__smbhome.uscs.susx.ac.uk_bw233_Desktop_SRO_SRO - Veronica Sanz_10.1007-JHEP03(2016)176.pdf (1.33 MB)
On the interpretation of a possible ~ 750 GeV particle decaying into ??
journal contribution
posted on 2023-06-09, 07:27 authored by John Ellis, Sebastian A R Ellis, Jérémie Quevillon, Veronica Sanz, Tevong YouWe consider interpretations of the recent ~ 3s reports by the CMS and ATLAS collaborations of a possible X (~750 GeV) state decaying into ?? final states. We focus on the possibilities that this is a scalar or pseudoscalar electroweak isoscalar state produced by gluon-gluon fusion mediated by loops of heavy fermions. We consider several models for these fermions, including a single vector-like charge 2/3 T quark, a doublet of vector-like quarks (T, B), and a vector-like generation of quarks, with or without leptons that also contribute to the X ? ?? decay amplitude. We also consider the possibility that X (750) is a dark matter mediator, with a neutral vector-like dark matter particle. These scenarios are compatible with the present and prospective direct limits on vector-like fermions from LHC Runs 1 and 2, as well as indirect constraints from electroweak precision measurements, and we show that the required Yukawa-like couplings between the X particle and the heavy vector-like fermions are small enough to be perturbative so long as the X particle has dominant decay modes into gg and ??. The decays X ? ZZ, Z? and W+W- are interesting prospective signatures that may help distinguish between different vector-like fermion scenarios.
Funding
Particle Physics Theory at Royal Holloway and Sussex; G0742; STFC-SCIENCE AND TECHNOLOGY FACILITIES COUNCIL; ST/J000477/1
History
Publication status
- Published
File Version
- Published version
Journal
Journal of High Energy PhysicsISSN
1126-6708Publisher
Springer VerlagExternal DOI
Issue
3Volume
2016Article number
a176Department affiliated with
- Physics and Astronomy Publications
Research groups affiliated with
- Theoretical Particle Physics Research Group Publications
Full text available
- Yes
Peer reviewed?
- Yes
Legacy Posted Date
2017-07-27First Open Access (FOA) Date
2017-07-27First Compliant Deposit (FCD) Date
2017-07-27Usage metrics
Categories
No categories selectedKeywords
Licence
Exports
RefWorks
BibTeX
Ref. manager
Endnote
DataCite
NLM
DC