Nuclear Physics A最新文献

{"title":"A new measurement of 174Hf alpha decay","authors":"P. Belli ,&nbsp;R. Bernabei ,&nbsp;F. Cappella ,&nbsp;V. Caracciolo ,&nbsp;R. Cerulli ,&nbsp;A. Incicchitti ,&nbsp;M. Laubenstein ,&nbsp;A. Leoncini ,&nbsp;V. Merlo ,&nbsp;S.S. Nagorny ,&nbsp;V.V. Nahorna ,&nbsp;S. Nisi ,&nbsp;P. Wang","doi":"10.1016/j.nuclphysa.2024.122976","DOIUrl":"10.1016/j.nuclphysa.2024.122976","url":null,"abstract":"<div><div>A new measurement of ¹⁷⁴Hf alpha decay to the ground state of ¹⁷⁰Yb was performed deep underground at the Gran Sasso National Laboratory (LNGS) of the INFN (Italy). The experimental data were accumulated over 97.7 days with a 16.87 g Cs₂HfCl₆ single crystal. A new half-life value of ¹⁷⁴Hf <em>α</em> decay: T_1/2 = <span><math><mo>(</mo><msubsup><mrow><mn>3.8</mn></mrow><mrow><mo>−</mo><mn>0.9</mn></mrow><mrow><mo>+</mo><mn>1.7</mn></mrow></msubsup><mo>)</mo><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mn>16</mn></mrow></msup></math></span> yr, was evaluated. The total internal <em>α</em> activity of the crystal is 18.6(4) mBq/kg, and should be further improved, especially in terms of ¹⁴⁷Sm contamination (0.25 mBq/kg), in order to achieve a higher experimental sensitivity.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1053 ","pages":"Article 122976"},"PeriodicalIF":1.7,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142554125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental measurements and theoretical calculations of excitation functions of 103Rh(α,xn)106m,105g,104gAg and 103Rh(α,αxn)101m,102gRh reactions up to 40 MeV","authors":"Sk Wasim Raja ,&nbsp;R. Acharya ,&nbsp;A. Saha","doi":"10.1016/j.nuclphysa.2024.122974","DOIUrl":"10.1016/j.nuclphysa.2024.122974","url":null,"abstract":"<div><div>Activation cross sections of ¹⁰³Rh(α,xn)^{106m,105g,104g}Ag and ¹⁰³Rh(α,αxn)^101m,102gRh radionuclides were measured at energies ranging from their respective threshold energies up to 40 MeV. Standard stacked foil activation technique was employed for irradiation. Residual activity was assayed using high-resolution gamma-ray spectrometry. Excitation functions were also theoretically calculated using TALYS nuclear reaction model to reproduce the experimental cross section data. The present data are compared with the available literature data, TENDL-2023 data using default values as well as the theoretical data calculated by TALYS-1.96. The shape and amplitude of the experimentally obtained excitation functions were well reproduced theoretically for all the studied radionuclides except for ^105gAg, for which magnitude of the cross sections was not reproduced. The integral yields were also deduced using the measured cross sections and the stopping power of natural Rh from 40 MeV down to their threshold energies for these radionuclides, and compared with the experimental yield data available in the literature.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1053 ","pages":"Article 122974"},"PeriodicalIF":1.7,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142592766","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Superheavy magic nuclei: Ground-state properties, bubble structure and α-decay chains","authors":"R. Sharma ,&nbsp;A. Jain ,&nbsp;M. Kumawat ,&nbsp;J.K. Deegwal ,&nbsp;Abdul Quddus ,&nbsp;G. Saxena","doi":"10.1016/j.nuclphysa.2024.122973","DOIUrl":"10.1016/j.nuclphysa.2024.122973","url":null,"abstract":"<div><div>A systematic investigation of superheavy nuclei in the isotopic chains of proton numbers Z=106, 114, 120, and 126 together with isotonic chains of neutron numbers N=162, 172, and 184 is presented in the theoretical framework of relativistic mean-field density functionals based on density-dependent meson-nucleon couplings. Ground-state properties, including binding energy, shape, deformation, density profile, and radius, are estimated to provide compelling evidence of magicity in these even-even nuclei, aligning with the concept of the ‘island of stability.’ The analysis reveals central depletion in the charge density, indicating a bubble-like structure, primarily attributed to the substantial repulsive Coulomb field and the influence of higher <em>l</em>-states. A thorough examination of potential decay modes, employing various semi-empirical formulas, is presented. The probable <em>α</em>-decay chains are evaluated, demonstrating excellent agreement with available experimental data.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1053 ","pages":"Article 122973"},"PeriodicalIF":1.7,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142554124","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A novel four parameter formula for the rotational spectra of even-even nuclei","authors":"A. Obaid ,&nbsp;A.M. Khalaf ,&nbsp;M. Kotb ,&nbsp;H.A. Ghanem ,&nbsp;Nagat A. Elmahdy","doi":"10.1016/j.nuclphysa.2024.122972","DOIUrl":"10.1016/j.nuclphysa.2024.122972","url":null,"abstract":"<div><div>In this article, the authors presents a novel four parameter formula based on developing an expression for the moment of inertia in terms of Bohr-Mottelson Geometric Collective Model (GCM). The formula provides an excellent agreement with the experimental data for all nuclei under consideration. Some key quantities will also be derived such as the rotational frequency, the kinematic and dynamical moment of inertia, and their variation with spin will be investigated. A comparison between our proposed four parameter model with both the variable moment of inertia model, and the recently proposed <em>β</em>-stretching model is also presented. Various <span><math><mi>Δ</mi><mi>I</mi><mo>=</mo><mn>1</mn></math></span> and <span><math><mi>Δ</mi><mi>I</mi><mo>=</mo><mn>2</mn></math></span> energy staggering indices will be presented and compared to the experimental counterpart in the paper.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1053 ","pages":"Article 122972"},"PeriodicalIF":1.7,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142531793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Renormalization of three-body interaction in DDK system","authors":"Cheng-Nan Wu,&nbsp;Jin-Yi Pang","doi":"10.1016/j.nuclphysa.2024.122970","DOIUrl":"10.1016/j.nuclphysa.2024.122970","url":null,"abstract":"<div><div>In systems comprising three identical particles, the Efimov effect emerges in the unitary limit. This article, utilizing the method of effective field theory along with the effective range expansion (ERE) and low-momentum expansion, reproduces the Efimov effect beyond unitary limit and identical case and applies to <em>DDK</em> system. It also links the high-energy scale with the ultraviolet cutoff in the three-body system. We discuss a method for obtaining exact solutions for the three-body wave function below the threshold of dimer production, that is <em>D</em> and <span><math><msubsup><mrow><mi>D</mi></mrow><mrow><mi>s</mi><mn>0</mn></mrow><mrow><mo>⁎</mo></mrow></msubsup><mo>(</mo><mn>2317</mn><mo>)</mo></math></span>. It turns out that introducing this scale is a necessary condition for the emergence of <em>DDK</em> three-body bound state. Since without this scale, the wave function would be solved below threshold with arbitrary binding energy, which violates the conditions of unitarity and energy quantization. The calculation involving this scale results in a discrete spectrum below the threshold and restores unitarity, making the effects induced by this scale significant for the formation of <em>DDK</em> bound state. In order to establish this in a complete formalism, the paper further gives an analytical expression for the three-body coupling constant, and compares it to the numerical calculation in <em>DDK</em> system.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1053 ","pages":"Article 122970"},"PeriodicalIF":1.7,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142445995","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The nuclear shadowing effect of gluon at small x","authors":"B. Rezaei","doi":"10.1016/j.nuclphysa.2024.122971","DOIUrl":"10.1016/j.nuclphysa.2024.122971","url":null,"abstract":"<div><div>The ratio of nuclear gluon distribution functions <span><math><mi>x</mi><msup><mrow><mi>g</mi></mrow><mrow><mi>A</mi></mrow></msup><mo>/</mo><mi>A</mi><mi>x</mi><mi>g</mi></math></span> in the saturation region at small <em>x</em> (i.e., <span><math><mi>x</mi><mo>≲</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>3</mn></mrow></msup></math></span>) for light and heavy nuclei is investigated and compared with the HIJING2.0 model. The moments of the nuclear gluon distribution per nucleon, <span><math><mo>&lt;</mo><msup><mrow><mi>x</mi></mrow><mrow><mi>A</mi></mrow></msup><msub><mrow><mo>&gt;</mo></mrow><mrow><mi>g</mi></mrow></msub><mo>/</mo><mi>A</mi></math></span>, on a wide range of the scale <em>μ</em> with charm contribution are considered and compared with the parametrization groups. The importance of the binding energy for nuclei is also considered.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1053 ","pages":"Article 122971"},"PeriodicalIF":1.7,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142441905","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"(J/ψ,J/ψ), and (ηc,ηc) production through two intermediate photons in electron-positron annihilation at B-factories","authors":"Shashank Bhatnagar ,&nbsp;Hluf Negash","doi":"10.1016/j.nuclphysa.2024.122969","DOIUrl":"10.1016/j.nuclphysa.2024.122969","url":null,"abstract":"<div><div>We study the processes, <span><math><msup><mrow><mi>e</mi></mrow><mrow><mo>−</mo></mrow></msup><msup><mrow><mi>e</mi></mrow><mrow><mo>+</mo></mrow></msup><mo>→</mo><msup><mrow><mi>γ</mi></mrow><mrow><mo>⁎</mo></mrow></msup><msup><mrow><mi>γ</mi></mrow><mrow><mo>⁎</mo></mrow></msup><mo>→</mo><mi>J</mi><mo>/</mo><mi>ψ</mi><mo>+</mo><mi>J</mi><mo>/</mo><mi>ψ</mi></math></span>, and <span><math><msup><mrow><mi>e</mi></mrow><mrow><mo>−</mo></mrow></msup><msup><mrow><mi>e</mi></mrow><mrow><mo>+</mo></mrow></msup><mo>→</mo><msup><mrow><mi>γ</mi></mrow><mrow><mo>⁎</mo></mrow></msup><msup><mrow><mi>γ</mi></mrow><mrow><mo>⁎</mo></mrow></msup><mo>→</mo><msub><mrow><mi>η</mi></mrow><mrow><mi>c</mi></mrow></msub><mo>+</mo><msub><mrow><mi>η</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span> at <span><math><msqrt><mrow><mi>s</mi></mrow></msqrt><mo>=</mo><mn>10.6</mn></math></span> GeV in the framework of <span><math><mn>4</mn><mo>×</mo><mn>4</mn></math></span> Bethe-Salpeter equation. For <span><math><mi>J</mi><mo>/</mo><mi>ψ</mi><mo>+</mo><mi>J</mi><mo>/</mo><mi>ψ</mi></math></span> production, the dominant contribution is through fragmentation process, while for <span><math><msub><mrow><mi>η</mi></mrow><mrow><mi>c</mi></mrow></msub><mo>+</mo><msub><mrow><mi>η</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span> production, the quark rearrangement diagrams contribute. Our results of cross section for <span><math><mi>J</mi><mo>/</mo><mi>ψ</mi><mo>+</mo><mi>J</mi><mo>/</mo><mi>ψ</mi></math></span> and <span><math><mi>ψ</mi><mo>(</mo><mn>2</mn><mi>S</mi><mo>)</mo><mo>+</mo><mi>ψ</mi><mo>(</mo><mn>2</mn><mi>S</mi><mo>)</mo></math></span> are compatible with the experimental upper limits set by Belle Collaboration, while in the absence of experimental data for <span><math><msub><mrow><mi>η</mi></mrow><mrow><mi>c</mi></mrow></msub><mo>(</mo><mn>1</mn><mi>S</mi><mo>)</mo><mo>+</mo><msub><mrow><mi>η</mi></mrow><mrow><mi>c</mi></mrow></msub><mo>(</mo><mn>1</mn><mi>S</mi><mo>)</mo></math></span>, and <span><math><msub><mrow><mi>η</mi></mrow><mrow><mi>c</mi></mrow></msub><mo>(</mo><mn>2</mn><mi>S</mi><mo>)</mo><mo>+</mo><msub><mrow><mi>η</mi></mrow><mrow><mi>c</mi></mrow></msub><mo>(</mo><mn>2</mn><mi>S</mi><mo>)</mo></math></span> production, we have given theoretical prediction of their cross sections, and compared with NRQCD prediction.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1053 ","pages":"Article 122969"},"PeriodicalIF":1.7,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142441904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quasi-stationary alpha-states from non-Hermitian Hamiltonians of even-even heavy isotones","authors":"Réka Szilvási,&nbsp;István Andorfi,&nbsp;Dániel P. Kis","doi":"10.1016/j.nuclphysa.2024.122968","DOIUrl":"10.1016/j.nuclphysa.2024.122968","url":null,"abstract":"<div><div>Three isotone groups (N=128,130,132) with alpha-decaying, short-lifetime even-even nuclei of large mass number are studied in order to show that the tunneling phase of the alpha decay process is appropriately describable by a specific non-hermitian mean-field model. In this model the mean-field lifetime of the alpha cluster is extracted directly by the complex diagonalization of the non-hermitian Hamiltonian of the system. In this paper, we demonstrate that by calculating the mean-field width of the alpha clusters, in each isotone groups, by non-perturbative complex spectral calculations, then, due to the distinct patterns the isotones are naturally organized into with respect to the half-life and proton number, the total width of the alpha-decay can be approximated by matching the calculated results to experimental data.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1053 ","pages":"Article 122968"},"PeriodicalIF":1.7,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142441906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Alpha spectroscopy of purified beams of exotic nuclei at the FRS Ion Catcher","authors":"Nazarena Tortorelli ,&nbsp;Moritz Pascal Reiter ,&nbsp;Ann Kathrin Rink ,&nbsp;Sivaji Purushothaman ,&nbsp;Samuel Ayet San Andrés ,&nbsp;Julian Bergmann ,&nbsp;Timo Dickel ,&nbsp;Marcel Diwisch ,&nbsp;Jens Ebert ,&nbsp;Hans Geissel ,&nbsp;Florian Greiner ,&nbsp;Emma Haettner ,&nbsp;Christine Hornung ,&nbsp;Aleksandra Kelic-Heil ,&nbsp;Ronja Knoebel ,&nbsp;Wayne Lippert ,&nbsp;Ivan Miskun ,&nbsp;Iain D. Moore ,&nbsp;Stephane Pietri ,&nbsp;Wolfgang R. Plaß ,&nbsp;Xiaodong Xu","doi":"10.1016/j.nuclphysa.2024.122967","DOIUrl":"10.1016/j.nuclphysa.2024.122967","url":null,"abstract":"<div><div>The FRS Ion Catcher (FRS-IC) is located at the final focal plane of the Fragment Separator FRS at GSI. The FRS-IC setup is well known for high-precision experiments with stopped exotic nuclei produced by projectile fragmentation and fission. The facility consists of the cryogenic gas-filled stopping cell (CSC), an RFQ-based beamline (DISTRICT), and a multiple-reflection time-of-flight mass spectrometer (MR-TOF-MS). This paper illustrates how alpha spectroscopy performed at this facility has emerged as a promising tool to unveil the nuclear structure of exotic nuclei, i.e., half-live and decay energy measurements. First studies of that kind were performed on the decay chains of ²¹⁸Rn, ²¹⁹Rn, ²²¹Ac, ²²⁰Fr, and ^223,224Th produced by projectile fragmentation of ²³⁸U. The <em>α</em> decay energy measurements performed and the deduced Q_<em>α</em> values confirm the known maximum at N=128 and the values of Q_<em>α</em> at N<span><math><mo>=</mo><mn>132</mn><mo>−</mo><mn>133</mn></math></span> follow the predicted increasing in Q_<em>α</em> values compared to the values for At isotopes at the same neutron number N. Further, the production rate ratio of the isomer to the ground state of ²¹¹Po was measured. It allows an estimate of the angular momentum distribution of ²¹¹Po fragments following fragmentation of ²³⁸U in a ⁹Be target at relativistic energies. In addition, the potential of mass-selected decay spectroscopy behind the MR-TOF-MS was demonstrated with short-lived ²¹⁵Po ions (<span><math><msub><mrow><mi>t</mi></mrow><mrow><mn>1</mn><mo>/</mo><mn>2</mn></mrow></msub><mo>=</mo><mn>1.78</mn></math></span> ms). This demonstrates that the FRS-IC is a reliable setup for <em>α</em> spectroscopy studies and related nuclear structure studies.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1053 ","pages":"Article 122967"},"PeriodicalIF":1.7,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142432765","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Erratum to “Localization of peripheral reactions and sensitivity to the imaginary potential” [Nucl. Phys. A 1006 (2021) 122109]","authors":"Imane Moumene ,&nbsp;Angela Bonaccorso","doi":"10.1016/j.nuclphysa.2024.122966","DOIUrl":"10.1016/j.nuclphysa.2024.122966","url":null,"abstract":"<div><div>We have found a typo mistake in the code used to obtain the double folding results discussed in the above paper. However the single folding results were unaffected as they were calculated with a different code.</div><div>The correct code provides values bringing the double folding and the single folding results closer to each other at an incident energy around 60 A.MeV, as it can be seen in <span><span>Table 1</span><svg><path></path></svg></span> and <span><span>Figs. 1 and 2</span><svg><path></path></svg></span> presented in the following. However the main conclusions of the paper are qualitatively unaffected because the single folding model still provides larger reaction cross sections and strong absorption radii indicating the important effect of surface absorption. This is particularly true in the high energy case for which there are also data shown in the four panels of <span><span>Fig. 3</span><svg><path></path></svg></span> where the energy dependence of the reaction cross section for four different projectiles is studied comparing data with the single folding and double folding results. There are only a few small projectile cases shown in <span><span>Table 1</span><svg><path></path></svg></span> for which the single folding provides smaller cross sections and strong absorption radii than the double folding.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1053 ","pages":"Article 122966"},"PeriodicalIF":1.7,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142427521","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}