<?xml version="1.0" encoding="ISO-8859-1"?><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<front>
<journal-meta>
<journal-id>0864-084X</journal-id>
<journal-title><![CDATA[Nucleus]]></journal-title>
<abbrev-journal-title><![CDATA[Nucleus]]></abbrev-journal-title>
<issn>0864-084X</issn>
<publisher>
<publisher-name><![CDATA[CUBAENERGIA]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S0864-084X2018000100030</article-id>
<title-group>
<article-title xml:lang="en"><![CDATA[Elastic scattering of 9Be+80Se and the breakup threshold anomaly]]></article-title>
<article-title xml:lang="es"><![CDATA[Dispersión elástica de 9Be+80Se y la anomalía de umbral de ruptura]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Abriola]]></surname>
<given-names><![CDATA[Daniel]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Gollan]]></surname>
<given-names><![CDATA[Fernando]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
<xref ref-type="aff" rid="Aaf"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Arazi]]></surname>
<given-names><![CDATA[Andrés]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
<xref ref-type="aff" rid="Aaf"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Martí]]></surname>
<given-names><![CDATA[Guillermo V.]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Testoni]]></surname>
<given-names><![CDATA[Jorge E.]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
</contrib-group>
<aff id="Af1">
<institution><![CDATA[,Laboratorio TANDAR Gerencia de Investigación y Aplicaciones Departamento de Física Experimental]]></institution>
<addr-line><![CDATA[San Martín Buenos Aires]]></addr-line>
<country>Argentina</country>
</aff>
<aff id="Af2">
<institution><![CDATA[,CONICET  ]]></institution>
<addr-line><![CDATA[ Buenos Aires]]></addr-line>
<country>Argentina</country>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>06</month>
<year>2018</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>06</month>
<year>2018</year>
</pub-date>
<numero>63</numero>
<fpage>30</fpage>
<lpage>33</lpage>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://scielo.sld.cu/scielo.php?script=sci_arttext&amp;pid=S0864-084X2018000100030&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://scielo.sld.cu/scielo.php?script=sci_abstract&amp;pid=S0864-084X2018000100030&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://scielo.sld.cu/scielo.php?script=sci_pdf&amp;pid=S0864-084X2018000100030&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="en"><p><![CDATA[Abstract We study the threshold anomaly displayed in the energy dependence of optical potentials describing elastic-scattering angular distributions of weakly bound nuclei with three different models: a) a semi-microscopic double folding potential with two free parameters, b) a phenomenological Wood-Saxon potential with six free parameters and c) an exponential potential with two free parameters. In this kind of nuclei, the coupling to the breakup channel is reflected as an increasing of the imaginary part of the potential as the bombarding energy decreases below the Coulomb barrier, while the real part of the potential (linked to the imaginary part by the dispersion relation) decreases in strength. This behavior is called breakup threshold anomaly (BTA). In this work, we apply this analysis to experimental data for the elastic scattering in the 9Be+80Se systemat eleven bombarding energies around the Coulomb barrier, obtained at the 20 MV tandem accelerator of the TANDAR Laboratory at Buenos Aires. Using the covariance-matrix method to estimate the uncertainties, the presence of the BTA in this system is unambiguously determined, independently of the model chosen for the nuclear potential.]]></p></abstract>
<abstract abstract-type="short" xml:lang="es"><p><![CDATA[Resumen Estudiamos la anomalía de umbral presente en la dependencia con la energía de potenciales ópticos que describen la dispersión elástica de núcleos débilmente ligados, usando tres tipos de potenciales ópticos para la descripción de las distribuciones angulares: a) un potencial semimicroscópico doblemente plegado con dos parámetros libres, b) un potencial fenomenológico tipo Wood-Saxon con seis parámetros libres y c) un potencial exponencial con dos parámetros libres. En este tipo de núcleos, el acoplamiento al canal de ruptura se refleja como un aumento de la parte imaginaria del potencial al decrecer la energía de bombardeo por debajo de la barrera de Coulomb, mientras que la parte real (vinculada a la parte imaginaria por la relación de dispersión) disminuye en intensidad. Este comportamiento se denomina anomalía de umbral de ruptura (BTA). En el presente trabajo, se aplica este análisis a datos experimentales concernientes a la dispersión elástica en el sistema 9Be + 80Se a 11 energías de bombardeo alrededor de la barrera de Coulomb, obtenidos con el acelerador de 20MV del Laboratorio TANDAR en Buenos Aires. Se utilizó el método de matriz de covarianza para estimar las incertidumbres, se determina inequívocamente la presencia de la BTA en este sistema, independientemente del modelo elegido para el potencial nuclear.]]></p></abstract>
<kwd-group>
<kwd lng="en"><![CDATA[elastic scattering]]></kwd>
<kwd lng="en"><![CDATA[optical models]]></kwd>
<kwd lng="en"><![CDATA[energy dependence]]></kwd>
<kwd lng="en"><![CDATA[beryllium 9]]></kwd>
<kwd lng="en"><![CDATA[selenium 80]]></kwd>
<kwd lng="en"><![CDATA[threshold energy]]></kwd>
<kwd lng="es"><![CDATA[dispersión elástica]]></kwd>
<kwd lng="es"><![CDATA[modelos ópticos]]></kwd>
<kwd lng="es"><![CDATA[dependencia energética]]></kwd>
<kwd lng="es"><![CDATA[berilio 9]]></kwd>
<kwd lng="es"><![CDATA[selenio 80]]></kwd>
<kwd lng="es"><![CDATA[umbral de energía]]></kwd>
</kwd-group>
</article-meta>
</front><back>
<ref-list>
<ref id="B1">
<label>1</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[SATCHLER]]></surname>
<given-names><![CDATA[GR]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Heavy-ion scattering and reactions near the Coulomb barrier and &#8220;threshold anomalies&#8221;]]></article-title>
<source><![CDATA[Phys. Rep]]></source>
<year>1991</year>
<volume>199</volume>
<numero>3</numero>
<issue>3</issue>
<page-range>147-90</page-range></nlm-citation>
</ref>
<ref id="B2">
<label>2</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[ABRIOLA]]></surname>
<given-names><![CDATA[D]]></given-names>
</name>
<name>
<surname><![CDATA[DIGREGORIO]]></surname>
<given-names><![CDATA[D]]></given-names>
</name>
<name>
<surname><![CDATA[TESTONI]]></surname>
<given-names><![CDATA[JE]]></given-names>
</name>
<name>
<surname><![CDATA[ETCHEGOYEN]]></surname>
<given-names><![CDATA[A]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Energy dependence of the optical potential for the 16O+144Sm system near the Coulomb barrier]]></article-title>
<source><![CDATA[Phys. Rev. C]]></source>
<year>1989</year>
<volume>39</volume>
<numero>2</numero>
<issue>2</issue>
<page-range>546-52</page-range></nlm-citation>
</ref>
<ref id="B3">
<label>3</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[ABRIOLA]]></surname>
<given-names><![CDATA[D]]></given-names>
</name>
<name>
<surname><![CDATA[SONZOGNI]]></surname>
<given-names><![CDATA[AA]]></given-names>
</name>
<name>
<surname><![CDATA[di TADA]]></surname>
<given-names><![CDATA[M]]></given-names>
</name>
<name>
<surname><![CDATA[ETCHEGOYEN]]></surname>
<given-names><![CDATA[A]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Fusion and elastic scattering for the 12C+144Sm system at energies near to the Coulomb barrier]]></article-title>
<source><![CDATA[Phys. Rev. C]]></source>
<year>1992</year>
<volume>46</volume>
<page-range>244-9</page-range></nlm-citation>
</ref>
<ref id="B4">
<label>4</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[SAKURAGI]]></surname>
<given-names><![CDATA[Y]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Energy and target dependence of projectile breakup effect in elastic scattering of 6Li]]></article-title>
<source><![CDATA[Phys. Rev C]]></source>
<year>1987</year>
<volume>35</volume>
<numero>6</numero>
<issue>6</issue>
<page-range>2161-74</page-range></nlm-citation>
</ref>
<ref id="B5">
<label>5</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[MAHAUX]]></surname>
<given-names><![CDATA[C]]></given-names>
</name>
<name>
<surname><![CDATA[NGO]]></surname>
<given-names><![CDATA[H.]]></given-names>
</name>
<name>
<surname><![CDATA[SATCHLER]]></surname>
<given-names><![CDATA[GR]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Causality and the threshold anomaly of the nucleus-nucleus potential]]></article-title>
<source><![CDATA[Nucl. Phys A]]></source>
<year>1986</year>
<volume>449</volume>
<page-range>354-94</page-range></nlm-citation>
</ref>
<ref id="B6">
<label>6</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[KEELEY]]></surname>
<given-names><![CDATA[N]]></given-names>
</name>
<name>
<surname><![CDATA[BENNETT]]></surname>
<given-names><![CDATA[SJ]]></given-names>
</name>
<name>
<surname><![CDATA[CLARKE]]></surname>
<given-names><![CDATA[NM]]></given-names>
</name>
<name>
<surname><![CDATA[FULTON]]></surname>
<given-names><![CDATA[BR]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Optical model analyses of 6,7Li + 208Pb elastic scattering near the Coulomb barrier]]></article-title>
<source><![CDATA[Nucl. Phys A]]></source>
<year>1994</year>
<volume>571</volume>
<numero>2</numero>
<issue>2</issue>
<page-range>326-36</page-range></nlm-citation>
</ref>
<ref id="B7">
<label>7</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[GOMES]]></surname>
<given-names><![CDATA[PRS]]></given-names>
</name>
<name>
<surname><![CDATA[ANJOS]]></surname>
<given-names><![CDATA[RM]]></given-names>
</name>
<name>
<surname><![CDATA[MURI]]></surname>
<given-names><![CDATA[C]]></given-names>
</name>
<name>
<surname><![CDATA[LUBIAN]]></surname>
<given-names><![CDATA[J]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Threshold anomaly with weakly bound projectiles: Elastic scattering of 9Be+27Al]]></article-title>
<source><![CDATA[Phys. Rev C]]></source>
<year>2004</year>
<volume>70</volume>
<numero>5</numero>
<issue>5</issue>
<page-range>054605</page-range></nlm-citation>
</ref>
<ref id="B8">
<label>8</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[FIGUEIRA]]></surname>
<given-names><![CDATA[JM]]></given-names>
</name>
<name>
<surname><![CDATA[ABRIOLA]]></surname>
<given-names><![CDATA[D]]></given-names>
</name>
<name>
<surname><![CDATA[FERNÁNDEZ NIELLO]]></surname>
<given-names><![CDATA[JO]]></given-names>
</name>
<name>
<surname><![CDATA[ARAZI]]></surname>
<given-names><![CDATA[A]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Absence of the threshold anomaly in the elastic scattering of the weakly bound projectile7Li on 27Al]]></article-title>
<source><![CDATA[Phys. Rev C]]></source>
<year>2006</year>
<volume>73</volume>
<page-range>054603</page-range></nlm-citation>
</ref>
<ref id="B9">
<label>9</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[HUSSEIN]]></surname>
<given-names><![CDATA[MS]]></given-names>
</name>
<name>
<surname><![CDATA[GOMES]]></surname>
<given-names><![CDATA[PRS]]></given-names>
</name>
<name>
<surname><![CDATA[LUBIAN]]></surname>
<given-names><![CDATA[J]]></given-names>
</name>
<name>
<surname><![CDATA[CHAMON]]></surname>
<given-names><![CDATA[LC]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[New manifestation of the dispersion relation: Breakup threshold anomaly]]></article-title>
<source><![CDATA[Phys. Rev. C]]></source>
<year>2006</year>
<volume>73</volume>
<page-range>044610</page-range></nlm-citation>
</ref>
<ref id="B10">
<label>10</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[CANTO]]></surname>
<given-names><![CDATA[LF]]></given-names>
</name>
<name>
<surname><![CDATA[GOMES]]></surname>
<given-names><![CDATA[PRS]]></given-names>
</name>
<name>
<surname><![CDATA[LUBIAN]]></surname>
<given-names><![CDATA[J]]></given-names>
</name>
<name>
<surname><![CDATA[CHAMON]]></surname>
<given-names><![CDATA[LC]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Disentangling static and dynamic effects of low breakup threshold in fusion reactions]]></article-title>
<source><![CDATA[Phys. Rep]]></source>
<year>2006</year>
<volume>424</volume>
<page-range>1-9</page-range></nlm-citation>
</ref>
<ref id="B11">
<label>11</label><nlm-citation citation-type="">
<person-group person-group-type="author">
<name>
<surname><![CDATA[GOLLAN]]></surname>
<given-names><![CDATA[F]]></given-names>
</name>
<name>
<surname><![CDATA[ABRIOLA]]></surname>
<given-names><![CDATA[D]]></given-names>
</name>
<name>
<surname><![CDATA[ARAZI]]></surname>
<given-names><![CDATA[A]]></given-names>
</name>
<name>
<surname><![CDATA[PACHECO]]></surname>
<given-names><![CDATA[A]]></given-names>
</name>
</person-group>
<source><![CDATA[Estudio del proceso de quiebre del núcleo 9Be en reacciones de dispersión elástica to be submitted to PRC]]></source>
<year></year>
</nlm-citation>
</ref>
<ref id="B12">
<label>12</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[ABRIOLA]]></surname>
<given-names><![CDATA[D]]></given-names>
</name>
<name>
<surname><![CDATA[ARAZI]]></surname>
<given-names><![CDATA[A]]></given-names>
</name>
<name>
<surname><![CDATA[TESTONI]]></surname>
<given-names><![CDATA[JE]]></given-names>
</name>
<name>
<surname><![CDATA[GOLLAN]]></surname>
<given-names><![CDATA[F]]></given-names>
</name>
<name>
<surname><![CDATA[MARTÍ]]></surname>
<given-names><![CDATA[GV]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Uncertainties of optical-model parameters for the study of the threshold anomaly]]></article-title>
<source><![CDATA[J Phys]]></source>
<year>2015</year>
<volume>630</volume>
<page-range>012021</page-range></nlm-citation>
</ref>
<ref id="B13">
<label>13</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[ABRIOLA]]></surname>
<given-names><![CDATA[D]]></given-names>
</name>
<name>
<surname><![CDATA[MARTÍ]]></surname>
<given-names><![CDATA[GV]]></given-names>
</name>
<name>
<surname><![CDATA[TESTONI]]></surname>
<given-names><![CDATA[JE]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Bootstrap method for constructing covariance matrices ofoptical-model parameters in the study of the threshold anomaly]]></article-title>
<source><![CDATA[EPJ Web of Conferences]]></source>
<year>2017</year>
<volume>146</volume>
<page-range>02050</page-range></nlm-citation>
</ref>
</ref-list>
</back>
</article>
