Abstract: The spectroscopic studies of very neutron-rich nucleus 128Ag have been performed for the first time at the Radioactive Isotope Beam Factory of RIKEN. A new seniority isomer with a half-life of 1.60(7) μs has been identified and is proposed to have a spin-parity of 16-with a maximally aligned configuration comprising three proton holes in the g9/2 orbital and one neutron hole in the h11/2 orbital. The new level structure in 128Ag is quite well described by shell model calculations without invoking excitations across the Z = 50 and N = 82 shell gaps, and presents a good case of seniority scheme in odd-odd nuclei in the south vicinity of the double-magic nucleus 132Sn. With a classification of various components of the proton-neutron interaction, the inversion of lowest-lying 9-and 10-states between 128Ag and its neighboring isotone 130In is found to be dynamically ascribed to the seniority-nonconserving proton-neutron interaction components. The structure above 10-up to the 16-isomer in 128Ag shows remarkable similarities to seniority structures in the semimagic nuclei 128Pd and 130Cd. These spectroscopic features in 128Ag indicate that the N = 82 shell closure is still robust in silver isotopes.

Abstract: An amplitude analysis of B- -> D- (DKS0)-K-0 decays is performed using proton-proton collision data, corresponding to an integrated luminosity of 9 fb(-1), collected with the LHCb detector at center-of-mass energies of 7, 8, and 13 TeV. A resonant structure of spin-parity 0(+) is observed in the (DKS0)-K-0 invariant-mass spectrum with a significance of 5.3s. The mass and width of the state, modeled with a Breit-Wigner line shape, are determined to be 2883 +/- 11 +/- 8 MeV/c(2) and 87(-47)(+22) +/- 17 MeV, respectively, where the first uncertainties are statistical and the second systematic. These properties and the quark content are consistent with those of the open-charm tetraquark candidate T-cs0(*)(2870)(0) observed previously in the D+K- final state of the B- -> D-D+K- decay. This result confirms the existence of the T-cs0(*)(2870)(0) state in a new decay mode. The T-c10(*) (2900)(0) state, reported in the B- -> D-D+K- decay, is also searched for in the (DKS0)-K-0 invariant-mass spectrum of the B- -> D- (DKS0)-K-0 decay, without finding evidence for it.

Abstract: The LUXE experiment will investigate the strong-field QED regime by using the interactions of high-energy electrons from the European XFEL in a powerful laser field. It will measure the production of electron-positron pairs as a function of the laser field strength, up to the non-perturbative non-linear regime. LUXE foresees a positron detection system consisting of a tracker and a granular and unprecedentedly compact silicon-tungsten electromagnetic sandwich calorimeter (ECAL-P). The ECAL-P has been designed to cope with the wide range of the expected number of positrons per bunch crossing. In addition, the energy distribution of the positrons has to be measured on top of a widely spread low-energy background. The ECAL-P is composed of tungsten absorber plates interspersed with thin sensor planes, consisting of silicon pad sensors, flexible Kapton printed circuit planes, and carbon fiber support. The sensor planes are less than 1 mm thick and will be read using dedicated front-end ASICs in 130 nm technology (FLAXE) and FPGAs for data pre-processing. GaAs sensor planes with integrated readout strips are also being considered as an alternative to silicon. Prototypes of individual sensor planes have been tested in a 5 GeV electron beam. A full compact calorimeter tower of up to 90 x 90 x 600 mm3 (15 X0) will be produced and tested in an electron beam. The design challenges, sensor characterization, prototyping, integration, commissioning, and the available results from a beam test in 2022 are discussed.