#high-energy-physics

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[hep-th]

Authors: Fabrizio Canfora, Francisco Correa, Alex Giacomini, Julio Oliva

In this paper an intrinsically non-Abelian black hole solution for the SU(2) Einstein-Yang-Mills theory in four dimensions is constructed. The gauge field of this solution has the form of a meron whereas the metric is the one of a Reissner-Nordström black hole in which, however, the coefficient of the term is not an integration constant. Even if the stress-energy tensor of the Yang-Mills field is spherically symmetric, the field strength of the Yang-Mills field itself is not. A remarkable consequence of this fact, which allows to distinguish the present solution from essentially Abelian configurations, is the Jackiw, Rebbi, Hasenfratz, 't Hooft mechanism according to which excitations of bosonic fields moving in the background of a gauge field with this characteristic behave as Fermionic degrees of freedom.

[hep-th]

Authors: Liu Zhao, Wei Xu, Pengfei Yu

Every classical Newtonian mechanical system can be equipped with a nonstandard Hamiltonian structure, in which the Hamiltonian is the square of the canonical Hamiltonian up to a constant shift, and the Poisson bracket is nonlinear. In such a formalism, time translation symmetry can be spontaneously broken, provided the potential function becomes negative. A nice analogy between time translation symmetry breaking and the Landau theory of second order phase transitions is established, together with several example cases illustrating time translation breaking ground states. In particular, the CDM model of FRW cosmology is reformulated as the time translation symmetry breaking ground states.

[hep-th]

Authors: Louise Dolan, Yang Sun

We compute the partition function of five-dimensional abelian gauge theory on a five-torus T5 with a general flat metric using the Dirac method of quantizing with constraints. We compare this with the partition function of a single fivebrane compactified on S1 times T5, which is obtained from the six-torus calculation of Dolan and Nappi. The radius R1 of the circle S1 is set to the dimensionful gauge coupling constant g^2= R1.

[hep-th]

Authors: Matthias Ihl (Dublin Inst.), Arnab Kundu (Texas U.), Sandipan Kundu (Texas U., TCC and Texas U.)

We consider back-reaction by non-supersymmetric D7/anti-D7 probe branes in the Kuperstein-Sonnenschein model at finite temperature. Using the smearing technique, we obtain an analytical solution for the back-reacted background to leading order in N_f/N_c. This back-reaction explicitly breaks the conformal invariance and introduces a dimension 6 operator in the dual field theory which is an irrelevant deformation of the original conformal field theory. We further probe this back-reacted background by introducing an additional set of probe brane/anti-brane. This additional probe sector undergoes a chiral phase transition at finite temperature, which is absent when the back-reaction vanishes. We investigate the corresponding phase diagram and the thermodynamics associated with this phase transition. We also argue that additional probes do not suffer from any instability caused by the back-reaction, which suggests that this system is stable beyond the probe limit.

[hep-th]

Authors: Takao Suyama

The planar resolvent for N=3 U(N)_k Chern-Simons theory coupled to an arbitrary number of adjoint matters is determined. Analytic continuation of the 't Hooft coupling t is analyzed. The eigenvalue distribution turns out to be confined in a finite region even for a large t. The vev of a Wilson loop does not exhibit an exponential growth although such a behavior would be expected for theories with classical gravity duals.

[hep-th]

Authors: M. Aa. Solberg

We prove there is no symmetry which, imposed on the general charge conjugation (C) invariant multi-Higgs-doublet model (NHDM), excludes exactly the O(4) violating terms from the potential. This is in part done by determining the exact subsymmetries of the custodial SO(4) symmetry of the standard model (SM) scalar Lagrangian. Furthermore, the Higgs family symmetries of the quadratic part of the general C invariant NHDM potential will also be symmetries of the O(4) violating terms of the potential, and hence cannot be applied to remove the O(4) violating terms from the potential. Finally, negative determinant elements of O(4) cannot be applied to expel the O(4) breaking terms from the NHDM potential either: We show there is no symmetries of the kinetic Higgs terms in the negative determinant part of O(4). This is also the case in the limit g' -> 0. Hence the custodial SO(4) symmetry is the largest symmetry group of the scalar sector of the SM in the limit g' -> 0.

[hep-th]

Authors: Claudio Coriano, Luigi Delle Rose, Carlo Marzo, Mirko Serino

We investigate the Standard Model in the nearly conformal limit, in which conformal symmetry is broken only by the dilatation anomaly, through a hierarchy of anomalous Ward identities for the divergence of its dilatation current. In this approximation, the identities allow to extract the coupling of the dilaton to the trace anomaly, which we compute up to the quartic order in the conformal breaking scale. Our approach can be easily extended to discuss the anomaly contributions to the dilaton effective action to an arbitrarily high order. They allow to make a distinction between the Higgs and a dilaton at a phenomenological level.