119272201
Angular momentum in non-relativistic QED and photon contribution to spin of hydrogen atom
Abstract We study angular momentum in non-relativistic quantum electrodynamics (NRQED). We construct the effective total angular momentum operator by applying Noether's theorem to the NRQED lagrangian. We calculate the NRQED matching for the individual components of the QED angular momentum up to one loop. We illustrate an application of our results by the first calculation of the angular momentum of the ground state hydrogen atom carried in radiative photons, α em 3 / 18 π , which might be measurable in future atomic experiments.
19788205
CP-violating phenomenology of flavor conserving two Higgs doublet models
We analyze the constraints on CP-violating, flavor conserving two Higgs doublet models implied by measurements of Higgs boson properties at the Large Hadron Collider (LHC) and by the nonobservation of permanent electric dipole moments (EDMs) of molecules, atoms, and neutrons. We find that the LHC and EDM constraints are largely complementary, with the LHC studies constraining the mixing between the neutral CP-even states and the EDMs probing the effect of mixing between the CP-even and CP-odd scalars. Presently, the most stringent constraints are implied by the nonobservation of the ThO molecule EDM signal. Future improvements in the sensitivity of neutron and diamagnetic atom EDM searches could yield competitive or even more severe constraints. We analyze the quantitative impact of hadronic and nuclear theory uncertainties on the interpretation of the latter systems and conclude that these uncertainties cloud the impact of projected improvements in the corresponding experimental sensitivities.
11648919
Complementarity of LHC and EDMs for exploring Higgs CP violation
A bstractWe analyze the constraints on a CP-violating, flavor conserving, two Higgs doublet model from the measurements of Higgs properties and from the search for heavy Higgs bosons at LHC, and show that the stronger limits typically come from the heavy Higgs search channels. The limits on CP violation arising from the Higgs sector measurements are complementary to those from EDM measurements. Combining all current constraints from low energy to colliders, we set generic upper bounds on the CP violating angle which parametrizes the CP odd component in the 126 GeV Higgs boson.
119264744
Effective angular momentum operators in NRQED and matching at one-loop order
We derive the effective angular momentum operator to 1/m2 and one-loop order in non-relativistic quantum electrodynamics (NRQED). In both dimensional and three-momentum-cutoff regularization schemes, we obtain the non-relativistic expansion for the spin and orbital angular momentum operators of the electron and photon, respectively. Our result is useful in precision calculations of the angular momentum properties for nonrelativistic QED bound states, such as atom systems.
119306471
Inert Doublet Dark Matter and Mirror/Extra Families after Xenon100
J. Stefan Institute, Ljubljana, Slovenia(Dated: May 31, 2011)It was shown recently that mirror fermions, naturally present in a number of directions for newphysics, seem to require an inert scalar doublet in order to pass the electroweak precision tests.This provides a further motivation for considering the inert doublet as a dark matter candidate.Moreover, the presence of extra families enhances the Standard Model Higgs-nucleon coupling, whichhas crucial impact on the Higgs and dark matter searches. We study the limits on the inert darkmatter mass in view of recent Xenon100 data. We nd that the mass of the inert dark mattermust lie in a very narrow window 75 1GeV while the Higgs must weigh more than 400GeV. Forthe sake of completeness we discuss the cases with fewer extra families, where the possibility ofa light Higgs boson opens up, enlarging the dark matter mass window to
41782509
Direct detection of baryogenesis mechanism from squark decays at LHC
We investigate the feasibility of directly detecting a generation mechanism of the cosmic baryon asymmetry by repeating the same particle physics process inside the LHC. We propose a framework with R-parity and CP violating squark decays responsible for baryogenesis, which can be embedded in supersymmetric models and is partly motivated by naturalness. We argue that the baryon number generation here is closely related to lepton charge asymmetry on the resonance. We emphasize the importance of the single charged lepton plus multijet channel in the absence of significant missing energy in search of such a scenario.
16641633
Quantized affine Lie algebras and diagonalization of braid generators
AbstractLet Uq
$$(\hat{\mathcal{G}})$$
 be a quantized affine Lie algebra. It is proven that the universal R-matrix R of Uq
$$(\hat{\mathcal{G}})$$
 satisfies the celebrated conjugation relationR+ =TR withT the usual twist map. As applications, the braid generator is shown to be diagonalizable on arbitrary tensor product modules of integrable irreducible highest weight Uq
$$(\hat{\mathcal{G}})$$
-module and a spectral decomposition formula for the braid generator is obtained which is the generalization of Reshetikhin and Gould forms to the present affine case. Casimir invariants are constructed and their eigenvalues computed by means of the spectral decomposition formula. As a by-product, an interesting identity is found.
119114407
Exploring the Higgs sector of a most natural NMSSM and its prediction on Higgs pair production at the LHC
A bstractAs a most natural realization of the Next-to Minimal Supersymmetry Standard Model (NMSSM), λ-SUSY is parameterized by a large λ around one and a low tan β below 10. In this work, we first scan the parameter space of λ-SUSY by considering various experimental constraints, including the limitation from the Higgs data updated by the ATLAS and CMS collaborations in the summer of 2014, then we study the properties of the Higgs bosons. We get two characteristic features of λ-SUSY in experimentally allowed parameter space. One is the triple self coupling of the SM-like Higgs boson may get enhanced by a factor over 10 in comparison with its SM prediction. The other is the pair production of the SM-like Higgs boson at the LHC may be two orders larger than its SM prediction. All these features seems to be unachievable in the Minimal Supersymmetric Standard Model and in the NMSSM with a low λ. Moreover, we also find that naturalness plays an important role in selecting the parameter space of λ-SUSY, and that the Higgs χ2 obtained with the latest data is usually significantly smaller than before due to the more consistency of the two collaboration measurements.
119694191
Construction of basis vectors for symmetric irreducible representations of O(5) $ \supset$ O(3)
Abstract.A recursive method for the construction of symmetric irreducible representations of $ O(2l+1)$ in the $ O(2l+1)\supset O(3)$ basis for identical boson systems is proposed. The formalism is realized based on the group chain $ U(2l+1)\supset U(2l-1)\otimes U(2)$ , of which the symmetric irreducible representations are simply reducible. The basis vectors for symmetric irreducible representations of the $ O(2l+1)\supset O(2l-1)\otimes U(1)$ can easily be constructed from those of U(2l + 1) $ \supset$U(2l - 1) ⊗ U(2) $ \supset$O(2l - 1) ⊗ U(1) with no l -boson pairs, namely with the total boson number exactly equal to the seniority number in the system, from which one can construct symmetric irreducible representations of $ O(2l+1)$ in the $ O(2l-1)\otimes U(1)$ basis when all symmetric irreducible representations of O(2l - 1) are known. As a starting point, basis vectors of symmetric irreducible representations of O(5) are constructed in the $ O_{1}(3)\otimes U(1)$ basis, where $ O_{1}(3)\equiv O(2l-1)$ , when l = 2 , which is generated not by the angular momentum operators of the d -boson system, but by the operators constructed from d -boson creation (annihilation) operators $ d^{\dagger}_{\mu}$ ( $ d_{\mu}$ with $ \mu=1$ , 0, -1 . Matrix representations of $ O(5)\supset O_{1}(3)\otimes U(1)$ , together with the elementary Wigner coefficients, are presented. After the angular momentum projection, a three-term relation in determining the expansion coefficients of the $ O(5)\supset O(3)$ basis vectors, where the O(3) group is generated by the angular momentum operators of the d -boson system, in terms of those of $ O_{1}(3)\otimes U(1)$ is derived. The eigenvectors of the projection matrix with zero eigenvalues constructed according to the three-term relation completely determine the basis vectors of $ O(5)\supset O(3)$ . Formulae for evaluating the elementary Wigner coefficients of $ O(5)\supset O(3)$ are derived explicitly. Analytical expressions of some elementary Wigner coefficients of $ O(5)\supset O(3)$ for the coupling $ (\tau 0)\otimes(1 0)$ with resultant angular momentum quantum number L = 2$ \tau$ + 2 - k for $ k=0,2,3,\ldots,6$ with a multiplicity 2 case for k = 6 are presented.
17226943
Superconformal Affine Liouville Theory
We present a superconformally invariant and integrable model based on the twisted affine KacMoody superalgebra ˆ osp(2|2) (2) which is the supersymmetrization of the purely bosonic conformal affine Liouville theory recently proposed by Babelon and Bonora. Our model reduces to the super-Liouville or to the super sinh-Gordon theories under certain limit conditions and can be obtained, via hamiltonian reduction, from a superspace WZNW model with values in the corresponding affine KM supergroup. The reconstruction formulae for classical solutions are given. The classical r-matrices in the homogeneous grading and the exchange algebras are worked out. Address after October 1, 1992: Laboratoire de Physique Théorique ENSLAPP, Ecole Normale Supérieure de Lyon, 46 Allée d’Italie, 69007 Lyon, France Address after 28 October 1992: Department of Mathematics, University of Queensland, Brisbane, Qld 4072, Australia
15807894
Super coherent states, boson-fermion realizations and representations of superalgebras
Super coherent states are useful in the explicit construction of representations of superalgebras and quantum superalgebras. In this contribution, we describe how they are used to construct (quantum) boson-fermion realizations and representations of (quantum) superalgebras. We work through a few examples: $osp(1|2)$ and its quantum version $U_t[osp(1|2)]$, $osp(2|2)$ in the non-standard and standard bases and $gl(2|2)$ in the non-standard basis. We obtain free boson-fermion realizations of these superalgebras. Applying the boson-fermion realizations, we explicitly construct their finite-dimensional representations. Our results are expected to be useful in the study of current superalgebras and their corresponding conformal field theories.