H. Georgi - Academia.edu (original) (raw)
Papers by H. Georgi
Physical Review D, 1994
We study nonleptonic decays of the orbitally excited, SU(6) 70-plet baryons in order to test the ... more We study nonleptonic decays of the orbitally excited, SU(6) 70-plet baryons in order to test the hypothesis that the successes of the nonrelativistic quark model have a natural explanation in the large-N c limit of
Physics Letters B, 1980
We examine the neutral current structure of a class of topless gauge theories in which b decay an... more We examine the neutral current structure of a class of topless gauge theories in which b decay and CP violation are mediated by neutral gauge bosons, N. We find a good fit to all data(better than the fit to the standard model) for sin2theta = 0.205 and MN2/MW2 ~ 10. Permanent address: College of Engineering and Physical Sciences, University of New Hampshire, Durham, NH 03824, USA.
Physical Review D, 1978
%'e show how the standard SU(2) X U{1) gauge model may be generalized to include several neutral ... more %'e show how the standard SU(2) X U{1) gauge model may be generalized to include several neutral intermediate vector bosons, without changing the predictions of the model for neutral-current neutrino interactions. The expanded gauge models involve at least one neutral intermediate vector boson which is lighter than the Z (80 GeV) of the standard model.
Journal of High Energy Physics, 2010
The Harvard community has made this article openly available. Please share how this access benefi... more The Harvard community has made this article openly available. Please share how this access benefits you. Your story matters Citation Georgi, Howard, and Yevgeny Kats. Forthcoming. Unparticle selfinteractions. Journal of High Energy Physics.
Physics Letters B, 2001
We discuss the form of the chiral anomaly on an S 1 /Z 2 orbifold with chiral boundary conditions... more We discuss the form of the chiral anomaly on an S 1 /Z 2 orbifold with chiral boundary conditions. We find that the 4-divergence of the higher-dimensional current evaluated at a given point in the extra dimension is proportional to the probability of finding the chiral zero mode there. Nevertheless the anomaly, appropriately defined as the five dimensional divergence of the current, lives entirely on the orbifold fixed planes and is independent of the shape of the zero mode. Therefore long distance four dimensional anomaly cancellation ensures the consistency of the higher dimensional orbifold theory.
Physics Letters B, 1984
Currently two scenarios exist which explain SU(2) × U(1) breaking: the Higgs mechanism, and stand... more Currently two scenarios exist which explain SU(2) × U(1) breaking: the Higgs mechanism, and standard hypercolor schemes. In this paper, a third scenario called "oblique hypercolor" is proposed. A hyperquark condensate is formed which, although kinematically allowed to point in an SU(2) × U(1) preserving direction, is forced by Yukawa interactions of the hyperquarks to misalign by a small angle, breaking SU(2) × U(1). The low energy spectrum involves normal fermions with correct masses, a partially composite Higgs boson, and physical charged scalars.
Physics Letters B, 1987
We characterize a class of composite models in which the quarks and leptons and techniferrnions a... more We characterize a class of composite models in which the quarks and leptons and techniferrnions are built from fermions (preons) bound by strong gauge interactions. We argue that if the preon dynamics has as [SU(3) x U(1)] 5 flavor symmetry that is explicitly broken only by preon mass terms proportional to the quark and lepton mass matrices, then the composite-technicolor theory has a GIM mechanism that suppresses dangerous flavor changing neutral current effects. We show that the compositeness scale must be between ~1 TeV and-~ 2.5 TeV, giving rise to observable deviations from the standard electroweak interactions, and that B-B mixing and CP violation in K mesons can differ significantly from the standard model predictions. The lepton flavor symmetries may be observable in the near future in the comparison of the compositeness effects in e+e-* ~+~-with those in e+e-~ e+e- .
Physics Letters B, 1984
In an interesting class of composite Higgs models, the composite Higgs mass can be calculated to ... more In an interesting class of composite Higgs models, the composite Higgs mass can be calculated to be m H = 1.7 MwV~-/N where the confining ultracolor group which binds the Higgs is SU(N), N >/3. Thus m H ~< 1.7 M w. In these models, there is an additional gauged U(1) coupled to ordinary matter and broken at the ultracolor scale.
Physical Review Letters, 1974
Physical Review Letters, 2001
We construct renormalizable, asymptotically free, four dimensional gauge theories that dynamicall... more We construct renormalizable, asymptotically free, four dimensional gauge theories that dynamically generate a fifth dimension.
Physical Review Letters, 1976
Physical Review D, 1998
Topcolor and topcolor-assisted technicolor provide examples of dynamical electroweak symmetry bre... more Topcolor and topcolor-assisted technicolor provide examples of dynamical electroweak symmetry breaking which include top-condensation, thereby naturally incorporating a heavy top quark. In this note we discuss the roles of the Nambu-Jona-Lasinio (NJL) and large-N approximations often used in phenomenological analyses of these models. We show that, in order to provide for top-condensation but not bottom-condensation, the top-color coupling must be adjusted to equal the critical value for chiral symmetry breaking up to O(1/N) in any theory in which the isospin-violating "tilting" interaction is a U (1) gauge interaction. A consequence of these considerations is that the potentially dangerous "bottom-pions" are naturally light. We also show that the contributions to ρ − 1 previously estimated are of leading-order in N , are not included in the usual NJL analysis, and are the result of "vacuum-alignment".
Physical Review D, 1981
Measurements of p+ polarizations from proton decay will give valuable insight into the nature of ... more Measurements of p+ polarizations from proton decay will give valuable insight into the nature of unification theories. We discuss the is+ polarizations expected in a class of O(10) models for two plausible, flavor-mixing schemes.
Physical Review D, 1974
Calculability conditions are discussed for local gauge theories with Higgs type symmetry breaking... more Calculability conditions are discussed for local gauge theories with Higgs type symmetry breaking. We focus on the naturalness of Ve-universality; the naturalness of the Cabibbo angle 0 ; the naturalness. of. CP-violating phases; and the naturalness of non-leptonic AI = 1/2. In this context we examine many published gauge models and construct others to illuminate the questions at hand. We note that naturalness of Ve-universality for charged currents does not necessarily imply universality for neutral currents, (natural "res,tricted ,, universality) and emphasize the need for ve-beam experiments. For SU(2) x U(1) and SU(2) >(U(1) >(U(1) we give first examples of how a non-trivial natural 0 can appear. Models with CP-violation are classified as to whether their CP-violating phases are natural or not. For 0(4) x U(1) we give a first example in which all the above naturalness criteria. can be implemented. Here the natural Ve-universality is necessarily restricted. The principal tool used in these investigations is the strict renormalizability relative to a gauge group 11 enlarged by discrete symmetries; and the union of representations reducibie '43 • under the gauge group to irreducible ones under the enlarged group. To implement this program, it is sometimes necessary to introduce Higgs couplings involving * Work supported in part by U.S. Atomic Energy Commission under Contract Number .AT(11-1)-2232 and in part by the Air Force Office of Scientific Research under Contract F44620-70-C-0030 and the National Science Foundation under Grant GP30819X.
Annual Review of Nuclear and Particle Science, 1993
Annals of Physics, 1978
We estimate the cross section for charmed particle production in proton-proton scattering. An ana... more We estimate the cross section for charmed particle production in proton-proton scattering. An analysis of all possible sources of charmed particles reveals that the dominant mechanism at high energy involves the annihilation of constituent gluon partons. This process is as effective as the annihilation of constituent quark and antiquark partons in protonantiproton scattering. Our unorthodox conclusion is that proton-proton collisions are practically as effective as proton-antiproton collisions for the production of charmed particles, or for the production of states involving heavier quarks. Gluon-gluon collisions may also produce light quark pairs. The possible relation between this process and the observed rising pp total cross section is discussed.
... Yevgeniya V. Zastavker, a Paul Gueye, b Kelly M. Mack, c Rachel Ivie, d Elizabeth H. Simmons,... more ... Yevgeniya V. Zastavker, a Paul Gueye, b Kelly M. Mack, c Rachel Ivie, d Elizabeth H. Simmons, e Lea F. Santos, f Luz J. Martínez-Miranda, g Arthur Bienenstock, h Jacob Clark Blickenstaff, i K. Renee Horton, j Anne J. MacLachlan, k Nora Berrah, l and Beverly K. Hartline m ...
AIP Conference Proceedings, Apr 19, 2009
The underrepresentation of women in physics and related fields in the US remains significant desp... more The underrepresentation of women in physics and related fields in the US remains significant despite an increase in doctoral degrees earned over the past 10 years. An even greater disparity is seen among minority women. Increasing recognition of the contributions of women to discovery and education in physics and related fields has led to government initiatives and other programs to promote broader inclusion, balance, and gender equity. These actions for advocating women in physics in the US since the first IUPAP Women in ...
Physical Review D, 1994
We study nonleptonic decays of the orbitally excited, SU(6) 70-plet baryons in order to test the ... more We study nonleptonic decays of the orbitally excited, SU(6) 70-plet baryons in order to test the hypothesis that the successes of the nonrelativistic quark model have a natural explanation in the large-N c limit of
Physics Letters B, 1980
We examine the neutral current structure of a class of topless gauge theories in which b decay an... more We examine the neutral current structure of a class of topless gauge theories in which b decay and CP violation are mediated by neutral gauge bosons, N. We find a good fit to all data(better than the fit to the standard model) for sin2theta = 0.205 and MN2/MW2 ~ 10. Permanent address: College of Engineering and Physical Sciences, University of New Hampshire, Durham, NH 03824, USA.
Physical Review D, 1978
%'e show how the standard SU(2) X U{1) gauge model may be generalized to include several neutral ... more %'e show how the standard SU(2) X U{1) gauge model may be generalized to include several neutral intermediate vector bosons, without changing the predictions of the model for neutral-current neutrino interactions. The expanded gauge models involve at least one neutral intermediate vector boson which is lighter than the Z (80 GeV) of the standard model.
Journal of High Energy Physics, 2010
The Harvard community has made this article openly available. Please share how this access benefi... more The Harvard community has made this article openly available. Please share how this access benefits you. Your story matters Citation Georgi, Howard, and Yevgeny Kats. Forthcoming. Unparticle selfinteractions. Journal of High Energy Physics.
Physics Letters B, 2001
We discuss the form of the chiral anomaly on an S 1 /Z 2 orbifold with chiral boundary conditions... more We discuss the form of the chiral anomaly on an S 1 /Z 2 orbifold with chiral boundary conditions. We find that the 4-divergence of the higher-dimensional current evaluated at a given point in the extra dimension is proportional to the probability of finding the chiral zero mode there. Nevertheless the anomaly, appropriately defined as the five dimensional divergence of the current, lives entirely on the orbifold fixed planes and is independent of the shape of the zero mode. Therefore long distance four dimensional anomaly cancellation ensures the consistency of the higher dimensional orbifold theory.
Physics Letters B, 1984
Currently two scenarios exist which explain SU(2) × U(1) breaking: the Higgs mechanism, and stand... more Currently two scenarios exist which explain SU(2) × U(1) breaking: the Higgs mechanism, and standard hypercolor schemes. In this paper, a third scenario called "oblique hypercolor" is proposed. A hyperquark condensate is formed which, although kinematically allowed to point in an SU(2) × U(1) preserving direction, is forced by Yukawa interactions of the hyperquarks to misalign by a small angle, breaking SU(2) × U(1). The low energy spectrum involves normal fermions with correct masses, a partially composite Higgs boson, and physical charged scalars.
Physics Letters B, 1987
We characterize a class of composite models in which the quarks and leptons and techniferrnions a... more We characterize a class of composite models in which the quarks and leptons and techniferrnions are built from fermions (preons) bound by strong gauge interactions. We argue that if the preon dynamics has as [SU(3) x U(1)] 5 flavor symmetry that is explicitly broken only by preon mass terms proportional to the quark and lepton mass matrices, then the composite-technicolor theory has a GIM mechanism that suppresses dangerous flavor changing neutral current effects. We show that the compositeness scale must be between ~1 TeV and-~ 2.5 TeV, giving rise to observable deviations from the standard electroweak interactions, and that B-B mixing and CP violation in K mesons can differ significantly from the standard model predictions. The lepton flavor symmetries may be observable in the near future in the comparison of the compositeness effects in e+e-* ~+~-with those in e+e-~ e+e- .
Physics Letters B, 1984
In an interesting class of composite Higgs models, the composite Higgs mass can be calculated to ... more In an interesting class of composite Higgs models, the composite Higgs mass can be calculated to be m H = 1.7 MwV~-/N where the confining ultracolor group which binds the Higgs is SU(N), N >/3. Thus m H ~< 1.7 M w. In these models, there is an additional gauged U(1) coupled to ordinary matter and broken at the ultracolor scale.
Physical Review Letters, 1974
Physical Review Letters, 2001
We construct renormalizable, asymptotically free, four dimensional gauge theories that dynamicall... more We construct renormalizable, asymptotically free, four dimensional gauge theories that dynamically generate a fifth dimension.
Physical Review Letters, 1976
Physical Review D, 1998
Topcolor and topcolor-assisted technicolor provide examples of dynamical electroweak symmetry bre... more Topcolor and topcolor-assisted technicolor provide examples of dynamical electroweak symmetry breaking which include top-condensation, thereby naturally incorporating a heavy top quark. In this note we discuss the roles of the Nambu-Jona-Lasinio (NJL) and large-N approximations often used in phenomenological analyses of these models. We show that, in order to provide for top-condensation but not bottom-condensation, the top-color coupling must be adjusted to equal the critical value for chiral symmetry breaking up to O(1/N) in any theory in which the isospin-violating "tilting" interaction is a U (1) gauge interaction. A consequence of these considerations is that the potentially dangerous "bottom-pions" are naturally light. We also show that the contributions to ρ − 1 previously estimated are of leading-order in N , are not included in the usual NJL analysis, and are the result of "vacuum-alignment".
Physical Review D, 1981
Measurements of p+ polarizations from proton decay will give valuable insight into the nature of ... more Measurements of p+ polarizations from proton decay will give valuable insight into the nature of unification theories. We discuss the is+ polarizations expected in a class of O(10) models for two plausible, flavor-mixing schemes.
Physical Review D, 1974
Calculability conditions are discussed for local gauge theories with Higgs type symmetry breaking... more Calculability conditions are discussed for local gauge theories with Higgs type symmetry breaking. We focus on the naturalness of Ve-universality; the naturalness of the Cabibbo angle 0 ; the naturalness. of. CP-violating phases; and the naturalness of non-leptonic AI = 1/2. In this context we examine many published gauge models and construct others to illuminate the questions at hand. We note that naturalness of Ve-universality for charged currents does not necessarily imply universality for neutral currents, (natural "res,tricted ,, universality) and emphasize the need for ve-beam experiments. For SU(2) x U(1) and SU(2) >(U(1) >(U(1) we give first examples of how a non-trivial natural 0 can appear. Models with CP-violation are classified as to whether their CP-violating phases are natural or not. For 0(4) x U(1) we give a first example in which all the above naturalness criteria. can be implemented. Here the natural Ve-universality is necessarily restricted. The principal tool used in these investigations is the strict renormalizability relative to a gauge group 11 enlarged by discrete symmetries; and the union of representations reducibie '43 • under the gauge group to irreducible ones under the enlarged group. To implement this program, it is sometimes necessary to introduce Higgs couplings involving * Work supported in part by U.S. Atomic Energy Commission under Contract Number .AT(11-1)-2232 and in part by the Air Force Office of Scientific Research under Contract F44620-70-C-0030 and the National Science Foundation under Grant GP30819X.
Annual Review of Nuclear and Particle Science, 1993
Annals of Physics, 1978
We estimate the cross section for charmed particle production in proton-proton scattering. An ana... more We estimate the cross section for charmed particle production in proton-proton scattering. An analysis of all possible sources of charmed particles reveals that the dominant mechanism at high energy involves the annihilation of constituent gluon partons. This process is as effective as the annihilation of constituent quark and antiquark partons in protonantiproton scattering. Our unorthodox conclusion is that proton-proton collisions are practically as effective as proton-antiproton collisions for the production of charmed particles, or for the production of states involving heavier quarks. Gluon-gluon collisions may also produce light quark pairs. The possible relation between this process and the observed rising pp total cross section is discussed.
... Yevgeniya V. Zastavker, a Paul Gueye, b Kelly M. Mack, c Rachel Ivie, d Elizabeth H. Simmons,... more ... Yevgeniya V. Zastavker, a Paul Gueye, b Kelly M. Mack, c Rachel Ivie, d Elizabeth H. Simmons, e Lea F. Santos, f Luz J. Martínez-Miranda, g Arthur Bienenstock, h Jacob Clark Blickenstaff, i K. Renee Horton, j Anne J. MacLachlan, k Nora Berrah, l and Beverly K. Hartline m ...
AIP Conference Proceedings, Apr 19, 2009
The underrepresentation of women in physics and related fields in the US remains significant desp... more The underrepresentation of women in physics and related fields in the US remains significant despite an increase in doctoral degrees earned over the past 10 years. An even greater disparity is seen among minority women. Increasing recognition of the contributions of women to discovery and education in physics and related fields has led to government initiatives and other programs to promote broader inclusion, balance, and gender equity. These actions for advocating women in physics in the US since the first IUPAP Women in ...