Tue·May 31, 2022Tuesday·May 31, 2022

1. 01*

   Photonuclear reactions ${}^{65}\mathrm{Cu}(\gamma ,n{)}^{64}\mathrm{Cu}$ and ${}^{63}\mathrm{Cu}(\gamma ,xn{)}^{63-x}\mathrm{Cu}$ cross-sections in the energy range $E_{\gamma \max }$ = 35-94 MeV

   O.S. Deiev🇺🇦 · I.S. Timchenko🇺🇦 · S.M. Olejnik🇺🇦 · S.M. Potin🇺🇦 · V.A. Kushnir🇺🇦 · V.V. Mytrochenko · S.A. Perezhogin🇺🇦 · B.I. Shramenko

   The bremsstrahlung flux-averaged cross-sections $⟨\sigma (E_{\gamma \max })⟩$ for the photonuclear reactions ${}^{65}\mathrm{Cu}(\gamma ,n{)}^{64}\mathrm{Cu}$, ${}^{63}\mathrm{Cu}(\gamma ,n{)}^{62}\mathrm{Cu}$, ${}^{63}\mathrm{Cu}(\gamma ,2n{)}^{61}\mathrm{Cu}$ and ${}^{63}\mathrm{Cu}(\gamma ,3n{)}^{60}\mathrm{Cu}$ have been measured in the range of bremsstrahlung end-point energies $E_{\gamma \max }$ = 35-94 MeV. The experiments were performed with the electron beam from the NSC KIPT linear accelerator LUE-40 with the use of the activation and off-line $\gamma$-ray spectrometric technique. The calculation of the flux-average cross-sections $⟨\sigma (E_{\gamma \max }){⟩}_{\mathrm{th}}$ was carried out using the cross-section $\sigma (E)$ values from the TALYS1.95 code with the default options. It is shown that the experimental average cross-sections for the reactions ${}^{65}\mathrm{Cu}(\gamma ,n{)}^{64}\mathrm{Cu}$, ${}^{63}\mathrm{Cu}(\gamma ,n{)}^{62}\mathrm{Cu}$, ${}^{63}\mathrm{Cu}(\gamma ,2n{)}^{61}\mathrm{Cu}$ are systematically higher than the theoretical estimates in the TALYS1.95 code. The obtained $⟨\sigma (E_{\gamma \max })⟩$ supplement the data of different laboratories for the case of reactions $(\gamma ,n)$ and $(\gamma ,2n)$. For the reaction ${}^{63}\mathrm{Cu}(\gamma ,3n{)}^{60}\mathrm{Cu}$, the values of $⟨\sigma (E_{\gamma \max })⟩$ were measured for the first time.

   nucl-ex0 citations
2. 02*

   Constraining the $\overline{\mathrm{K}}\mathrm{N}$ coupled channel dynamics using femtoscopic correlations at the LHC

   ALICE Collaboration

   The interaction of ${\mathrm{K}}^{-}$ with protons is characterised by the presence of several coupled channels, systems like ${\overline{\mathrm{K}}}^0$n and $\pi \Sigma$ with a similar mass and the same quantum numbers as the ${\mathrm{K}}^{-}$p state. The strengths of these couplings to the ${\mathrm{K}}^{-}$p system are of crucial importance for the understanding of the nature of the $\Lambda (1405)$ resonance and of the attractive ${\mathrm{K}}^{-}$p strong interaction. In this article, we present measurements of the ${\mathrm{K}}^{-}$p correlation functions in relative momentum space obtained in pp collisions at $\sqrt{s}=13$ TeV, in p-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV, and (semi)peripheral Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV. The emitting source size, composed of a core radius anchored to the ${\mathrm{K}}^{+}$p correlation and of a resonance halo specific to each particle pair, varies between 1 and 2 fm in these collision systems. The strength and the effects of the ${\overline{\mathrm{K}}}^0$n and $\pi \Sigma$ inelastic channels on the measured ${\mathrm{K}}^{-}$p correlation function are investigated in the different colliding systems by comparing the data with state-of-the-art models of chiral potentials. A novel approach to determine the conversion weights $\omega$, necessary to quantify the amount of produced inelastic channels in the correlation function, is presented. In this method, particle yields are estimated from thermal model predictions, and their kinematic distribution from blast-wave fits to measured data. The comparison of chiral potentials to the measured ${\mathrm{K}}^{-}$p interaction indicates that, while the $\pi \Sigma -{\mathrm{K}}^{-}$p dynamics is well reproduced by the model, the coupling to the ${\overline{\mathrm{K}}}^0$n channel in the model is currently underestimated.

   nucl-exhep-exEPJC(2023)·61 citations
3. 03*

   On the definition of electromagnetic local spatial densities for composite spin-$1/2$ systems

   J.Yu. Panteleeva🇩🇪 · E. Epelbaum🇩🇪 · J. Gegelia🇩🇪 · U.-G. Meißner🇩🇪

   An unambiguous definition of the electromagnetic spatial densities for a spin-1/2 system is proposed and worked out in the zero average momentum frame and in moving frames. The obtained results are compared with the traditional definition of the densities in terms of the three-dimensional Fourier transforms of the electromagnetic form factors in the Breit frame.

   ↳ hep-phhep-thnucl-exnucl-thPRD(2022)·36 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.