The semitauonic $$ {B}_c^{-}\to J/\psi {\tau}^{-}{\overline{\nu}}_{\tau } $$ decay provides an ideal and clean mode to scrutinize possible new physics effects in $$ b\to c{\tau}^{-}{\overline{\nu}}_{\tau } $$ transitions as indicated by the current data on R(D (*)) anomalies. In this work, we use the spin density matrix method to obtain the maximum information on the underlying physics of $$ {B}_c^{-}\to J/\psi {\tau}^{-}{\overline{\nu}}_{\tau } $$ decay with both polarized τ lepton and J/ψ meson. Their subsequent decays, with J/ψ → μ + μ − as well as τ − → π − ν τ , τ − → ρ − ν τ and $$ {\tau}^{-}\to {\ell}^{-}{\overline{\nu}}_{\ell }{\nu}_{\tau } $$ , are exploited to extract the energy and angular distributions of the charged final-state particles in the processes. Starting with the most general effective Hamiltonian relevant for the $$ b\to c{\tau}^{-}{\overline{\nu}}_{\tau } $$ transitions, including all possible Lorentz structures of the dimension-six operators with both left- and right-handed neutrinos, we first derive the five-fold differential decay rate in terms of the visible final-state kinematics. From this distribution, we then construct in total 34 normalized observables, among which nine refer to the CP-violating triple product asymmetries that vanish within the Standard Model. We also construct five new observables based on the combinations of these normalized observables that can only be attributed to the right-handed neutrinos. On the other hand, considering the low statistics of the fully differential distribution, we introduce some integrated observables with only one kinematic variable left, which are more promising to be measured due to the largely increased statistics. The sensitivities of all these observables to the different new physics scenarios are investigated in detail. Finally, assuming an ideal circumstance, we give an estimate of the statistical uncertainties of the nine CP-conserving observables at LHCb and found that τ − → π − ν τ has the highest analyzing power among the three τ decay channels.
{
"_oai": {
"updated": "2023-08-24T00:32:34Z",
"id": "oai:repo.scoap3.org:77842",
"sets": [
"JHEP"
]
},
"authors": [
{
"affiliations": [
{
"country": "China",
"value": "Institute of Particle Physics and Key Laboratory of Quark and Lepton Physics (MOE), Central China Normal University, Wuhan, Hubei, 430079, China",
"organization": "Central China Normal University"
},
{
"country": "China",
"value": "Center for High Energy Physics, Peking University, Beijing, 100871, China",
"organization": "Peking University"
}
],
"surname": "Li",
"email": "xqli@mail.ccnu.edu.cn",
"full_name": "Li, Xin-Qiang",
"given_names": "Xin-Qiang"
},
{
"affiliations": [
{
"country": "China",
"value": "Institute of Particle Physics and Key Laboratory of Quark and Lepton Physics (MOE), Central China Normal University, Wuhan, Hubei, 430079, China",
"organization": "Central China Normal University"
}
],
"surname": "Xu",
"email": "xuxin@mails.ccnu.edu.cn",
"full_name": "Xu, Xin",
"given_names": "Xin"
},
{
"affiliations": [
{
"country": "China",
"value": "Institute of Particle Physics and Key Laboratory of Quark and Lepton Physics (MOE), Central China Normal University, Wuhan, Hubei, 430079, China",
"organization": "Central China Normal University"
},
{
"country": "China",
"value": "Institute of Particle and Nuclear Physics, Henan Normal University, Xinxiang, 453007, China",
"organization": "Henan Normal University"
}
],
"surname": "Yang",
"email": "yangyd@mail.ccnu.edu.cn",
"full_name": "Yang, Ya-Dong",
"given_names": "Ya-Dong"
},
{
"affiliations": [
{
"country": "China",
"value": "Institute of Particle Physics and Key Laboratory of Quark and Lepton Physics (MOE), Central China Normal University, Wuhan, Hubei, 430079, China",
"organization": "Central China Normal University"
}
],
"surname": "Zheng",
"email": "zhengdh@mails.ccnu.edu.cn",
"full_name": "Zheng, Dong-Hui",
"given_names": "Dong-Hui"
}
],
"titles": [
{
"source": "Springer",
"title": "<math> <msubsup> <mi>B</mi> <mi>c</mi> <mo>\u2212</mo> </msubsup> <mo>\u2192</mo> <mi>J</mi> <mo>/</mo> <mi>\u03c8</mi> <mfenced> <mrow> <mo>\u2192</mo> <msup> <mi>\u03bc</mi> <mo>+</mo> </msup> <msup> <mi>\u03bc</mi> <mo>\u2212</mo> </msup> </mrow> </mfenced> <msup> <mi>\u03c4</mi> <mo>\u2212</mo> </msup> <mfenced> <mrow> <mo>\u2192</mo> <msup> <mi>\u03c0</mi> <mo>\u2212</mo> </msup> <msub> <mi>\u03bd</mi> <mi>\u03c4</mi> </msub> </mrow> <mrow> <msup> <mi>\u03c1</mi> <mo>\u2212</mo> </msup> <msub> <mi>\u03bd</mi> <mi>\u03c4</mi> </msub> </mrow> <mrow> <msup> <mi>\u2113</mi> <mo>\u2212</mo> </msup> <msub> <mover> <mi>\u03bd</mi> <mo>\u00af</mo> </mover> <mi>\u2113</mi> </msub> <msub> <mi>\u03bd</mi> <mi>\u03c4</mi> </msub> </mrow> </mfenced> <msub> <mover> <mi>\u03bd</mi> <mo>\u00af</mo> </mover> <mi>\u03c4</mi> </msub> </math> $$ {B}_c^{-}\\to J/\\psi \\left(\\to {\\mu}^{+}{\\mu}^{-}\\right){\\tau}^{-}\\left(\\to {\\pi}^{-}{\\nu}_{\\tau },{\\rho}^{-}{\\nu}_{\\tau },{\\ell}^{-}{\\overline{\\nu}}_{\\ell }{\\nu}_{\\tau}\\right){\\overline{\\nu}}_{\\tau } $$ decays with visible final-state kinematics"
}
],
"dois": [
{
"value": "10.1007/JHEP05(2023)173"
}
],
"publication_info": [
{
"page_end": "41",
"journal_title": "Journal of High Energy Physics",
"material": "article",
"journal_volume": "2023",
"artid": "JHEP05(2023)173",
"year": 2023,
"page_start": "1",
"journal_issue": "5"
}
],
"$schema": "http://repo.scoap3.org/schemas/hep.json",
"acquisition_source": {
"date": "2023-08-24T00:31:13.308393",
"source": "Springer",
"method": "Springer",
"submission_number": "5c13f3c8421511ee91ac6ee2827c7def"
},
"page_nr": [
41
],
"license": [
{
"url": "https://creativecommons.org/licenses//by/4.0",
"license": "CC-BY-4.0"
}
],
"copyright": [
{
"holder": "The Author(s)",
"year": "2023"
}
],
"control_number": "77842",
"record_creation_date": "2023-05-23T12:30:05.855729",
"_files": [
{
"checksum": "md5:675c53102a9700391de4a0c23c6c6908",
"filetype": "xml",
"bucket": "5cfbd63e-b6ba-42e4-a97c-0ba61a012b50",
"version_id": "0349690e-ead6-48ca-ae72-440e18fe5765",
"key": "10.1007/JHEP05(2023)173.xml",
"size": 25937
},
{
"checksum": "md5:4b81a50d3ad47e9f54b02868fa761a5c",
"filetype": "pdf/a",
"bucket": "5cfbd63e-b6ba-42e4-a97c-0ba61a012b50",
"version_id": "14f7ca5c-d654-4cb8-94cc-23580ceced2f",
"key": "10.1007/JHEP05(2023)173_a.pdf",
"size": 1698027
}
],
"collections": [
{
"primary": "Journal of High Energy Physics"
}
],
"arxiv_eprints": [
{
"categories": [
"hep-ph",
"hep-ex"
],
"value": "2302.13743"
}
],
"abstracts": [
{
"source": "Springer",
"value": "The semitauonic <math> <msubsup> <mi>B</mi> <mi>c</mi> <mo>\u2212</mo> </msubsup> <mo>\u2192</mo> <mi>J</mi> <mo>/</mo> <mi>\u03c8</mi> <msup> <mi>\u03c4</mi> <mo>\u2212</mo> </msup> <msub> <mover> <mi>\u03bd</mi> <mo>\u00af</mo> </mover> <mi>\u03c4</mi> </msub> </math> $$ {B}_c^{-}\\to J/\\psi {\\tau}^{-}{\\overline{\\nu}}_{\\tau } $$ decay provides an ideal and clean mode to scrutinize possible new physics effects in <math> <mi>b</mi> <mo>\u2192</mo> <mi>c</mi> <msup> <mi>\u03c4</mi> <mo>\u2212</mo> </msup> <msub> <mover> <mi>\u03bd</mi> <mo>\u00af</mo> </mover> <mi>\u03c4</mi> </msub> </math> $$ b\\to c{\\tau}^{-}{\\overline{\\nu}}_{\\tau } $$ transitions as indicated by the current data on R(D (*)) anomalies. In this work, we use the spin density matrix method to obtain the maximum information on the underlying physics of <math> <msubsup> <mi>B</mi> <mi>c</mi> <mo>\u2212</mo> </msubsup> <mo>\u2192</mo> <mi>J</mi> <mo>/</mo> <mi>\u03c8</mi> <msup> <mi>\u03c4</mi> <mo>\u2212</mo> </msup> <msub> <mover> <mi>\u03bd</mi> <mo>\u00af</mo> </mover> <mi>\u03c4</mi> </msub> </math> $$ {B}_c^{-}\\to J/\\psi {\\tau}^{-}{\\overline{\\nu}}_{\\tau } $$ decay with both polarized \u03c4 lepton and J/\u03c8 meson. Their subsequent decays, with J/\u03c8 \u2192 \u03bc + \u03bc \u2212 as well as \u03c4 \u2212 \u2192 \u03c0 \u2212 \u03bd \u03c4 , \u03c4 \u2212 \u2192 \u03c1 \u2212 \u03bd \u03c4 and <math> <msup> <mi>\u03c4</mi> <mo>\u2212</mo> </msup> <mo>\u2192</mo> <msup> <mi>\u2113</mi> <mo>\u2212</mo> </msup> <msub> <mover> <mi>\u03bd</mi> <mo>\u00af</mo> </mover> <mi>\u2113</mi> </msub> <msub> <mi>\u03bd</mi> <mi>\u03c4</mi> </msub> </math> $$ {\\tau}^{-}\\to {\\ell}^{-}{\\overline{\\nu}}_{\\ell }{\\nu}_{\\tau } $$ , are exploited to extract the energy and angular distributions of the charged final-state particles in the processes. Starting with the most general effective Hamiltonian relevant for the <math> <mi>b</mi> <mo>\u2192</mo> <mi>c</mi> <msup> <mi>\u03c4</mi> <mo>\u2212</mo> </msup> <msub> <mover> <mi>\u03bd</mi> <mo>\u00af</mo> </mover> <mi>\u03c4</mi> </msub> </math> $$ b\\to c{\\tau}^{-}{\\overline{\\nu}}_{\\tau } $$ transitions, including all possible Lorentz structures of the dimension-six operators with both left- and right-handed neutrinos, we first derive the five-fold differential decay rate in terms of the visible final-state kinematics. From this distribution, we then construct in total 34 normalized observables, among which nine refer to the CP-violating triple product asymmetries that vanish within the Standard Model. We also construct five new observables based on the combinations of these normalized observables that can only be attributed to the right-handed neutrinos. On the other hand, considering the low statistics of the fully differential distribution, we introduce some integrated observables with only one kinematic variable left, which are more promising to be measured due to the largely increased statistics. The sensitivities of all these observables to the different new physics scenarios are investigated in detail. Finally, assuming an ideal circumstance, we give an estimate of the statistical uncertainties of the nine CP-conserving observables at LHCb and found that \u03c4 \u2212 \u2192 \u03c0 \u2212 \u03bd \u03c4 has the highest analyzing power among the three \u03c4 decay channels."
}
],
"imprints": [
{
"date": "2023-05-22",
"publisher": "Springer"
}
]
}