Model-independent analysis of new physics effects in $$B\rightarrow K^*_2(1430)\mu ^+ \mu ^-$$ decay
Abstract Recently, the LHCb Collaboration provided updated measurements for the lepton flavour ratios $$R_K$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>R</mml:mi> <mml:mi>K</mml:mi> </mml:msub> </mml:math> and $$R_{K^*}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>R</mml:mi> <mml:msup> <mml:mi>K</mml:mi> <mml:mo>∗</mml:mo> </mml:msup> </mml:msub> </mml:math> . The currently observed values align with the predictions of the standard model. In light of these recent updates, our investigation delves into the repercussions of new physics characterized by universal couplings to electrons and muons. We specifically focus on their impact on various observables within the $$B\rightarrow K_2^*(1430)(\rightarrow K\pi )\mu ^+ \mu ^-$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>B</mml:mi> <mml:mo>→</mml:mo> <mml:msubsup> <mml:mi>K</mml:mi> <mml:mn>2</mml:mn> <mml:mo>∗</mml:mo> </mml:msubsup> <mml:mrow> <mml:mo>(</mml:mo> <mml:mn>1430</mml:mn> <mml:mo>)</mml:mo> </mml:mrow> <mml:mrow> <mml:mo>(</mml:mo> <mml:mo>→</mml:mo> <mml:mi>K</mml:mi> <mml:mi>π</mml:mi> <mml:mo>)</mml:mo> </mml:mrow> <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> decay. These observables include the differential branching ratio, forward-backward asymmetry ( $$A_{FB}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>A</mml:mi> <mml:mrow> <mml:mi>FB</mml:mi> </mml:mrow> </mml:msub> </mml:math> ), longitudinal polarization asymmetry ( $$F_L$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>F</mml:mi> <mml:mi>L</mml:mi> </mml:msub> </mml:math> ), and a set of optimized observables ( $$P_i$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>P</mml:mi> <mml:mi>i</mml:mi> </mml:msub> </mml:math> ). Our findings indicate that the branching ratio of $$B\rightarrow K_2^*(\rightarrow K\pi )\mu ^+ \mu ^-$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>B</mml:mi> <mml:mo>→</mml:mo> <mml:msubsup> <mml:mi>K</mml:mi> <mml:mn>2</mml:mn> <mml:mo>∗</mml:mo> </mml:msubsup> <mml:mrow> <mml:mo>(</mml:mo> <mml:mo>→</mml:mo> <mml:mi>K</mml:mi> <mml:mi>π</mml:mi> <mml:mo>)</mml:mo> </mml:mrow> <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> decay can be suppressed up to $$25\%$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mn>25</mml:mn> <mml:mo>%</mml:mo> </mml:mrow> </mml:math> for various new physics solutions. Furthermore, all permissible new physics scenarios demonstrate finite enhancement in the muon forward-backward asymmetry $$(A_{FB})$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mo>(</mml:mo> <mml:msub> <mml:mi>A</mml:mi> <mml:mrow> <mml:mi>FB</mml:mi> </mml:mrow> </mml:msub> <mml:mo>)</mml:mo> </mml:mrow> </mml:math> as well as an increase in the value of the optimized angular observable $$P_2$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>P</mml:mi> <mml:mn>2</mml:mn> </mml:msub> </mml:math> . Moreover, in the presence of new physics zero crossing points for $$A_{FB}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>A</mml:mi> <mml:mrow> <mml:mi>FB</mml:mi> </mml:mrow> </mml:msub> </mml:math> and $$P_2$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>P</mml:mi> <mml:mn>2</mml:mn> </mml:msub> </mml:math> shift towards higher $$q^2$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mi>q</mml:mi> <mml:mn>2</mml:mn> </mml:msup> </mml:math> . The current data have a mild deviation from SM predictions in $$P_5'$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mi>P</mml:mi> <mml:mn>5</mml:mn> <mml:mo>′</mml:mo> </mml:msubsup> </mml:math> observable in the low- $$q^2$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mi>q</mml:mi> <mml:mn>2</mml:mn> </mml:msup> </mml:math> bin. We also explored massive $$Z'$$ <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, which can generate universal 1D new physics scenarios, characterized by $$C_9^{NP}<0$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msubsup> <mml:mi>C</mml:mi> <mml:mn>9</mml:mn> <mml:mrow> <mml:mi>NP</mml:mi> </mml:mrow> </mml:msubsup> <mml:mo><</mml:mo> <mml:mn>0</mml:mn> </mml:mrow> </mml:math> , $$C_9^{NP}=-C_{10}^{NP}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msubsup> <mml:mi>C</mml:mi> <mml:mn>9</mml:mn> <mml:mrow> <mml:mi>NP</mm
Authors
- Ria Sain (ORCID: https://orcid.org/0000-0002-5461-2091)
- Juhi Vardani
Institutions
- Indian Institute of Technology Guwahati (IN)
- Indian Institute of Technology Jodhpur (IN)
Publication Details
- Journal
- The European Physical Journal C
- Published
- 2024-11-15
- DOI
- https://doi.org/10.1140/epjc/s10052-024-13508-9
- Citations
- 2
- Primary Topic
- Particle physics theoretical and experimental studies
- Type
- article
- Field-Weighted Citation Impact
- 1.32