Fri·Mar 7, 2025Friday·March 7, 2025

1. 01*

   Innovating Bolometers' Mounting: A Gravity-Based Approach

   The CUPID Collaboration: K. Alfonso🇺🇸 · A. Armatol🇺🇸 · C. Augier🇫🇷 · F. T. Avignone III🇺🇸 · O. Azzolini🇮🇹 · A. S. Barabash🇷🇺 · G. Bari🇮🇹 · A. Barresi🇮🇹 · D. Baudin🇫🇷 · F. Bellini🇮🇹 · G. Benato🇮🇹 · L. Benussi🇮🇹 and 180 other authors

   Cryogenic calorimeters, also known as bolometers, are among the leading technologies for searching for rare events. The CUPID experiment is exploiting this technology to deploy a tonne-scale detector to search for neutrinoless double-beta decay of ${}^{100}$Mo. The CUPID collaboration proposed an innovative approach to assembling bolometers in a stacked configuration, held in position solely by gravity. This gravity-based assembly method is unprecedented in the field of bolometers and offers several advantages, including relaxed mechanical tolerances and simplified construction. To assess and optimize its performance, we constructed a medium-scale prototype hosting 28 Li${}_2$MoO${}_4$ crystals and 30 Ge light detectors, both operated as cryogenic calorimeters at the Laboratori Nazionali del Gran Sasso (Italy). Despite an unexpected excess of noise in the light detectors, the results of this test proved (i) a thermal stability better than $\pm$0.5 mK at 10 mK, (ii) a good energy resolution of Li${}_2$MoO${}_4$ bolometers, (6.6 $\pm$ 2.2) keV FWHM at 2615 keV, and (iii) a Li${}_2$MoO${}_4$ light yield measured by the closest light detector of 0.36 keV/MeV, sufficient to guarantee the particle identification requested by CUPID.

   ↳ physics.ins-dethep-exnucl-ex1 citation
2. 02*

   Charge dependent directed flow splitting from baryon inhomogeneity and electromagnetic field

   Tribhuban Parida🇮🇳 · Sandeep Chatterjee🇮🇳 · Subhash Singha🇨🇳

   This work aims to understand the recent experimental data from the STAR collaboration on the system size dependence of directed flow splitting between oppositely charged hadrons [arXiv:2412.18326]. Previously, we have studied the role of baryon inhomogeneity on charge dependent directed flow. We now incorporate the effects of the electromagnetic (EM) field albeit perturbatively, as implemented in Ref. [arXiv:1806.05288]. This enables us to compare the relative contributions between baryon inhomogeneity and EM field on charge dependent directed flow. Our model calculation describes the experimental data on the centrality and system size dependence of the mid-rapidity directed flow slope splitting, $\Delta d{v}_1/dy$, between protons and anti-protons. Our results indicate that in central collisions, where the EM field strength is negligible, the inclusion of EM field effects does not influence the splitting between protons and anti-protons. This suggests that the observed system size dependence of $\Delta d{v}_1/dy(p-\bar{p})$ in central collisions arises solely from enhanced baryon stopping in larger collision systems. However, in semi-central and peripheral collisions, both baryon diffusion and EM field effects contribute to the splitting. Furthermore, the centrality dependence of $\Delta d{v}_1/dy(p-\bar{p})$ is highly sensitive to the electrical conductivity of the medium, making it a potential probe for extracting this transport coefficient in the QCD medium through model-to-data comparisons. However, achieving this requires a precise determination of the background baseline originating from baryon diffusion. Additionally, further investigation is needed to understand $\Delta d{v}_1/dy$ for oppositely charged kaons and pions, particularly by incorporating the diffusion of other conserved charges.

   ↳ nucl-thhep-exhep-phnucl-ex7 citations
3. 03*

   Towards a Study of Low Energy Antiproton Annihilations on Nuclei

   Viktoria Kraxberger🇦🇹 · Marcus Bumbar🇨🇭 · Angela Gligorova🇦🇹 · Claude Amsler🇦🇹 · Matias Bayo · Horst Breuker🇯🇵 · Matti Cerwenka🇦🇹 · Giovanni Costantini🇮🇹 · Rafael Ferragut🇮🇹 · Marco Giammarchi🇮🇹 · Giulia Gosta🇮🇹 · Hiroyuki Higaki🇯🇵 and 21 other authors

   A study of antiproton annihilations at rest on thin solid targets is underway at the ASACUSA facility, which now features a dedicated beam line for slow extraction at 250 eV. The experiment will employ new technologies, such as the Timepix4 ASICs coupled to silicon sensors, to measure the total multiplicity, energy, and angular distribution of various prongs produced in thin solid targets. A detection system consisting of seven Timepix4, covering most of the solid angle, is being constructed. A 3D annihilation vertex reconstruction algorithm from particle tracks in the single-plane detectors has been developed using Monte Carlo simulations. The measurements will enable a study of pbar-nucleus interactions, their dependence on nucleus mass and branching ratios. The results will be used to assess and potentially improve various simulation models.

   ↳ physics.ins-detnucl-exPoS(2025)·1 citation
4. 04*

   Reconstructing jet anisotropies with cumulants

   Tanner Mengel🇺🇸 · Niseem Magdy🇺🇸 · Ron Belmont🇺🇸 · Anthony Timmins🇺🇸 · Christine Nattrass🇺🇸

   In relativistic heavy-ion collisions, where quark-gluon plasma forms, hadron production is anisotropic at both low and high transverse momentum, driven by flow dynamics and spatial anisotropies. To better understand these mechanisms, we use multi-particle correlations to reconstruct jet anisotropies. We simulate data using \textsc{TennGen}\xspace as a hydro-like background and combine it with \textsc{Pythia-8}\xspace generated jets, clustering them with the anti-$k_{\mathrm{t}}$\xspace algorithm. Jet anisotropies are unfolded using a Bayesian technique, ensuring the robustness of the reconstructed signals. Our results demonstrate that multi-particle cumulant methods can accurately capture the differential jet azimuthal anisotropies, providing crucial insights into high-$p_T\text{xspace}$ behavior and the dynamics within heavy-ion collisions.

   ↳ nucl-thnucl-exPRC(2025)·0 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.