Fri·Sep 30, 2022Friday·September 30, 2022

1. 01*

   Muonic atom spectroscopy with microgram target material

   A. Adamczak🇵🇱 · A. Antognini🇨🇭 · N. Berger🇩🇪 · T. E. Cocolios🇧🇪 · N. Deokar🇩🇪 · Ch. E. Düllmann🇩🇪 · A. Eggenberger🇨🇭 · R. Eichler🇨🇭 · M. Heines🇧🇪 · H. Hess🇩🇪 · P. Indelicato🇫🇷 · K. Kirch🇨🇭 and 17 other authors

   Muonic atom spectroscopy -- the measurement of the x rays emitted during the formation process of a muonic atom -- has a long standing history in probing the shape and size of nuclei. In fact, almost all stable elements have been subject to muonic atom spectroscopy measurements and the absolute charge radii extracted from these measurements typically offer the highest accuracy available. However, so far only targets of at least a few hundred milligram could be used as it required to stop a muon beam directly in the target to form the muonic atom. We have developed a new method relying on repeated transfer reactions taking place inside a 100-bar hydrogen gas cell with an admixture of 0.25% deuterium that allows us to drastically reduce the amount of target material needed while still offering an adequate efficiency. Detailed simulations of the transfer reactions match the measured data, suggesting good understanding of the processes taking place inside the gas mixture. As a proof of principle we demonstrate the method with a measurement of the 2p-1s muonic x rays from a 5-{\mu}g gold target.

   nucl-exphysics.atom-phEPJA(2023)·20 citations
2. 02*

   Searching for an Enhanced Signal of the onset of Color Transparency in Baryons with D(e,e'p)n scattering

   Shujie Li🇺🇸 · Carlos Yero🇺🇸 · Jennifer Rittenhouse West🇺🇸 · Clare Bennett🇺🇸 · Wim Cosyn🇺🇸 · Douglas Higinbotham🇺🇸 · Misak Sargsian🇺🇸 · Holly Szumila-Vance🇺🇸

   Observation of the onset of color transparency in baryons would provide a new means of studying the nuclear strong force and would be the first clear evidence of baryons transforming into a color-neutral point-like size in the nucleus as predicted by quantum chromodynamics. Recent C$(e,e^{\prime }p)$ results from electron-scattering did not observe the onset of color transparency (CT) in protons up to spacelike four-momentum transfers squared, $Q^2=14.2$ GeV${}^2$. The traditional methods of searching for CT in $(e,e^{\prime }p)$ scattering use heavy targets favoring kinematics with already initially reduced final state interactions (FSIs) such that any CT effect that further reduces FSIs will be small. The reasoning behind this choice is the difficulty in accounting for all FSIs. D$(e,e^{\prime }p)n$, on the other hand, has well-understood FSI contributions from double scattering with a known dependence on the kinematics and can show an increased sensitivity to hadrons in point-like configurations. Double scattering is the square of the re-scattering amplitude in which the knocked-out nucleon interacts with the spectator nucleon, a process that is suppressed in the presence of point-like configurations and is particularly well-studied for the deuteron. This suppression yields a quadratic sensitivity to CT effects and is strongly dependent on the choice of kinematics. Here, we describe a possible JLab electron-scattering experiment that utilizes these kinematics and explores the potential signal for the onset of CT with enhanced sensitivity as compared to recent experiments.

   nucl-exhep-exnucl-thMDPI Physics(2022)·7 citations
3. 03*

   Electroweak-boson production from small to large collision systems with ALICE at the LHC

   Giullaume Taillepied🇩🇪

   Recent measurements of the electroweak-boson production performed by the ALICE Collaboration are reported. The W-boson production was measured at midrapidity in pp collisions at $\sqrt{s}=13$ TeV, via the electronic decay of the boson. It was also measured in association with a hadron emitted back-to-back with respect to the electron. In heavy-ion collisions, the W- and Z-boson production was measured at forward rapidity in p--Pb collisions at $\sqrt{s_{\mathrm{NN}}}=8.16$ TeV and Pb--Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV, in their muonic decay channel. Measurements in pp collisions shed light on multiple parton interactions and colour reconnection mechanisms. In heavy-ion collisions the measurements of electroweak bosons allow to probe the initial state of the collision.

   nucl-exEPJ Web Conf.(2023)·0 citations
4. 04*

   Timing performance of radiation hard MALTA monolithic Pixel sensors

   G. Gustavino🇨🇭 · P. Allport🇬🇧 · I. Asensi🇨🇭 · D.V. Berlea🇩🇪 · D. Bortoletto🇬🇧 · C. Buttar🇬🇧 · F. Dachs🇨🇭 · V. Dao🇨🇭 · H. Denizli🇹🇷 · D. Dobrijevic🇨🇭 · L. Flores🇨🇭 · A. Gabrielli🇨🇭 and 17 other authors

   The MALTA family of Depleted Monolithic Active Pixel Sensor (DMAPS) produced in Tower 180 nm CMOS technology targets radiation hard applications for the HL-LHC and beyond. Several process modifications and front-end improvements have resulted in radiation hardness up to $2\times 10^{15}1\text{MeV}{\text{n}}_{eq}/{\text{cm}}^2$ and time resolution below 2 ns, with uniform charge collection efficiency across the Pixel of size $36.4\times 36.4\mu {\text{m}}^2$ with a $3\mu {\text{m}}^2$ electrode size. The MALTA2 demonstrator produced in 2021 on high-resistivity epitaxial silicon and on Czochralski substrates implements a new cascoded front-end that reduces the RTS noise and has a higher gain. This contribution shows results from MALTA2 on timing resolution at the nanosecond level from the CERN SPS test-beam campaign of 2021.

   ↳ physics.ins-dethep-exnucl-exJINST(2022)·10 citations
5. 05*

   Precision QCD, Hadronic Structure & Forward QCD, Heavy Ions: Report of Energy Frontier Topical Groups 5, 6, 7 submitted to Snowmass 2021

   M. Begel · S. Hoeche · M. Schmitt · H.-W. Lin · P.M. Nadolsky · C. Royon · Y-J. Lee · S. Mukherjee · C. Baldenegro · J. Campbell · G. Chachamis · F.G. Celiberto and 38 other authors

   This report was prepared on behalf of three Energy Frontier Topical Groups of the Snowmass 2021 Community Planning Exercise. It summarizes the status and implications of studies of strong interactions in high-energy experiments and QCD theory. We emphasize the rich landscape and broad impact of these studies in the decade ahead. Hadronic interactions play a central role in the high-luminosity Large Hadron Collider (LHC) physics program, and strong synergies exist between the (HL-)LHC and planned or proposed experiments at the U.S. Electron-Ion Collider, CERN forward physics experiments, high-intensity facilities, and future TeV-range lepton and hadron colliders. Prospects for precision determinations of the strong coupling and a variety of nonperturbative distribution and fragmentation functions are examined. We also review the potential of envisioned tests of new dynamical regimes of QCD in high-energy and high-density scattering processes with nucleon, ion, and photon initial states. The important role of the high-energy heavy-ion program in studies of nuclear structure and the nuclear medium, and its connections with QCD involving nucleons are summarized. We address ongoing and future theoretical advancements in multi-loop QCD computations, lattice QCD, jet substructure, and event generators. Cross-cutting connections between experimental measurements, theoretical predictions, large-scale data analysis, and high-performance computing are emphasized.

   ↳ hep-phhep-exhep-latnucl-ex+135 citations
6. 06*

   The Nuclear Physics of Neutron Stars

   J. Piekarewicz🇺🇸

   Neutron stars -- compact objects with masses similar to that of our Sun but radii comparable to the size of a city -- contain the densest form of matter in the universe that can be probed in terrestrial laboratories as well as in earth- and space-based observatories. The historical detection of gravitational waves from a binary neutron star merger has opened the brand new era of multimessenger astronomy and has propelled neutron stars to the center of a variety of disciplines, such as astrophysics, general relativity, nuclear physics, and particle physics. The main input required to study the structure of neutron stars is the pressure support generated by its constituents against gravitational collapse. These include neutrons, protons, electrons, and perhaps even more exotic constituents. As such, nuclear physics plays a prominent role in elucidating the fascinating structure, dynamics, and composition of neutron stars.

   ↳ nucl-thastro-ph.HEnucl-ex14 citations
7. 07*

   Cosmogenic activation of sodium iodide

   R. Saldanha🇺🇸 · W.G. Thompson🇺🇸 · Y.Y. Zhong🇦🇺 · L.J. Bignell🇦🇺 · R.H.M. Tsang🇺🇸 · S.J. Hollick🇺🇸 · S.R. Elliott🇺🇸 · G.J. Lane🇦🇺 · R.H. Maruyama🇺🇸 · L. Yang🇺🇸

   The production of radioactive isotopes by interactions of cosmic-ray particles with sodium iodide (NaI) crystals can produce radioactive backgrounds in detectors used to search for rare events. Through controlled irradiation of NaI crystals with a neutron beam that matches the cosmic-ray neutron spectrum, followed by direct counting and fitting the resulting spectrum across a broad range of energies, we determined the integrated production rate of several long-lived radioisotopes. The measurements were then extrapolated to determine the sea-level cosmogenic neutron activation rate, including the first experimental determination of the tritium production rate: $(80\pm 21)$ atoms/kg/day. These results will help constrain background estimates and determine the maximum time that NaI-based detectors can remain unshielded above ground before cosmogenic backgrounds impact the sensitivity of next-generation experiments.

   ↳ hep-exnucl-exphysics.ins-detPRD(2023)·6 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.