Mon·Jun 6, 2022Monday·June 6, 2022

1. 01*

   Single-particle properties of the near-threshold proton-emitting resonance in ${}^{11}$B

   Le-Anh Nguyen · Minh-Loc Bui🇻🇳 · Naftali Auerbach🇮🇱 · Vladimir Zelevinsky🇺🇸

   The excitation function of proton elastic scattering from ${}^{10}$Be at keV energy is calculated using the self-consistent Skyrme Hartree-Fock in the continuum method. The calculation successfully reproduces the narrow near-threshold proton-emitting resonance ($E_x=11.4$ MeV, $\Gamma =6$ keV, and quantum number $J^{\pi }=1/2^{+}$) in ${}^{11}$B relevant to the $\beta$-delayed proton emission of ${}^{11}$Be. This supports the recent experimental result of Y. Ayyad \textit{et al.} at the ReA3 re-accelerator facility of the National Superconducting Cyclotron Laboratory (NSCL) at the Michigan State University. The resonance is interpreted as the $s_{1/2}$ single-proton resonance state in the Skyrme Hartree-Fock mean-field theory.

   ↳ nucl-thnucl-exPRC(2022)·11 citations
2. 02*

   Radiative proton capture on ${}^{15}\mathrm{N}$ within effective field theory

   Sangyeong Son🇰🇷 · Shung-Ichi Ando🇰🇷 · Yongseok Oh🇰🇷

   The astrophysical $S$ factor for the radiative proton capture process on the ${}^{15}\mathrm{N}$ nucleus, i.e., ${}^{15}\mathrm{N}(p,\gamma {)}^{16}\mathrm{O}$, at stellar energies are studied within the framework of the cluster effective field theory. The thermonuclear ${}^{15}\mathrm{N}(p,\gamma {)}^{16}\mathrm{O}$ reaction links the type-I to type-II cycles of the carbon-nitrogen-oxygen cycle and affects the abundances of elements in the univere. For investigating this reaction in the effective field theory formalism, we first construct an effective Lagrangian that is appropriate for this reaction at low-energies. Since the intermediate excited states of the ${}^{16}\mathrm{O}$ nucleus have a crucial role in this reaction, we include these resonances in the formalism. The corresponding radiative capture amplitudes and cross section are calculated, which lead to the astrophysical $S$ factor. The low energy constants introduced in the effective Lagrangian are determined by fitting the theoretical results to the observed $S$ factors in the range of $130\mathrm{keV}<E_p<2500\mathrm{keV}$ using three different experimental data sets. Considering the recent data sets, we obtain $S(0)=29.8\text{mbox}-34.1\mathrm{keV}\mathrm{b}$, which is in a good agreement with the estimates from $R$-matrix approaches in the literature. The values of $S$ at the Gamow energy are found to be larger than $S(0)$ values by about $10\%$.

   ↳ nucl-thnucl-exPRC(2022)·5 citations
3. 03*

   Towards a theory of hadron resonances

   Maxim Mai🇺🇸 · Ulf-G. Meißner🇩🇪 · Carsten Urbach🇩🇪

   In this review, we present the current state of the art of our understanding of the spectrum of excited strongly interacting particles and discuss methods that allow for a systematic and model-independent calculation of the hadron spectrum. These are lattice QCD and effective field theories. Synergies between both approaches can be exploited allowing for deeper understanding of the hadron spectrum. Results based on effective field theories and hadron-hadron scattering in lattice QCD or combinations thereof are presented and discussed. We also show that the often used Breit-Wigner parameterization is at odds with chiral symmetry and should not be used in case of strongly coupled channels.

   ↳ hep-phhep-exhep-latnucl-ex+1Phys.Rept.(2023)·156 citations
4. 04*

   Electron Mass Singularities in Semileptonic Kaon Decays

   Chien-Yeah Seng🇩🇪 · William J. Marciano🇺🇸 · Ulf-G. Meißner🇩🇪

   We show that recent improvements in the $O(\alpha )$ long-distance quantum electrodynamics (QED) corrections to the radiative inclusive $K_{e3}$ decay rate using the Sirlin representation are free from infrared divergences and collinear electron mass singularities in the limit $m_e\to 0$, as predicted by the Kinoshita-Lee-Nauenberg theorem. We also verify that in massless QED with the simultaneous dimensional regularization of QED photon infrared divergences and electron mass singularities leads to the same result for the inclusive rate in the limit of four space-time dimensions. The equivalence of the two approaches results in part from an interesting interplay between a small chirality-breaking effect in the massless electron limit and the generalization of space-time algebra and phase space integrals to $d>4$ dimensions. Our finding supports the small theoretical uncertainty claimed for $K_{e3}$ radiative inclusive rates and reaffirms its utility in precision unitarity tests of the quark mixing matrix.

   ↳ hep-phhep-exhep-latnucl-ex+1PRD(2022)·3 citations
5. 05*

   Correcting the $B_A$ coalescence factor at GSI-HADES and RHIC-BES energies

   Apiwit Kittiratpattana🇩🇪 · Tom Reichert🇩🇪 · Jan Steinheimer🇩🇪 · Christoph Herold🇹🇭 · Ayut Limphirat🇹🇭 · Yupeng Yan🇹🇭 · Marcus Bleicher🇩🇪

   We investigate the coalescence factors $B_2$ and $B_3$ at low collision energies ($\sqrt{s_{\mathrm{NN}}}<6$ GeV) with special focus on the HADES and RHIC-BES experiments. It is shown that, in order to properly interpret the coalescence factors $B_A$, two important corrections are necessary: I) $B_2$ has to be calculated using the proton $\times$ neutron yields in the denominator, instead of the square of the proton yield, and II) the primordial proton (neutron) densities have to be used for the normalization and not the final state (free) protons (neutrons). Both effects lead to a drastic reduction of $B_2$ and $B_3$ at low energies. This reduction decreases the discrepancy between the volumes extracted from HBT measurements and the volumes extracted from the coalescence factor ($V\propto 1/B_2$). While at HADES and low RHIC-BES energies these corrections are substantial, they become irrelevant above $\sqrt{s_{\mathrm{NN}}}>6$ GeV. The proposed correction method is model independent and is only based on the measurement of protons, clusters and charged pions.

   ↳ nucl-thnucl-exPRC(2022)·10 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.