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Title: Searching for Lee-Wick Gauge Bosons at the LHC

Abstract

In an extension of the Standard Model(SM) based on the ideas of Lee and Wick, Grinstein, O'Connell and Wise have found an interesting way to remove the usual quadratically divergent contributions to the Higgs mass induced by radiative corrections. Phenomenologically, the model predicts the existence of Terascale, negative-norm copies of the usual SM fields with rather unique properties: ghost-like propagators and negative decay widths, but with otherwise SM-like couplings. The model is both unitary and causal on macroscopic scales. In this paper we examine whether or not such states with these unusual properties can be uniquely identified as such at the LHC. We find that in the extended strong and electroweak gauge boson sector of the model, which is the simplest one to analyze, such an identification can be rather difficult. Observation of heavy gluon-like resonances in the dijet channel offers the best hope for this identification.

Authors:
Publication Date:
Research Org.:
Stanford Linear Accelerator Center (SLAC)
Sponsoring Org.:
USDOE
OSTI Identifier:
903006
Report Number(s):
SLAC-PUB-12481
arXiv:0704.3458; TRN: US0703093
DOE Contract Number:
AC02-76SF00515
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of High Energy Physics (JHEP)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; BOSONS; PARTICLE DECAY; RADIATIVE CORRECTIONS; STRONG INTERACTIONS; WEAK INTERACTIONS; Phenomenology-HEP,HEPPH, HEPTH

Citation Formats

Rizzo, Thomas G. Searching for Lee-Wick Gauge Bosons at the LHC. United States: N. p., 2007. Web. doi:10.1088/1126-6708/2007/06/070.
Rizzo, Thomas G. Searching for Lee-Wick Gauge Bosons at the LHC. United States. doi:10.1088/1126-6708/2007/06/070.
Rizzo, Thomas G. Mon . "Searching for Lee-Wick Gauge Bosons at the LHC". United States. doi:10.1088/1126-6708/2007/06/070. https://www.osti.gov/servlets/purl/903006.
@article{osti_903006,
title = {Searching for Lee-Wick Gauge Bosons at the LHC},
author = {Rizzo, Thomas G.},
abstractNote = {In an extension of the Standard Model(SM) based on the ideas of Lee and Wick, Grinstein, O'Connell and Wise have found an interesting way to remove the usual quadratically divergent contributions to the Higgs mass induced by radiative corrections. Phenomenologically, the model predicts the existence of Terascale, negative-norm copies of the usual SM fields with rather unique properties: ghost-like propagators and negative decay widths, but with otherwise SM-like couplings. The model is both unitary and causal on macroscopic scales. In this paper we examine whether or not such states with these unusual properties can be uniquely identified as such at the LHC. We find that in the extended strong and electroweak gauge boson sector of the model, which is the simplest one to analyze, such an identification can be rather difficult. Observation of heavy gluon-like resonances in the dijet channel offers the best hope for this identification.},
doi = {10.1088/1126-6708/2007/06/070},
journal = {Journal of High Energy Physics (JHEP)},
number = ,
volume = ,
place = {United States},
year = {Mon Apr 30 00:00:00 EDT 2007},
month = {Mon Apr 30 00:00:00 EDT 2007}
}
  • Grinstein, O'Connell and Wise have recently presented an extension of the Standard Model (SM), based on the ideas of Lee and Wick (LW), which demonstrates an interesting way to remove the quadratically divergent contributions to the Higgs mass induced by radiative corrections. This model predicts the existence of negative-norm copies of the usual SM fields at the TeV scale with ghost-like propagators and negative decay widths, but with otherwise SM-like couplings. In earlier work, it was demonstrated that the LW states in the gauge boson sector of these models, though easy to observe, cannot be uniquely identified as such atmore » the LHC. In this paper, we address the issue of whether or not this problem can be resolved at an e{sup +}e{sup -} collider with a suitable center of mass energy range. We find that measurements of the cross section and the left-right polarization asymmetry associated with Bhabha scattering can lead to a unique identification of the neutral electroweak gauge bosons of the Lee-Wick type.« less
  • Here, new massive resonances are predicted in many extensions to the Standard Model (SM) of particle physics and constitutes one of the most promising searches for new physics at the LHC. We present a feasibility study to search for new heavy neutral gauge bosons using vector boson fusion (VBF) processes, which become especially important as the LHC probes higher collision energies. In particular, we consider the possibility that the discovery of a Z' boson may have eluded searches at the LHC. The coupling of the Z' boson to the SM quarks can be small, and thus the Z' would notmore » be discoverable by the searches conducted thus far. In the context of a simplified phenomenological approach, we consider the Z'→ττ and Z'→μμ decay modes to show that the requirement of a dilepton pair combined with two high p T forward jets with large separation in pseudorapidity and with large dijet mass is effective in reducing SM backgrounds. The expected exclusion bounds (at 95% confidence level) are m(Z') < 1.8 TeV and m(Z')<2.5 TeV in the ττj fj f and μμj fj f channels, respectively, assuming 1000 fb –1 of 13 TeV data from the LHC. The use of the VBF topology to search for massive neutral gauge bosons provides a discovery reach with expected significances greater than 5σ (3σ) for Z' masses up to 1.4 (1.6) TeV and 2.0 (2.2) TeV in the ττj fj f and μμj fj f channels.« less
  • Here, new massive resonances are predicted in many extensions to the Standard Model (SM) of particle physics and constitutes one of the most promising searches for new physics at the LHC. We present a feasibility study to search for new heavy neutral gauge bosons using vector boson fusion (VBF) processes, which become especially important as the LHC probes higher collision energies. In particular, we consider the possibility that the discovery of a Z' boson may have eluded searches at the LHC. The coupling of the Z' boson to the SM quarks can be small, and thus the Z' would notmore » be discoverable by the searches conducted thus far. In the context of a simplified phenomenological approach, we consider the Z'→ττ and Z'→μμ decay modes to show that the requirement of a dilepton pair combined with two high p T forward jets with large separation in pseudorapidity and with large dijet mass is effective in reducing SM backgrounds. The expected exclusion bounds (at 95% confidence level) are m(Z') < 1.8 TeV and m(Z')<2.5 TeV in the ττj fj f and μμj fj f channels, respectively, assuming 1000 fb –1 of 13 TeV data from the LHC. The use of the VBF topology to search for massive neutral gauge bosons provides a discovery reach with expected significances greater than 5σ (3σ) for Z' masses up to 1.4 (1.6) TeV and 2.0 (2.2) TeV in the ττj fj f and μμj fj f channels.« less