Tue·Sep 24, 2024Tuesday·September 24, 2024

1. 01*

   Investigating the fission-like fragments in the ${}^{12}$C + ${}^{208}$Pb system at E${}^{\star }$ $\approx$ 31.8--45.4 MeV

   Rupinderjeet Kaur🇮🇳 · Amanjot🇮🇳 · Priyanka🇮🇳 · Malika Kaushik🇮🇳 · Subham Kumar🇮🇳 · Arshiya Sood🇫🇷 · Yashraj Jangid🇮🇳 · R. Kumar🇮🇳 · Manoj Kumar Sharma🇮🇳 · Pushpendra P. Singh🇮🇳

   In this work, the cross-sections of 25 fission-like fragments within the mass range 76$\le$A$\le$141, expected to be populated via fission of moderately excited compound nucleus produced as a result of complete and/or incomplete fusion in ${}^{12}$C+${}^{208}$Pb reaction at E${}_{\mathrm{lab}}$ = 81.9 and 75.8 MeV, have been measured using activation technique followed by offline $\gamma$-ray spectroscopy. The yields of different fission-like fragments have been analyzed to generate isotopic and isobaric yield distributions. The value of the mass dispersion parameter, ${\sigma }_A^2$, is found to be 2.93 and 2.65 for Antimony (Sb) isotope at excitation energy E${}^{\star }$ = 45.4 and 39.6 MeV, and 1.24 for Indium (In) isotope at E${}^{\star }$ = 45.4 MeV. The charge dispersion parameter ${\sigma }_Z$ for Sb is estimated to be 0.769 and 0.714 at E${}^{\star }$ = 45.4 and 39.6 MeV, respectively. For In isotopes, the value of ${\sigma }_Z$ is estimated to be 0.430 at E${}^{\star }$ = 45.4 MeV. The value of mass and charge dispersion parameters for Sb and In isotopes have been found to be in good agreement with the values reported in the literature for similar systems. The mass distribution of fission-like fragments is found to be fitted with a Gaussian function, except for a few data points, indicating their population via compound nucleus fission. Further, the mass variance (${\sigma }_M^2$) displays linear increment with an increase in excitation energy. Two medically important isotopes, ${}^{99m}$Tc and ${}^{111}$In, are populated in this system, suggesting a potential formation route.

   nucl-ex0 citations
2. 02*

   Highlights of Unstable States in Relativistic Dissociation of Light Nuclei in Nuclear Emulsion

   D.A. Artemenkov🇷🇺 · N.K. Kornegrutsa · N.G. Peresadko · V.V. Rusakova · A.A. Zaitsev🇷🇺 · P.I. Zarubin🇷🇺 · I.G. Zarubina

   The results of the study of unstable states in relativistic dissociation of isotopes ${}^{9,7}$Be, ${}^{10}$B, ${}^{12,11,10}$C, ${}^{14}$N and ${}^{16}$O in nuclear emulsion have been summarized. Their decays are identified in distributions by invariant masses determined by fragment emission angles in the velocity conservation approximation. The observed diversity enables us to assume universality in the formation of nuclear-molecular states near the bond thresholds as a consequence of coalescence of emerging $\alpha$-particles and nucleons.

   nucl-exIJMPE(2024)·4 citations
3. 03*

   Dissociation of Relativistic ${}^{10}$B Nuclei in Nuclear Track Emulsion

   A. A. Zaitsev · D. A. Artemenkov🇷🇺 · V. Bradnova · P. I. Zarubin🇷🇺 · I. G. Zarubina · R. R. Kattabekov · N. K. Kornegrutsa · K. Z. Mamatkulov · E. K. Mitsova · A. Neagu · P. A. Rukoyatkin · V. V. Rusakova and 4 other authors

   The structural features of ${}^{10}$B are studied by analyzing the dissociation of nuclei of this isotope at an energy of 1 A GeV in nuclear track emulsion. The fraction of the ${}^{10}$B $\to$ 2He + H channel in the charge state distribution of fragments is 78\%. It was determined based on the measurements of fragment emission angles that unstable ${}^8$Be${}_{g.s.}$ nuclei appear with a probability of (26 $\pm$ 4)\%, and (14 $\pm$ 3)\% of them are produced in decays of an unstable ${}^9$B${}_{g.s.}$ nucleus. The Be + H channel was suppressed to approximately 1\%.

   nucl-exPhys.Part.Nucl.(2017)·4 citations
4. 04*

   Discovery of a new long-lived isomer in ${}^{114}$Rh via Penning-trap mass spectrometry

   M. Stryjczyk🇫🇮 · A. Jaries🇫🇮 · W. Ryssens🇧🇪 · M. Bender🇫🇷 · A. Kankainen🇫🇮 · T. Eronen🇫🇮 · Z. Ge🇫🇮 · I.D. Moore🇫🇮 · M. Mougeot🇫🇮 · A. Raggio🇫🇮 · J. Ruotsalainen🇫🇮

   We report on mass measurements of three long-lived states in ${}^{114}$Rh performed with the JYFLTRAP Penning-trap mass spectrometer: the ground state and two isomers with estimated half-lives of about one second. The used Phase-Imaging Ion-Cyclotron-Resonance technique allowed for the discovery of a so far unknown second long-lived isomer. All three states were produced directly in proton-induced fission on a uranium target, whereas only the isomeric states were populated in the $\beta$ decay of the ${}^{114}$Ru ground state with spin-parity $0^{+}$. We propose spin-parity assignments of $(6^{-})$ for the ground state, and $(3^{+})$ and $(0^{-})$ for the isomers. They resolve the puzzle of anomalous fission yields of this isotope despite the existing literature assigning a low angular momentum to the ground state. The experimental evidence is further supported by a detailed analysis based on mean-field calculations with the BSkG3 model. As for many other nuclei in this mass region, considering triaxial shapes is decisive for the interpretation of low-lying states of this nucleus. The discovery of a new isomer in ${}^{114}$Rh and our theoretical work challenge the currently adopted spin-parity assignments in this and several other odd-odd neutron-rich Rh isotopes.

   nucl-exnucl-thPLB(2025)·5 citations
5. 05*

   Exploring ${\beta }^{+}$ decay/EC residues in ${}^{118}$Sn(${}^{12}$C,x)${}^{130}$Ba reaction

   Priyanka🇮🇳 · Amanjot🇮🇳 · Rupinderjeet Kaur🇮🇳 · Arshiya Sood🇫🇷 · Malika Kaushik🇮🇳 · Yashraj Jangid🇮🇳 · Rakesh Kumar🇮🇳 · Manoj K. Sharma🇮🇳 · Pushpendra P. Singh🇮🇳

   The fusion cross-sections of ${}^{126}$Ba, ${}^{127,126,125}$Cs, ${}^{125,123,122}$Xe and ${}^{124,123}$I residues, populated via $x$n, p$x$n, $\alpha$$x$n, and $\alpha$p$x$n channels, have been measured in ${}^{12}$C+${}^{118}$Sn system at E${}_{\text{lab}}$ $\approx$ 65-85 MeV using offline $\gamma$-spectroscopy. To gain insights into the formation and decay modes of these residues, experimentally measured cross-sections have been analyzed using the statistical model codes PACE4 and EMPIRE. In the analysis, the cross-sections of p$x$n (${}^{127,126,125}$Cs), $\alpha$xn (${}^{125}$Xe), and $\alpha$p$x$n (${}^{123}$I) channels are substantially fed from their higher charge isobars via ${\beta }^{+}$ decay and electron capture. The contribution of ${\beta }^{+}$ decay and electron capture has been calculated using the prescription of Cavinato $et$ $al.$\cite{cavinato1995study} and the independent cross-sections of these residues have been compared with PACE4 and EMPIRE calculations, which fairly reproduce the independent cross-sections of evaporation-residue within the experimental uncertainties. Interestingly, it has been observed that the $\alpha$-emitting channels, contrary to established findings in reactions involving $\alpha$ cluster projectiles (e.g., ${}^{12}$C, ${}^{16}$O, etc.) at the studied energy range, display negligible or no contribution of incomplete fusion (ICF) in ${}^{12}$C+${}^{118}$Sn system. The absence of ICF has been verified through a complementary experiment in which the forward recoil ranges of ${}^{126}$Ba(4n) and ${}^{125}$Xe($\alpha$n) channels have been measured. Present measurements reveal anomalous suppression of ICF in the ${}^{12}$C+${}^{118}$Sn system, providing new constraints on entrance-channel mass-asymmetry systematics absent in prior data.

   nucl-ex0 citations
6. 06*

   Measurements of a LYSO crystal array from threshold to 100 MeV

   O. Beesley🇺🇸 · J. Carlton🇺🇸 · B. Davis-Purcell🇨🇦 · D. Ding🇨🇳 · S. Foster🇺🇸 · K. Frahm · L. Gibbons🇺🇸 · T. Gorringe🇺🇸 · D. W. Hertzog🇺🇸 · S. Hochrein · J. Hui🇨🇳 · P. Kammel🇺🇸 and 7 other authors

   We report measurements of ten custom-made high-homogeneity LYSO crystals. The investigation is motivated by the need for a compact, high-resolution, and fast electromagnetic calorimeter for a new rare pion decay experiment. Each $2.5\times 2.5\times 18$ cm${}^3$ crystal was first characterized for general light yield properties and then its longitudinal response uniformity and energy resolution were measured using low-energy gamma sources. The ten crystals were assembled as an array and subjected to a 30 - 100 MeV positron beam with excellent momentum definition. The energy and timing resolutions were measured as a function of energy, and the spatial resolution was determined at 70 MeV. An additional measurement using monoenergetic 17.6 MeV gammas produced through a p-Li resonance was later made after the photosensors used in positron testing were improved. As an example of the results, the energy resolution at 70 MeV of 1.52 $\pm$ 0.03% is more than two times better than reported results using previous generation LYSO crystals.

   ↳ physics.ins-dethep-exnucl-exNucl.Instrum.Meth.A(2025)·4 citations
7. 07*

   Effect of isoscalar and isovector scalar fields on baryon semileptonic decays in nuclear matter

   Koichi Saito🇯🇵 · Tsuyoshi Miyatsu🇰🇷 · Myung-Ki Cheoun🇰🇷

   The precise determination of the Cabibbo-Kobayashi-Maskawa (CKM) matrix elements is very important, because it could be a clue to new physics beyond Standard Theory. This is particular true of $V_{ud}$, because it is the main contribution to the unitary condition of the CKM matrix elements. The level of accuracy for the test of the unitarity involving the element $V_{ud}$ is now of the order of $10^{-4}$. Because the precise data for $V_{ud}$ is usually extracted from super-allowed nuclear $\beta$ decay, it is quite significant to investigate the breaking of SU(3) flavor symmetry on the weak vector coupling constant in nuclear matter. The purpose of this paper is to investigate how the isoscalar scalar ($\sigma$) and the isovector scalar ($\delta$ or $a_0$) mean-fields affect the weak vector and axial-vector coupling constants for semileptonic baryon (neutron, $\Lambda$ or ${\Xi }^{-}$) decay in asymmetric nuclear matter. To do so, we use the quark-meson coupling (QMC) model, where nuclear matter consists of nucleons including quark degrees of freedom bound by the self-consistent exchange of scalar and vector mesons. We pay careful attention to the center of mass correction to the quark currents in matter. We then find that, for neutron $\beta$ decay in asymmetric nuclear matter, the defect of the vector coupling constant due to the $\delta$ field can be of the order of $10^{-4}$ at the nuclear saturation density, which is the same amount as the level of the current uncertainty in the measurements. It is also interesting that, in neutron-rich matter, there exists a certain low density at which isospin symmetry is restored, that is, the $u$-$d$ quark mass difference vanishes. We conclude that the effect of the isoscalar scalar and the isovector scalar fields should be considered in baryon semileptonic decays in nuclei.

   ↳ hep-phnucl-exnucl-thPRD(2024)·4 citations
8. 08*

   First image-guided treatment of a mouse tumor with radioactive ion beams

   Daria Boscolo · Giulio Lovatti · Olga Sokol · Tamara Vitacchio · Francesco Evangelista · Emma Haettner · Walter Tinganelli · Christian Graeff · Uli Weber · Christoph Schuy · Munetaka Nitta · Martina Moglioni and 7 other authors

   Radioactive ion beams (RIB) are a key focus of current research in nuclear physics. Already long ago it was proposed that they could have applications in cancer therapy. In fact, while charged particle therapy is potentially the most effective radiotherapy technique available, it is highly susceptible to uncertainties in the beam range. RIB are well-suited for image-guided particle therapy, as isotopes that undergo \b{eta}+-decay can be precisely visualized using positron emission tomography (PET), enabling accurate real-time monitoring of the beam range. We successfully treated a mouse osteosarcoma using a radioactive 11C-ion beam. The tumor was located in the neck, in close proximity to the spinal cord, increasing the risk of radiation-induced myelopathy from even slight variations in the beam range caused by anatomical changes or incorrect calibration of the planning CT. We managed to completely control the tumor with the highest dose while minimizing toxicity. Low-grade neurological side effects were correlated to the positron activity measured in the spine. The biological washout of the activity from the tumor volume was dependent on the dose, indicating a potential component of vascular damage at high doses. This experiment marks the first instance of tumor treatment using RIB and paves the way for future clinical applications.

   ↳ physics.med-phnucl-exphysics.acc-phphysics.app-ph+1Nat.Phys.(2025)·2 citations
9. 09*

   Disentangling nuclear structure through multiparticle azimuthal correlations in high-energy isobar collisions

   Zaining Wang🇨🇳 · Jinhui Chen🇨🇳 · Jiangyong Jia🇺🇸 · Yu-Gang Ma🇨🇳 · Chunjian Zhang🇨🇳

   Event-by-event fluctuations in the amplitudes of flow harmonics offer a novel approach to probing the initial-state characteristics in heavy-ion collisions. In this study, we conduct a systematic investigation of correlations among various flow harmonics utilizing multiparticle cumulants in ${}^{96}$Ru+${}^{96}$Ru and ${}^{96}$Zr+${}^{96}$Zr collisions at $\text{sqrtsnn}=$ 200 GeV within the framework of a multiphase transport model. Correlated nuclear density distributions specific to the isobar systems are incorporated to evaluate the sensitivity of selected observables to variations in nuclear deformation and neutron skin thickness. The analysis reveals that multiparticle azimuthal correlations are responsive to these nuclear structure features, predominantly in the most central collision events. Furthermore, the examined correlations exhibit shallow dependence on the assumed shear viscosity values. These findings provide a quantitative evaluation of the extent to which multiparticle flow observables can discern nuclear structure effects in isobar collisions and offer valuable guidance for future detailed dynamical investigations and experimental measurements.

   ↳ nucl-thnucl-exPRC(2026)·6 citations
10. 10*

    Towards Flexible Intensity Control of Resonantly Scattered $\gamma$-Rays Using Multi-Frequency Vibrating Resonant Absorber

    Aleš Stejskal · Vlastimil Vrba🇨🇿 · Vít Procházka

    We report a method for coherent control of $\gamma$-photons, enabling the shaping of $\gamma$-ray intensity in nearly arbitrary waveforms. Different intensity waveforms are created by adjusting the motion profile of a resonant absorber (an ensemble of Mössbauer nuclei) and tuning the energy of the incident radiation. A crucial aspect of this method is the use of a low fundamental frequency of vibrations, which broadens the possibilities for $\gamma$-ray control. The results of numerical simulations are experimentally validated by generating single and double $\gamma$-pulses and inducing short-term absorption. For this, a resonant absorber containing ${}^{57}$Fe nuclei was vibrated with different motion profiles composed of 12 harmonics with a fundamental frequency of 1\,MHz. The proposed technique represents an advancement in the manipulation of $\gamma$-rays and potentially X-rays, paving the way for the performance of unique types of $\gamma$-ray or X-ray quantum experiments and the development of tools such as adjustable tabletop $\gamma$-pulse sources or $\gamma$-ray or X-ray delays and gates. Moreover, inverse application of the method enables investigation of motion at the picometer scale.

    ↳ physics.ins-detnucl-exAppl.Phys.Lett.(2025)·3 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.