Tatsu Takeuchi
Virginia Tech, Physics, Faculty Member
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In this contribution to Peter Suranyi Festschrift, we study the Halliday-Suranyi perturbation method for calculating the energy eigenvalues of the quartic anharmonic oscillator.
Research Interests: Mathematics and Physics
Abstract: We use the Borexino 153.6 ton·year data to place constraints on non-standard neutrino-electron interactions, taking into account the uncertainties in the 7Be solar neu-trino flux and the mixing angle θ23, and backgrounds due to... more
Abstract: We use the Borexino 153.6 ton·year data to place constraints on non-standard neutrino-electron interactions, taking into account the uncertainties in the 7Be solar neu-trino flux and the mixing angle θ23, and backgrounds due to 85Kr and 210Bi β-decay. We find that the bounds are comparable to existing bounds from all other experiments. Fur-ther improvement can be expected in Phase II of Borexino due to the reduction in the 85Kr background.
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We discuss how new physics not encompassed within the STU oblique correction framework can be constrained from precision electroweak measurements via vertex corrections to Z–pole observables. 1. Limitations of the Oblique Correction... more
We discuss how new physics not encompassed within the STU oblique correction framework can be constrained from precision electroweak measurements via vertex corrections to Z–pole observables. 1. Limitations of the Oblique Correction Analysis In constructing models beyond the Standard Model (SM) such as technicolor or supersymmetric theories, it is important to test their viability by looking for possible conflicts with currently available experimental data. A popular procedure has been the STU oblique correction analysis of Ref. [1]. However, the method can only be applied to theories which satisfy three conditions, namely (1) the electroweak gauge group is the standard SU(2)L × U(1)Y , (2) vertex and box corrections from new physics are negligible, and (3) the scale of new physics is large compared to the electroweak scale. Furthermore, the oblique correction analysis requires (4) the model to be completely specified since any particle with electroweak gauge quantum numbers will sh...
The energy spectrum of the Coulomb potential with minimal length commutation relations [Xi,Pj]=iℏ{δij(1+βP2)+β′PiPj} is determined both numerically and perturbatively for arbitrary values of β′/β and angular momenta ℓ. The constraint on... more
The energy spectrum of the Coulomb potential with minimal length commutation relations [Xi,Pj]=iℏ{δij(1+βP2)+β′PiPj} is determined both numerically and perturbatively for arbitrary values of β′/β and angular momenta ℓ. The constraint on the minimal length scale from precision hydrogen spectroscopy data is of order of a few GeV^(-1) weaker than previously claimed.
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We discuss a possible interpretation of the $750$ GeV diphoton resonance, recently reported at the LHC, within a class of Pati-Salam models with gauge coupling unification. The unification is imposed by the underlying non-commutative... more
We discuss a possible interpretation of the $750$ GeV diphoton resonance, recently reported at the LHC, within a class of Pati-Salam models with gauge coupling unification. The unification is imposed by the underlying non-commutative geometry (NCG), which in these models is extended to a left-right symmetric completion of the Standard Model (SM). Within such unified Pati-Salam models the Higgs content is restrictively determined from the underlying NCG, instead of being arbitrarily selected as in canonical, non-unified, Pati-Salam models. We show that the observed cross sections involving the $750$ GeV diphoton resonance could be realized through a SM singlet scalar field accompanied by colored scalars, present in these unified models. In view of this result we discuss the underlying rigidity of these models in the NCG framework and the wider implications of the NCG approach for physics beyond the SM.
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We consider the introduction of a complex scalar field carrying a global lepton number charge to the Standard Model and the Higgs inflation framework. The conditions are investigated under which this model can simultaneously ensure Higgs... more
We consider the introduction of a complex scalar field carrying a global lepton number charge to the Standard Model and the Higgs inflation framework. The conditions are investigated under which this model can simultaneously ensure Higgs vacuum stability up to the Planck scale, successful inflation, non-thermal Leptogenesis via the pendulum mechanism, and light neutrino masses. These can be simultaneously achieved when the scalar lepton is minimally coupled to gravity, that is, when standard Higgs inflation and reheating proceed without the interference of the additional scalar degrees of freedom. If the scalar lepton also has a non-minimal coupling to gravity, a multi-field inflation scenario is induced, with interesting interplay between the successful inflation constraints and those from vacuum stability and Leptogenesis. The parameter region that can simultaneously achieve the above goals is explored.
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A new scenario of baryogenesis via the ratchet mechanism is proposed based on an analogy with the forced pendulum. The oscillation of the inflaton field during the reheating epoch after inflation plays the role of the driving force, while... more
A new scenario of baryogenesis via the ratchet mechanism is proposed based on an analogy with the forced pendulum. The oscillation of the inflaton field during the reheating epoch after inflation plays the role of the driving force, while the phase [Formula: see text] of a scalar baryon field (a complex scalar field with baryon number) plays the role of the angle of the pendulum. When the inflaton is coupled to the scalar baryon, the behavior of the phase [Formula: see text] can be analogous to that of the angle of the forced pendulum. If the oscillation of the driving force is adjusted to the pendulum’s motion, a directed rotation of the pendulum is obtained with a nonvanishing value of [Formula: see text], which models successful baryogenesis since [Formula: see text] is proportional to the baryon number density. Similar ratchet models which lead to directed motion have been used in the study of molecular motors in biology. There, the driving force is supplied by chemical reaction...
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In this lecture, I would like to investigate what precision electroweak measurements have to tell us about the Higgs sector. I will show that the radiative corrections to electroweak interaction observables coming from the Higgs sector... more
In this lecture, I would like to investigate what precision electroweak measurements have to tell us about the Higgs sector. I will show that the radiative corrections to electroweak interaction observables coming from the Higgs sector can be summarized into three parameters S, T, and U. The precision measurements of the observables will constrain S and T. By comparing these constraints with the theoretically predicted values of S and T, we will be able to tell which Higgs sector theories are more viable than others.
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In the [Formula: see text]CDM model, dark energy is viewed as a constant vacuum energy density, the cosmological constant in the Einstein–Hilbert action. This assumption can be relaxed in various models that introduce a dynamical dark... more
In the [Formula: see text]CDM model, dark energy is viewed as a constant vacuum energy density, the cosmological constant in the Einstein–Hilbert action. This assumption can be relaxed in various models that introduce a dynamical dark energy. In this paper, we argue that the mixing between infrared (IR) and ultraviolet (UV) degrees of freedom in quantum gravity leads to infinite statistics, the unique statistics consistent with Lorentz invariance in the presence of nonlocality, and yields a fine structure for dark energy. Introducing IR and UV cutoffs into the quantum gravity action, we deduce the form of [Formula: see text] as a function of redshift and translate this to the behavior of the Hubble parameter.
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In this letter we discuss infinite statistics and motivate its role in quantum gravity. Then, we connect infinite statistics to a dynamical form of dark energy, and we obtain an expression for the evolution of the Hubble parameter that we... more
In this letter we discuss infinite statistics and motivate its role in quantum gravity. Then, we connect infinite statistics to a dynamical form of dark energy, and we obtain an expression for the evolution of the Hubble parameter that we compare to observation. The equation of state parameter $w_{eff} < -1$ in this framework.
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Abstract: We discuss a direct test of the relation of time and energy in the very long-lived decay of tritium (31H) (meanlife τ ∼ 18 yrs) with the width Γ ∼ 10−24 eV [set by the time-energy uncertainty (TEU)], using the newfound... more
Abstract: We discuss a direct test of the relation of time and energy in the very long-lived decay of tritium (31H) (meanlife τ ∼ 18 yrs) with the width Γ ∼ 10−24 eV [set by the time-energy uncertainty (TEU)], using the newfound possibility of resonance reactions 3 1H ↔ 32He with ∆E/E ∼ 5 × 10−29. The TEU is a keystone of quantum mechanics, but probed for the first time in this extreme time-energy regime. Forestalling an apparent deviation from the TEU, we discuss the ramifications and a possible generalization of the TEU as ∆E∆t ≥ (~/2)[1 + (∆t/T∗)n] where ∆t = τ is the time of measurement (the lifetime of the state), T ∗ = L∗/c the time for light to cross the Universe ∼ 3 × 1018 s, and n a parameter subject to future measurements. (by R. S. Raghavan.)
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We consider the Kaluza–Klein (KK) scenario in which only gravity exists in the bulk. Without the assumption of symmetric connection, the presence of brane fermions induces torsion. The result is a universal axial contact interaction that... more
We consider the Kaluza–Klein (KK) scenario in which only gravity exists in the bulk. Without the assumption of symmetric connection, the presence of brane fermions induces torsion. The result is a universal axial contact interaction that dominates those induced by KK gravitons. This enhancement arises from a large spin density on the brane. Using a global fit to Z–pole observables, we find the 3σ bound on the scale of quantum gravity to be 28 TeV for n = 2. If Dirac or light sterile neutrinos are present, the data from SN1987A increase the bound to √ nMS ≥ 210 TeV. 11.10.Kk, 04.50.+h, 13.38.Dg Typeset using REVTEX electronic address: laynam@vt.edu electronic address: lebedev@quasar.phys.vt.edu electronic address: loinaz@alumni.princeton.edu electronic address: takeuchi@vt.edu 1 Consistent string theories require dimensions beyond the usual four, that could in principle be as large as a millimeter. These large extra dimensions provide new avenues for solution to the hierarchy problem...
This article summarizes a new approach to quantum gravity based on the concepts of modular spacetime, Born geometry, and metastring theory and their applications to quantum gravity phenomenology. In particular, we discuss a new... more
This article summarizes a new approach to quantum gravity based on the concepts of modular spacetime, Born geometry, and metastring theory and their applications to quantum gravity phenomenology. In particular, we discuss a new understanding of dark matter in terms of metaparticles (zero modes of the metastring) and its relation to dark energy (the curvature of dual spacetime) in view of the actual astronomical observations.
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We study constraints on type–II two Higgs doublet models at large tan β from LEP/SLD Z–pole data and from lepton universality violation in W decay. We perform a global fit and find that, in the context of Z decay, the LEP/SLD experimental... more
We study constraints on type–II two Higgs doublet models at large tan β from LEP/SLD Z–pole data and from lepton universality violation in W decay. We perform a global fit and find that, in the context of Z decay, the LEP/SLD experimental values for lepton universality violation, Rb, and Ab all somewhat disfavor the model. Contributions from the neutral Higgs sector can be used to constrain the scalar–pseudoscalar Higgs mass splittings. Contributions from the charged Higgs sector allow us to constrain the charged Higgs mass. For tan β = 100 we obtain the 1σ classical (Bayesian) bounds of
We offer an interpretation of super-quantum correlations in terms of a “doubly” quantum theory. We argue that string theory, viewed as a quantum theory with two deformation parameters, the string tension α and the string coupling constant... more
We offer an interpretation of super-quantum correlations in terms of a “doubly” quantum theory. We argue that string theory, viewed as a quantum theory with two deformation parameters, the string tension α and the string coupling constant gs, is such a super-quantum theory, one that transgresses the usual quantum violations of Bell’s inequalities. We also discuss the ~ → ∞ limit of quantum mechanics in this context. As a super-quantum theory, string theory should display distinct experimentally observable super-correlations of entangled stringy states.
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We discuss the existence of an acceleration scale in galaxies and galaxy clusters and its relevance for the nature of dark matter. The presence of the same acceleration scale found at very different length scales, and in very different... more
We discuss the existence of an acceleration scale in galaxies and galaxy clusters and its relevance for the nature of dark matter. The presence of the same acceleration scale found at very different length scales, and in very different astrophysical objects, strongly supports the existence of a fundamental acceleration scale governing the observed gravitational physics. We comment on the implications of such a fundamental acceleration scale for constraining cold dark matter models as well as its relevance for structure formation to be explored in future numerical simulations.
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Motivated by possible scalar-leptoquark explanations of the recently reported B-decay anomalies, we investigate whether the required leptoquarks can be accommodated within models based on noncommutative geometry (NCG). The models... more
Motivated by possible scalar-leptoquark explanations of the recently reported B-decay anomalies, we investigate whether the required leptoquarks can be accommodated within models based on noncommutative geometry (NCG). The models considered have the gauge structure of Pati-Salam models, SU(4) × SU(2) L × SU(2) R , with gauge coupling unification at a single scale. In one of the models, we find a unique scalar leptoquark with quantum numbers $$ {\left(3,1,-\frac{1}{3}\right)}_{321} $$ 3 , 1 , − 1 3 321 , originating from a complex multiplet (6, 1, 1)422, which can potentially explain the B-decay anomalies if its mass is on the order of a few TeV. The unification of couplings can be realized with the inclusion of a single step of intermediate symmetry breaking. The scalar leptoquark under consideration does not contribute to proton decay due to the absence of diquark couplings, as dictated by the underlying noncommutative geometry.
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We discuss the possibility that the cold dark matter mass profiles contain information on the cosmological constant [Formula: see text], and that such information constrains the nature of cold dark matter (CDM). We call this approach... more
We discuss the possibility that the cold dark matter mass profiles contain information on the cosmological constant [Formula: see text], and that such information constrains the nature of cold dark matter (CDM). We call this approach Modified Dark Matter (MDM). In particular, we examine the ability of MDM to explain the observed mass profiles of 13 galaxy clusters. Using general arguments from gravitational thermodynamics, we provide a theoretical justification for our MDM mass profile. In order to properly fit the shape of the mass profiles in galaxy clusters, we find it necessary to generalize the MDM mass profile from the one we used previously to fit galactic rotation curves. We successfully compare it to the NFW mass profiles both on cluster and galactic scales, though differences in form appear with the change in scales. Our results suggest that indeed the CDM mass profiles contain information about the cosmological constant in a nontrivial way.
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We analyze the compatibility of the unified left–right symmetric Pati–Salam models motivated by noncommutative geometry and the TeV-scale right-handed [Formula: see text] boson suggested by recent LHC data. We find that the... more
We analyze the compatibility of the unified left–right symmetric Pati–Salam models motivated by noncommutative geometry and the TeV-scale right-handed [Formula: see text] boson suggested by recent LHC data. We find that the unification/matching conditions place conflicting demands on the symmetry breaking scales and that generating the required [Formula: see text] mass and coupling is nontrivial.
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Research Interests: Physics, Quantum Physics, Quantum Mechanics, String Theory, Atomic and Molecular Physics, and 9 moreNoncommutative Geometry, Elementary Particle Physics and Field Theory, Physical, Wave Equation, Quantum Harmonic Oscillator, Bound States, Eigenvalues and Eigenfunctions, Exact solution methods, and Strong magnetic field
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Page 1. Theory of neutrinos: a white paper This article has been downloaded from IOPscience. Please scroll down to see the full text article. 2007 Rep. Prog. Phys. 70 1757 (http://iopscience.iop.org/0034-4885/70/11/R02) Download ...
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This paper presents the physics case for a new high-energy, ultra-high statistics neutrino scattering experiment, NuSOnG (Neutrino Scattering on Glass). This experiment uses a Tevatron-based neutrino beam to obtain over an order of... more
This paper presents the physics case for a new high-energy, ultra-high statistics neutrino scattering experiment, NuSOnG (Neutrino Scattering on Glass). This experiment uses a Tevatron-based neutrino beam to obtain over an order of magnitude higher statistics than presently available for the purely weak processes νμ + e- → νμ + e- and νμ + e- → νe + μ-. A sample of Deep Inelastic Scattering events which is over two orders of magnitude larger than past samples will also be obtained. As a result, NuSOnG will be unique among present and planned experiments for its ability to probe neutrino couplings to Beyond the Standard Model physics. Many Beyond Standard Model theories physics predict a rich hierarchy of TeV-scale new states that can correct neutrino cross-sections, through modifications of Zνν couplings, tree-level exchanges of new particles such as Z′'s, or through loop-level oblique corrections to gauge boson propagators. These corrections are generic in theories of extra dim...
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We offer an interpretation of superquantum correlations in terms of a “doubly” quantum theory. We argue that string theory, viewed as a quantum theory with two deformation parameters, the string tensionα', and the string coupling... more
We offer an interpretation of superquantum correlations in terms of a “doubly” quantum theory. We argue that string theory, viewed as a quantum theory with two deformation parameters, the string tensionα', and the string coupling constantgs, is such a superquantum theory that transgresses the usual quantum violations of Bell's inequalities. We also discuss theℏ→∞limit of quantum mechanics in this context. As a superquantum theory, string theory should display distinct experimentally observable supercorrelations of entangled stringy states.
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We discuss a possible interpretation of the 750 GeV diphoton resonance, recently reported at the large hadron collider (LHC), within a class of [Formula: see text] models with gauge coupling unification. The unification is imposed by the... more
We discuss a possible interpretation of the 750 GeV diphoton resonance, recently reported at the large hadron collider (LHC), within a class of [Formula: see text] models with gauge coupling unification. The unification is imposed by the underlying noncommutative geometry (NCG), which in these models is extended to a left–right symmetric completion of the Standard Model (SM). Within such unified [Formula: see text] models the Higgs content is restrictively determined from the underlying NCG, instead of being arbitrarily selected. We show that the observed cross-sections involving the 750 GeV diphoton resonance could be realized through a SM singlet scalar field accompanied by colored scalars, present in these unified models. In view of this result, we discuss the underlying rigidity of these models in the NCG framework and the wider implications of the NCG approach for physics beyond the SM.
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We consider extensions of the Standard Model with an extra U(1) gauge boson which couples to B − (αLe + βLμ + γLτ ) with α + β + γ = 3. We show that the extra gauge boson necessarily mixes with the Z, leading to potentially significant... more
We consider extensions of the Standard Model with an extra U(1) gauge boson which couples to B − (αLe + βLμ + γLτ ) with α + β + γ = 3. We show that the extra gauge boson necessarily mixes with the Z, leading to potentially significant corrections to the Zff̄ vertex. The constraints on the size of this correction imposed by the Z–pole data from LEP and SLD are derived. 12.15.Lk, 12.60.-i, 12.60.Cn, 13.38.Dg Typeset using REVTEX electronic address: laynam@vt.edu electronic address: olebedev@vt.edu electronic address: loinaz@alumni.princeton.edu electronic address: takeuchi@vt.edu 1
Modified dark matter (MDM) is a phenomenological model of dark matter, inspired by gravitational thermodynamics. For an accelerating universe with positive cosmological constant ([Formula: see text]), such phenomenological considerations... more
Modified dark matter (MDM) is a phenomenological model of dark matter, inspired by gravitational thermodynamics. For an accelerating universe with positive cosmological constant ([Formula: see text]), such phenomenological considerations lead to the emergence of a critical acceleration parameter related to [Formula: see text]. Such a critical acceleration is an effective phenomenological manifestation of MDM, and it is found in correlations between dark matter and baryonic matter in galaxy rotation curves. The resulting MDM mass profiles, which are sensitive to [Formula: see text], are consistent with observational data at both the galactic and cluster scales. In particular, the same critical acceleration appears both in the galactic and cluster data fits based on MDM. Furthermore, using some robust qualitative arguments, MDM appears to work well on cosmological scales, even though quantitative studies are still lacking. Finally, we comment on certain nonlocal aspects of the quanta ...
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In this note we discuss the question of gauge invariance in the presence of a minimal length. This contribution is prepared for the celebration of the 60th anniversary of the Yang-Mills theory.
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We discuss a possible interpretation of the 750 GeV diphoton resonance, recently reported at the LHC, within a class of Pati-Salam models with gauge coupling unification. The unification is imposed by the underlying non-commutative... more
We discuss a possible interpretation of the 750 GeV diphoton resonance, recently reported at the LHC, within a class of Pati-Salam models with gauge coupling unification. The unification is imposed by the underlying non-commutative geometry (NCG), which in these models is extended to a left-right symmetric completion of the Standard Model (SM). Within such unified Pati-Salam models the Higgs content is restrictively determined from the underlying NCG, instead of being arbitrarily selected as in canonical, non-unified, Pati-Salam models. We show that the observed cross sections involving the 750 GeV diphoton resonance could be realized through a SM singlet scalar field accompanied by colored scalars, present in these unified models. In view of this result we discuss the underlying rigidity of these models in the NCG framework and the wider implications of the NCG approach for physics beyond the SM.
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In this note we discuss the question of gauge invariance in the presence of a minimal length. This contribution is prepared for the celebration of the 60th anniversary of the Yang-Mills theory.
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The energy spectrum of the Coulomb potential with minimal length commutation relations [Xi,Pj]=iℏ{δij(1+βP2)+β′PiPj} is determined both numerically and perturbatively for arbitrary values of β′/β and angular momenta ℓ. The constraint on... more
The energy spectrum of the Coulomb potential with minimal length commutation relations [Xi,Pj]=iℏ{δij(1+βP2)+β′PiPj} is determined both numerically and perturbatively for arbitrary values of β′/β and angular momenta ℓ. The constraint on the minimal length scale from precision hydrogen spectroscopy data is of order of a few GeV^(-1) weaker than previously claimed.