Single production of an exotic vectorlike Y quark at future high energy pp colliders

Vectorlike quarks have been predicted in various new physics scenarios beyond the Standard Model. In a simplified modelling of a <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mo stretchy="false">(</a:mo><a:mi>B</a:mi><a:mo>,</a:mo><a:mi>Y</a:mi><a:mo stretchy="false">)</a:mo></a:math> doublet including a vectorlike quark <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"><e:mi>Y</e:mi></e:math>, with charge <g:math xmlns:g="http://www.w3.org/1998/Math/MathML" display="inline"><g:mrow><g:mo>−</g:mo><g:mfrac><g:mrow><g:mn>4</g:mn></g:mrow><g:mrow><g:mn>3</g:mn></g:mrow></g:mfrac><g:mi mathvariant="normal">e</g:mi></g:mrow></g:math>, there are only two free parameters: the <j:math xmlns:j="http://www.w3.org/1998/Math/MathML" display="inline"><j:mi>Y</j:mi></j:math> coupling <l:math xmlns:l="http://www.w3.org/1998/Math/MathML" display="inline"><l:msub><l:mi>κ</l:mi><l:mi>Y</l:mi></l:msub></l:math> and mass <n:math xmlns:n="http://www.w3.org/1998/Math/MathML" display="inline"><n:msub><n:mi>m</n:mi><n:mi>Y</n:mi></n:msub></n:math>. In the five flavor scheme, we investigate the single production of the <p:math xmlns:p="http://www.w3.org/1998/Math/MathML" display="inline"><p:mi>Y</p:mi></p:math> state decaying into <r:math xmlns:r="http://www.w3.org/1998/Math/MathML" display="inline"><r:mi>W</r:mi><r:mi>b</r:mi></r:math> at the Large Hadron Collider (LHC) run-III and High-Luminosity LHC (HL-LHC) operating at <t:math xmlns:t="http://www.w3.org/1998/Math/MathML" display="inline"><t:msqrt><t:mi>s</t:mi></t:msqrt><t:mo>=</t:mo><t:mn>14</t:mn><t:mtext> </t:mtext><t:mtext> </t:mtext><t:mi>TeV</t:mi></t:math>, the possible High-Energy LHC (HE-LHC) with <v:math xmlns:v="http://www.w3.org/1998/Math/MathML" display="inline"><v:msqrt><v:mi>s</v:mi></v:msqrt><v:mo>=</v:mo><v:mn>27</v:mn><v:mtext> </v:mtext><v:mtext> </v:mtext><v:mi>TeV</v:mi></v:math> as well as the Future Circular Collider in hadron-hadron mode (FCC-hh) with <x:math xmlns:x="http://www.w3.org/1998/Math/MathML" display="inline"><x:msqrt><x:mi>s</x:mi></x:msqrt><x:mo>=</x:mo><x:mn>100</x:mn><x:mtext> </x:mtext><x:mtext> </x:mtext><x:mi>TeV</x:mi></x:math>. Through detailed signal-to-background analyses and detector simulations, we assess the exclusion capabilities of the <z:math xmlns:z="http://www.w3.org/1998/Math/MathML" display="inline"><z:mi>Y</z:mi></z:math> state at the different colliders. We find that this can be improved significantly with increasing collision energy, especially at the HE-LHC and FCC-hh, both demonstrating an obvious advantage with respect to the HL-LHC in the case of high <bb:math xmlns:bb="http://www.w3.org/1998/Math/MathML" display="inline"><bb:msub><bb:mi>m</bb:mi><bb:mi>Y</bb:mi></bb:msub></bb:math>. Assuming a 10% systematic uncertainty on the background event rate, the exclusion capabilities are summarized as follows: (1) the LHC run-III can exclude the correlated regions of <db:math xmlns:db="http://www.w3.org/1998/Math/MathML" display="inline"><db:msub><db:mi>κ</db:mi><db:mi>Y</db:mi></db:msub><db:mo>∈</db:mo><db:mo stretchy="false">[</db:mo><db:mn>0.06</db:mn><db:mo>,</db:mo><db:mn>0.5</db:mn><db:mo stretchy="false">]</db:mo></db:math> and <hb:math xmlns:hb="http://www.w3.org/1998/Math/MathML" display="inline"><hb:msub><hb:mi>m</hb:mi><hb:mi>Y</hb:mi></hb:msub><hb:mo>∈</hb:mo><hb:mo stretchy="false">[</hb:mo><hb:mn>1500</hb:mn><hb:mtext> </hb:mtext><hb:mtext> </hb:mtext><hb:mi>GeV</hb:mi><hb:mo>,</hb:mo><hb:mn>3800</hb:mn><hb:mtext> </hb:mtext><hb:mtext> </hb:mtext><hb:mi>GeV</hb:mi><hb:mo stretchy="false">]</hb:mo></hb:math> with integrated luminosity <lb:math xmlns:lb="http://www.w3.org/1998/Math/MathML" display="inline"><lb:mi>L</lb:mi><lb:mo>=</lb:mo><lb:mn>300</lb:mn><lb:mtext> </lb:mtext><lb:mtext> </lb:mtext><lb:msup><lb:mi>fb</lb:mi><lb:mrow><lb:mo>−</lb:mo><lb:mn>1</lb:mn></lb:mrow></lb:msup></lb:math>; (2) the HL-LHC can exclude the correlated regions of <nb:math xmlns:nb="http://www.w3.org/1998/Math/MathML" display="inline"><nb:msub><nb:mi>κ</nb:mi><nb:mi>Y</nb:mi></nb:msub><nb:mo>∈</nb:mo><nb:mo stretchy="false">[</nb:mo><nb:mn>0.05</nb:mn><nb:mo>,</nb:mo><nb:mn>0.5</nb:mn><nb:mo stretchy="false">]</nb:mo></nb:math> and <rb:math xmlns:rb="http://www.w3.org/1998/Math/MathML" display="inline"><rb:msub><rb:mi>m</rb:mi><rb:mi>Y</rb:mi></rb:msub><rb:mo>∈</rb:mo><rb:mo stretchy="false">[</rb:mo><rb:mn>1500</rb:mn><rb:mtext> </rb:mtext><rb:mtext> </rb:mtext><rb:mi>GeV</rb:mi><rb:mo>,</rb:mo><rb:mn>3970</rb:mn><rb:mtext> </rb:mtext><rb:mtext> </rb:mtext><rb:mi>GeV</rb:mi><rb:mo stretchy="false">]</rb:mo></rb:math> with <vb:math xmlns:vb="http://www.w3.org/1998/Math/MathML" display="inline"><vb:mi>L</vb:mi><vb:mo>=</vb:mo><vb:mn>3</vb:mn><vb:mtext> </vb:mtext><vb:mtext> </vb:mtext><vb:mrow><vb:msup><vb:mrow><vb:mi>ab</vb:mi></vb:mrow><vb:mrow><vb:mo>−</vb:mo><vb:mn>1</vb:mn></vb:mrow></vb:msup></vb:mrow></vb:math>; (3) the HE-LHC can exclude the correlated regions of <xb:math xmlns:xb="http://www.w3.org/1998/Math/MathML" display="inline"><xb:msub><xb:mi>κ</xb:mi><xb:mi>Y</xb:mi></xb:msub><xb:mo>∈</xb:mo><xb:mo stretchy="false">[</xb:mo><xb:mn>0.06</xb:mn><xb:mo>,</xb:mo><xb:mn>0.5</xb:mn><xb:mo stretchy="false">]</xb:mo></xb:math> and <bc:math xmlns:bc="http://www.w3.org/1998/Math/MathML" display="inline"><bc:msub><bc:mi>m</bc:mi><bc:mi>Y</bc:mi></bc:msub><bc:mo>∈</bc:mo><bc:mo stretchy="false">[</bc:mo><bc:mn>1500</bc:mn><bc:mtext> </bc:mtext><bc:mtext> </bc:mtext><bc:mi>GeV</bc:mi><bc:mo>,</bc:mo><bc:mn>6090</bc:mn><bc:mtext> </bc:mtext><bc:mtext> </bc:mtext><bc:mi>GeV</bc:mi><bc:mo stretchy="false">]</bc:mo></bc:math> with <fc:math xmlns:fc="http://www.w3.org/1998/Math/MathML" display="inline"><fc:mi>L</fc:mi><fc:mo>=</fc:mo><fc:mn>3</fc:mn><fc:mtext> </fc:mtext><fc:mtext> </fc:mtext><fc:mrow><fc:msup><fc:mrow><fc:mi>ab</fc:mi></fc:mrow><fc:mrow><fc:mo>−</fc:mo><fc:mn>1</fc:mn></fc:mrow></fc:msup></fc:mrow></fc:math>; (4) the FCC-hh can exclude the correlated regions of <hc:math xmlns:hc="http://www.w3.org/1998/Math/MathML" display="inline"><hc:msub><hc:mi>κ</hc:mi><hc:mi>Y</hc:mi></hc:msub><hc:mo>∈</hc:mo><hc:mo stretchy="false">[</hc:mo><hc:mn>0.08</hc:mn><hc:mo>,</hc:mo><hc:mn>0.5</hc:mn><hc:mo stretchy="false">]</hc:mo></hc:math> and <lc:math xmlns:lc="http://www.w3.org/1998/Math/MathML" display="inline"><lc:msub><lc:mi>m</lc:mi><lc:mi>Y</lc:mi></lc:msub><lc:mo>∈</lc:mo><lc:mo stretchy="false">[</lc:mo><lc:mn>1500</lc:mn><lc:mtext> </lc:mtext><lc:mtext> </lc:mtext><lc:mi>GeV</lc:mi><lc:mo>,</lc:mo><lc:mn>10080</lc:mn><lc:mtext> </lc:mtext><lc:mtext> </lc:mtext><lc:mi>GeV</lc:mi><lc:mo stretchy="false">]</lc:mo></lc:math> with <pc:math xmlns:pc="http://www.w3.org/1998/Math/MathML" display="inline"><pc:mi>L</pc:mi><pc:mo>=</pc:mo><pc:mn>3</pc:mn><pc:mtext> </pc:mtext><pc:mtext> </pc:mtext><pc:mrow><pc:msup><pc:mrow><pc:mi>ab</pc:mi></pc:mrow><pc:mrow><pc:mo>−</pc:mo><pc:mn>1</pc:mn></pc:mrow></pc:msup></pc:mrow></pc:math>. Published by the American Physical Society 2024