Searching for a vector-like B quark through a tW decay channel at future electron–positron colliders
Lin Han, Jie-Fen Shen, Yao-Bei Liu
Abstract
Abstract Vector-like quarks are predicted by several theoretical scenarios of new physics which could solve the hierarchy problem in particular and might be produced through electroweak interactions. In this work, we investigate the prospects for discovering the SU (2) singlet vector-like bottom quark (VLQ- B ) in $$e^{+}e^{-}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msup> <mml:mi>e</mml:mi> <mml:mo>+</mml:mo> </mml:msup> <mml:msup> <mml:mi>e</mml:mi> <mml:mo>-</mml:mo> </mml:msup> </mml:mrow> </mml:math> collisions at the future proposed 3 TeV Compact Linear Collider (CLIC). The analysis is performed within the framework of a simplified model featuring only two free parameters: the VLQ- B mass $$m_B$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>m</mml:mi> <mml:mi>B</mml:mi> </mml:msub> </mml:math> and the coupling constant $$g^{*}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mi>g</mml:mi> <mml:mrow> <mml:mrow/> <mml:mo>∗</mml:mo> </mml:mrow> </mml:msup> </mml:math> . We study its single production process $$e^{+}e^{-}\rightarrow B{\bar{b}}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msup> <mml:mi>e</mml:mi> <mml:mo>+</mml:mo> </mml:msup> <mml:msup> <mml:mi>e</mml:mi> <mml:mo>-</mml:mo> </mml:msup> <mml:mo>→</mml:mo> <mml:mi>B</mml:mi> <mml:mover> <mml:mrow> <mml:mi>b</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>¯</mml:mo> </mml:mrow> </mml:mover> </mml:mrow> </mml:math> and perform a detailed analysis in the decay channel $$B\rightarrow tW^{-}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>B</mml:mi> <mml:mo>→</mml:mo> <mml:mi>t</mml:mi> <mml:msup> <mml:mi>W</mml:mi> <mml:mo>-</mml:mo> </mml:msup> </mml:mrow> </mml:math> at the 3 TeV CLIC. The $$2\sigma $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mn>2</mml:mn> <mml:mi>σ</mml:mi> </mml:mrow> </mml:math> exclusion limit and $$5\sigma $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mn>5</mml:mn> <mml:mi>σ</mml:mi> </mml:mrow> </mml:math> discovery prospects are obtained for the model parameters, respectively. Our results show that the future CLIC will be an ideal hunting ground for such vector-like quarks which have electroweak interactions.