{"title":"衰变中新物理效应的模型独立分析","authors":"Juhi Vardani, Ria Sain","doi":"10.1140/epjc/s10052-024-13508-9","DOIUrl":null,"url":null,"abstract":"<div><p>Recently, the LHCb Collaboration provided updated measurements for the lepton flavour ratios <span>\\(R_K\\)</span> and <span>\\(R_{K^*}\\)</span>. 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 <span>\\(B\\rightarrow K_2^*(1430)(\\rightarrow K\\pi )\\mu ^+ \\mu ^-\\)</span> decay. These observables include the differential branching ratio, forward-backward asymmetry (<span>\\(A_{FB}\\)</span>), longitudinal polarization asymmetry (<span>\\(F_L\\)</span>), and a set of optimized observables (<span>\\(P_i\\)</span>). Our findings indicate that the branching ratio of <span>\\(B\\rightarrow K_2^*(\\rightarrow K\\pi )\\mu ^+ \\mu ^-\\)</span> decay can be suppressed up to <span>\\(25\\%\\)</span> for various new physics solutions. Furthermore, all permissible new physics scenarios demonstrate finite enhancement in the muon forward-backward asymmetry <span>\\((A_{FB})\\)</span> as well as an increase in the value of the optimized angular observable <span>\\(P_2\\)</span>. Moreover, in the presence of new physics zero crossing points for <span>\\(A_{FB}\\)</span> and <span>\\(P_2\\)</span> shift towards higher <span>\\(q^2\\)</span>. The current data have a mild deviation from SM predictions in <span>\\(P_5'\\)</span> observable in the low-<span>\\(q^2\\)</span> bin. We also explored massive <span>\\(Z'\\)</span> models, which can generate universal 1D new physics scenarios, characterized by <span>\\(C_9^{NP}<0\\)</span>, <span>\\(C_9^{NP}=-C_{10}^{NP}\\)</span>, and <span>\\(C_9^{NP}=-C_9'\\)</span>. Using additional constraints coming from <span>\\(B_s-\\overline{B_s}\\)</span> mixing and neutrino trident process, we find that the conclusions of the model-independent analysis remain valid.</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"84 11","pages":""},"PeriodicalIF":4.2000,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-024-13508-9.pdf","citationCount":"0","resultStr":"{\"title\":\"Model-independent analysis of new physics effects in \\\\(B\\\\rightarrow K^*_2(1430)\\\\mu ^+ \\\\mu ^-\\\\) decay\",\"authors\":\"Juhi Vardani, Ria Sain\",\"doi\":\"10.1140/epjc/s10052-024-13508-9\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Recently, the LHCb Collaboration provided updated measurements for the lepton flavour ratios <span>\\\\(R_K\\\\)</span> and <span>\\\\(R_{K^*}\\\\)</span>. 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 <span>\\\\(B\\\\rightarrow K_2^*(1430)(\\\\rightarrow K\\\\pi )\\\\mu ^+ \\\\mu ^-\\\\)</span> decay. These observables include the differential branching ratio, forward-backward asymmetry (<span>\\\\(A_{FB}\\\\)</span>), longitudinal polarization asymmetry (<span>\\\\(F_L\\\\)</span>), and a set of optimized observables (<span>\\\\(P_i\\\\)</span>). Our findings indicate that the branching ratio of <span>\\\\(B\\\\rightarrow K_2^*(\\\\rightarrow K\\\\pi )\\\\mu ^+ \\\\mu ^-\\\\)</span> decay can be suppressed up to <span>\\\\(25\\\\%\\\\)</span> for various new physics solutions. Furthermore, all permissible new physics scenarios demonstrate finite enhancement in the muon forward-backward asymmetry <span>\\\\((A_{FB})\\\\)</span> as well as an increase in the value of the optimized angular observable <span>\\\\(P_2\\\\)</span>. Moreover, in the presence of new physics zero crossing points for <span>\\\\(A_{FB}\\\\)</span> and <span>\\\\(P_2\\\\)</span> shift towards higher <span>\\\\(q^2\\\\)</span>. The current data have a mild deviation from SM predictions in <span>\\\\(P_5'\\\\)</span> observable in the low-<span>\\\\(q^2\\\\)</span> bin. We also explored massive <span>\\\\(Z'\\\\)</span> models, which can generate universal 1D new physics scenarios, characterized by <span>\\\\(C_9^{NP}<0\\\\)</span>, <span>\\\\(C_9^{NP}=-C_{10}^{NP}\\\\)</span>, and <span>\\\\(C_9^{NP}=-C_9'\\\\)</span>. 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Model-independent analysis of new physics effects in \(B\rightarrow K^*_2(1430)\mu ^+ \mu ^-\) decay
Recently, the LHCb Collaboration provided updated measurements for the lepton flavour ratios \(R_K\) and \(R_{K^*}\). 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 \(B\rightarrow K_2^*(1430)(\rightarrow K\pi )\mu ^+ \mu ^-\) decay. These observables include the differential branching ratio, forward-backward asymmetry (\(A_{FB}\)), longitudinal polarization asymmetry (\(F_L\)), and a set of optimized observables (\(P_i\)). Our findings indicate that the branching ratio of \(B\rightarrow K_2^*(\rightarrow K\pi )\mu ^+ \mu ^-\) decay can be suppressed up to \(25\%\) for various new physics solutions. Furthermore, all permissible new physics scenarios demonstrate finite enhancement in the muon forward-backward asymmetry \((A_{FB})\) as well as an increase in the value of the optimized angular observable \(P_2\). Moreover, in the presence of new physics zero crossing points for \(A_{FB}\) and \(P_2\) shift towards higher \(q^2\). The current data have a mild deviation from SM predictions in \(P_5'\) observable in the low-\(q^2\) bin. We also explored massive \(Z'\) models, which can generate universal 1D new physics scenarios, characterized by \(C_9^{NP}<0\), \(C_9^{NP}=-C_{10}^{NP}\), and \(C_9^{NP}=-C_9'\). Using additional constraints coming from \(B_s-\overline{B_s}\) mixing and neutrino trident process, we find that the conclusions of the model-independent analysis remain valid.
期刊介绍:
Experimental Physics I: Accelerator Based High-Energy Physics
Hadron and lepton collider physics
Lepton-nucleon scattering
High-energy nuclear reactions
Standard model precision tests
Search for new physics beyond the standard model
Heavy flavour physics
Neutrino properties
Particle detector developments
Computational methods and analysis tools
Experimental Physics II: Astroparticle Physics
Dark matter searches
High-energy cosmic rays
Double beta decay
Long baseline neutrino experiments
Neutrino astronomy
Axions and other weakly interacting light particles
Gravitational waves and observational cosmology
Particle detector developments
Computational methods and analysis tools
Theoretical Physics I: Phenomenology of the Standard Model and Beyond
Electroweak interactions
Quantum chromo dynamics
Heavy quark physics and quark flavour mixing
Neutrino physics
Phenomenology of astro- and cosmoparticle physics
Meson spectroscopy and non-perturbative QCD
Low-energy effective field theories
Lattice field theory
High temperature QCD and heavy ion physics
Phenomenology of supersymmetric extensions of the SM
Phenomenology of non-supersymmetric extensions of the SM
Model building and alternative models of electroweak symmetry breaking
Flavour physics beyond the SM
Computational algorithms and tools...etc.