D→f energy transfer in heteronuclear Ir(III)/Ln(III) near-infrared luminescent complexes

A series of d/f dinuclear complexes Ir•Ln [where Ln = Eu(III), Gd(III), Yb(III) and Nd(III)] are reported. The core structure consists of a rigid skeleton containing two different types of receptor site in a single molecular motif designed to combine a transition metal ion [Ir(III)] and a lanthanide ion [Ln(III)] in different binding sites at either end of fully conjugated bridge to facilitate d→f energy-transfer following photoexcitation of the Ir(III)-based antenna unit. Steady state and time-resolved photophysical experiments on these compounds revealed that the energy-transfer is feasible only in case of Ir•Yb and Ir•Nd systems, affording sensitized emission from the Yb(III) or Nd(III) centres. Such EnT is not possible in the Ir•Eu dyad as the excited state energy of the Ir(III) unit is insufficient to sensitise the excited state of the Eu(III) centre

Software performance of the ATLAS track reconstruction for LHC run 3

Charged particle reconstruction in the presence of many simultaneous proton–proton (pp) collisions in the LHC is a challenging task for the ATLAS experiment’s reconstruction software due to the combinatorial complexity. This paper describes the major changes made to adapt the software to reconstruct high-activity collisions with an average of 50 or more simultaneous pp interactions per bunch crossing (pileup) promptly using the available computing resources. The performance of the key components of the track reconstruction chain and its dependence on pile-up are evaluated, and the improvement achieved compared to the previous software version is quantified. For events with an average of 60 pp collisions per bunch crossing, the updated track reconstruction is twice as fast as the previous version, without significant reduction in reconstruction efficiency and while reducing the rate of combinatorial fake tracks by more than a factor two