Thu·Jan 19, 2023Thursday·January 19, 2023

1. 01*

   Systematic study for relation between nuclear structure and reaction in ${}^{10}$Be nucleus

   T. Furumoto🇯🇵 · T. Suhara · N. Itagaki🇯🇵

   We systematically investigate the relation between the nuclear structure and reaction in the ${}^{10}$Be nucleus using a theoretical framework. The structure of the ${}^{10}$Be nucleus is constructed with a cluster model based on a microscopic viewpoint. In this paper, the ${}^{10}$Be nucleus with different structures is prepared by manipulating the parameters of an effective nucleon-nucleon interaction. The nuclear structure and expectation values of physical quantities are drastically changed by the modification. We summarize such changes and show the effects on the elastic and inelastic scatterings for the proton and ${}^{12}$C targets in the microscopic coupled-channel calculation. Especially, we recently reported the visualization of dineutron correlation in ${}^{10}$Be on proton inelastic scattering in [Phys. Rev. C104, 034613 (2021)]. In this preceding work, we found that the changing the degree of dineutron correlation in ${}^{10}$Be leads to drastic changes of the inelastic cross section for the 2${}_2^{+}$ state. The development (or breaking) of the dineutron correlation is governed by the strength of the spin-orbit interaction of the structure calculation. However, in the previous work, some of the realistic physical points were missing, for example, the binding energy. Therefore, we reconstruct the ${}^{10}$Be nucleus by adjusting the effective nucleon-nucleon interaction to obtain the reasonable binding energy of the ground state. With this improvement, we again discuss the dineutron correlation in the ${}^{10}$Be nucleus. We reconfirm the way to measure the degree of the development (or breaking) of dineutron cluster structure; the sensitivity to the inelastic cross section of the ground state to the 2${}_2^{+}$ state of ${}^{10}$Be.

   ↳ nucl-thnucl-exPTEP(2023)·2 citations
2. 02*

   Three-body coupled channel framework for two-neutron halo nuclei

   Jin-Yi Pang🇨🇳 · Li-Tan Li · Feng-Kun Guo🇨🇳 · Jia-Jun Wu🇨🇳

   We study the Borromean nuclei formed by a core nucleus and two neutrons in a nonrelativistic effective field theory formalism considering both neutron-neutron and neutron-core interactions. We provide formulae of the charge and matter radii, and successfully reproduce the universal relation proposed by Hongo and Son based on the approximation of an infinite neutron-neutron scattering length and neglecting the neutron-core scattering. Once the realistic finite neutron-neutron and neutron-core scattering lengths are used, the charge and matter radii are influenced by the neutron-core channel in a growingly relevant manner. We obtain a relation among the binding energy of the three-body Borromean system, the ratio between charge and matter radii, and the ratio between the neutron-neutron and core-neutron scattering lengths. We find that the two-neutron separation energy for ${}^{22}$C needs to be $\lesssim 2$ keV in order to be consistent with the experimental constraints of the matter radius of ${}^{22}$C and the ${}^{20}\mathrm{C}n$ $S$-wave scattering length.

   ↳ nucl-thhep-phnucl-ex2 citations
3. 03*

   Three-body calculations of beta decay applied to ${}^{11}$Li

   E. Garrido🇪🇸 · A.S. Jensen🇩🇰 · H.O.U. Fynbo🇩🇰 · K. Riisager🇩🇰

   A novel practical few-body method is formulated to include isospin symmetry for nuclear halo structures. The method is designed to describe beta decay, where the basic concept of isospin symmetry facilitates a proper understanding. Both isobaric analogue and anti-analogue states are treated. We derive general and explicit formulas for three-body systems using hyperspherical coordinates. The example of the beta decaying ${}^{11}$Li (${}^9$Li+$n$+$n$) is chosen as a challenging application for numerical calculations of practical interest. The detailed results are compared to existing experimental data and good agreement is found at high excitation energies, where the isobaric analogue and anti-analogue states are situated in the daughter nucleus. An interpretation of the decay pattern at lower excitation energies is suggested. Decays of the ${}^9$Li-core and the two halo-neutrons are individually treated and combined to the daughter system with almost unique isospin, which we predict to be broken by about $0.4\%$ probability. Properties of decay products are predicted as possible future tests of this model.

   ↳ nucl-thnucl-exPRC(2023)·1 citation
4. 04*

   First measurement of the forward rapidity gap distribution in pPb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 8.16 TeV

   CMS Collaboration

   For the first time at LHC energies, the forward rapidity gap spectra from proton-lead collisions for both proton and lead dissociation processes are presented. The analysis is performed over 10.4 units of pseudorapidity at a center-of-mass energy per nucleon pair of $\sqrt{s_{\mathrm{NN}}}$ = 8.16 TeV, almost 300 times higher than in previous measurements of diffractive production in proton-nucleus collisions. For lead dissociation processes, which correspond to the pomeron-lead event topology, the EPOS-LHC generator predictions are a factor of two below the data, but the model gives a reasonable description of the rapidity gap spectrum shape. For the pomeron-proton topology, the EPOS-LHC, QGSJET II, and HIJING predictions are all at least a factor of five lower than the data. The latter effect might be explained by a significant contribution of ultra-peripheral photoproduction events mimicking the signature of diffractive processes. These data may be of significant help in understanding the high energy limit of quantum chromodynamics and for modeling cosmic ray air showers.

   ↳ hep-exnucl-exPRD(2023)·10 citations
5. 05*

   Target mass corrections in lepton--nucleus DIS: theory and applications to nuclear PDFs

   R. Ruiz🇵🇱 · K. F. Muzakka🇩🇪 · C. Leger🇫🇷 · P. Risse🇩🇪 · A. Accardi🇺🇸 · P. Duwentäster🇩🇪 · T. J. Hobbs🇺🇸 · T. Ježo🇩🇪 · C. Keppel🇺🇸 · M. Klasen🇩🇪 · K. Kovařík🇩🇪 · A. Kusina🇵🇱 and 5 other authors

   Motivated by the wide range of kinematics covered by current and planned deep-inelastic scattering (DIS) facilities, we revisit the formalism, practical implementation, and numerical impact of target mass corrections (TMCs) for DIS on unpolarized nuclear targets. An important aspect is that we only use nuclear and later partonic degrees of freedom, carefully avoiding a picture of the nucleus in terms of nucleons. After establishing that formulae used for individual nucleon targets $(p,n)$, derived in the Operator Product Expansion (OPE) formalism, are indeed applicable to nuclear targets, we rewrite expressions for nuclear TMCs in terms of \mbox{re-scaled} (or averaged) kinematic variables. As a consequence, we find a representation for nuclear TMCs that is approximately independent of the nuclear target. We go on to construct a single-parameter fit for all nuclear targets that is in good numerical agreement with full computations of TMCs. We discuss in detail qualitative and quantitative differences between nuclear TMCs built in the OPE and the parton model formalisms, as well as give numerical predictions for current and future facilities.

   ↳ hep-phhep-exnucl-exnucl-thPPNP(2024)·34 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.