Fri·Jun 24, 2022Friday·June 24, 2022

1. 01*

   Two-dimensional total absorption spectroscopy with conditional generative adversarial networks

   Cade Dembski · Michelle P. Kuchera🇺🇸 · Sean Liddick🇺🇸 · Raghu Ramanujan🇺🇸 · Artemis Spyrou

   We explore the use of machine learning techniques to remove the response of large volume $\gamma$-ray detectors from experimental spectra. Segmented $\gamma$-ray total absorption spectrometers (TAS) allow for the simultaneous measurement of individual $\gamma$-ray energy (E${}_{\gamma }$) and total excitation energy (E${}_x$). Analysis of TAS detector data is complicated by the fact that the E${}_x$ and E${}_{\gamma }$ quantities are correlated, and therefore, techniques that simply unfold using E${}_x$ and E${}_{\gamma }$ response functions independently are not as accurate. In this work, we investigate the use of conditional generative adversarial networks (cGANs) to simultaneously unfold $E_x$ and $E_{\gamma }$ data in TAS detectors. Specifically, we employ a \texttt{Pix2Pix} cGAN, a generative modeling technique based on recent advances in deep learning, to treat \rawmatrix~ matrix unfolding as an image-to-image translation problem. We present results for simulated and experimental matrices of single-$\gamma$ and double-$\gamma$ decay cascades. Our model demonstrates characterization capabilities within detector resolution limits for upwards of 93% of simulated test cases.

   nucl-excs.AINucl.Instrum.Meth.A(2024)·2 citations
2. 02*

   Shear-induced anomalous transport and charge asymmetry of triangular flow in heavy-ion collisions

   Matteo Buzzegoli🇺🇸 · Dmitri E. Kharzeev🇺🇸 · Yu-Chen Liu🇺🇸 · Shuzhe Shi🇺🇸 · Sergei A. Voloshin🇺🇸 · Ho-Ung Yee🇺🇸

   Chiral anomaly implies the existence of non-dissipative transport phenomena, such as the chiral magnetic effect. At second order in the derivative expansion, novel quantum transport phenomena emerge. In this paper, we focus on the anomalous transport driven by a combination of shear, vorticity and magnetic field. We find that the corresponding transport phenomena -- shear-induced chiral magnetic and chiral vortical effects (siCME and siCVE) -- induce characteristic charge correlations among the hadrons produced in heavy ion collisions. We propose the charge asymmetry of triangular flow as a signature of the anomalous transport, and estimate the strength of the signal, as well as the background, using hydrodynamical model simulations. We find that the signal-to-background ratio for the proposed observable is favorable for experimental detection.

   ↳ hep-phnucl-exnucl-thPRC(2022)·9 citations
3. 03*

   Contextual Isotope Ranking Criteria for Peak Identification in Gamma Spectroscopy Using a Large Database

   Alexis Aguilar-Arevalo🇲🇽 · Xavier Bertou🇦🇷 · Carles Canet🇲🇽 · Miguel A. Cruz-Pérez🇬🇧 · Alexander Deisting🇲🇽 · Adriana Dias · Juan Carlos D'Olivo🇲🇽 · J. Francisco Favela-Pérez · Estela A. Garcés🇲🇽 · Adiv González Muñoz · Jaime Octavio Guerra-Pulido🇲🇽 · Javier Mancera-Alejandrez🇲🇽 and 9 other authors

   Isotope identification is a recurrent problem in gamma spectroscopy with high purity germanium detectors. In this work, new strategies are introduced to facilitate this type of analysis. Five criteria are used to identify the parent isotopes making a query on a large database of gamma-lines from a multitude of isotopes producing an output list whose entries are sorted so that the gamma-lines with the highest chance of being present in a sample are placed at the top. A metric to evaluate the performance of the different criteria is introduced and used to compare them. Two of the criteria are found to be superior than the others: one based on fuzzy logic, and another that makes use of the gamma relative emission probabilities. A program called histoGe implements these criteria using a SQLite database containing the gamma-lines of isotopes which was parsed from WWW Table of Radioactive Isotopes. histoGe is Free Software and is provided along with the database so they can be used to analyze spectra obtained with generic gamma-ray detectors.

   ↳ physics.comp-phnucl-exphysics.ins-detIEEE Trans.Nucl.Sci.(2022)·0 citations
4. 04*

   Formation of large chunk of nuclear matter in heavy-ion collisions

   Gao-Chan Yong🇨🇳

   In terrestrial laboratory with existing accelerators, the maximum multinucleon system produced so far is limited to that with total nucleon number being less than the sum of two colliding nuclei. Such situation may hinder our studies on the properties of nuclear many-body system. Here a way of producing large multinucleon system via multi-nucleus collision device Collider Plus in terrestrial laboratory is proposed. It is shown that large chunk of nucleonic matter can be produced through nuclear ternary fusion reactions at lower beam energies and also large block of dense matter can be formed via ternary collisions of heavy nuclei at intermediate energies. These investigations may shed lights on the studies of the synthesis of superheavy elements and the properties of bulk superdense nuclear matter.

   ↳ nucl-thnucl-exPLB(2022)·0 citations
5. 05*

   Remembering Professor H. H. Bolotin

   Andrew Stuchbery🇦🇺

   Herb Bolotin was an excellent physicist and educator with a sense of fun and unique humor. He came to Australia as the Chamber of Manufacturers Professor of Physics at the University of Melbourne in 1971, a position he held until retirement in 1995. He established nuclear structure research using the new 5U Pelletron accelerator in Melbourne, and his group became regular users of the 14UD Pelletron Accelerator at the Australian National University (now part of the Heavy Ion Accelerator Facility). Upon retirement in 1996 Herb changed direction and worked successfully on bone densitometry as Emeritus Professor at Melbourne and then as Adjunct Professor at RMIT. He published in this field until 2009. He died suddenly on July 8th 2020.

   ↳ physics.hist-phnucl-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.