Searcharxiv⌕ Search

arXiv subjects

Antonio Capolupo

Publications and source records attributed to Antonio Capolupo.

87 records · Page 5Linked to original sources
arXiv2010

Energy concentration in composite quantum systems

The spontaneous emission of photons from optical cavities and from trapped atoms has been studied extensively in the framework of quantum optics. Theoretical predictions based on the rotating wave approximation (RWA) are in general in very good agreement with experimental findings. However, current experiments aim at combining better and better cavities with large numbers of tightly confined atoms. Here we predict an energy concentrating mechanism in the behavior of such a composite quantum system which cannot be described by the RWA. Its result is the continuous leakage of photons through the cavity mirrors, even in the absence of external driving. We conclude with a discussion of the predicted phenomenon in the context of thermodynamics.

cond-mat.other↗
arXiv2009

Particle mixing, flavor condensate and dark energy

The mixing of neutrinos and quarks generate a vacuum condensate that, at the present epoch, behaves as a cosmological constant. The value of the dark energy is constrained today by the very small breaking of the Lorentz invariance.

hep-th↗
arXiv2009

Quantum Optical Heating in Sonoluminescence Experiments

Sonoluminescence occurs when tiny bubbles rilled with noble gas atoms are driven by a sound wave. Each cycle of the driving field is accompanied by a collapse phase in which the bubble radius decreases rapidly until a short but very strong light flash is emitted. The spectrum of the light corresponds to very high temperatures and hints at the presence of a hot plasma core. While everyone accepts that the effect is real, the main energy focussing mechanism is highly controversial. Here we suggest that the heating of the bubble might be due to a weak but highly inhomogeneous electric field as it occurs during rapid bubble deformations [A. Kurcz et al. (submitted)]. It is shown that such a field couples the quantised motion of the atoms to their electronic states, thereby resulting in very high heating rates.

cond-mat.other↗
arXiv2009

Sonoluminescence and quantum optical heating

Sonoluminescence is the intriguing phenomenon of strong light flashes from tiny bubbles in a liquid. The bubbles are driven by an ultrasonic wave and need to be filled with noble gas atoms. Approximating the emitted light by blackbody radiation indicates very high temperatures. Although sonoluminescence has been studied extensively, the origin of the sudden energy concentration within the bubble collapse phase is still controversial. It is hence difficult to further increase the temperature inside the bubble for applications like sonochemistry and table top fusion. Here we show that the strongly confined nobel gas atoms inside the bubble can be heated very rapidly by a weak but highly inhomogeneous electric field as it might occur naturally during rapid bubble deformations. An indirect proof of the proposed quantum optical heating mechanism would be the detection of the non-thermal emission of photons in the optical regime prior to the light flash. Our model implies that it is possible to increase the temperature inside the bubble with the help of appropriately detuned laser fields.

cond-mat.other↗
arXiv2009

Non-cyclic phases for neutrino oscillations in quantum field theory

We show the presence of non-cyclic phases for oscillating neutrinos in the context of quantum field theory. Such phases carry information about the non-perturbative vacuum structure associated with the field mixing. By subtracting the condensate contribution of the flavor vacuum, the previously studied quantum mechanics geometric phase is recovered.

hep-th↗
arXiv2005

Lepton charge and neutrino mixing in pion decay processes

We consider neutrino mixing and oscillations in quantum field theory and compute the neutrino lepton charge in decay processes where neutrinos are generated. We also discuss the proper definition of flavor charge and states and clarify the issues of the possibility of different mass parameters in field mixing.

hep-ph↗
arXiv2004

Neutrino mixing as a source for cosmological constant

We report on recent results showing that neutrino mixing may lead to a non-zero contribution to the cosmological constant. This contribution is of a completely different nature with respect to the usual one by a massive spinor field. We also study the problem of field mixing in Quantum Field Theory in curved space-time, for the case of a scalar field in the Friedmann-Robertson-Walker metric.

hep-th↗
arXiv2004

Neutrino mixing and cosmological constant

We report on the recent result that the non--perturbative vacuum structure associated with neutrino mixing leads to a non--zero contribution to the value of the cosmological constant. Its value is estimated by using the natural cut--off appearing in the quantum field theory formalism for neutrino mixing.

hep-th↗
arXiv2004

Aspects of particle mixing in Quantum Field Theory

The results obtained on the particle mixing in Quantum Field Theory are reviewed. The Quantum Field Theoretical formulation of fermion and boson mixed fields is analyzed in detail and new oscillation formulas exhibiting corrections with respect to the usual quantum mechanical ones are presented. It is proved that the space for the mixed field states is unitary inequivalent to the state space where the unmixed field operators are defined. The structure of the currents and charges for the charged mixed fields is studied. Oscillation formulas for neutral fields are also derived. Moreover the study some aspects of three flavor neutrino mixing is presented, particular emphasis is given to the related algebraic structures and their deformation in the presence of CP violation. The non-perturbative vacuum structure associated with neutrino mixing is shown to lead to a non-zero contribution to the value of the cosmological constant. Finally, phenomenological aspects of the non-perturbative effects are analyzed. The systems where this phenomena could be detected are the $η-η'$ and $ϕ-ω$ mesons.

hep-th↗
arXiv2004

Phenomenology of flavor oscillations with non-perturbative effects from quantum field theory

We analyze phenomenological aspects of the quantum field theoretical formulation of meson mixing and obtain the exact oscillation formula in the presence of the decay. This formula is different from quantum mechanical formula by additional high-frequency oscillation terms. In the infinite volume limit, the space of the flavor quantum states is unitarily inequivalent to the space of energy eigenstates.

hep-ph↗
arXiv2002

Quantum Field Theory of three flavor neutrino mixing and oscillations with CP violation

We study in detail the Quantum Field Theory of mixing among three generations of Dirac fermions (neutrinos). We construct the Hilbert space for the flavor fields and determine the generators of the mixing transformations. By use of these generators, we recover all the known parameterizations of the three-flavor mixing matrix and we find a number of new ones. The algebra of the currents associated with the mixing transformations is shown to be a deformed $su(3)$ algebra, when CP violating phases are present. We then derive the exact oscillation formulas, exhibiting new features with respect to the usual ones. CP and T violation are also discussed.

hep-th↗
arXiv2001

Comment on ``Remarks on flavor-neutrino propagators and oscillation formulae''

We comment on the paper ``Remarks on flavor-neutrino propagators and oscillation formulae'' [Phys. Rev. D64, 013011 (2001)]. We show that the conclusions presented in that paper do not apply to the exact field theoretical oscillation formulae obtained in the BV formalism (for three flavors) which are free from the dependence on arbitrary mass parameters, account for CP violation and reduce to the usual quantum mechanical (Pontecorvo) three flavor oscillation formulae in the relativistic limit.

hep-ph↗
arXiv2001

Quantum Field Theory of boson mixing

We consider the quantum field theoretical formulation of boson field mixing and obtain the exact oscillation formula. This formula does not depend on arbitrary mass parameters. We show that the space for the mixed field states is unitarily inequivalent to the state space where the unmixed field operators are defined. We also study the structure of the currents and charges for the mixed fields.

hep-ph↗