2026/02/10 by A. Hayrapetyan, CMS Collaboration, V. Makarenko +98 · 2 voices
Physics and Astronomy · #Particle physics theoretical and experimental studies #High-Energy Particle Collisions Research #Quantum Chromodynamics and Particle Interactions
paper · pdf · doi:10.1103/36cv-vst3
Production fraction ratios of <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:math> , <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"> <c:msup> <c:mi>B</c:mi> <c:mn>0</c:mn> </c:msup> </c:math> , and <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"> <e:msubsup> <e:mi>B</e:mi> <e:mi>s</e:mi> <e:mn>0</e:mn> </e:msubsup> </e:math> mesons are measured in proton-proton collisions at <g:math xmlns:g="http://www.w3.org/1998/Math/MathML" display="inline"> <g:mrow> <g:msqrt> <g:mrow> <g:mi>s</g:mi> </g:mrow> </g:msqrt> <g:mo>=</g:mo> <g:mn>13</g:mn> <g:mtext> </g:mtext> <g:mtext> </g:mtext> <g:mi>TeV</g:mi> </g:mrow> </g:math> using a special dataset recorded in 2018 with high-rate triggers designed to collect an unbiased sample of <i:math xmlns:i="http://www.w3.org/1998/Math/MathML" display="inline"> <i:mn>1</i:mn> <i:msup> <i:mn>0</i:mn> <i:mn>10</i:mn> </i:msup> </i:math> <k:math xmlns:k="http://www.w3.org/1998/Math/MathML" display="inline"> <k:mi>b</k:mi> </k:math> hadrons with the CMS experiment at the LHC. These data allow the study of the open-charm decays of <m:math xmlns:m="http://www.w3.org/1998/Math/MathML" display="inline"> <m:mi>B</m:mi> </m:math> mesons ( <o:math xmlns:o="http://www.w3.org/1998/Math/MathML" display="inline"> <o:msub> <o:mi>B</o:mi> <o:mrow> <o:mo stretchy="false">(</o:mo> <o:mi>s</o:mi> <o:mo stretchy="false">)</o:mo> </o:mrow> </o:msub> <o:mo stretchy="false">→</o:mo> <o:mi>π</o:mi> <o:msub> <o:mi>D</o:mi> <o:mrow> <o:mo stretchy="false">(</o:mo> <o:mi>s</o:mi> <o:mo stretchy="false">)</o:mo> </o:mrow> </o:msub> </o:math> ) where the <v:math xmlns:v="http://www.w3.org/1998/Math/MathML" display="inline"> <v:mi>D</v:mi> </v:math> meson decays into fully hadronic final states. By utilizing known branching fractions and precise theoretical calculations, production fraction ratios as functions of <x:math xmlns:x="http://www.w3.org/1998/Math/MathML" display="inline"> <x:mi>B</x:mi> </x:math> meson transverse momentum <z:math xmlns:z="http://www.w3.org/1998/Math/MathML" display="inline"> <z:mrow> <z:mo stretchy="false">(</z:mo> <z:msub> <z:mrow> <z:mi>p</z:mi> </z:mrow> <z:mrow> <z:mi mathvariant="normal">T</z:mi> </z:mrow> </z:msub> <z:mo stretchy="false">)</z:mo> </z:mrow> </z:math> and rapidity ( <eb:math xmlns:eb="http://www.w3.org/1998/Math/MathML" display="inline"> <eb:mi>y</eb:mi> </eb:math> ) are measured using open-charm decays in the kinematic range of <gb:math xmlns:gb="http://www.w3.org/1998/Math/MathML" display="inline"> <gb:mrow> <gb:mn>8</gb:mn> <gb:mo><</gb:mo> <gb:msub> <gb:mrow> <gb:mi>p</gb:mi> </gb:mrow> <gb:mrow> <gb:mi mathvariant="normal">T</gb:mi> </gb:mrow> </gb:msub> <gb:mo><</gb:mo> <gb:mn>60</gb:mn> <gb:mtext> </gb:mtext> <gb:mtext> </gb:mtext> <gb:mrow> <gb:mi>GeV</gb:mi> </gb:mrow> </gb:mrow> </gb:math> and <jb:math xmlns:jb="http://www.w3.org/1998/Math/MathML" display="inline"> <jb:mrow> <jb:mo stretchy="false">|</jb:mo> <jb:mi>y</jb:mi> <jb:mo stretchy="false">|</jb:mo> </jb:mrow> <jb:mo><</jb:mo> <jb:mn>2.25</jb:mn> </jb:math> . In addition, the same dataset is used to measure the relative production fraction ratios with the charmonium decay channels [ <nb:math xmlns:nb="http://www.w3.org/1998/Math/MathML" display="inline"> <nb:msub> <nb:mi>B</nb:mi> <nb:mrow> <nb:mo stretchy="false">(</nb:mo> <nb:mi>s</nb:mi> <nb:mo stretchy="false">)</nb:mo> </nb:mrow> </nb:msub> <nb:mo stretchy="false">→</nb:mo> <nb:mi>X</nb:mi> <nb:mrow> <nb:mi>J</nb:mi> <nb:mo stretchy="false">/</nb:mo> <nb:mi>ψ</nb:mi> </nb:mrow> </nb:math> with <tb:math xmlns:tb="http://www.w3.org/1998/Math/MathML" display="inline"> <tb:mi>X</tb:mi> </tb:math> indicating a <vb:math xmlns:vb="http://www.w3.org/1998/Math/MathML" display="inline"> <vb:msup> <vb:mi>K</vb:mi> <vb:mo>+</vb:mo> </vb:msup> </vb:math> , <xb:math xmlns:xb="http://www.w3.org/1998/Math/MathML" display="inline"> <xb:mrow> <xb:mrow> <xb:msup> <xb:mrow> <xb:mi>K</xb:mi> </xb:mrow> <xb:mrow> <xb:mo>*</xb:mo> </xb:mrow> </xb:msup> <xb:mo stretchy="false">(</xb:mo> <xb:mn>892</xb:mn> </xb:mrow> <xb:msup> <xb:mrow> <xb:mo stretchy="false">)</xb:mo> </xb:mrow> <xb:mrow> <xb:mn>0</xb:mn> </xb:mrow> </xb:msup> </xb:mrow> </xb:math> , or <bc:math xmlns:bc="http://www.w3.org/1998/Math/MathML" display="inline"> <bc:mi>ϕ</bc:mi> <bc:mo stretchy="false">(</bc:mo> <bc:mn>1020</bc:mn> <bc:mo stretchy="false">)</bc:mo> </bc:math> meson] where the <fc:math xmlns:fc="http://www.w3.org/1998/Math/MathML" display="inline"> <fc:mi>J</fc:mi> <fc:mo stretchy="false">/</fc:mo> <fc:mi>ψ</fc:mi> </fc:math> meson decays into a pair of muons. The open-charm results are used to normalize the relative production fraction ratios obtained from the charmonium samples. Measurements of the ratios of branching fractions of <ic:math xmlns:ic="http://www.w3.org/1998/Math/MathML" display="inline"> <ic:mi>B</ic:mi> </ic:math> meson decays to charmonium and open-charm final states are also reported, which will improve the world-average values of these ratios. Finally, we test isospin invariance in <kc:math xmlns:kc="http://www.w3.org/1998/Math/MathML" display="inline"> <kc:mi>B</kc:mi> </kc:math>