1498438
Gravitino in six-dimensional warped supergravity
Abstract We consider the gravitino spectrum for the general warped solution in a specific six-dimensional gauged supergravity. We find that although the brane tensions introduced at the conical singularities break the bulk supersymmetry explicitly, massless modes of the gravitino can exist with a nontrivial wave function profile, due to a nonzero U ( 1 ) R gauge flux. We also compute the wave function and the mass spectrum of Kaluza–Klein massive modes of the gravitino explicitly. We show that the introduction of a gravitino mass term on a regularized brane can give a suppressed effective gravitino mass compared to the compactification scale, due to the delocalization of the wave function of the zero-mode gravitino.
11210523
TeV scale 5D SU(3)W unification and the fixed point anomaly cancellation with chiral split multiplets
A possibility of 5D gauge unification of SU(2)L × U(1)Y in SU(3)W is examined. The orbifold compactification allows fixed points where SU(2)L × U(1)Y representations can be assigned. We present a few possibilities which give long proton lifetime, top-bottom mass hierarchy from geometry, and reasonable neutrino masses. In general, these chiral models can lead to fixed point anomalies. We can show easily, due to the simplicity of the model, that these anomalies are cancelled by the relevant Chern-Simons terms for all the models we consider. It is also shown that the fixed point U(1)-graviton-graviton anomaly cancels without the help from the Chern-Simons term. Hence, we conjecture that the fixed point anomalies can be cancelled if the effective 4D theory is made anomaly free by locating chiral fermions at the fixed points.
14096456
Wave function of the radion in the brane background with a massless scalar field and a self-tuning problem
We consider flat solutions in a brane world model with a massless scalar field appearing in 5D ${H}_{\mathrm{MNPQ}}^{2}.$ Since those solutions have naked bulk singularities or are such that the 4D Planck mass is divergent, we should have a compact extra dimension, the size of which is then fixed by brane tension(s) and the bulk cosmological constant. By inspecting scalar perturbations around the flat solutions, we find that there is no zero mode for the radion and radion modes have only positive masses. This result confirms the fact that the radius of the extra dimension cannot be adjusted independently of the parameters of the model, and thus that the model considered does not solve the problems encountered in other approaches to the self-tuning of the cosmological constant.
119248157
Vector Higgs-portal dark matter and the invisible Higgs
The Higgs sector of the Standard Model offers a unique probe of the hidden sector. In this work, we explore the possibility of renormalizable Higgs couplings to the hidden sector vector fields which can constitute dark matter (DM). Abelian gauge sectors with minimal field content, necessary to render the gauge fields massive, have a natural Z2 parity. This symmetry ensures stability of the vector fields making them viable dark matter candidates, while evading the usual electroweak
204934408
Gravity in the Einstein-Gauss-Bonnet Theory with the Randall-Sundrum Background
We obtain the full 5D graviton propagator in the Randall-Sundrum model with the Gauss-Bonnet interaction. From the decomposition of the graviton propagator on the brane, we show that localization of gravity arises in the presence of the Gauss-Bonnet term. We also obtain the metric perturbation for observers on the brane with considering the brane bending and compute the amplitude of one massless graviton exchange. For the positive definite amplitude or no ghost states, the sign of the Gauss-Bonnet coefficient should be negative in our convention, which is compatible with string amplitude computations. In that case, the ghost-free condition is sufficient for obtaining the Newtonian gravity. For a vanishing Gauss-Bonnet coefficient, the brane bending allows us to reproduce the correct graviton polarizations for the effective 4D Einstein gravity.
119217517
U(1)R mediation from the flux compactification in six dimensions
We consider a supersymmetric completion of codimension‐two branes with nonzero tension in a 6D gauged supergravity. As a consequence, we obtain the football solution with 4D Minkowski space as a new supersymmetric background that preserves 4D N = 1 SUSY. In the presence of brane multiplets, we derive the 4D effective supergravity action for the football background and show that the remaining modulus can be stabilized by a bulk non‐perturbative correction with brane uplifting potentials at a zero vacuum energy. We find that the U(1)R mediation can be a dominant source of SUSY breaking for a brane scalar with nonzero R charge.
14087471
Generalized lepton number and dark left-right gauge model
In a left-right gauge model of particle interactions, the left-handed fermion doublet $(\ensuremath{\nu},e{)}_{L}$ is connected to its right-handed counterpart $(n,e{)}_{R}$ through a scalar bidoublet so that ${e}_{L}$ pairs with ${e}_{R}$, and ${\ensuremath{\nu}}_{L}$ with ${n}_{R}$ to form mass terms. Suppose the latter link is severed without affecting the former, then ${n}_{R}$ is not the mass partner of ${\ensuremath{\nu}}_{L}$, and as we show in this paper, becomes a candidate for dark matter which is relevant for the recent PAMELA and ATIC observations. We accomplish this in a specific nonsupersymmetric model, where a generalized lepton number can be defined, so that ${n}_{R}$ and ${W}_{R}^{\ifmmode\pm\else\textpm\fi{}}$ are odd under $R\ensuremath{\equiv}(\ensuremath{-}1{)}^{3B+L+2j}$. Fermionic leptoquarks are also predicted.
119388416
Rotation symmetry and nonAbelian Berry potential
We study the role of rotational symmetry in the systems where nonabelian Berry potentials emerge as a result of integrating out fast degrees of freedom. The conserved angular momentum is constructed in the presence of a non-abelian Berry potential, which is formulated using Grassmann variables. The modifications on conventional angular momentum are discussed in close analogy with monopole systems. The diatomic molecular system discussed by Zygelman is found to have a similar structure to that of a non-abelian $SU(2)$ charge coupled to a 't Hooft - Polyakov monopole. The abelian limit of the Berry potential in diatomic systems is shown to be the same as $U(1)$ monopole and in a large separation limit, we observe the decoupling associated with a vanishing field tensor.
118567855
Muon $g−2$, rare kaon decays, and parity violation from dark bosons
The muon g-2 discrepancy between theory and experiment may be explained by a light vector boson Z_d that couples to the electromagnetic current via kinetic mixing with the photon. We illustrate how the existing electron g-2, pion Dalitz decay, and other direct production data disfavor that explanation if the Z_d mainly decays into e+e-, mu+mu-. Implications of a dominant invisible Z_d decay channel, such as light dark matter, along with the resulting strong bounds from the rare K -> pi + 'missing energy' decay are examined. The K decay constraints may be relaxed if destructive interference effects due to Z-Z_d mass mixing are included. In that scenario, we show that accommodating the muon g-2 data through relaxation of K decay constraints leads to interesting signals for dark parity violation. As an illustration, we examine the alteration of the weak mixing angle running at low Q^2, which can be potentially observable in polarized electron scattering or atomic physics experiments.
14608251
Bounds on the mass and coupling constant of radion in the Randall–Sundrum theory
Abstract Assuming the Goldberger–Wise mechanism, we investigated the effective potential at the one-loop level in the Randall–Sundrum theory. We found the lower and upper bounds of the radion mass m φ and the radion-SM coupling constant, 0.8 GeV≲ m φ ≲260 GeV and 1400 GeV≲ Λ φ ≲1500 GeV for the one-loop level potential. These bounds were determined from two constraints of warp factor= O ( M W / M Pl ) and Higgs  vev ≃246 GeV, which can produce strong bounds of m φ and Λ φ . It is phenomenologically important that the one-loop allowed upper bound of the radion mass is about five times larger than the tree-level one, but the radion is still lighter than the Kaluza–Klein modes.
118552297
Muon g − 2 anomaly and dark leptonic gauge boson
One of the major motivations to search for a dark gauge boson of MeV-GeV scale is the long-standing muon g-2 anomaly. Because of active searches such as fixed target experiments and rare meson decays, the muon g-2 favored parameter region has been rapidly reduced. With the most recent data, it is practically excluded now in the popular dark photon model. We overview the issue and investigate a potentially alternative model based on the gauged lepton number or U(1)_L, which is under different experimental constraints.