Motivated by the success of the flavour physics programme carried out over the last decade at the Large Hadron Collider (LHC), we characterize in detail the physics potential of its High-Luminosity and High-Energy upgrades in this domain of physics. We document the extraordinary breadth of the HL/HE-LHC programme enabled by a putative Upgrade II of the dedicated flavour physics experiment LHCb and the evolution of the established flavour physics role of the ATLAS and CMS general purpose experiments. We connect the dedicated flavour physics programme to studies of the top quark, Higgs boson, and direct high-$p_T$ searches for new particles and force carriers. We discuss the complementarity of their discovery potential for physics beyond the Standard Model, affirming the necessity to fully exploit the LHC's flavour physics potential throughout its upgrade eras.

The first measurement of the Z boson production cross-section at centre-of-mass energy s = 5.02 TeV in the forward region is reported, using pp collision data collected by the LHCb experiment in year 2017, corresponding to an integrated luminosity of 100 ± 2 pb−1. The production cross-section is measured for final-state muons in the pseudorapidity range 2.0 < η < 4.5 with transverse momentum pT> 20 GeV/c. The integrated cross-section is determined to be (Formula presented.) for the di-muon invariant mass in the range 60 < Mμμ< 120 GeV/c2. This result and the differential cross-section results are in good agreement with theoretical predictions at next-to-next-to-leading order in the strong coupling constant. Based on a previous LHCb measurement of the Z boson production cross-section in pPb collisions at sNN = 5.02 TeV, the nuclear modification factor RpPb is measured for the first time at this energy. The measured values are 1.2−0.3+0.5 (stat) ± 0.1(syst) in the forward region (1.53

The production of prompt D + and Ds+ mesons is studied in proton-lead collisions at a centre-of-mass energy of sNN = 5.02 TeV. The data sample corresponding to an integrated luminosity of (1.58 ± 0.02)nb −1 is collected by the LHCb experiment at the LHC. The differential production cross-sections are measured using D + and Ds+ candidates with transverse momentum in the range of 0 < p T < 14 GeV/c and rapidities in the ranges of 1.5 < y ∗ < 4.0 and –5.0 < y ∗ < –2.5 in the nucleon-nucleon centre-of-mass system. For both particles, the nuclear modification factor and the forward-backward production ratio are determined. These results are compared with theoretical models that include initial-state nuclear effects. In addition, measurements of the cross-section ratios between D +, Ds+ and D 0 mesons are presented, providing a baseline for studying the charm hadronization in lead-lead collisions at LHC energies. [Figure not available: see fulltext.].

A model-independent study of CP violation in B0→DK∗0 decays is presented using data corresponding to an integrated luminosity of 9\,fb-1 collected by the LHCb experiment at centre-of-mass energies of s=7,8 and 13\,TeV. The CKM angle γ is determined by examining the distributions of signal decays in phase-space bins of the self-conjugate D→KS0h+h- decays, where h=π,K. Observables related to CP violation are measured and the angle γ is determined to be γ=(49-19+22)∘. Measurements of the amplitude ratio and strong-phase difference between the favoured and suppressed B0 decays are also presented.