showing 3 related works from this author
Vacuum polarization around stars: Nonlocal approximation
2004
We compute the vacuum polarization associated with quantum massless fields around stars with spherical symmetry. The nonlocal contribution to the vacuum polarization is dominant in the weak field limit, and induces quantum corrections to the exterior metric that depend on the inner structure of the star. It also violates the null energy conditions. We argue that similar results also hold in the low energy limit of quantum gravity. Previous calculations of the vacuum polarization in spherically symmetric spacetimes, based on local approximations, are not adequate for newtonian stars.
The Demise of Flavour Tagging and its Delta-T Dependence
2007
In this work we discuss how the loss of particle-antiparticle identity due to CPT violation affects the observables in the decay of two neutral EPR-correlated $B$-mesons. We study this possible new effect in the context of equal-sign flavour specific decays and we find a considerable modification in the $\Delta t$-dependence of the equal-sign dilepton charge asymmetry, $A_{sl}$. Although the more important changes occur right outside the $\Dt$ region that has been up-to-the-date effectively explored, we show that a deeper experimental research may be able to distinguish a possible existence of this new CPT violating parameter, $\w$. In any case, using the available data for $A_{sl}$, we put…
CPT violation in entangled B0–B¯0 states and the demise of flavour tagging
2005
Abstract We discuss the demise of flavour tagging due to the loss of the particle–antiparticle identity of neutral B -mesons in the Einstein–Podolsky–Rosen correlated states. Such a situation occurs in cases where the CPT operator is ill-defined, as happens, for example, in quantum gravity models with induced decoherence in the matter sector. The time evolution of the perturbed B 0 – B ¯ 0 initial state, as produced in B -factories, is sufficient to generate new two-body states. For flavour specific decays at equal times, we discuss two definite tests of the two body entanglement: (i) search for the would-be forbidden B 0 B 0 and B ¯ 0 B ¯ 0 states; (ii) deviations from the indistinguishabl…