- Studying particles and fields.edit
We investigate whether or not perturbative unitarity is preserved in the Unhiggs model for the scattering process of heavy quarks and longitudinal gauge bosons q̄q → V + L V − L . With the Yukawa coupling given in the original formulation... more
We investigate whether or not perturbative unitarity is preserved in the Unhiggs model for the scattering process of heavy quarks and longitudinal gauge bosons q̄q → V + L V − L . With the Yukawa coupling given in the original formulation of the Unhiggs model, the model preserves unitarity for Unhiggs scaling dimensions d ≤ 1.5. We examine the LHC phenomenology that is implied by the Unhiggs model in this parameter range in detail and discuss to what extent the LHC can test d if an excess is measured in the phenomenologically clean ZZ channel in the future or if the LHC measurement remains consistent with the background. We then make use of the AdS/CFT correspondence to derive a new Yukawa coupling that is conformally invariant at high energies, and show that with this Yukawa coupling the theory is unitary for 1 ≤ d < 2.
We explore kinetic mixing between two Abelian gauge theories that have both electric and magnetic charges. When one of the photons becomes massive, novel effects arise in the low-energy effective theory, including the failure of Dirac... more
We explore kinetic mixing between two Abelian gauge theories that have both electric and magnetic charges. When one of the photons becomes massive, novel effects arise in the low-energy effective theory, including the failure of Dirac charge quantization as particles from one sector obtain parametrically small couplings to the photon of the other. We maintain a manifest SL(2,Z) duality throughout our analysis, which is the diagonal subgroup of the dualities of the two un-mixed gauge theories.
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Theories with both electric and magnetic charges (“mutually non-local” theories) have several major obstacles to calculating scattering amplitudes. Even when the interaction arises through the kinetic mixing of two, otherwise independent,... more
Theories with both electric and magnetic charges (“mutually non-local” theories) have several major obstacles to calculating scattering amplitudes. Even when the interaction arises through the kinetic mixing of two, otherwise independent, U(1)’s, so that all low-energy interactions are perturbative, difficulties remain: using a self-dual, local formalism leads to spurious poles at any finite order in perturbation theory. Correct calculations must show how the spurious poles cancel in observable scattering amplitudes. Consistency requires that one type of charge is confined as a result of one of the U(1)’s being broken. Here we show how the constraints of confinement and parity conservation on observable processes manages to cancel the spurious poles in scattering and pair production amplitudes, paving the way for systematic studies of the experimental signatures of “dark” electric-magnetic processes. Along the way we demonstrate some novel effects in electric-magnetic interactions, ...
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While the evidence for dark matter continues to grow, the nature of dark matter remains a mystery. A dark U(1) D gauge theory can have a small kinetic mixing with the visible photon which provides a portal to the dark sector. Magnetic... more
While the evidence for dark matter continues to grow, the nature of dark matter remains a mystery. A dark U(1) D gauge theory can have a small kinetic mixing with the visible photon which provides a portal to the dark sector. Magnetic monopoles of the dark U(1) D can obtain small magnetic couplings to our photon through this kinetic mixing. This coupling is only manifest below the mass of the dark photon; at these scales the monopoles are bound together by tubes of dark magnetic flux. These flux tubes can produce phase shifts in Aharonov-Bohm type experiments. We outline how this scenario might be realized, examine the existing constraints, and quantify the experimental sensitivity required to detect magnetic dipole dark matter in this novel way.
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We explore kinetic mixing between two Abelian gauge theories that have both electric and magnetic charges. When one of the photons becomes massive, novel effects arise in the low-energy effective theory, including the failure of Dirac... more
We explore kinetic mixing between two Abelian gauge theories that have both electric and magnetic charges. When one of the photons becomes massive, novel effects arise in the low-energy effective theory, including the failure of Dirac charge quantization as particles from one sector obtain parametrically small couplings to the photon of the other. We maintain a manifest SL(2, ℤ) duality throughout our analysis, which is the diagonal subgroup of the dualities of the two un-mixed gauge theories.
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Long ago Weinberg showed, from first principles, that the amplitude for a single photon exchange between an electric current and a magnetic current violates Lorentz invariance. The obvious conclusion at the time was that monopoles were... more
Long ago Weinberg showed, from first principles, that the amplitude for a single photon exchange between an electric current and a magnetic current violates Lorentz invariance. The obvious conclusion at the time was that monopoles were not allowed in quantum field theory. Since the discovery of topological monopoles there has thus been a paradox. On the one hand, topological monopoles are constructed in Lorentz invariant quantum field theories, while on the other hand, the low-energy effective theory for such monopoles will reproduce Weinberg’s result. We examine a toy model where both electric and magnetic charges are perturbatively coupled and show how soft-photon resummation for hard scattering exponentiates the Lorentz violating pieces to a phase that is the covariant form of the Aharonov-Bohm phase due to the Dirac string. The modulus of the scattering amplitudes (and hence observables) are Lorentz invariant, and when Dirac charge quantization is imposed the amplitude itself is...
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Inspired by the Contino-Pomarol-Rattazzi mechanism we explore scenarios with a very light (1 keV to 10 GeV) radion which could be associated with the suppression of the electroweak contribution to vacuum energy. We construct explicit,... more
Inspired by the Contino-Pomarol-Rattazzi mechanism we explore scenarios with a very light (1 keV to 10 GeV) radion which could be associated with the suppression of the electroweak contribution to vacuum energy. We construct explicit, realistic models that realize this mechanism and explore the phenomenological constraints on this class of models. Compared with axion-like particles in this mass range, the bounds from SN 1987a and from cosmology can be much weaker, depending on the mass of the radion and its coupling to other particles. With couplings suppressed by a scale lower than 100 TeV, much of the mass window from 100 keV to 10 GeV is still open.
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Research Interests: Field Theory, Physics, Theoretical Physics, Quantum Physics, Particle Physics, and 15 moreHigh Energy Physics Phenomenology, Gauge theory, Standard Model, Physical, Higgs boson, Elastic Scattering, Spectrum, Symmetry Breaking, Gauge Field, Kaluza-Klein, Boundary Condition, Degree of Freedom, Gauge Symmetry, Lawrence Berkeley Laboratory, and Spontaneous symmetry breaking
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Research Interests: Field Theory, Physics, Quantum Physics, Particle Physics, Dark Matter, and 12 moreGalaxy Clusters, Beyond the Standard Model Physics, Electromagnetic Radiation, Physical, Mathematical Model, Elastic Scattering, Degeneration, Bound States, Ionizing Radiation, Gamma Ray, Elementary Particles, and Gamma radiation
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SLAC-PUB-7397 CLNS 97/1473 April, 1997 ... T IMOTHY L. B ARKLOW 1 Stanford Linear Accelerator Center, Stanford University, Stanford CA 94309 G USTAVO B URDMAN 2 Department of Physics, University of Wisconsin, Madison, WI 53706 R. S EKHAR... more
SLAC-PUB-7397 CLNS 97/1473 April, 1997 ... T IMOTHY L. B ARKLOW 1 Stanford Linear Accelerator Center, Stanford University, Stanford CA 94309 G USTAVO B URDMAN 2 Department of Physics, University of Wisconsin, Madison, WI 53706 R. S EKHAR C HIVUKULA AND B ...
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We examine interacting Abelian theories at low energies and show that holomorphically normalized photon helicity amplitudes transform into dual amplitudes under SL(2,Z) as modular forms with weights that depend on the number of positive... more
We examine interacting Abelian theories at low energies and show that holomorphically normalized photon helicity amplitudes transform into dual amplitudes under SL(2,Z) as modular forms with weights that depend on the number of positive and negative helicity photons and on the number of internal photon lines. Moreover, canonically normalized helicity amplitudes transform by a phase, so that even though the amplitudes are not duality invariant, their squares are duality invariant. We explicitly verify the duality transformation at one loop by comparing the amplitudes in the case of an electron and the dyon that is its SL(2,Z) image, and extend the invariance of squared amplitudes order by order in perturbation theory. We demonstrate that S-duality is property of all low-energy effective Abelian theories with electric and/or magnetic charges and see how the duality generically breaks down at high energies.
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We examine interacting Abelian theories at low energies and show that holomorphically normalized photon helicity amplitudes transform into dual amplitudes under SL(2, Z) as modular forms with weights that depend on the number of positive... more
We examine interacting Abelian theories at low energies and show that holomorphically normalized photon helicity amplitudes transform into dual amplitudes under SL(2, Z) as modular forms with weights that depend on the number of positive and negative helicity photons and on the number of internal photon lines. Moreover, canonically normalized helicity amplitudes transform by a phase, so that even though the amplitudes are not duality invariant, their squares are duality invariant. We explicitly verify the duality transformation at one loop by comparing the amplitudes in the case of an electron and the dyon that is its SL(2, Z) image, and extend the invariance of squared amplitudes order by order in perturbation theory. We demonstrate that S-duality is property of all low-energy effective Abelian theories with electric and/or magnetic charges and see how the duality generically breaks down at high energies.
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We examine interacting Abelian theories at low energies and show that holomorphically normalized photon helicity amplitudes transform into dual amplitudes under SL(2, Z) as modular forms with weights that depend on the number of positive... more
We examine interacting Abelian theories at low energies and show that holomorphically normalized photon helicity amplitudes transform into dual amplitudes under SL(2, Z) as modular forms with weights that depend on the number of positive and negative helicity photons and on the number of internal photon lines. Moreover, canonically normalized helicity amplitudes transform by a phase, so that even though the amplitudes are not duality invariant, their squares are duality invariant. We explicitly verify the duality transformation at one loop by comparing the amplitudes in the case of an electron and the dyon that is its SL(2, Z) image, and extend the invariance of squared amplitudes order by order in perturbation theory. We demonstrate that S-duality is property of all low-energy effective Abelian theories with electric and/or magnetic charges and see how the duality generically breaks down at high energies.