Nuclear Theory·nucl-th

Monday·February 8, 2021

6 papers—2 primary·4 cross-listed

01
Halo EFT calculation of charge form factor for two-neutron $^{6} He$ halo nucleus: two-body resonant P-wave interaction
S. Jesri🇮🇷 · M. Moeini Arani🇮🇷 · S. Bayegan🇮🇷
We take a new look at $^{6} He$ halo nucleus and set up a halo effective field theory at low energies to calculate the charge form factor of $^{6} He$ system with resonant P-wave interaction. P-wave Lagrangian has been introduced and the charge form factor of $^{6} He$ halo nucleus has been obtained at Leading-Order. In this study, the mean-square charge radius of $^{6} He$ nucleus relative to $^{4} He$ core and the root-mean-square (r.m.s) charge radius of $^{6} He$ nucleus have been estimated as $⟨ r_{E}^{2} ⟩ = 1.408 fm^{2}$ and $⟨ r_{E}^{2} ⟩_{^{6} H e}^{\frac{1}{2}} = 2.058 fm$ , respectively. We have compared our results with the other available theoretical and experimental data.
nucl-thEPJA(2021)·1 citation
02
A study of open shell nuclei using chiral two-body interactions
Giovanni Puddu🇮🇹
We apply the Hybrid-Multi-Determinant method using the recent chiral two-body interactions of Entem-Machleidt-Nosyk (EMN) without renormalization to few nuclei up to A=48. Mostly we use the bare fifth order NN interaction N4LO-450. For $^{24} M g$ and $^{48} C r$ the excitation energies of the $2_{1}^{+}$ states are far larger than the corresponding experimental values.
nucl-thJ.Phys.G(2021)·2 citations
03
The Fermi constant from muon decay versus electroweak fits and CKM unitarity
Andreas Crivellin🇨🇭 · Martin Hoferichter🇨🇭 · Claudio Andrea Manzari🇨🇭
The Fermi constant ( $G_{F}$ ) is extremely well measured through the muon lifetime, defining one of the key fundamental parameters in the Standard Model (SM). Therefore, to search for physics beyond the SM (BSM) via $G_{F}$ , the constraining power is determined by the precision of the second-best independent determination of $G_{F}$ . The best alternative extractions of $G_{F}$ proceed either via the global electroweak (EW) fit or from superallowed $β$ decays in combination with the Cabibbo angle measured in kaon, $τ$ , or $D$ decays. Both variants display some tension with $G_{F}$ from muon decay, albeit in opposite directions, reflecting the known tensions within the EW fit and hints for the apparent violation of CKM unitarity, respectively. We investigate how BSM physics could bring the three determinations of $G_{F}$ into agreement using SM effective field theory and comment on future perspectives.
↳ hep-phhep-exhep-latnucl-ex+1PRL(2021)·77 citations
04
Hot QCD at finite isospin density: confronting SU(3) Nambu-Jona-Lasinio model with recent lattice data
Bruno. S. Lopes🇧🇷 · Sidney S. Avancini🇧🇷 · Aritra Bandyopadhyay🇨🇳 · Dyana C. Duarte🇺🇸 · Ricardo L. S. Farias🇧🇷
Extending our recently published $S U (2)$ results for zero temperature we now compute the QCD equation of state for finite isospin density within the three flavor Nambu-Jona-Lasinio model in the mean field approximation, motivated by the recently obtained Lattice QCD results for both zero and finite temperatures. Like our previous study, here also we have considered both the commonly used Traditional cutoff Regularization Scheme and the Medium Separation Scheme. Our results are compared with recent high-precision lattice simulations as well as previously obtained results in two-flavor Nambu-Jona-Lasinio model. The agreement between the lattice results and the predictions from three-flavor NJL model is very good for low values of $μ_{I}$ (for both zero and finite temperatures). For larger values of $μ_{I}$ , the agreement between lattice data and the two-flavor NJL predictions is surprisingly good and better than with the three-flavor predictions.
↳ hep-phhep-lathep-thnucl-thPRD(2021)·31 citations
05
On the interpretation of $Λ$ spin polarization measurements
Wojciech Florkowski🇵🇱 · Radoslaw Ryblewski🇵🇱
The physics interpretation of the recent measurements of the spin polarization of $Λ$ hyperons produced in relativistic heavy-ion collisions is discussed. We suggest that the polarization measured in the $Λ$ rest frame should be projected along the direction of the total angular momentum that is first transformed to the same frame, and only then averaged over $Λ$ 's with different momenta in the center-of-mass frame. While this procedure does not affect the current measurements done in a broad transverse-momentum range, it may become important (represent a correction of about 10\%) for the most energetic hyperons under study (with transverse momenta reaching 4-5 GeV/c). The proposed treatment is generally more appropriate for relativistic $Λ$ 's. Throughout the paper, we deliver explicit expressions for various boosts, rotations, and transformations of angular distributions, which may help to compare model predictions with the experimental results.
↳ hep-phnucl-exnucl-thPRC(2022)·18 citations
06
Extracting the low-energy constant $L_{0}^{r}$ at three flavors from pion-kaon scattering
Chaitra Kalmahalli Guruswamy🇩🇪 · Ulf-G. Meißner🇩🇪 · Chien-Yeah Seng🇩🇪
Based on our analysis of the contributions from the connected and disconnected contraction diagrams to the pion-kaon scattering amplitude, we provide the first determination of the only free low-energy constant at $O (p^{4})$ , known as $L_{0}^{r}$ , in SU $(4∣1)$ Partially-Quenched Chiral Perturbation Theory using the data from the Extended Twisted Mass Collaboration, $L_{0}^{r} (μ = M_{ρ}) = 0.77 (20) (25) (7) (7) (2) \cdot 1 0^{- 3}$ . The theory uncertainties originate from the unphysical scattering length, the physical low-energy constants, the higher-oder chiral corrections, the (lattice) meson masses and the pion decay constant, respectively
↳ hep-lathep-phnucl-thCommun.Theor.Phys.(2022)·1 citation

Affiliations

first authorsco-authorsvia INSPIRE

Halo EFT calculation of charge form factor for two-neutron 6He halo nucleus: two-body resonant P-wave interaction

A study of open shell nuclei using chiral two-body interactions

The Fermi constant from muon decay versus electroweak fits and CKM unitarity

Hot QCD at finite isospin density: confronting SU(3) Nambu-Jona-Lasinio model with recent lattice data

On the interpretation of Λ spin polarization measurements

Extracting the low-energy constant L0r​ at three flavors from pion-kaon scattering

Affiliations

Halo EFT calculation of charge form factor for two-neutron $^{6} He$ halo nucleus: two-body resonant P-wave interaction

On the interpretation of $Λ$ spin polarization measurements

Extracting the low-energy constant $L_{0}^{r}$ at three flavors from pion-kaon scattering