Wed·Oct 2, 2024Wednesday·October 2, 2024

1. 01*

   Feasibility studies of dark photon searches with the J-PET detector

   Justyna Mędrala-Sowa🇵🇱 · Elena Perez del Rio🇵🇱 · Wojciech Krzemień🇵🇱

   The positronium, a bound state of electron and positron is a unique system to perform highly precise tests, due to no hadronic background and precise Quantum Electrodynamics (QED) predictions. Being a system of lepton and antilepton, its properties are precisely described by QED in the Standard Model (SM). The final events topology can be simulated using Monte Carlo techniques. The J-PET detector is a multi-purpose, large acceptance system that is very well-suitable to the studies of positronium decay due to its excellent angular (1${}^o$) and timing resolutions. \\ We present preliminary results on the feasibility of searching for Dark Matter (DM) candidates in the decay o-Ps $\to$ invisible with the J-PET, which is well suited for the detection of positronium decay products. Toy Monte Carlo simulations have been prepared to incorporate DM decay models to the o-Ps decay expectations in order to assess the detector capabilities to search for such an elusive component of our Universe.

   nucl-exActa Phys.Polon.Supp.(2024)·2 citations
2. 02*

   Precise Mass Measurement of the Longest Odd-Odd Chain of \boldmath $1^{+}$ Ground States

   B. Liu🇺🇸 · M. Brodeur🇺🇸 · J.A. Clark🇺🇸 · I. Dedes🇵🇱 · J. Dudek🇫🇷 · F. G. Kondev🇺🇸 · D. Ray🇨🇦 · G. Savard🇺🇸 · A.A. Valverde🇺🇸 · A. Baran🇵🇱 · D.P. Burdette🇺🇸 · A.M. Houff🇺🇸 and 5 other authors

   Precise mass measurements of the ground and isomeric states of the odd-odd ${}^{108,110,112,114,116}$Rh were performed using the Canadian Penning Trap at Argonne National Laboratory, showing good agreement with recent JYFLTRAP measurements. A new possible isomeric state of ${}^{114}$Rh was also observed. These isotopes are part of the longest odd-odd chain of identical ground-state spin-parity assignment of 1${}^{+}$, spanning ${}^{104-118}$Rh, despite being in a region of deformation. Realistic phenomenological mean-field calculations using ``universal'' Wood-Saxon Hamiltonian were performed, which explained this phenomenon for the first time. In addition, multi-quasiparticle blocking calculations were performed to study the configuration of low-lying states in the odd-odd Rh nuclei, elucidating anomalous isomeric yield ratio observed for ${}^{114}$Rh.

   nucl-exnucl-thPRC(2025)·7 citations
3. 03*

   Electric dipole polarizability of ${}^{58}$Ni

   I. Brandherm · F. Bonaiti🇺🇸 · P. von Neumann-Cosel🇩🇪 · S. Bacca🇩🇪 · G. Colò🇮🇹 · G.R. Jansen🇺🇸 · Z.Z. Li🇨🇳 · H. Matsubara🇯🇵 · Y.F. Niu🇨🇳 · P.-G. Reinhard🇩🇪 · A. Richter · X. Roca-Maza🇮🇹 · A. Tamii🇯🇵

   The electric dipole strength distribution in ${}^{58}$Ni between 6 and 20 MeV has been determined from proton inelastic scattering experiments at very forward angles at RCNP, Osaka. The experimental data are rather well reproduced by quasiparticle random-phase approximation calculations including vibration coupling, despite a mild dependence on the adopted Skyrme interaction. They allow an estimate of the experimentally inaccessible high-energy contribution above 20 MeV, leading to an electric dipole polarizability ${\alpha }_{\mathrm{D}}{(}^{58}\mathrm{Ni})=3.48(31)$ fm${}^3$. This serves as a test case for recent extensions of coupled-cluster calculations with chiral effective field theory interactions to nuclei with two nucleons on top of a closed-shell system.

   nucl-exnucl-thPRC(2025)·10 citations
4. 04*

   Recent $J/\psi$ measurements at the PHENIX experiment

   Xuan Li (on behalf of the PHENIX collaboration)🇺🇸

   Quarkonium is an ideal probe to explore the properties of quantum chromodynamics (QCD). Unlike Large Hadron Collider (LHC) measurements, quarkonium production at the Relativistic Heavy Ion Collider (RHIC) has different production mechanisms, can access different kinematic phase space and may experience different medium densities/temperatures. The PHENIX experiment has collected a large $J/\psi \to {\mu }^{+}{\mu }^{-}$ data set within its unique pseudorapidity region of $1.2<|\eta |<2.2$ in $p+p$, $p+A$ and $A+A$ collisions at $\sqrt{s}$ = 200 GeV from 2014 to 2016. Latest results of normalized charged particle multiplicity dependent normalized forward $J/\psi$ yields and normalized forward $\psi (2S)$ to $J/\psi$ ratio in 200 GeV $p+p$ collisions as well as forward $J/\psi$ azimuthal anisotropy in 200 GeV Au+Au collisions will be shown. Comparison with other RHIC and LHC measurements and latest theoretical calculations will be discussed. These PHENIX results provide their unique contributions in improving the understanding of the multi-parton interaction contribution to charmonium production and the recombination/coalescence contribution to charmonium formation within Quark Gluon Plasma (QGP) at RHIC energies.

   nucl-exhep-exnucl-thPoS(2025)·0 citations
5. 05*

   Fully upgraded $\beta$-NMR setup at ISOLDE for high-precision high-field studies

   M. Jankowski🇨🇭 · N. Azaryan🇵🇱 · M. Baranowski🇨🇭 · M. L. Bissell🇬🇧 · H. Brand🇩🇪 · M. Chojnacki🇨🇭 · J. Croese🇨🇭 · K. M. Dziubinska-Kühn🇨🇭 · B. Karg🇨🇭 · M. Madurga Flores🇺🇸 · M. Myllymäki🇫🇮 · M. Piersa-Silkowska🇨🇭 and 4 other authors

   $\beta$-NMR is an advancing technique that enables measurements relevant to various fields of research, ranging from physics to chemistry and biology. Among the recent achievements of the $\beta$-NMR setup located at the ISOLDE facility at CERN is the determination of the magnetic moment of a shortlived nucleus with a part-per-million accuracy. Presented here are major upgrades and extensions of that $\beta$-NMR setup. The most important advancement is the installation of a 4.7 T superconducting solenoidal magnet, leading to sub-ppm spatial homogeneity and temporal stability of the magnetic field. A detector array optimised for such magnetic field has also been implemented and a more powerful, time-resolved, fully-digital data acquisition system has been deployed. To commission the upgraded beamline, $\beta$-NMR resonances of short-lived 26Na were recorded in solid and liquid samples. These showed 3-fold narrower linewidths and 15-fold higher resolving power than using the previous setup. Hence, the improvements achieved here permit more accurate bio-$\beta$-NMR studies, investigating, e.g., the interaction of metal ions with biomolecules, such as DNA. They also pave the way for the first studies of the distribution of the magnetisation inside short-lived nuclei.

   ↳ physics.ins-detnucl-exJINST(2026)·1 citation
6. 06*

   Enhancing DUNE's solar neutrino capabilities with neutral-current detection

   Stephan A. Meighen-Berger🇦🇺 · Jayden L. Newstead🇦🇺 · John F. Beacom🇺🇸 · Nicole F. Bell🇦🇺 · Matthew J. Dolan🇦🇺

   We show that the Deep Underground Neutrino Experiment (DUNE) has the potential to make a precise measurement of the total active flux of 8B solar neutrinos via neutral-current (NC) interactions with argon. This would complement proposed precise measurements of solar-neutrino fluxes in DUNE via charged-current (CC) interactions with argon and mixed CC/NC interactions with electrons. Together, these would enable DUNE to make a SNO-like comparison of rates and thus to make the most precise measurements of ${\sin }^2{\theta }_{12}$ and $\Delta m_{21}^2$ using solar neutrinos. Realizing this potential requires dedicated but realistic efforts to improve DUNE's low-energy capabilities and separately to reduce neutrino-argon cross section uncertainties. Comparison of mixing-parameter results obtained using solar neutrinos in DUNE and reactor antineutrinos in JUNO (Jiangmen Underground Neutrino Observatory) would allow unprecedented tests of new physics.

   ↳ hep-phhep-exnucl-exnucl-th+1PRL(2025)·13 citations
7. 07*

   Mirror and triplet energy differences in $sd$-shell nuclei using microscopic interactions with isospin-symmetry breaking effects

   Chandan Sarma🇬🇧 · Praveen C. Srivastava🇮🇳 · Toshio Suzuki🇯🇵 · Noritaka Shimizu🇯🇵

   In this study, we developed and tested two different isospin symmetry-breaking (ISB) versions of the microscopic DJ16A interaction. Starting with the isospin symmetric DJ16A interaction, we introduced two different Coulomb interactions- Coulomb-CD and Coulomb-w/SRC- along with phenomenological charge symmetry breaking (CSB) and charge independence breaking (CIB) effects. Then, we employed these interactions to calculate $b$- and $c$-parameters of the isobaric multiplet mass equation for $|T_z|=1/2$ and $|T_z|=1$ nuclei across the $sd$-shell. Our results indicate that the DJ16A${}^{†}$ interaction provides the most accurate $b$-parameter predictions between the two DJ16A-based interactions. Additionally, we explored mirror energy differences (MEDs) in low-energy spectra around $A=20$ and demonstrated that large MEDs are primarily associated with high occupancies of the $1s_{1/2}$ orbital. Furthermore, $E2$ transition strengths were calculated using both DJ16A-based ISB interactions agreed with the experimental data, with minimal ISB effects observed on these transitions. Overall, the DJ16A${}^{†}$ interaction serves as a complementary set to the newly developed USD-family interactions, USDC, and USDCm and can be further tested for other mirror nuclei across the $sd$-shell to study nuclear structure properties and ISB effects in nuclear $\beta$-decay.

   ↳ nucl-thnucl-ex3 citations
8. 08*

   Fast timing silicon R$\&$D for the future Electron-Ion Collider

   Xuan Li🇺🇸 · Eric Renner🇺🇸 · Ming Liu🇺🇸 · Walter Sondheim🇺🇸 · Carlos Solans Sanchez🇨🇭 · Marcos Vazquez Nuñez🇪🇸 · Vicente Gonzalez🇪🇸 · Yasser Corrales Morales🇺🇸

   The proposed Electron-Ion Collider (EIC) will utilize high-luminosity high-energy electron+proton ($e+p$) and electron+nucleus ($e+A$) collisions to solve several fundamental questions including searching for gluon saturation and studying the proton/nuclear structure. Complementary to the ongoing EIC project detector technical prototype carried out by the ePIC collaboration, a Depleted Monolithic Active Pixel Sensor (i.e., MALTA2) based fast timing silicon tracking detector (FMT) has been proposed to provide additional hits for track reconstruction in the forward and backward region at the EIC to improve the overall track reconstruction quality. The fast timing resolution of the MALTA2 technology will help reject background events at the EIC as well. Progress of latest MALTA2 R$\&$D, the development of a new MALTA2 quad-sensor prototype module and impacts of the proposed FMT in EIC physics studies will be discussed.

   ↳ physics.ins-dethep-exnucl-exEPJ Web Conf.(2025)·1 citation
9. 09*

   Production and study of antideuterium with the GBAR beamline

   Philipp Blumer🇨🇭 · Ben Ohayon🇮🇱 · Paolo Crivelli🇨🇭

   The potential of circulating antideuterons ($\overline{\mathrm{d}}$) in the AD/ELENA facility at CERN is under active investigation. Approximately 100 $\overline{\mathrm{d}}$ per bunch could be delivered as a $100\mathrm{keV}$ beam based on measured cross-sections. These $\overline{\mathrm{d}}$ could be further decelerated to $12\mathrm{keV}$ using the GBAR scheme, enabling the synthesis of antideuterium ($\overline{\mathrm{D}}$) via charge exchange with positronium, a technique successfully demonstrated with $6\mathrm{keV}$ antiprotons for antihydrogen production. The AD/ELENA facility is currently studying the possibility of increasing the $\overline{\mathrm{d}}$ rate using an optimized new target geometry. Assuming this is feasible, we propose further enhancing the anti-atom production by using laser-excited positronium in the $2P$ state within a cavity, which is expected to increase the $\overline{\mathrm{D}}(2S)$ production cross-section by almost an order of magnitude for $\overline{\mathrm{d}}$ with $2\mathrm{keV}$ energy. We present the projected precision for measuring the antideuterium Lamb shift and extracting the antideuteron charge radius, as a function of the beam flux.

   ↳ physics.atom-phhep-exhep-phnucl-exEur.Phys.J.D(2025)·4 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.