F. Alemanno

The DArk Matter Particle Explorer (DAMPE) is a spaceborne high-energy particle detector that surveys the γ -ray sky above ∼2 GeV with a peak acceptance of ∼0.2 m ² sr. With the 102 months of data collected by DAMPE, we show that the Fermi bubbles are detected at a significance of ∼26 σ and identify a GeV excess in the direction of the Galactic center at ∼7 σ confidence. Both spectra and morphology are consistent with those observed by the Fermi Large Area Telescope (Fermi-LAT) and the GeV excess component can be interpreted by dark matter annihilation with a mass of ∼50 GeV and a velocity-averaged cross section of ∼10 ⁻²⁶ cm ³ s ⁻¹ for the χ χ → b b ¯ channel. Our results thus provide the first independent detection of these two intriguing diffuse γ -ray sources besides Fermi-LAT.

The Deep Underground Neutrino Experiment (DUNE) is a next-generation long-baseline experiment for neutrino physics currently under construction in the US, aiming to measure neutrino oscillation parameters, search for beyond standard model physics and detect supernova neutrinos. DUNE will include a Near Detector (ND) and a Far Detector (FD), located 1300 km away from the ND and 1.5 km underground. The FD will consist of four 17-kton Liquid argon Time Projection Chambers (LArTPCs). In Phase I, two FD modules implementing horizontal (HD) and vertical (VD) drift technologies will be used. To test these technologies, two 750-ton LArTPCs (ProtoDUNEs) were built at CERN and were operated over the past two years. In particular, the FD Photon Detection System (PDS) is critical for the DUNE physics program. The topology of a neutrino interaction in the LArTPC is reconstructed from the tracks of secondary charged particles, which produce scintillation light and ionization charge carriers during their propagation in LAr. The reference time of the event is provided by the scintillation light, detected by X-ARAPUCA modules, i.e. photon traps consisting of a box with highly reflective internal walls instrumented with an array of Silicon PhotoMultipliers (SiPMs). In this paper, the designs of the DUNE PDS of the first two modules are presented, along with first results from ProtoDUNE-HD and ProtoDUNE-VD PDS operations. The preliminary results demonstrate the successful operation of the PDS, marking a crucial step toward validating the horizontal and vertical drift designs for the first FD modules.

Nickel, one of the most stable elements alongside iron, is the most abundant heavy element beyond iron in cosmic rays. With DAMPE's excellent charge resolution and broad energy range, a high-precision energy spectrum provides valuable insights into the acceleration sources of heavy nuclei and their propagation through the interstellar medium. In this analysis, we report the direct measurement of cosmic-ray nickel spectrum from 10 GeV/n to 2 TeV/n with nine years of flight data. The nickel spectrum is consistent with a single power law with spectral index -2.60 +/- 0.03 from 40 GeV/n to 1 TeV/n. This work provides an accurate measurement of differential flux of nickel with kinetic energy extending to TeV/n for the first time.