Actinide–lanthanide interaction has led to many fascinating results in the past pertaining to applications in the area of energy, health, and the environment. In this work, we utilized UO2 2+ ion codoping to enhance the luminescent properties of the europium ion in a Li2B4O7 (LTB) host. We could achieve 75% energy transfer efficiency, leading to almost doubling of internal quantum yield (IQY) from ∼34 to 64%. The efficacy of energy transfer from a uranyl to a europium ion and enhancement in europium emission was clearly demonstrated using density functional theory calculations, and it proceeds via formation of a UO2–Eu coordination complex. Because of the different extent of UO2 2+ → Eu3+ energy transfer at different europium ion concentrations, color-tunable emission from green–yellow–near-white could be achieved. The optical enhancement has also been explained by detailed electronic structure analysis of LTB in the presence of Eu and U. Here, we also present the feasibility for sensing uranyl (VI) ions through the exploration of a unique Förster resonance energy transfer process to europium(III) using selective excitation of a near-UV 320 nm photon. This work on the LTB:U6+,Eu3+ luminescent phosphor displays the first example demonstrating UO2 2+ → Eu3+ energy-transfer-induced enhancement in IQY and applying the same for designing color-tunable phosphor and an on–off fluorescent sensor for uranyl (VI) ions.

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The first measurement of the top quark pair ($$ \textrm{t}\overline{\textrm{t}} $$ t t ¯ ) production cross section in proton-proton collisions at $$ \sqrt{s} $$ s = 13.6 TeV is presented. Data recorded with the CMS detector at the CERN LHC in Summer 2022, corresponding to an integrated luminosity of 1.21 fb−1, are analyzed. Events are selected with one or two charged leptons (electrons or muons) and additional jets. A maximum likelihood fit is performed in event categories defined by the number and flavors of the leptons, the number of jets, and the number of jets identified as originating from b quarks. An inclusive $$ \textrm{t}\overline{\textrm{t}} $$ t t ¯ production cross section of 881 ± 23 (stat + syst) ± 20 (lumi) pb is measured, in agreement with the standard model prediction of $$ {924}_{-40}^{+32} $$ 924 − 40 + 32 pb.

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