Study of angular observables in exclusive semileptonic Bc decays

In this work, we investigate angular observables such as the longitudinal polarization of charged leptons, <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mi>τ</a:mi></a:math>-polarization, and forward-backward asymmetry in semileptonic <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:msub><c:mi>B</c:mi><c:mi>c</c:mi></c:msub></c:math> decays. Additionally, we provide predictions for lepton flavor violating observables, the <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"><e:mi mathvariant="script">R</e:mi></e:math> ratios in the decay channels <h:math xmlns:h="http://www.w3.org/1998/Math/MathML" display="inline"><h:msub><h:mi>B</h:mi><h:mi>c</h:mi></h:msub><h:mo stretchy="false">→</h:mo><h:msub><h:mi>η</h:mi><h:mi>c</h:mi></h:msub><h:mo stretchy="false">(</h:mo><h:mi>J</h:mi><h:mo>/</h:mo><h:mi>ψ</h:mi><h:mo stretchy="false">)</h:mo><h:mi>l</h:mi><h:msub><h:mi>ν</h:mi><h:mi>l</h:mi></h:msub></h:math> and <m:math xmlns:m="http://www.w3.org/1998/Math/MathML" display="inline"><m:msub><m:mi>B</m:mi><m:mi>c</m:mi></m:msub><m:mo stretchy="false">→</m:mo><m:mi>D</m:mi><m:mo stretchy="false">(</m:mo><m:msup><m:mi>D</m:mi><m:mo>*</m:mo></m:msup><m:mo stretchy="false">)</m:mo><m:mi>l</m:mi><m:msub><m:mi>ν</m:mi><m:mi>l</m:mi></m:msub></m:math> across the entire <r:math xmlns:r="http://www.w3.org/1998/Math/MathML" display="inline"><r:msup><r:mi>q</r:mi><r:mn>2</r:mn></r:msup></r:math> region. Our analysis is conducted within the relativistic independent quark model, focusing on the potential model-dependent aspects of these observables. We compare our model predictions with existing lattice predictions, highlighting the strong applicability of our framework in describing <t:math xmlns:t="http://www.w3.org/1998/Math/MathML" display="inline"><t:msub><t:mi>B</t:mi><t:mi>c</t:mi></t:msub></t:math> decays. Considering the forthcoming experimental upgrades and the Run 3 data results on <v:math xmlns:v="http://www.w3.org/1998/Math/MathML" display="inline"><v:msub><v:mi>B</v:mi><v:mi>c</v:mi></v:msub></v:math> meson decays, rapid confirmation of these quantities could indicate significant discoveries of physics beyond the Standard Model. This may open up new avenues for understanding the complex flavor dynamics in heavy meson decays.