Thu·Mar 16, 2023Thursday·March 16, 2023

1. 01*

   New detection systems for an enhanced sensitivity in key stellar (n,$\gamma$) measurements

   J. Lerendegui-Marco · V. Babiano-Suárez · J. Balibrea-Correa · C. Domingo-Pardo · I. Ladarescu · A. Tarifeño-Saldivia · V. Alcayne · D. Cano-Ott · E. González-Romero · T. Martínez · E. Mendoza · C. Guerrero and 8 other authors

   Neutron capture cross-section measurements are fundamental in the study of astrophysical phenomena, such as the slow neutron capture (s-) process of nucleosynthesis operating in red-giant and massive stars. However, neutron capture measurements via the time-of-flight (TOF) technique on key $s$-process nuclei are often challenging. Difficulties arise from the limited mass ($\sim$mg) available and the high sample-related background in the case of the unstable $s$-process branching points. Measurements on neutron magic nuclei, that act as $s$-process bottlenecks, are affected by low (n,$\gamma$) cross sections and a dominant neutron scattering background. Overcoming these experimental challenges requires the combination of facilities with high instantaneous flux, such as n\_TOF-EAR2, with detection systems with an enhanced detection sensitivity and high counting rate capabilities. This contribution reviews some of the latest detector developments in detection systems for (n,$\gamma$) measurements at n\_TOF, such as i-TED, an innovative detection system which exploits the Compton imaging technique to reduce the dominant neutron scattering background and s-TED, a highly segmented total energy detector intended for high flux facilities. The discussion will be illustrated with results of the first measurement of key the $s$-process branching-point reaction ${}^{79}$Se(n,$\gamma$).

   nucl-exastro-ph.IMEPJ Web Conf.(2023)·13 citations
2. 02*

   New perspectives for neutron capture measurements in the upgraded CERN-n_TOF Facility

   J. Lerendegui-Marco · A. Casanovas · V. Alcayne · the n_TOF Collaboration

   The n_TOF facility has just undergone in 2021 a major upgrade with the installation of its third generation spallation target that has been designed to optimize the performance of the two n_TOF time-of-flight lines. This contribution describes the key features and limitations for capture measurements in the two beam lines prior to the target upgrade and presents first results of (n,$\gamma$) measurements carried out as part of the commissioning of the upgraded facility. In particular, the energy resolution, a key factor for both increasing the signal-to-background ratio and obtaining accurate resonance parameters, has been clearly improved for the 20 m long vertical beam-line with the new target design while keeping the remarkably high resolution of the long beamline n_TOF-EAR1. The improvements in the n_TOF neutron beam-lines need to be accompanied by improvements in the instrumentation. A review is given on recent detector R&D projects aimed at tackling the existing challenges and further improving the capabilities of this facility.

   nucl-exphysics.ins-detEPJ Web Conf.(2023)·6 citations
3. 03*

   Motivation for Two Detectors at a Particle Physics Collider

   Paul D. Grannis🇺🇸 · Hugh E. Montgomery🇺🇸

   It is generally accepted that it is preferable to build two general purpose detectors at any given collider facility. We reinforce this point by discussing a number of aspects and particular instances in which this has been important. The examples are taken mainly, but not exclusively, from experience at the Tevatron collider.

   ↳ hep-exhep-phnucl-ex3 citations
4. 04*

   Interpretable Machine Learning Methods Applied to Jet Background Subtraction in Heavy Ion Collisions

   Tanner Mengel🇺🇸 · Patrick Steffanic🇺🇸 · Charles Hughes🇺🇸 · Antonio Carlos Oliveira da Silva🇺🇸 · Christine Nattrass🇺🇸

   Jet measurements in heavy ion collisions can provide constraints on the properties of the quark gluon plasma, but the kinematic reach is limited by a large, fluctuating background. We present a novel application of symbolic regression to extract a functional representation of a deep neural network trained to subtract the background for measurements of jets in relativistic heavy ion collisions. We show that the deep neural network is approximately the same as a method using the particle multiplicity in a jet. This demonstrates that interpretable machine learning methods can provide insight into underlying physical processes.

   ↳ hep-exnucl-exPRC(2023)·15 citations
5. 05*

   Evidence of Space weather in Radon Decay

   Carol Scarlett · Ephraim Fischbach · Belvin Freeman · Jennifer Coy · Patrice Edwards · Reed Burkhart · Oksana Piatibratova · Theresa Monsue · Daniel Osborne · Lameck Mwibanda · Abdullah Alsayegh

   The Electron, Proton and Alpha Monitor, EPAM, located at the L1 Position approximately 1-million miles from the earth in the direction of the sun, was designed to detect fluctuations in solar output through counting the numbers of various particles hitting the detector. The EPAM detector is part of an early warning system that can alert the earth to coronal mass ejection events that can damage our electronic grids and satellite equipment. EPAM gives a real-time estimate of changes in the local solar magnetic field directed towards the earth, recorded in the fluctuations of solar particles being ejected. This paper presents an analysis of fluctuations in data taken by the Geological Survey of Israel, GSI, compared to the changes in detected numbers of protons as seen by EPAM. Surprisingly, the GSI and EPAM detectors show an unexpected correlation between the variation in count rate detected by the GSI detectors and an increased numbers of protons seen at EPAM; well above statistical significance of 5-sigma, indicating a non-random connection between the data sets. The statistically significant overlap between data taken by these two detectors, subject to very different conditions, may hint at a Primakoff mechanism whereby exotic particles, e.g. galactic Dark Matter, couple through magnetic fields to both photons and even nuclei. This work builds on an earlier paper on the observations of Radon decay and their implications for particle physics.

   ↳ hep-exastro-ph.GAnucl-exphysics.space-ph0 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.