Wed·Jun 5, 2024Wednesday·June 5, 2024

1. 01*

   Femtoscopy at NA61/SHINE using symmetric Lévy sources in central ${}^{40}$Ar+${}^{45}$Sc from 40$A$ GeV/$c$ to 150$A$ GeV/$c$

   Barnabas Porfy (for the NA61/SHINE Collaboration)🇭🇺

   In the recent decades of high energy physics research, it was demonstrated that strongly interacting quark-gluon plasma (sQGP) is created in ultra-relativistic nucleus-nucleus collisions. Investigation and understanding of properties of the hadronic matter is among the important goals of NA61/SHINE collaboration at CERN SPS. Mapping of the phase diagram is achieved by varying the collision energy (5 GeV $<\sqrt{s_{\text{NN}}}<$17 GeV) and by changing the collision system (p+p, p+Pb, Be+Be, Ar+Sc, Xe+La, Pb+Pb). We report on the measurement of femtoscopic correlations in intermediate system at intermediate SPS energies. Interpreting the results of measurements within the symmetric Lévy source formalism, we discuss the values of Lévy source parameters as a function of average pair transverse mass. One of the physical parameters is particularly important, the Lévy exponent $\alpha$, which describes the shape of the source and may be related to the critical exponent $\eta$ in the proximity of the critical point. Therefore, measuring it may shed light on the location of the critical endpoint of the QCD phase diagram.

   nucl-exhep-exInt.J.Mod.Phys.A(2025)·5 citations
2. 02*

   A universal reduced basis for the calibration of covariant energy density functionals

   Amy L. Anderson · J. Piekarewicz🇺🇸

   The reduced basis method is used to construct a "universal" basis of Dirac orbitals that may be applicable throughout the nuclear chart to calibrate covariant energy density functionals. Relative to our earlier work using the non-relativistic Schrödinger equation, the Dirac equation adds an extra layer of complexity due to the existence of negative energy states. However, once this problem is mitigated, the resulting reduced basis is able to accurately and efficiently reproduce the high-fidelity model at a fraction of the computational cost. We are confident that the resulting reduced basis will serve as a foundational element in developing rapid and accurate emulators. In turn, these emulators will play a critical role in the Bayesian optimization of covariant energy density functionals.

   ↳ nucl-thnucl-exPRC(2024)·2 citations
3. 03*

   Validating Automated Resonance Evaluation with Synthetic Data

   Oleksii Zivenko · Noah A. W. Walton · William Fritsch · Jacob Forbes🇳🇿 · Amanda M. Lewis🇺🇸 · Aaron Clark · Jesse M. Brown · Vladimir Sobes

   The integrity and precision of nuclear data are crucial for a broad spectrum of applications, from national security and nuclear reactor design to medical diagnostics, where the associated uncertainties can significantly impact outcomes. A substantial portion of uncertainty in nuclear data originates from the subjective biases in the evaluation process, a crucial phase in the nuclear data production pipeline. Recent advancements indicate that automation of certain routines can mitigate these biases, thereby standardizing the evaluation process, reducing uncertainty and enhancing reproducibility. This article contributes to developing a framework for automated evaluation techniques testing, emphasizing automated fitting methods that do not require the user to provide any prior information. This approach simplifies the process and reduces the manual effort needed in the initial evaluation stage. It highlights the capability of the framework to validate and optimize subroutines, targeting the performance analysis and optimization of the fitting procedure using high-fidelity synthetic data (labeled experimental data) and the concept of a fully controlled computational experiment. An error metric is introduced to provide a clear and intuitive measure of the fitting quality by quantifying the accuracy and performance across the specified energy. This metric sets a scale for comparison and optimization of routines or hyperparameter selection, improving the entire evaluation process methodology and increasing reproducibility and objectivity.

   ↳ physics.comp-phnucl-exnucl-thphysics.med-ph0 citations
4. 04*

   First demonstration of a TES based cryogenic Li${}_2$MoO${}_4$detector for neutrinoless double beta decay search

   G. Bratrud🇺🇸 · C. L. Chang🇺🇸 · R. Chen🇺🇸 · E. Cudmore🇨🇦 · E. Figueroa-Feliciano🇺🇸 · Z. Hong🇨🇦 · K. T. Kennard🇺🇸 · S. Lewis🇺🇸 · M. Lisovenko🇺🇸 · L. O. Mateo🇺🇸 · V. Novati🇺🇸 · V. Novosad🇺🇸 and 13 other authors

   Cryogenic calorimetric experiments to search for neutrinoless double-beta decay ($0\nu \beta \beta$) are highly competitive, scalable and versatile in isotope. The largest planned detector array, CUPID, is comprised of about 1500 individual Li${}_2^{100}$MoO${}_4$ detector modules with a further scale up envisioned for a follow up experiment (CUPID-1T). In this article, we present a novel detector concept targeting this second stage with a low impedance TES based readout for the Li${}_2$MoO${}_4$ absorber that is easily mass-produced and lends itself to a multiplexed readout. We present the detector design and results from a first prototype detector operated at the NEXUS shallow underground facility at Fermilab. The detector is a 2-cm-side cube with 21g mass that is strongly thermally coupled to its readout chip to allow rise-times of $\sim$0.5ms. This design is more than one order of magnitude faster than present NTD based detectors and is hence expected to effectively mitigate backgrounds generated through the pile-up of two independent two neutrino decay events coinciding close in time. Together with a baseline resolution of 1.95keV (FWHM) these performance parameters extrapolate to a background index from pile-up as low as $5\cdot 10^{-6}$counts/keV/kg/yr in CUPID size crystals. The detector was calibrated up to the MeV region showing sufficient dynamic range for $0\nu \beta \beta$ searches. In combination with a SuperCDMS HVeV detector this setup also allowed us to perform a precision measurement of the scintillation time constants of Li${}_2$MoO${}_4$. The crystal showed a significant fast scintillation emission with O(10$\mu$s) time-scale, more than an order below the detector response of presently considered light detectors suggesting the possibility of further progress in pile-up rejection through better light detectors in the future.

   ↳ hep-exnucl-exphysics.ins-detEPJC(2025)·9 citations
5. 05*

   A novel measurement method for SiPM external crosstalk probability at low temperature

   Guanda Li · Lei Wang · Xilei Sun🇨🇳 · Fang Liu🇨🇳 · Cong Guo🇨🇳 · Kangkang Zhao🇨🇳 · Lei Tian🇨🇦 · Zeyuan Yu🇨🇳 · Zhilong Hou🇨🇳 · Chi Li · Yu Lei · Bin Wang · Rongbin Zhou🇨🇳

   Silicon photomultipliers (SiPMs) are being considered as potential replacements for conventional photomultiplier tubes (PMTs). However, a significant disadvantage of SiPMs is crosstalk (CT), wherein photons propagate through other pixels, resulting in secondary avalanches. CT can be categorized into internal crosstalk and external crosstalk based on whether the secondary avalanche occurs within the same SiPM or a different one. Numerous methods exist for quantitatively estimating the percentage of internal crosstalk (iCT). However, external crosstalk (eCT) has not been extensively studied. This article presents a novel measurement method for the probability of emitting an external crosstalk photon during a single pixel avalanche, using a setup involving two identical SiPMs facing each other, and without the need for complex optical designs. The entire apparatus is enclosed within a stainless steel chamber, functioning as a light-tight enclosure, and maintained at liquid nitrogen temperature. The experimental setup incorporates two Sensl J-60035 SiPM chips along with two 0.5-inch Hamamatsu Photonics (HPK) VUV4 S13370-6050CN SiPM arrays. The findings show a linear relationship between the probability of emitting an external crosstalk photon and the SiPM overvoltage for both SiPM samples. Surprisingly, this novel measurement method also rovides measurements of the SiPM photon detection efficiency (PDE) for eCT photons at low temperature.

   ↳ physics.ins-detnucl-exIEEE Trans.Nucl.Sci.(2024)·4 citations
6. 06*

   Nuclear Data to Quantify Urca Cooling in Accreting Neutron Stars

   Rahul Jain🇮🇳

   Neutron stars in Low Mass X-ray Binaries (LMXBs) can accrete matter onto their surface from the companion star. Transiently accreting neutron stars go through alternating phases of active accretion outbursts and quiescence. X-ray observations during the quiescence phase show a drop in X-ray luminosity with the time in quiescence. This is also inferred as the drop in surface temperature or the cooling of accreting neutron stars in quiescence. Analyzing these cooling curves reveals a great deal of information about the structure and composition of neutron stars. However, model-observation comparisons of such cooling curves are challenging - partly due to observational uncertainties, and partly due to incomplete knowledge of heating mechanisms during accretion outbursts. This situation is further exacerbated by the recent discovery of Urca cooling in the neutron star crust. These are cycles that alternate between electron-capture and beta-decay to produce a large flux of neutrinos and anti-neutrinos. These freely stream out of the star and carry energy with them, essentially cooling the neutron star crust without changing the composition. As a result, it is necessary to accurately quantify the strength of Urca cooling to constrain the heat sources in neutron star crusts and facilitate better model-observation comparisons of the cooling curves.

   ↳ astro-ph.HEnucl-ex0 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.