Signatures of vector-like top partners decaying into new neutral scalar or pseudoscalar bosons

R. Benbrik (Laboratoire de Physique Fondamentale et Appliquée Safi, Faculté Polydisciplinaire de Safi, Université Cadi Ayyad, Sidi Bouzid, P.O.B, Safi, 4162, Maroc) ; E. Kuutmann (Department of Physics and Astronomy, Uppsala University, Box 516, Uppsala, SE-751 20, Sweden) ; D. Franzosi (Department of Physics, Chalmers University of Technology, Fysikgården 1, Göteborg, 412 96, Sweden) ; V. Ellajosyula (Department of Physics and Astronomy, Uppsala University, Box 516, Uppsala, SE-751 20, Sweden) ; R. Enberg (Department of Physics and Astronomy, Uppsala University, Box 516, Uppsala, SE-751 20, Sweden) ; et al. - Show all 12 authors

We explore the phenomenology of models containing one Vector-Like Quark (VLQ), t′, which can decay into the Standard Model (SM) top quark, t, and a new spin-0 neutral boson, S, the latter being either a scalar or pseudoscalar state. We parametrise the underlying interactions in terms of a simplified model which enables us to capture possible Beyond the SM (BSM) scenarios. We discuss in particular three such scenarios: one where the SM state is supplemented by an additional scalar, one which builds upon a 2-Higgs Doublet Model (2HDM) framework and another which realises a Composite Higgs Model (CHM) through partial compositeness. Such exotic decays of the t′ can be competitive with decays into SM particles, leading to new possible discovery channels at the Large Hadron Collider (LHC). Assuming t′ pair production via strong interactions, we design signal regions optimised for one t′ → S t transition (while being inclusive on the other t ¯ $$ \overline{t} $$ ′ decay, and vice versa), followed by the decay of S into the two very clean experimental signatures S → γ γ and S → Z (→ ℓ + ℓ − )γ. We perform a dedicated signal- to-background analysis in both channels, by using Monte Carlo (MC) event simulations modelling the dynamics from the proton-proton to the detector level. Under the assumption of BR(t′ → S t) = 100%, we are therefore able to realistically quantify the sensitivity of the LHC to both the t′ and S masses, assuming both current and foreseen luminosities. This approach paves the way for the LHC experiments to surpass current VLQ search strategies based solely on t′ decays into SM bosons (W ± , Z , h).

{
  "_oai": {
    "updated": "2020-10-23T17:17:25Z", 
    "id": "oai:repo.scoap3.org:54286", 
    "sets": [
      "JHEP"
    ]
  }, 
  "authors": [
    {
      "affiliations": [
        {
          "country": "Morocco", 
          "value": "Laboratoire de Physique Fondamentale et Appliqu\u00e9e Safi, Facult\u00e9 Polydisciplinaire de Safi, Universit\u00e9 Cadi Ayyad, Sidi Bouzid, P.O.B, Safi, 4162, Maroc", 
          "organization": "Facult\u00e9 Polydisciplinaire de Safi, Universit\u00e9 Cadi Ayyad"
        }
      ], 
      "surname": "Benbrik", 
      "email": "r.benbrik@uca.ac.ma", 
      "full_name": "Benbrik, R.", 
      "given_names": "R."
    }, 
    {
      "affiliations": [
        {
          "country": "Sweden", 
          "value": "Department of Physics and Astronomy, Uppsala University, Box 516, Uppsala, SE-751 20, Sweden", 
          "organization": "Uppsala University"
        }
      ], 
      "surname": "Kuutmann", 
      "email": "elin.bergeaas.kuutmann@physics.uu.se", 
      "full_name": "Kuutmann, E.", 
      "given_names": "E."
    }, 
    {
      "affiliations": [
        {
          "country": "Sweden", 
          "value": "Department of Physics, Chalmers University of Technology, Fysikg\u00e5rden 1, G\u00f6teborg, 412 96, Sweden", 
          "organization": "Chalmers University of Technology"
        }
      ], 
      "surname": "Franzosi", 
      "email": "diogo.buarque.franzosi@gmail.com", 
      "full_name": "Franzosi, D.", 
      "given_names": "D."
    }, 
    {
      "affiliations": [
        {
          "country": "Sweden", 
          "value": "Department of Physics and Astronomy, Uppsala University, Box 516, Uppsala, SE-751 20, Sweden", 
          "organization": "Uppsala University"
        }
      ], 
      "surname": "Ellajosyula", 
      "email": "venugopal.ellajosyula@physics.uu.se", 
      "full_name": "Ellajosyula, V.", 
      "given_names": "V."
    }, 
    {
      "affiliations": [
        {
          "country": "Sweden", 
          "value": "Department of Physics and Astronomy, Uppsala University, Box 516, Uppsala, SE-751 20, Sweden", 
          "organization": "Uppsala University"
        }
      ], 
      "surname": "Enberg", 
      "email": "rikard.enberg@physics.uu.se", 
      "full_name": "Enberg, R.", 
      "given_names": "R."
    }, 
    {
      "affiliations": [
        {
          "country": "Sweden", 
          "value": "Department of Physics, Chalmers University of Technology, Fysikg\u00e5rden 1, G\u00f6teborg, 412 96, Sweden", 
          "organization": "Chalmers University of Technology"
        }
      ], 
      "surname": "Ferretti", 
      "email": "ferretti@chalmers.se", 
      "full_name": "Ferretti, G.", 
      "given_names": "G."
    }, 
    {
      "affiliations": [
        {
          "country": "Sweden", 
          "value": "Department of Physics and Astronomy, Uppsala University, Box 516, Uppsala, SE-751 20, Sweden", 
          "organization": "Uppsala University"
        }
      ], 
      "surname": "Isacson", 
      "email": "max.isacson@physics.uu.se", 
      "full_name": "Isacson, M.", 
      "given_names": "M."
    }, 
    {
      "affiliations": [
        {
          "country": "China", 
          "value": "Henan Institute of Science and Technology, Xinxiang, 453003, People\u2019s Republic of China", 
          "organization": "Henan Institute of Science and Technology"
        }
      ], 
      "surname": "Liu", 
      "email": "liuyaobei@hist.edu.cn", 
      "full_name": "Liu, Y.B.", 
      "given_names": "Y.B."
    }, 
    {
      "affiliations": [
        {
          "country": "Sweden", 
          "value": "Department of Physics and Astronomy, Uppsala University, Box 516, Uppsala, SE-751 20, Sweden", 
          "organization": "Uppsala University"
        }
      ], 
      "surname": "Mandal", 
      "email": "tanumoym@gmail.com", 
      "full_name": "Mandal, T.", 
      "given_names": "T."
    }, 
    {
      "affiliations": [
        {
          "country": "Sweden", 
          "value": "Department of Physics and Astronomy, Uppsala University, Box 516, Uppsala, SE-751 20, Sweden", 
          "organization": "Uppsala University"
        }
      ], 
      "surname": "Mathisen", 
      "email": "thomas.mathisen@physics.uu.se", 
      "full_name": "Mathisen, T.", 
      "given_names": "T."
    }, 
    {
      "affiliations": [
        {
          "country": "UK", 
          "value": "School of Physics & Astronomy, University of Southampton, Highfield, Southampton, SO17 1BJ, U.K.", 
          "organization": "University of Southampton"
        }
      ], 
      "surname": "Moretti", 
      "email": "stefano.moretti@cern.ch", 
      "full_name": "Moretti, S.", 
      "given_names": "S."
    }, 
    {
      "affiliations": [
        {
          "country": "Sweden", 
          "value": "Department of Physics and Astronomy, Uppsala University, Box 516, Uppsala, SE-751 20, Sweden", 
          "organization": "Uppsala University"
        }
      ], 
      "surname": "Panizzi", 
      "email": "luca.panizzi@physics.uu.se", 
      "full_name": "Panizzi, L.", 
      "given_names": "L."
    }
  ], 
  "titles": [
    {
      "source": "Springer", 
      "title": "Signatures of vector-like top partners decaying into new neutral scalar or pseudoscalar bosons"
    }
  ], 
  "dois": [
    {
      "value": "10.1007/JHEP05(2020)028"
    }
  ], 
  "publication_info": [
    {
      "page_end": "48", 
      "journal_title": "Journal of High Energy Physics", 
      "material": "article", 
      "journal_volume": "2020", 
      "artid": "JHEP05(2020)028", 
      "year": 2020, 
      "page_start": "1", 
      "journal_issue": "5"
    }
  ], 
  "$schema": "http://repo.scoap3.org/schemas/hep.json", 
  "acquisition_source": {
    "date": "2020-05-09T08:30:28.649442", 
    "source": "Springer", 
    "method": "Springer", 
    "submission_number": "8246357091be11eaad8602163e01809a"
  }, 
  "page_nr": [
    48
  ], 
  "license": [
    {
      "url": "https://creativecommons.org/licenses/by/3.0", 
      "license": "CC-BY-3.0"
    }
  ], 
  "copyright": [
    {
      "holder": "The Author(s)", 
      "year": "2020"
    }
  ], 
  "control_number": "54286", 
  "record_creation_date": "2020-05-09T08:30:28.649462", 
  "_files": [
    {
      "checksum": "md5:9e76bca3212f0a1fd55d671018473e50", 
      "filetype": "xml", 
      "bucket": "79043d16-49cd-4391-9207-6f59d9128bda", 
      "version_id": "66d59ef6-d00c-4ba2-9946-75113db0d633", 
      "key": "10.1007/JHEP05(2020)028.xml", 
      "size": 20054
    }, 
    {
      "checksum": "md5:d7700bc629bef1d324998dfe0f8206fe", 
      "filetype": "pdf/a", 
      "bucket": "79043d16-49cd-4391-9207-6f59d9128bda", 
      "version_id": "ade512e9-d4af-4525-98e4-6e875aef2c45", 
      "key": "10.1007/JHEP05(2020)028_a.pdf", 
      "size": 9945711
    }
  ], 
  "collections": [
    {
      "primary": "Journal of High Energy Physics"
    }
  ], 
  "arxiv_eprints": [
    {
      "categories": [
        "hep-ph"
      ], 
      "value": "1907.05929"
    }
  ], 
  "abstracts": [
    {
      "source": "Springer", 
      "value": "We explore the phenomenology of models containing one Vector-Like Quark (VLQ), t\u2032, which can decay into the Standard Model (SM) top quark, t, and a new spin-0 neutral boson, S, the latter being either a scalar or pseudoscalar state. We parametrise the underlying interactions in terms of a simplified model which enables us to capture possible Beyond the SM (BSM) scenarios. We discuss in particular three such scenarios: one where the SM state is supplemented by an additional scalar, one which builds upon a 2-Higgs Doublet Model (2HDM) framework and another which realises a Composite Higgs Model (CHM) through partial compositeness. Such exotic decays of the t\u2032 can be competitive with decays into SM particles, leading to new possible discovery channels at the Large Hadron Collider (LHC). Assuming t\u2032 pair production via strong interactions, we design signal regions optimised for one t\u2032 \u2192 S t transition (while being inclusive on the other   <math> <mover> <mi>t</mi> <mo>\u00af</mo> </mover> </math>  $$ \\overline{t} $$  \u2032 decay, and vice versa), followed by the decay of S into the two very clean experimental signatures S \u2192 \u03b3 \u03b3 and S \u2192 Z (\u2192 \u2113 + \u2113  \u2212 )\u03b3. We perform a dedicated signal- to-background analysis in both channels, by using Monte Carlo (MC) event simulations modelling the dynamics from the proton-proton to the detector level. Under the assumption of BR(t\u2032 \u2192 S t) = 100%, we are therefore able to realistically quantify the sensitivity of the LHC to both the t\u2032 and S masses, assuming both current and foreseen luminosities. This approach paves the way for the LHC experiments to surpass current VLQ search strategies based solely on t\u2032 decays into SM bosons (W \u00b1 , Z , h)."
    }
  ], 
  "imprints": [
    {
      "date": "2020-05-07", 
      "publisher": "Springer"
    }
  ]
}
Published on:
07 May 2020
Publisher:
Springer
Published in:
Journal of High Energy Physics , Volume 2020 (2020)
Issue 5
Pages 1-48
DOI:
https://doi.org/10.1007/JHEP05(2020)028
arXiv:
1907.05929
Copyrights:
The Author(s)
Licence:
CC-BY-3.0

Fulltext files: