Thu·Jun 2, 2022Thursday·June 2, 2022

1. 01*

   An automated testing system for the RD51 VMM hybrid and yield measurement of the first production batches

   Finn Jaekel🇩🇪 · Klaus Desch🇩🇪 · Jochen Kaminski🇩🇪 · Michael Lupberger🇩🇪 · Lucian Scharenberg🇩🇪 · Patrick Schwaebig🇩🇪

   We present the development of an automated testing system for the VMM hybrid of the RD51 collaboration. The VMM hybrid is a new front-end board for the RD51 common readout system, the Scalable Readout System, and will become the workhorse for the next decade to read out Micro-Pattern Gaseous Detectors. It uses the VMM chip developed for the ATLAS New Small Wheel to convert charge signals from detectors to digital data. Our testing system automatically characterises the quality of the VMM chips on the hybrid after production during multiple tests. Results are evaluated to classify the chips and hybrids and uploaded to a database. We evaluated those results for the first two production batches to measure the production yield. The yield is better than the threshold below which chip testing on a wafer level offers financial benefits. Observations on prominent chip failures were propagated back to the hybrid production process to further increase the yield for future productions.

   ↳ physics.ins-dethep-exnucl-exNucl.Instrum.Meth.A(2023)·0 citations
2. 02*

   Material Effects on Electron Capture Decays in Cryogenic Sensors

   Amit Samanta (1)🇺🇸 · Stephan Friedrich (1)🇺🇸 · Kyle G. Leach (2)🇺🇸 · Vincenzo Lordi (1) ((1) Lawrence Livermore National Laboratory, (2) Colorado School of Mines)🇺🇸

   Several current searches for physics beyond the standard model are based on measuring the electron capture (EC) decay of radionuclides implanted into cryogenic high-resolution sensors. The sensitivity of these experiments has already reached the level where systematic effects related to atomic-state energy changes from the host material are a limiting factor. One example is a neutrino mass study based on the nuclear EC decay of ${}^7$Be to ${}^7$Li inside cryogenic Ta-based sensors. To understand the material effects at the required level we have used density functional theory and modeled the electronic structure of lithium atoms in different atomic environments of the polycrystalline Ta absorber film. The calculations reveal that the Li 1s binding energies can vary by more than 2 eV due to insertion at different lattice sites, at grain boundaries, in disordered Ta, and in the vicinity of various impurities. However, the total range of Li 1s shifts does not exceed 4 eV, even for extreme amorphous disorder. Further, when investigating the effects on the Li 2s levels, we find broadening of more than 5 eV due to hybridization with the Ta band structure. Materials effects are shown to contribute significantly to peak broadening in Ta-based sensors that are used to search for physics beyond the standard model in the EC decay of ${}^7$Be, but they do not explain the full extent of observed broadening. Understanding these in-medium effects will be required for current- and future-generation experiments that observe low-energy radiation from the EC decay of implanted isotopes to evaluate potential limitations on the measurement sensitivity.

   ↳ cond-mat.mtrl-scinucl-exphysics.ins-detPhys.Rev.Applied(2023)·11 citations
3. 03*

   Spin symmetry energy and equation of state of spin-polarized neutron star matter

   Nguyen Hoang Dang Khoa · Ngo Hai Tan🇻🇳 · Dao T. Khoa🇻🇳

   Equation of states (EOS) of the spin-polarized nuclear matter (NM) is studied within the Hartree-Fock (HF) formalism using the realistic density dependent nucleon-nucleon interaction. With a nonzero fraction $\Delta$ of spin-polarized baryons in NM, the spin- and spin-isospin dependent parts of the HF energy density give rise to the \emph{spin symmetry} energy that behaves in about the same manner as the \emph{isospin symmetry} energy, widely discussed in literature as the nuclear symmetry energy. The present HF study shows a strong correlation between the spin symmetry energy and nuclear symmetry energy over the whole range of baryon densities. The important contribution of the spin symmetry energy to the EOS of the spin-polarized NM is found to be comparable with that of the nuclear symmetry energy to the EOS of the isospin-polarized or asymmetric (neutron-rich) NM. Based on the HF energy density, the EOS of the spin-polarized ($\beta$-stable) np$e\mu$ matter is obtained for the determination of the macroscopic properties of neutron star (NS). A realistic density dependence of the spin-polarized fraction $\Delta$ have been suggested to explore the impact of the spin symmetry energy to the gravitational mass $M$ and radius $R$, as well as the tidal deformability of NS. Given the empirical constrains inferred from a coherent Bayesian analysis of gravitational wave signals of the NS merger GW170817 and the observed masses of the heaviest pulsars, the strong impacts of the spin symmetry energy $W$, nuclear symmetry energy $S$, and nuclear incompressibility $K$ to the EOS of nucleonic matter in magnetar were revealed.

   ↳ nucl-thastro-ph.HEastro-ph.SRnucl-exPRC(2022)·4 citations
4. 04*

   Kinetic mass shifts of $\rho$(770) and $K^{\ast }$(892) in Au+Au reaction at $E_{\mathrm{beam}}=1.23A$GeV

   Tom Reichert🇩🇪 · Marcus Bleicher🇩🇪

   We explore the properties of the last generation of $\rho$(770) and $K^{\ast }$(892) resonances created in Au+Au reactions at E${}_{\mathrm{lab}}=1.23$~AGeV via the reconstruction in the hadronic channel using the UrQMD model. Such resonance studies allow to obtain detailed information on the emission source in such reactions in a complementary way to di-lepton or HBT studies. We observe a freeze-out hierarchy and predict mass shifts for the $\rho$(770) resonance ($\Delta m_{\rho }\approx -330$ MeV) and the $K^{\ast }$(892) resonance ($\Delta m_{K^{\ast }}\approx -30$ MeV). These mass shifts are related to the regeneration cycles of each resonance species and are of purely kinetic origin. Experimentally our predictions can be tested using the GSI-HADES experiment or the lowest RHIC-BES energy.

   ↳ nucl-thnucl-exNPA(2022)·11 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.