Joydip Mitra

Fermion localization in a generalized Randall-Sundrum model

A generalized two-brane Randall-Sundrum warped braneworld model has solutions of the warp factor for both positive or negative cosmological constant on the visible 3-brane which can resolve the naturalness problem in connection with the fine-tuning of Higgs mass in the standard model of elementary particles. To explore the location of the standard model fermions in such a generalized warped model, we, in this work, determine the dependence of the localization profile of a bulk fermion on the brane cosmological constant brane tension and the bulk fermion mass. Our results reveal that for a positive and small value of the induced cosmological constant a bulk fermion is localized close to the brane. On the other hand for a visible brane with negative cosmological constant and positive tension, the fermions are localized inside the bulk leading to phenomenologically interesting possibilities.

Chiral fermions in a spacetime with multiple warping

In a six-dimensional brane world model with multiple S{sub 1}/Z{sub 2} warping, two of the 4-branes at the boundaries have coordinate-dependent brane tensions in order to implement the orbifolded boundary conditions consistently. Such brane tension is shown to be equivalent to a scalar field distribution on the brane [D. Choudhury and S. SenGupta, Phys. Rev. D 76, 064030 (2007).]. We show that in such a scenario a massless left chiral fermion on the 4-brane localizes naturally on the standard model 3-brane located at one edge of the compact manifold while the massless right chiral fermion wave function, as well as the wave functions for the massive fermion modes, peak away from this brane. This offers a mechanism of obtaining a massless chiral fermion with only one of its chiral components present in our brane.

Modulus stabilization in higher curvature dilaton gravity

A bstractWe propose a framework of modulus stabilization in two brane warped geometry scenario in presence of higher curvature gravity and dilaton in bulk space-time. In the prescribed setup we study various features of the stabilized potential for the modulus field, generated by a bulk scalar degrees of freedom with quartic interactions localized on the two 3-branes placed at the orbifold fixed points. We determine the parameter space for the gravidilaton and Gauss-Bonnet couplings required to stabilize the modulus in such higher curvature dilaton gravity setup.

Fermion localization in higher curvature spacetime

Fermion localization in a braneworld model in presence of dilaton coupled higher curvature Gauss-Bonnet bulk gravity is discussed. It is shown that the lowest mode of left handed fermions can be naturally localized on the visible brane due to the dilaton coupled higher curvature term without the necessity of any external localizing bulk field.

Scalar Kaluza-Klein modes in a multiply warped braneworld

The Kaluza-Klein (KK) modes of a massive scalar field on a 3-brane embedded in a six-dimensional multiply warped spacetime are determined. Due to the presence of warping along both the extra dimensions the KK mass spectrum splits into two closely spaced branches which is a distinct feature of this model compared to the five-dimensional Randall-Sundrum model. This new cluster of the KK mode spectrum is expected to have interesting phenomenological implications for the upcoming collider experiments. It is also shown that the effective scalar self-couplings of all orders are enhanced due to the presence of an extra warped dimension. Such a scenario may also be extended for even larger number of orbifolded extra dimensions.

Modulus stabilization of the generalized Randall-Sundrum model with a bulk scalar field

We study the stabilization of the inter-brane spacing modulus of generalized warped brane models with a nonzero brane cosmological constant. Employing the Goldberger-Wise stabilization prescription of braneworld models with a bulk scalar field, we show that the stabilized value of the modulus generally depends on the value of the brane cosmological constant. Our result further reveals that the stabilized modulus value corresponding to a vanishingly small cosmological constant can only resolve the gauge hierarchy problem simultaneously. This in turn vindicates the original Randall-Sundrum model, where the 3-brane cosmological constant was chosen to be zero.

Kaluza–Klein modes of bulk fields in a generalized Randall–Sundrum scenario

Abstract We consider a generalised two brane Randall–Sundrum model with non-zero cosmological constant on the visible TeV brane. Massive Kaluza–Klein modes for various bulk fields namely graviton, gauge field and antisymmetric second rank Kalb–Ramond field in a such generalized Randall–Sundrum scenario are determined. The masses for the Kaluza–Klein excitations of different bulk fields are found to depend on the brane cosmological constant indicating interesting consequences in warped brane particle phenomenology.

Energy fluctuation and discontinuity of specific heat

Specific heat per particle (

Fermion localization in higher curvature and scalar–tensor theories of gravity

c_v

Soft supersymmetry breaking with tiny cosmological constant in flux compactified N=1 supergravity

) of an ideal gas, in many occasions, is interpreted as energy fluctuation per particle (