The decay A0 → h0Z(∗) in the inverted hierarchy scenario and its detection prospects at the large hadron collider
The decay A0 → h0Z(∗) in the inverted hierarchy scenario and its detection prospects at the large hadron collider
Searches are being carried out at the large hadron collider (LHC) for the decay of the CP-odd scalar (A0) in two-Higgs-doublet models (2HDMs) with natural flavour conservation (NFC) in the channel A0 → h0Z (with ${m}_{{h}^{0}}=125\,\mathrm{GeV}$ and Z on-shell). In the absence of any signal, limits on the parameter space of $[\tan \beta ,\cos (\beta -\alpha ),{m}_{{A}^{0}}]$ in each 2HDM are derived for ${m}_{{A}^{0}}\gt 225\,\mathrm{GeV}$. In this work, we consider the scenario of inverted hierarchy with ${m}_{{h}^{0}}\lt 125\,\mathrm{GeV}$ and ${m}_{{H}^{0}}=125\,\mathrm{GeV}$ in which the decay A0 → h0Z(∗) (i.e. including the case of an off-shell Z) can have a large branching ratio in the 2HDM (Type I) for ${m}_{{A}^{0}}\lt 225\,\mathrm{GeV}$. We calculate the signal cross section $\sigma ({gg}\to {A}^{0})\,\times \mathrm{BR}({A}^{0}\to {h}^{0}Z(\ast ))\times \mathrm{BR}({h}^{0}\to b\overline{b})$ in the 2HDM (Type I) with NFC and compare its magnitude with the cross section for the case of normal hierarchy (${m}_{{h}^{0}}=125$ GeV) that is currently being searched for at the LHC. For the experimentally unexplored region ${m}_{{A}^{0}}\lt 225$ GeV it is shown that the above cross section for signal events in the scenario of inverted hierarchy can be of the order of a few picobarns. Such sizeable cross sections are several orders of magnitude larger than the cross sections for the case of normal hierarchy, thus motivating an extension of the ongoing searches for A0 → h0Z(∗) to probe the scenario of inverted hierarchy.
electrically neutral Higgs bosons, large hadron collider, two Higgs doublet model
1-25
Akeroyd, A G
e5de827d-7119-41c2-9f1e-5ef123afdf98
Alanazi, S.
7c8bdb4d-f7e9-459e-9bc0-c3d00f15495d
Moretti, Stefano
b57cf0f0-4bc3-4e02-96e3-071255366614
1 September 2023
Akeroyd, A G
e5de827d-7119-41c2-9f1e-5ef123afdf98
Alanazi, S.
7c8bdb4d-f7e9-459e-9bc0-c3d00f15495d
Moretti, Stefano
b57cf0f0-4bc3-4e02-96e3-071255366614
Akeroyd, A G, Alanazi, S. and Moretti, Stefano
(2023)
The decay A0 → h0Z(∗) in the inverted hierarchy scenario and its detection prospects at the large hadron collider.
Journal of Physics G: Nuclear and Particle Physics, 50 (9), , [095001].
(doi:10.1088/1361-6471/ace3e1).
Abstract
Searches are being carried out at the large hadron collider (LHC) for the decay of the CP-odd scalar (A0) in two-Higgs-doublet models (2HDMs) with natural flavour conservation (NFC) in the channel A0 → h0Z (with ${m}_{{h}^{0}}=125\,\mathrm{GeV}$ and Z on-shell). In the absence of any signal, limits on the parameter space of $[\tan \beta ,\cos (\beta -\alpha ),{m}_{{A}^{0}}]$ in each 2HDM are derived for ${m}_{{A}^{0}}\gt 225\,\mathrm{GeV}$. In this work, we consider the scenario of inverted hierarchy with ${m}_{{h}^{0}}\lt 125\,\mathrm{GeV}$ and ${m}_{{H}^{0}}=125\,\mathrm{GeV}$ in which the decay A0 → h0Z(∗) (i.e. including the case of an off-shell Z) can have a large branching ratio in the 2HDM (Type I) for ${m}_{{A}^{0}}\lt 225\,\mathrm{GeV}$. We calculate the signal cross section $\sigma ({gg}\to {A}^{0})\,\times \mathrm{BR}({A}^{0}\to {h}^{0}Z(\ast ))\times \mathrm{BR}({h}^{0}\to b\overline{b})$ in the 2HDM (Type I) with NFC and compare its magnitude with the cross section for the case of normal hierarchy (${m}_{{h}^{0}}=125$ GeV) that is currently being searched for at the LHC. For the experimentally unexplored region ${m}_{{A}^{0}}\lt 225$ GeV it is shown that the above cross section for signal events in the scenario of inverted hierarchy can be of the order of a few picobarns. Such sizeable cross sections are several orders of magnitude larger than the cross sections for the case of normal hierarchy, thus motivating an extension of the ongoing searches for A0 → h0Z(∗) to probe the scenario of inverted hierarchy.
Text
Akeroyd_2023_J._Phys._G__Nucl._Part._Phys._50_095001
- Version of Record
More information
Accepted/In Press date: 4 July 2023
e-pub ahead of print date: 26 July 2023
Published date: 1 September 2023
Additional Information:
Funding Information:
SA acknowledges the use of the IRIDIS High Performance Computing Facility, and associated support services at the University of Southampton. SA acknowledges support from a scholarship of the Imam Mohammad Ibn Saud Islamic University. AA and SM are funded in part through the STFC CG ST/L000296/1. SM is funded in part through the NExT Institute. We thank Souad Semlali for useful discussions.
Funding Information:
SA acknowledges the use of the IRIDIS High Performance Computing Facility, and associated support services at the University of Southampton. SA acknowledges support from a scholarship of the Imam Mohammad Ibn Saud Islamic University. AA and SM are funded in part through the STFC CG ST/L000296/1. SM is funded in part through the NExT Institute. We thank Souad Semlali for useful discussions.
Publisher Copyright:
© 2023 The Author(s). Published by IOP Publishing Ltd
Keywords:
electrically neutral Higgs bosons, large hadron collider, two Higgs doublet model
Identifiers
Local EPrints ID: 481472
URI: http://eprints.soton.ac.uk/id/eprint/481472
ISSN: 0954-3899
PURE UUID: 8f98abd3-c198-4d6d-83f9-579f2fb81a26
Catalogue record
Date deposited: 29 Aug 2023 17:17
Last modified: 13 Jun 2024 01:43
Export record
Altmetrics
Download statistics
Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.
View more statistics
