Fri·Sep 6, 2024Friday·September 6, 2024

1. 01*

   Pion electroproduction measurements in the nucleon resonance region

   R. Li🇺🇸 · N. Sparveris🇺🇸 · H. Atac🇺🇸 · M. K. Jones🇺🇸 · M. Paolone🇺🇸 · Z. Akbar🇺🇸 · M. Ali🇺🇸 · C. Ayerbe Gayoso🇺🇸 · V. Berdnikov🇺🇸 · D. Biswas🇺🇸 · M. Boer🇺🇸 · A. Camsonne🇺🇸 and 37 other authors

   We report new pion electroproduction measurements in the $\Delta (1232)$ resonance, utilizing the SHMS - HMS magnetic spectrometers of Hall C at Jefferson Lab. The data focus on a region that exhibits a strong and rapidly changing interplay of the mesonic cloud and quark-gluon dynamics in the nucleon. The results are in reasonable agreement with models that employ pion cloud effects and chiral effective field theory calculations, but at the same time they suggest that an improvement is required to the theoretical calculations and provide valuable input that will allow their refinements. The data illustrate the potential of the magnetic spectrometers setup in Hall C towards the study the $\Delta (1232)$ resonance. These first reported results will be followed by a series of measurements in Hall C, that will expand the studies of the $\Delta (1232)$ resonance offering a high precision insight within a wide kinematic range from low to high momentum transfers.

   nucl-exnucl-thEPJA(2024)·0 citations
2. 02*

   Deciphering the influence of neutron transfer in Si-based fusion reactions around the Coulomb barrier

   Rinku Prajapat

   Purpose: We aim to investigate the role of a few neutron transfer channels on the dynamics of fusion reactions around the Coulomb barrier by judicially selecting 11 different ${}^{28,30}$Si-induced systems. These reactions are chosen in such a way that they possess positive and negative Q-values for neutron transfer channels to make the comparison more apparent. Furthermore, a comparative study on fusion barrier parameters using different proximity potentials and parametrizations is also a prime goal. Method: A channel coupling approach within the framework of a semiclassical model is being used to investigate the role of multi-neutron transfer with positive Q-values on fusion phenomena near and below the Coulomb barrier. The fusion barrier parameters have been extracted and analyzed within the framework of seven different potential models. Results: The sub-barrier fusion enhancement compared to the one-dimensional barrier penetration model (uncoupled) is investigated by considering collective excitations in colliding nuclei and multi-neutron transfer channels with Q $>$ 0 within the channel coupling model. Furthermore, GRAZING calculations are performed to predict the cross-section of target-like fragments after 2n pickup transfer. Conclusion: All the fusion excitation functions (EFs) have been successfully explained by the coupled channel calculations using the channel coupling model. Only the significant effect of up to 2n pickup transfer with Q $>$ 0 was found on sub-barrier fusion. Despite having positive Q values for transfer channels, no noticeable impact of more than 2n transfer was observed. GRAZING predictions are grossly in the same order as the quantitative contribution of 2n transfer channels observed by channel coupling model calculations.

   ↳ nucl-thnucl-exEPJA(2025)·0 citations
3. 03*

   On-orbit calibration and long-term performance of the DAMPE trigger system

   Wen-Hao Li (1 and 2)🇨🇳 · Chuan Yue (1)🇨🇳 · Yong-Qiang Zhang (1)🇨🇳 · Jian-Hua Guo (1 and 2)🇨🇳 · Qiang Yuan (1 and 2) ((1) Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing, (2) School of Astronomy and Space Science, University of Science and Technology of China, Hefei)🇨🇳

   The DArk Matter Particle Explorer (DAMPE) is a satellite-borne particle detector for measurements of high-energy cosmic rays and {\gamma}-rays. DAMPE has been operating smoothly in space for more than 8 years since launch on December 17, 2015. The trigger logic of DAMPE is designed according to the deposited energy information recorded by the calorimeter. The precise calibration of the trigger thresholds and their long-term evolutions are very important for the scientific analysis of DAMPE. In this work, we develop a new method for the threshold calibration, considering the influence from the electronic noise, and obtain the long-term evolutions of the trigger thresholds. The average increase rate of the trigger thresholds for the first 4 layers of the calorimeter is found to be about 0.9% per year, resulting in variations of the high-energy trigger efficiency of cosmic ray electrons by about -5% per year at 2 GeV and less than about -0.05% above 30 GeV.

   ↳ physics.ins-detastro-ph.IMnucl-exNucl.Instrum.Meth.A(2024)·2 citations
4. 04*

   Physics case for quarkonium studies at the Electron Ion Collider

   Daniël Boer🇳🇱 · Chris A. Flett🇫🇷 · Carlo Flore🇮🇹 · Daniel Kikoła🇵🇱 · Jean-Philippe Lansberg🇫🇷 · Maxim Nefedov🇫🇷 · Charlotte Van Hulse🇫🇷 · Shohini Bhattacharya🇺🇸 · Jelle Bor🇳🇱 · Mathias Butenschoen🇩🇪 · Federico Ceccopieri🇫🇷 · Longjie Chen🇨🇳 and 32 other authors

   The physics case for quarkonium-production studies accessible at the US Electron Ion Collider is described.

   ↳ hep-phhep-exnucl-exnucl-thPPNP(2025)·39 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.