Large hadron collider constraints on some simple $$Z^\prime $$ models for $$b\rightarrow s \mu ^+\mu ^-$$ anomalies
B. C. Allanach, J. M. Butterworth, Tyler Corbett
Abstract
Abstract We examine current Large Hadron Collider constraints on some simple $$Z^\prime $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mi>Z</mml:mi> <mml:mo>′</mml:mo> </mml:msup> </mml:math> models that significantly improve on Standard Model fits to $$b\rightarrow s \mu ^+\mu ^-$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>b</mml:mi> <mml:mo>→</mml:mo> <mml:mi>s</mml:mi> <mml:msup> <mml:mi>μ</mml:mi> <mml:mo>+</mml:mo> </mml:msup> <mml:msup> <mml:mi>μ</mml:mi> <mml:mo>-</mml:mo> </mml:msup> </mml:mrow> </mml:math> transition data. The models that we consider are the ‘third family baryon number minus second family lepton number’ ( $${B_3-L_2}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>B</mml:mi> <mml:mn>3</mml:mn> </mml:msub> <mml:mo>-</mml:mo> <mml:msub> <mml:mi>L</mml:mi> <mml:mn>2</mml:mn> </mml:msub> </mml:mrow> </mml:math> ) model and the ‘third family hypercharge’ model and variants. The constraints are applied on parameter regions of each model that fit the $$b\rightarrow s \mu ^+\mu ^-$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>b</mml:mi> <mml:mo>→</mml:mo> <mml:mi>s</mml:mi> <mml:msup> <mml:mi>μ</mml:mi> <mml:mo>+</mml:mo> </mml:msup> <mml:msup> <mml:mi>μ</mml:mi> <mml:mo>-</mml:mo> </mml:msup> </mml:mrow> </mml:math> transition data and come from high-mass Drell–Yan di-muons and measurements of Standard Model processes. This latter set of observables place particularly strong bounds upon the parameter space of the $${B_3-L_2}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>B</mml:mi> <mml:mn>3</mml:mn> </mml:msub> <mml:mo>-</mml:mo> <mml:msub> <mml:mi>L</mml:mi> <mml:mn>2</mml:mn> </mml:msub> </mml:mrow> </mml:math> model when the mass of the $$Z^\prime $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mi>Z</mml:mi> <mml:mo>′</mml:mo> </mml:msup> </mml:math> boson is less than 300 GeV.