Subleading-power corrections to the radiative leptonic B → γℓν decay in QCD

Yu-Ming Wang (School of Physics, Nankai University, Weijin Road 94, Tianjin, 300071, China; Fakultät für Physik, Universität Wien, Boltzmanngasse 5, Vienna, 1090, Austria) ; Yue-Long Shen (College of Information Science and Engineering, Ocean University of China, Songling Road 238, Qingdao, Shandong, 266100, P.R. China)

Applying the method of light-cone sum rules with photon distribution amplitudes, we compute the subleading-power correction to the radiative leptonic B → γℓν decay from the twist-two hadronic photon contribution at next-to-leading order in QCD; and further evaluate the higher-twist “resolved photon” corrections at leading order in α s , up to twist-four accuracy. QCD factorization for the vacuum-to-photon correlation function with an interpolating current for the B-meson is established explicitly at leading power in Λ/m b employing the evanescent operator approach. Resummation of the parametrically large logarithms of m b 2/Λ2 entering the hard function of the leading-twist factorization formula is achieved by solving the QCD evolution equation for the light-ray tensor operator at two loops. The leading-twist hadronic photon effect turns out to preserve the symmetry relation between the two B → γ form factors due to the helicity conservation, however, the higher-twist hadronic photon corrections can yield symmetry-breaking effect already at tree level in QCD. Using the conformal expansion of photon distribution amplitudes with the non-perturbative parameters estimated from QCD sum rules, the twist-two hadronic photon contribution can give rise to approximately 30% correction to the leading-power “direct photon” effect computed from the perturbative QCD factorization approach. In contrast, the subleading-power corrections from the higher-twist two-particle and three-particle photon distribution amplitudes are estimated to be of O35% $$ \mathcal{O}\left(3\sim 5\%\right) $$ with the light-cone sum rule approach. We further predict the partial branching fractions of B → γℓν with a photon-energy cut E γ ≥ E cut, which are of interest for determining the inverse moment of the leading-twist B-meson distribution amplitude thanks to the forthcoming high-luminosity Belle II experiment at KEK.

{
  "license": [
    {
      "url": "https://creativecommons.org/licenses/by/3.0", 
      "license": "CC-BY-3.0"
    }
  ], 
  "copyright": [
    {
      "material": "Article", 
      "holder": "The Author(s)", 
      "year": "2018"
    }
  ], 
  "control_number": "40473", 
  "_oai": {
    "updated": "2018-11-20T10:14:40Z", 
    "id": "oai:repo.scoap3.org:40473", 
    "sets": [
      "JHEP"
    ]
  }, 
  "authors": [
    {
      "affiliations": [
        {
          "country": "China", 
          "value": "School of Physics, Nankai University, Weijin Road 94, Tianjin, 300071, China", 
          "organization": "Nankai University"
        }, 
        {
          "country": "Austria", 
          "value": "Fakult\u00e4t f\u00fcr Physik, Universit\u00e4t Wien, Boltzmanngasse 5, Vienna, 1090, Austria", 
          "organization": "Universit\u00e4t Wien"
        }
      ], 
      "surname": "Wang", 
      "email": "wangyuming@nankai.edu.cn", 
      "full_name": "Wang, Yu-Ming", 
      "given_names": "Yu-Ming"
    }, 
    {
      "affiliations": [
        {
          "country": "China", 
          "value": "College of Information Science and Engineering, Ocean University of China, Songling Road 238, Qingdao, Shandong, 266100, P.R. China", 
          "organization": "Ocean University of China"
        }
      ], 
      "surname": "Shen", 
      "email": "shenylmeteor@ouc.edu.cn", 
      "full_name": "Shen, Yue-Long", 
      "given_names": "Yue-Long"
    }
  ], 
  "_files": [
    {
      "checksum": "md5:45b863daf5852fd081a8c9539cb6b7f9", 
      "filetype": "xml", 
      "bucket": "5b593aa4-3f13-4e78-805a-8767a73c273d", 
      "version_id": "b9b5de7e-2cf3-4615-ab21-17cc172fc871", 
      "key": "10.1007/JHEP05(2018)184.xml", 
      "size": 13235
    }, 
    {
      "checksum": "md5:bf9771dbc1c56e907810828d983d3167", 
      "filetype": "pdf/a", 
      "bucket": "5b593aa4-3f13-4e78-805a-8767a73c273d", 
      "version_id": "9112ccff-0e28-470b-a439-e8db5eb00c4b", 
      "key": "10.1007/JHEP05(2018)184_a.pdf", 
      "size": 889563
    }
  ], 
  "record_creation_date": "2018-05-30T08:22:06.741999", 
  "titles": [
    {
      "source": "Springer", 
      "title": "Subleading-power corrections to the radiative leptonic B \u2192 \u03b3\u2113\u03bd decay in QCD"
    }
  ], 
  "collections": [
    {
      "primary": "Journal of High Energy Physics"
    }
  ], 
  "dois": [
    {
      "value": "10.1007/JHEP05(2018)184"
    }
  ], 
  "publication_info": [
    {
      "page_end": "36", 
      "journal_title": "Journal of High Energy Physics", 
      "material": "article", 
      "journal_volume": "2018", 
      "year": 2018, 
      "page_start": "1", 
      "journal_issue": "5"
    }
  ], 
  "$schema": "http://repo.scoap3.org/schemas/hep.json", 
  "abstracts": [
    {
      "source": "Springer", 
      "value": "Applying the method of light-cone sum rules with photon distribution amplitudes, we compute the subleading-power correction to the radiative leptonic B \u2192 \u03b3\u2113\u03bd decay from the twist-two hadronic photon contribution at next-to-leading order in QCD; and further evaluate the higher-twist \u201cresolved photon\u201d corrections at leading order in \u03b1  s , up to twist-four accuracy. QCD factorization for the vacuum-to-photon correlation function with an interpolating current for the B-meson is established explicitly at leading power in \u039b/m  b  employing the evanescent operator approach. Resummation of the parametrically large logarithms of m  b 2/\u039b2 entering the hard function of the leading-twist factorization formula is achieved by solving the QCD evolution equation for the light-ray tensor operator at two loops. The leading-twist hadronic photon effect turns out to preserve the symmetry relation between the two B \u2192 \u03b3 form factors due to the helicity conservation, however, the higher-twist hadronic photon corrections can yield symmetry-breaking effect already at tree level in QCD. Using the conformal expansion of photon distribution amplitudes with the non-perturbative parameters estimated from QCD sum rules, the twist-two hadronic photon contribution can give rise to approximately 30% correction to the leading-power \u201cdirect photon\u201d effect computed from the perturbative QCD factorization approach. In contrast, the subleading-power corrections from the higher-twist two-particle and three-particle photon distribution amplitudes are estimated to be of  <math><mi>O</mi><mfenced><mrow><mn>3</mn><mo>\u223c</mo><mn>5</mn><mo>%</mo></mrow></mfenced></math> $$ \\mathcal{O}\\left(3\\sim 5\\%\\right) $$ with the light-cone sum rule approach. We further predict the partial branching fractions of B \u2192 \u03b3\u2113\u03bd with a photon-energy cut E  \u03b3  \u2265 E cut, which are of interest for determining the inverse moment of the leading-twist B-meson distribution amplitude thanks to the forthcoming high-luminosity Belle II experiment at KEK."
    }
  ], 
  "imprints": [
    {
      "date": "2018-05-29", 
      "publisher": "Springer"
    }
  ], 
  "acquisition_source": {
    "date": "2018-11-20T10:15:11.764392", 
    "source": "Springer", 
    "method": "Springer", 
    "submission_number": "9e1fd546eca411e89d1402163e01809a"
  }
}
Published on:
29 May 2018
Publisher:
Springer
Published in:
Journal of High Energy Physics , Volume 2018 (2018)
Issue 5
Pages 1-36
DOI:
https://doi.org/10.1007/JHEP05(2018)184
Copyrights:
The Author(s)
Licence:
CC-BY-3.0

Fulltext files: