from the LHCb experiment will be presented.

The forward geometry and precision instrumentation of the LHCb spec- trometer provides unique insights into the production of heavy quarks at the LHC. Heavy quark production in pPb collisions are sensitive to the modification of nuclear parton distribution functions, energy loss in the nucleus, and the hadronization process, among other effects. In this talk, precision measurements of open charm production from a rich set of charmed hadrons in pPb collisions at 5.02 and 8.16 TeV will be presented, including new LHCb measurements of D mesons and Ξc baryons in pp and pPb collisions. Comparisons with theoretical models and related results will be discussed.

Bottomonium production is sensitive to both the structure of nucleons and the interactions of b quarks with the nuclear media produced in heavy-ion collisions. The LHCb detector’s forward geometry allows for studying bottomonium production in a unique kinematic regime. Recent LHCb studies of bottomonium production will be presented, including multiplicity-dependent measurements sensitive to final-state effects and multi-parton interactions in small collision systems.

Jet substructure measurements at the LHC produce precision tests of jet formation and fragmentation in vacuum as well as at the high temperatures and densities formed in heavy-ion collisions. Jets containing a heavy-flavor hadron drive these QCD measurements into a regime where parton mass and colour factors are critical, pushing the limits of theoretical calculations both in-vacuum and in-medium. Mapping out individual emissions in the Lund jet plane for heavy-flavour jets and comparing to light-quark-enriched jets tagged by a Z boson reveals significant mass-dependence to jet fragmentation, offering a decisive channel to decipher in-medium modification to jet fragmentation across different kinematics. At the same time, measuring heavy-flavour jet mass with a theoretically-safe flavour tagging algorithm for the first time tests perturbative QCD at unprecedented theoretical precision and probes the gluon splitting contribution to heavy-flavour production, a yet-unobserved probe of how the medium resolves quark entanglement. The LHCb collaboration presents recent jet substructure results at forward rapidity in collisions at centre-of-mass energy TeV. These measurements are compared to theoretical predictions, providing new insight on QCD fragmentation at forward rapidity and at low and moderate values of jet transverse momentum. These results provide a baseline for future measurements of jet quenching in PbPb collisions.

The innovative fixed-target programme initiated by the LHCb experiment during the LHC Run 2 has been enhanced for Run 3 with the introduction of a dedicated gas injection system, SMOG2. This upgrade features a gas cell to boost fixed-target luminosity and a new system that allows the injection of non-noble gases. SMOG2 enables the collection of large datasets from pA and PbA fixed-target collisions, including high-statistics samples of charm hadrons. Charm production measurements with SMOG2 provide a unique opportunity to deepen our understanding of charm hadronization processes in both small and large collision systems at the same energy scale, while also establishing important benchmarks for charmonium studies. This poster will present open charm production from the first data collected with the SMOG2 system, as well as future prospects for charm measurements in upcoming fixed-target collisions.

The nonperturbative process of hadronization has recently been the subject of intense experimental investigation at the LHC. Since heavy quark production is suppressed at the hadronization scale, heavy-flavour hadrons offer an insightful probe into this effect, connecting perturbative parton-level calculations with experimental final states. Jets produced in conjunction with heavy hadrons offer additional information about hadronic formation at various mass scales and how hadronization depends on the partonic final states. In particular, recent measurements of in-jet quarkonium production suggest significant parton shower production, where gluons split into heavy quark-antiquark pairs. This further complicates the interpretation of charmonium suppression in heavy-ion collisions as evidence of QGP formation. Jet substructure can also be used to probe the formation of exotic hadrons, whose structure is still not well understood. This talk presents recent studies of hadronization using heavy-flavour jets with the LHCb detector, including inclusive hadron production in heavy-flavor jets, as well as quarkonium and tetraquark production in jets. Results are compared to various models of hadronization, providing strong new constraints on theoretical predictions, and offering insight into interpretations of future measurements in PbPb collisions.

Photon-photon and photon-nucleus interactions in ultraperipheral collisions of nuclei lead to the production of a wide range of particle species, which can be observed with relatively low backgrounds. The particle species produced include heavy quark and anti-quark pairs, dileptons, vector mesons such as J/psi, and potentially exotic hadrons. The unique geometry and instrumentation of the LHCb spectrometer, combined with the detector particle identification capabilities, provides unparalleled access to hadrons produced in these interactions, which can be identified and reconstructed at very low transverse momentum. This talk will present new LHCb measurements of the KK mass spectrum produced in ultraperipheral collisions of Pb nuclei, and discuss the detailed structures observed therein.

In preparation to the LHC Run3, the LHCb gaseous fixed-target, SMOG, was upgraded to offer higher instantaneous luminosity by up to two orders of magnitude with respect to Run2, new gases, including non-noble ones such as hydrogen, and an increased experimental accuracy. Since 2022, LHCb is working with two independent collision points and as a collider and a fixed-target experiment simultaneously, a unique opportunity in the scientific panorama. In 2024, samples with larger statistics up to three orders of magnitude with respect to Run2 have been collected, giving access to very accurate measurements of abundant probes and the possibility to explore the rarer ones, such as bottomonia resonances, which is unique at this energy scale. In this contribution, the performance of the system from the 2024 acquired data, the first obtained results and the physics prospects for the incoming years will be presented.

Leveraging on the excellent performance of the LHCb spectrometer and on the flexibility of its online reconstruction, new methods for the identification of deuteron and helium nuclei have been developed at LHCb. These innovative methods, based on LHCb time of flight capabilities and on energy loss discrimination in the LHCb detectors, open a new window of possible measurements at LHCb. A nearly background-free sample of more than helium candidates is identified and used to reconstruct (anti)hypertriton production, while (anti)helium from (anti)Lambda-b decays are also studied. In fixed-target beam-gas collisions, deuterons at low momentum are identified with high precision. In both cases, a rich programme of QCD and astrophysics interest, exemplifying LHCb flexibility in exploring new research fields, is foreseen.

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