{"title":"Study of lepton flavor universality and angular distributions in \\(D\\rightarrow K^*_{J} (\\rightarrow K\\pi )\\ell \\nu _{\\ell }\\)","authors":"Fei Huang, Ji Xu","doi":"10.1140/epjc/s10052-024-13456-4","DOIUrl":null,"url":null,"abstract":"<div><p>The decay of the <i>D</i> meson into multibody final states is a complex process that provides valuable insights into the fundamental interactions within the Standard Model of particle physics. This study focuses on the decay cascade <span>\\(D^{+}\\rightarrow K^{*}_{J} \\ell ^{+}\\nu \\rightarrow K^{\\pm }\\pi ^{\\mp } \\ell ^{+}\\nu \\)</span> where the <span>\\(K^*_J\\)</span> resonance encompasses the <span>\\(K^*(892),K^{*}(1410),K^{*}_0(1430)\\)</span> states. We employ the helicity amplitude technique to derive the angular distributions for the decay chain, enabling the extraction of one-dimensional and two-dimensional distributions. Utilizing form factors for the <span>\\(D\\rightarrow K^*\\)</span> transition derived from the quark model, we calculate the differential and integrated partial decay widths, explicitly considering the electron and muon masses. Decay branching fractions are calculated, the ratios of the branching fractions are found to be <span>\\(\\frac{\\mathcal {B}r(D^{+}\\rightarrow K^{*}(892)(\\rightarrow K ^{-}\\pi ^{+}) \\, \\mu ^{+}\\nu _{\\mu })}{\\mathcal {B}r(D^{+}\\rightarrow K^{*}(892)(\\rightarrow K ^{-}\\pi ^{+}) \\, e^{+}\\nu _{e})} = 0.975\\)</span>, <span>\\(\\frac{\\mathcal {B}r(D^{+}\\rightarrow K^{*}(1410)(\\rightarrow K ^{-}\\pi ^{+}) \\, \\mu ^{+}\\nu _{\\mu })}{\\mathcal {B}r(D^{+}\\rightarrow K^{*}(1410)(\\rightarrow K ^{-}\\pi ^{+}) \\, e^{+}\\nu _{e})} = 0.714\\)</span> and <span>\\(\\frac{\\mathcal {B}r(D^{+}\\rightarrow K^{*}_{0}(1430)(\\rightarrow K ^{+}\\pi ^{-}) \\, \\mu ^{+}\\nu _{\\mu })}{\\mathcal {B}r(D^{+}\\rightarrow K^{*}_{0}(1430)(\\rightarrow K ^{+}\\pi ^{-}) \\, e^{+}\\nu _{e})} = 0.774\\)</span>. Results in this work will serve a calibration for the study of <span>\\(c \\rightarrow s \\)</span> in <i>D</i> meson decays in future and provide useful information towards the understanding of the properties of the <span>\\(K^{*}\\)</span> meson, as well as <span>\\(K \\pi \\)</span> system.</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":null,"pages":null},"PeriodicalIF":4.2000,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-024-13456-4.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"The European Physical Journal C","FirstCategoryId":"4","ListUrlMain":"https://link.springer.com/article/10.1140/epjc/s10052-024-13456-4","RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"PHYSICS, PARTICLES & FIELDS","Score":null,"Total":0}
引用次数: 0
Abstract
The decay of the D meson into multibody final states is a complex process that provides valuable insights into the fundamental interactions within the Standard Model of particle physics. This study focuses on the decay cascade \(D^{+}\rightarrow K^{*}_{J} \ell ^{+}\nu \rightarrow K^{\pm }\pi ^{\mp } \ell ^{+}\nu \) where the \(K^*_J\) resonance encompasses the \(K^*(892),K^{*}(1410),K^{*}_0(1430)\) states. We employ the helicity amplitude technique to derive the angular distributions for the decay chain, enabling the extraction of one-dimensional and two-dimensional distributions. Utilizing form factors for the \(D\rightarrow K^*\) transition derived from the quark model, we calculate the differential and integrated partial decay widths, explicitly considering the electron and muon masses. Decay branching fractions are calculated, the ratios of the branching fractions are found to be \(\frac{\mathcal {B}r(D^{+}\rightarrow K^{*}(892)(\rightarrow K ^{-}\pi ^{+}) \, \mu ^{+}\nu _{\mu })}{\mathcal {B}r(D^{+}\rightarrow K^{*}(892)(\rightarrow K ^{-}\pi ^{+}) \, e^{+}\nu _{e})} = 0.975\), \(\frac{\mathcal {B}r(D^{+}\rightarrow K^{*}(1410)(\rightarrow K ^{-}\pi ^{+}) \, \mu ^{+}\nu _{\mu })}{\mathcal {B}r(D^{+}\rightarrow K^{*}(1410)(\rightarrow K ^{-}\pi ^{+}) \, e^{+}\nu _{e})} = 0.714\) and \(\frac{\mathcal {B}r(D^{+}\rightarrow K^{*}_{0}(1430)(\rightarrow K ^{+}\pi ^{-}) \, \mu ^{+}\nu _{\mu })}{\mathcal {B}r(D^{+}\rightarrow K^{*}_{0}(1430)(\rightarrow K ^{+}\pi ^{-}) \, e^{+}\nu _{e})} = 0.774\). Results in this work will serve a calibration for the study of \(c \rightarrow s \) in D meson decays in future and provide useful information towards the understanding of the properties of the \(K^{*}\) meson, as well as \(K \pi \) system.
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.