Observation of the decays B+→Σc(2455)++<mml:mi mathvariant="…

We report the first observation of the two-body baryonic decays <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:msup><a:mi>B</a:mi><a:mo>+</a:mo></a:msup><a:mo stretchy="false">→</a:mo><a:msub><a:mi mathvariant="normal">Σ</a:mi><a:mi>c</a:mi></a:msub><a:mo stretchy="false">(</a:mo><a:mn>2455</a:mn><a:msup><a:mo stretchy="false">)</a:mo><a:mrow><a:mo>+</a:mo><a:mo>+</a:mo></a:mrow></a:msup><a:msubsup><a:mover accent="true"><a:mi mathvariant="normal">Ξ</a:mi><a:mo stretchy="false">¯</a:mo></a:mover><a:mi>c</a:mi><a:mo>−</a:mo></a:msubsup></a:math> and <j:math xmlns:j="http://www.w3.org/1998/Math/MathML" display="inline"><j:msup><j:mi>B</j:mi><j:mn>0</j:mn></j:msup><j:mo stretchy="false">→</j:mo><j:msub><j:mi mathvariant="normal">Σ</j:mi><j:mi>c</j:mi></j:msub><j:mo stretchy="false">(</j:mo><j:mn>2455</j:mn><j:msup><j:mo stretchy="false">)</j:mo><j:mn>0</j:mn></j:msup><j:msubsup><j:mover accent="true"><j:mi mathvariant="normal">Ξ</j:mi><j:mo stretchy="false">¯</j:mo></j:mover><j:mi>c</j:mi><j:mn>0</j:mn></j:msubsup></j:math> with significances of <s:math xmlns:s="http://www.w3.org/1998/Math/MathML" display="inline"><s:mn>7.3</s:mn><s:mi>σ</s:mi></s:math> and <u:math xmlns:u="http://www.w3.org/1998/Math/MathML" display="inline"><u:mn>6.2</u:mn><u:mi>σ</u:mi></u:math>, respectively, including statistical and systematic uncertainties. The branching fractions are measured to be <w:math xmlns:w="http://www.w3.org/1998/Math/MathML" display="inline"><w:mi mathvariant="script">B</w:mi><w:mo stretchy="false">(</w:mo><w:msup><w:mi>B</w:mi><w:mo>+</w:mo></w:msup><w:mo stretchy="false">→</w:mo><w:msub><w:mi mathvariant="normal">Σ</w:mi><w:mi>c</w:mi></w:msub><w:mo stretchy="false">(</w:mo><w:mn>2455</w:mn><w:msup><w:mo stretchy="false">)</w:mo><w:mrow><w:mo>+</w:mo><w:mo>+</w:mo></w:mrow></w:msup><w:msubsup><w:mover accent="true"><w:mi mathvariant="normal">Ξ</w:mi><w:mo stretchy="false">¯</w:mo></w:mover><w:mi>c</w:mi><w:mo>−</w:mo></w:msubsup><w:mo stretchy="false">)</w:mo><w:mo>=</w:mo><w:mo stretchy="false">(</w:mo><w:mn>5.74</w:mn><w:mo>±</w:mo><w:mn>1.11</w:mn><w:mo>±</w:mo><w:mn>0.4</w:mn><w:msubsup><w:mn>2</w:mn><w:mrow><w:mo>−</w:mo><w:mn>1.53</w:mn></w:mrow><w:mrow><w:mo>+</w:mo><w:mn>2.47</w:mn></w:mrow></w:msubsup><w:mo stretchy="false">)</w:mo><w:mo>×</w:mo><w:msup><w:mn>10</w:mn><w:mrow><w:mo>−</w:mo><w:mn>4</w:mn></w:mrow></w:msup></w:math> and <kb:math xmlns:kb="http://www.w3.org/1998/Math/MathML" display="inline"><kb:mi mathvariant="script">B</kb:mi><kb:mo stretchy="false">(</kb:mo><kb:msup><kb:mi>B</kb:mi><kb:mn>0</kb:mn></kb:msup><kb:mo stretchy="false">→</kb:mo><kb:msub><kb:mi mathvariant="normal">Σ</kb:mi><kb:mi>c</kb:mi></kb:msub><kb:mo stretchy="false">(</kb:mo><kb:mn>2455</kb:mn><kb:msup><kb:mo stretchy="false">)</kb:mo><kb:mn>0</kb:mn></kb:msup><kb:msubsup><kb:mover accent="true"><kb:mi mathvariant="normal">Ξ</kb:mi><kb:mo stretchy="false">¯</kb:mo></kb:mover><kb:mi>c</kb:mi><kb:mn>0</kb:mn></kb:msubsup><kb:mo stretchy="false">)</kb:mo><kb:mo>=</kb:mo><kb:mo stretchy="false">(</kb:mo><kb:mn>4.83</kb:mn><kb:mo>±</kb:mo><kb:mn>1.12</kb:mn><kb:mo>±</kb:mo><kb:mn>0.3</kb:mn><kb:msubsup><kb:mn>7</kb:mn><kb:mrow><kb:mo>−</kb:mo><kb:mn>0.60</kb:mn></kb:mrow><kb:mrow><kb:mo>+</kb:mo><kb:mn>0.72</kb:mn></kb:mrow></kb:msubsup><kb:mo stretchy="false">)</kb:mo><kb:mo>×</kb:mo><kb:msup><kb:mn>10</kb:mn><kb:mrow><kb:mo>−</kb:mo><kb:mn>4</kb:mn></kb:mrow></kb:msup></kb:math>. The first and second uncertainties are statistical and systematic, respectively, while the third ones arise from the absolute branching fractions of <yb:math xmlns:yb="http://www.w3.org/1998/Math/MathML" display="inline"><yb:msubsup><yb:mover accent="true"><yb:mi mathvariant="normal">Ξ</yb:mi><yb:mo stretchy="false">¯</yb:mo></yb:mover><yb:mi>c</yb:mi><yb:mo>−</yb:mo></yb:msubsup></yb:math> or <dc:math xmlns:dc="http://www.w3.org/1998/Math/MathML" display="inline"><dc:msubsup><dc:mover accent="true"><dc:mi mathvariant="normal">Ξ</dc:mi><dc:mo stretchy="false">¯</dc:mo></dc:mover><dc:mi>c</dc:mi><dc:mn>0</dc:mn></dc:msubsup></dc:math> decays. The data samples used for this analysis have integrated luminosities of <ic:math xmlns:ic="http://www.w3.org/1998/Math/MathML" display="inline"><ic:mn>711</ic:mn><ic:mtext> </ic:mtext><ic:mtext> </ic:mtext><ic:msup><ic:mi>fb</ic:mi><ic:mrow><ic:mo>−</ic:mo><ic:mn>1</ic:mn></ic:mrow></ic:msup></ic:math> and <kc:math xmlns:kc="http://www.w3.org/1998/Math/MathML" display="inline"><kc:mn>365</kc:mn><kc:mtext> </kc:mtext><kc:mtext> </kc:mtext><kc:msup><kc:mi>fb</kc:mi><kc:mrow><kc:mo>−</kc:mo><kc:mn>1</kc:mn></kc:mrow></kc:msup></kc:math>, and were collected at the <mc:math xmlns:mc="http://www.w3.org/1998/Math/MathML" display="inline"><mc:mi mathvariant="normal">ϒ</mc:mi><mc:mo stretchy="false">(</mc:mo><mc:mn>4</mc:mn><mc:mi>S</mc:mi><mc:mo stretchy="false">)</mc:mo></mc:math> resonance by the Belle and Belle II detectors operating at the KEKB and SuperKEKB asymmetric-energy <rc:math xmlns:rc="http://www.w3.org/1998/Math/MathML" display="inline"><rc:msup><rc:mi>e</rc:mi><rc:mo>+</rc:mo></rc:msup><rc:msup><rc:mi>e</rc:mi><rc:mo>−</rc:mo></rc:msup></rc:math> colliders, respectively.