Elizabeth Simmons | Michigan State University (original) (raw)
Papers by Elizabeth Simmons
arXiv preprint hep-ph/9702261, Feb 5, 1997
Abstract: We review the connection between m_t and the $ Zb\ bar b $ vertex in ETC models and dis... more Abstract: We review the connection between m_t and the $ Zb\ bar b $ vertex in ETC models and discuss how data on R_b constrains ETC models. Theories in which the ETC and weak gauge groups do not commute are consistent with electroweak data and predict effects on single top production that will be visible at Fermilab.
Physical Review D Particles Fields Gravitation and Cosmology, 2012
We report the first complete calculation of QCD corrections to the production of a massive coloro... more We report the first complete calculation of QCD corrections to the production of a massive coloroctet vector boson. Our next-to-leading-order (NLO) calculation includes both virtual corrections as well as corrections arising from the emission of gluons and light quarks, and we demonstrate the reduction in factorization-scale dependence relative to the leading-order approximation used in previous hadron collider studies. We show that the QCD NLO corrections to coloron production are as large as 30%, and that the residual factorization scale-dependence is reduced to of order 2%. We also calculate the K-factor and the pT spectrum for coloron production, since these are valuable for comparison with experiment. Our results apply directly to the production of the massive color-octet vector bosons in axigluon, topcolor, and coloron models, and approximately to the production of KK gluons in extra-dimensional models or color-octet technivector mesons in technicolor models.
Composite Higgs models based on the chiral symmetries of "theory space" can produce Higgs bosons ... more Composite Higgs models based on the chiral symmetries of "theory space" can produce Higgs bosons with masses of order 100 GeV from underlying strong dynamics at scales up to 10 TeV without fine tuning. This talk argues that flavor-violating interactions generically arising from underlying flavor dynamics constrain the Higgs compositeness scale to be ≳75 GeV, implying that significant fine-tuning is required. Bounds from CP violation and weak isospin violation are also discussed.
This thesis focuses on electroweak symmetry breaking and fermion mass generation. The particular ... more This thesis focuses on electroweak symmetry breaking and fermion mass generation. The particular questions considered are the identity of the electroweak symmetry and the relationship between the breaking of the electroweak gauge symmetry and the breaking of the global flavor symmetries among fermions of different generations. We introduce models of the symmetries and symmetry breakings and study their phenomenology including flavor-changing neutral currents, fermion masses, low-energy scattering processes, properties of the weak gauge bosons, and opportunities for detection of exotic fermions and gauge bosons.
We briefly describe the structure and phenomenology of a flavor-universal extension of the strong... more We briefly describe the structure and phenomenology of a flavor-universal extension of the strong interactions, focusing on the color-octet of massive gauge bosons (`colorons') present in the low-energy spectrum. We discuss current limits on the colorons and what future measurements may reveal.
We study elastic pion-pion scattering in global linear moose models and apply the results to a va... more We study elastic pion-pion scattering in global linear moose models and apply the results to a variety of Higgsless models in flat and AdS space using the Equivalence Theorem. In order to connect the global moose to Higgsless models, we first introduce a block-spin transformation which corresponds, in the continuum, to the freedom to perform coordinate transformations in the Higgsless model. We show that it is possible to make an "f-flat" deconstruction in which all of the f-constants f j of the linear moose model are identical; the phenomenologically relevant f-flat models are those in which the coupling constants of the groups at either end of the moose are small -corresponding to the global linear moose. In studying pion-pion scattering, we derive various sum rules, including one analogous to the KSRF relation, and use them in evaluating the low-energy and high-energy forms of the leading elastic partial wave scattering amplitudes. We obtain elastic unitarity bounds as a function of the mass of the lightest KK mode and discuss their physical significance.
Phys Lett B, 1993
A slowly running technicolor coupling will affect the size of non-oblique corrections to the Zb o... more A slowly running technicolor coupling will affect the size of non-oblique corrections to the Zb overlineb vertex from extended technicolor dynamics. We show that, while “walking technicolor” reduces the magnitude of the corrections, they generally remain large enough to be seen at LEP.
We review the connection between m_t and the ZbbarbZb\bar bZbbarb vertex in ETC models and discuss how data... more We review the connection between m_t and the ZbbarbZb\bar bZbbarb vertex in ETC models and discuss how data on R_b constrains ETC models. Theories in which the ETC and weak gauge groups do not commute are consistent with electroweak data and predict effects on single top production that will be visible at Fermilab.
As part of a Saturday Science Lab program at Boston University, high-energy theorists and experim... more As part of a Saturday Science Lab program at Boston University, high-energy theorists and experimentalists at Boston University have collaborated to create a lab for local high-school students. Each group of 30-40 students spends a morning "weighing the neutrino" with members of the Super-K collaboration and "hunting for new particles" with members of the D0 collaboration. This talk will discuss
Given the prevalence of autism spectrum disorder and significant policy changes to special educat... more Given the prevalence of autism spectrum disorder and significant policy changes to special education legislation, upwards of half of students with ASD will be educated in a mainstream setting. The heterogeneity of this population requires educators and specialists to be knowledgeable on a variety of instructional supports and interventions to meet these learners' diverse needs. These strategies range from traditional behaviorally based interventions to more contemporary approaches involving technology. Utilizing these available supports provides access to the curriculum, typically developing peer models, and ultimately improved likelihood of academic success for students with autism spectrum disorder.Keywords:classroom;instructional supports;intervention;mainstream education;technologyclassroom;instructional supports;intervention;mainstream education;technology
Strong Coupling Gauge Theories in LHC Era, 2011
We introduce a deconstructed model that incorporates both Higgsless and top-color mechanisms. The... more We introduce a deconstructed model that incorporates both Higgsless and top-color mechanisms. The model alleviates the typical tension in Higgsless models between obtaining the correct top quark mass and keeping ∆ρ small. It does so by singling out the top quark mass generation as arising from a Yukawa coupling to an effective top-Higgs which develops a small vacuum expectation value, while electroweak symmetry breaking results largely from a Higgsless mechanism. As a result, the heavy partners of the SM fermions can be light enough to be seen at the LHC. * This manuscript will appear in the proceedings of SCGT09; the speaker at the conference was E.H. Simmons
Physical Review D, 2014
ABSTRACT In a recent paper, we discussed the constraints on the renormalizable coloron model deri... more ABSTRACT In a recent paper, we discussed the constraints on the renormalizable coloron model derived from the requirements of vacuum stability, tree-level unitarity, electroweak precision measurements, and from LHC measurements of the properties of the observed Higgs-like scalar boson. In this Erratum we correct an error in our expression for the gluon-fusion contribution to Higgs boson production arising from the extra colored scalars and vectors present in the model. The corrections enhance the size of these contributions, and result in stronger constraints on the model parameters.
Strong Coupling Gauge Theories and Effective Field Theories - Proceedings of the 2002 International Workshop, 2003
In this talk we discuss the phenomenology of models with replicated electroweak gauge symmetries,... more In this talk we discuss the phenomenology of models with replicated electroweak gauge symmetries, based on a framework with the gauge structure [SU (2) or U (1)] × U (1) × SU (2) × SU (2).
We summarize the indirect effects of new physics in a variety of processes. We consider precision... more We summarize the indirect effects of new physics in a variety of processes. We consider precision electroweak measurements, the g − 2 of the muon, rare decays, meson mixing, CP violation, lepton number violating interactions, double beta decay, and the electric dipole moments of atoms, molecules, and the neutron. We include discussions of both model independent and dependent analyses where
Quest for the Origin of Particles and the Universe, 2013
Ongoing LHC searches for the standard model Higgs Boson in W W or ZZ decay modes strongly constra... more Ongoing LHC searches for the standard model Higgs Boson in W W or ZZ decay modes strongly constrain the top-Higgs state predicted in many models with new dynamics that preferentially affects top quarks. Such a state couples strongly to top-quarks, and is therefore produced through gluon fusion at a rate that can be greatly enhanced relative to the rate for the standard model Higgs boson. As we discuss in this talk, a top-Higgs state with mass less than 300 GeV is excluded at 95% CL if the associated top-pion has a mass of 150 GeV, and the constraint is even stronger if the mass of the top-pion state exceeds the top-quark mass or if the top-pion decay constant is a substantial fraction of the weak scale. These results have significant implications for theories with strong top dynamics, such as topcolor-assisted technicolor, top-seesaw models, and certain Higgsless models.
Strong Coupling Gauge Theories and Effective Field Theories - Proceedings of the 2002 International Workshop, 2003
Composite Higgs models based on the chiral symmetries of "theory space" can produce Higgs bosons ... more Composite Higgs models based on the chiral symmetries of "theory space" can produce Higgs bosons with masses of order 100 GeV from underlying strong dynamics at scales up to 10 TeV without fine tuning. This talk argues that flavor-violating interactions generically arising from underlying flavor dynamics constrain the Higgs compositeness scale to be > ∼75 GeV, implying that significant fine-tuning is required. Bounds from CP violation and weak isospin violation are also discussed.
Progress of Theoretical Physics Supplement, 1996
We review the connection between mt and the Zbb vertex in ETC models and demonstrate the power of... more We review the connection between mt and the Zbb vertex in ETC models and demonstrate the power of the resulting experimental constraint on models with weak-singlet ETC bosons. Some efforts to bring ETC models into agreement with experimental data on the Zbb vertex are mentioned, and the most promising one (non-commuting ETC) is discussed in detail.
Physics Letters B, 1994
CDF data from the 1988-1989 Tevatron run are used to constrain the characteristic scale of physic... more CDF data from the 1988-1989 Tevatron run are used to constrain the characteristic scale of physics beyond the Standard Model which couples to gluons. New gluonic physics would cause the inclusive jet cross section to deviate from that of pure QCD at high transverse jet energies. We find that the CDF data place a lower bound of 2.03 TeV at 95% CL on the characteristic scale of new gluon sector physics.
Physics Letters B, 1996
Recent results from CDF indicate that the inclusive cross section for jets with E T > 200 GeV is ... more Recent results from CDF indicate that the inclusive cross section for jets with E T > 200 GeV is significantly higher than that predicted by QCD. We describe here a simple flavor-universal variant of the "coloron" model of Hill and Parke that can accommodate such a jet excess, and which is not in contradiction with other experimental data. As such, the model serves as a useful baseline with which to compare both the data and other models proposed to describe the jet excess. An interesting theoretical feature of the model is that if the global chiral symmetries of the quarks remain unbroken in the confining phase of the coloron interaction, it realizes the possibility that the ordinary quarks are composite particles.
arXiv preprint hep-ph/9702261, Feb 5, 1997
Abstract: We review the connection between m_t and the $ Zb\ bar b $ vertex in ETC models and dis... more Abstract: We review the connection between m_t and the $ Zb\ bar b $ vertex in ETC models and discuss how data on R_b constrains ETC models. Theories in which the ETC and weak gauge groups do not commute are consistent with electroweak data and predict effects on single top production that will be visible at Fermilab.
Physical Review D Particles Fields Gravitation and Cosmology, 2012
We report the first complete calculation of QCD corrections to the production of a massive coloro... more We report the first complete calculation of QCD corrections to the production of a massive coloroctet vector boson. Our next-to-leading-order (NLO) calculation includes both virtual corrections as well as corrections arising from the emission of gluons and light quarks, and we demonstrate the reduction in factorization-scale dependence relative to the leading-order approximation used in previous hadron collider studies. We show that the QCD NLO corrections to coloron production are as large as 30%, and that the residual factorization scale-dependence is reduced to of order 2%. We also calculate the K-factor and the pT spectrum for coloron production, since these are valuable for comparison with experiment. Our results apply directly to the production of the massive color-octet vector bosons in axigluon, topcolor, and coloron models, and approximately to the production of KK gluons in extra-dimensional models or color-octet technivector mesons in technicolor models.
Composite Higgs models based on the chiral symmetries of "theory space" can produce Higgs bosons ... more Composite Higgs models based on the chiral symmetries of "theory space" can produce Higgs bosons with masses of order 100 GeV from underlying strong dynamics at scales up to 10 TeV without fine tuning. This talk argues that flavor-violating interactions generically arising from underlying flavor dynamics constrain the Higgs compositeness scale to be ≳75 GeV, implying that significant fine-tuning is required. Bounds from CP violation and weak isospin violation are also discussed.
This thesis focuses on electroweak symmetry breaking and fermion mass generation. The particular ... more This thesis focuses on electroweak symmetry breaking and fermion mass generation. The particular questions considered are the identity of the electroweak symmetry and the relationship between the breaking of the electroweak gauge symmetry and the breaking of the global flavor symmetries among fermions of different generations. We introduce models of the symmetries and symmetry breakings and study their phenomenology including flavor-changing neutral currents, fermion masses, low-energy scattering processes, properties of the weak gauge bosons, and opportunities for detection of exotic fermions and gauge bosons.
We briefly describe the structure and phenomenology of a flavor-universal extension of the strong... more We briefly describe the structure and phenomenology of a flavor-universal extension of the strong interactions, focusing on the color-octet of massive gauge bosons (`colorons') present in the low-energy spectrum. We discuss current limits on the colorons and what future measurements may reveal.
We study elastic pion-pion scattering in global linear moose models and apply the results to a va... more We study elastic pion-pion scattering in global linear moose models and apply the results to a variety of Higgsless models in flat and AdS space using the Equivalence Theorem. In order to connect the global moose to Higgsless models, we first introduce a block-spin transformation which corresponds, in the continuum, to the freedom to perform coordinate transformations in the Higgsless model. We show that it is possible to make an "f-flat" deconstruction in which all of the f-constants f j of the linear moose model are identical; the phenomenologically relevant f-flat models are those in which the coupling constants of the groups at either end of the moose are small -corresponding to the global linear moose. In studying pion-pion scattering, we derive various sum rules, including one analogous to the KSRF relation, and use them in evaluating the low-energy and high-energy forms of the leading elastic partial wave scattering amplitudes. We obtain elastic unitarity bounds as a function of the mass of the lightest KK mode and discuss their physical significance.
Phys Lett B, 1993
A slowly running technicolor coupling will affect the size of non-oblique corrections to the Zb o... more A slowly running technicolor coupling will affect the size of non-oblique corrections to the Zb overlineb vertex from extended technicolor dynamics. We show that, while “walking technicolor” reduces the magnitude of the corrections, they generally remain large enough to be seen at LEP.
We review the connection between m_t and the ZbbarbZb\bar bZbbarb vertex in ETC models and discuss how data... more We review the connection between m_t and the ZbbarbZb\bar bZbbarb vertex in ETC models and discuss how data on R_b constrains ETC models. Theories in which the ETC and weak gauge groups do not commute are consistent with electroweak data and predict effects on single top production that will be visible at Fermilab.
As part of a Saturday Science Lab program at Boston University, high-energy theorists and experim... more As part of a Saturday Science Lab program at Boston University, high-energy theorists and experimentalists at Boston University have collaborated to create a lab for local high-school students. Each group of 30-40 students spends a morning "weighing the neutrino" with members of the Super-K collaboration and "hunting for new particles" with members of the D0 collaboration. This talk will discuss
Given the prevalence of autism spectrum disorder and significant policy changes to special educat... more Given the prevalence of autism spectrum disorder and significant policy changes to special education legislation, upwards of half of students with ASD will be educated in a mainstream setting. The heterogeneity of this population requires educators and specialists to be knowledgeable on a variety of instructional supports and interventions to meet these learners' diverse needs. These strategies range from traditional behaviorally based interventions to more contemporary approaches involving technology. Utilizing these available supports provides access to the curriculum, typically developing peer models, and ultimately improved likelihood of academic success for students with autism spectrum disorder.Keywords:classroom;instructional supports;intervention;mainstream education;technologyclassroom;instructional supports;intervention;mainstream education;technology
Strong Coupling Gauge Theories in LHC Era, 2011
We introduce a deconstructed model that incorporates both Higgsless and top-color mechanisms. The... more We introduce a deconstructed model that incorporates both Higgsless and top-color mechanisms. The model alleviates the typical tension in Higgsless models between obtaining the correct top quark mass and keeping ∆ρ small. It does so by singling out the top quark mass generation as arising from a Yukawa coupling to an effective top-Higgs which develops a small vacuum expectation value, while electroweak symmetry breaking results largely from a Higgsless mechanism. As a result, the heavy partners of the SM fermions can be light enough to be seen at the LHC. * This manuscript will appear in the proceedings of SCGT09; the speaker at the conference was E.H. Simmons
Physical Review D, 2014
ABSTRACT In a recent paper, we discussed the constraints on the renormalizable coloron model deri... more ABSTRACT In a recent paper, we discussed the constraints on the renormalizable coloron model derived from the requirements of vacuum stability, tree-level unitarity, electroweak precision measurements, and from LHC measurements of the properties of the observed Higgs-like scalar boson. In this Erratum we correct an error in our expression for the gluon-fusion contribution to Higgs boson production arising from the extra colored scalars and vectors present in the model. The corrections enhance the size of these contributions, and result in stronger constraints on the model parameters.
Strong Coupling Gauge Theories and Effective Field Theories - Proceedings of the 2002 International Workshop, 2003
In this talk we discuss the phenomenology of models with replicated electroweak gauge symmetries,... more In this talk we discuss the phenomenology of models with replicated electroweak gauge symmetries, based on a framework with the gauge structure [SU (2) or U (1)] × U (1) × SU (2) × SU (2).
We summarize the indirect effects of new physics in a variety of processes. We consider precision... more We summarize the indirect effects of new physics in a variety of processes. We consider precision electroweak measurements, the g − 2 of the muon, rare decays, meson mixing, CP violation, lepton number violating interactions, double beta decay, and the electric dipole moments of atoms, molecules, and the neutron. We include discussions of both model independent and dependent analyses where
Quest for the Origin of Particles and the Universe, 2013
Ongoing LHC searches for the standard model Higgs Boson in W W or ZZ decay modes strongly constra... more Ongoing LHC searches for the standard model Higgs Boson in W W or ZZ decay modes strongly constrain the top-Higgs state predicted in many models with new dynamics that preferentially affects top quarks. Such a state couples strongly to top-quarks, and is therefore produced through gluon fusion at a rate that can be greatly enhanced relative to the rate for the standard model Higgs boson. As we discuss in this talk, a top-Higgs state with mass less than 300 GeV is excluded at 95% CL if the associated top-pion has a mass of 150 GeV, and the constraint is even stronger if the mass of the top-pion state exceeds the top-quark mass or if the top-pion decay constant is a substantial fraction of the weak scale. These results have significant implications for theories with strong top dynamics, such as topcolor-assisted technicolor, top-seesaw models, and certain Higgsless models.
Strong Coupling Gauge Theories and Effective Field Theories - Proceedings of the 2002 International Workshop, 2003
Composite Higgs models based on the chiral symmetries of "theory space" can produce Higgs bosons ... more Composite Higgs models based on the chiral symmetries of "theory space" can produce Higgs bosons with masses of order 100 GeV from underlying strong dynamics at scales up to 10 TeV without fine tuning. This talk argues that flavor-violating interactions generically arising from underlying flavor dynamics constrain the Higgs compositeness scale to be > ∼75 GeV, implying that significant fine-tuning is required. Bounds from CP violation and weak isospin violation are also discussed.
Progress of Theoretical Physics Supplement, 1996
We review the connection between mt and the Zbb vertex in ETC models and demonstrate the power of... more We review the connection between mt and the Zbb vertex in ETC models and demonstrate the power of the resulting experimental constraint on models with weak-singlet ETC bosons. Some efforts to bring ETC models into agreement with experimental data on the Zbb vertex are mentioned, and the most promising one (non-commuting ETC) is discussed in detail.
Physics Letters B, 1994
CDF data from the 1988-1989 Tevatron run are used to constrain the characteristic scale of physic... more CDF data from the 1988-1989 Tevatron run are used to constrain the characteristic scale of physics beyond the Standard Model which couples to gluons. New gluonic physics would cause the inclusive jet cross section to deviate from that of pure QCD at high transverse jet energies. We find that the CDF data place a lower bound of 2.03 TeV at 95% CL on the characteristic scale of new gluon sector physics.
Physics Letters B, 1996
Recent results from CDF indicate that the inclusive cross section for jets with E T > 200 GeV is ... more Recent results from CDF indicate that the inclusive cross section for jets with E T > 200 GeV is significantly higher than that predicted by QCD. We describe here a simple flavor-universal variant of the "coloron" model of Hill and Parke that can accommodate such a jet excess, and which is not in contradiction with other experimental data. As such, the model serves as a useful baseline with which to compare both the data and other models proposed to describe the jet excess. An interesting theoretical feature of the model is that if the global chiral symmetries of the quarks remain unbroken in the confining phase of the coloron interaction, it realizes the possibility that the ordinary quarks are composite particles.