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Aniello Quaranta

Publications and source records attributed to Aniello Quaranta.

At least 19 recordsLinked to original sources

Spin-dependent neutrino oscillations in torsion backgrounds: A quantum-field-theoretic analysis

We study neutrino mixing in a background with spacetime torsion within the quantum-field-theoretic formulation of flavor oscillations. Working in the Einstein--Cartan framework and neglecting curvature, we quantize Dirac fields in constant and linearly time-dependent axial-torsion backgrounds. A constant spatial torsion component lifts the degeneracy between the two spin orientations through spin-dependent effective masses and energies. In quantum field theory this splitting modifies not only the oscillation frequencies but also the amplitudes, because the Bogoliubov coefficients entering the flavor operators depend on spin. The effect is largest at low momentum when the torsion scale is comparable to the neutrino masses, while a dominant torsion term suppresses the relative mass splittings and can inhibit flavor conversion. We also discuss the induced spin dependence of the Dirac $CP$ asymmetry and of the condensate densities in the flavor vacuum. The results identify nonrelativistic neutrinos as the natural regime in which the difference between the field-theoretic and quantum-mechanical descriptions is most pronounced.

hep-ph

The X17 Anomaly: Experimental Evidence and Theoretical Interpretations

This review summarizes the experimental evidence for the hypothetical X17 particle, examines the theoretical frameworks in which it can be accommodated, and discusses its potential implications for the Standard Model and couplings to known particles. Future experimental prospects are also highlighted.

hep-ph

Addressing Standard Model Tensions via X17 Vector Boson

We investigate the effects of introducing a new vector boson on existing discrepancies within the Standard Model. Our analysis highlights the potential of this particle to alleviate these tensions while serving as a portal to the dark sector. This scenario provides a promising avenue for exploring extensions beyond the Standard Model and motivates further experimental and theoretical studies.

hep-ph

Particle Physics in Curved Spacetime and Dark Matter

We review recent results showing that, within the framework of quantum field theory in curved spacetime, the semiclassical energy-momentum tensor of the neutrino flavor vacuum fulfills the equation of state of dust and cold dark matter. By considering spherically symmetric spacetimes in the weak field approximation, the flavor vacuum is shown to contribute as a Yukawa correction to the Newtonian potential. We discuss how this modified potential provides a mechanism to account for the flat rotation curves of spiral galaxies. In this perspective, neutrino mixing is presented as a viable contributing factor to the dark matter content of the universe.

gr-qc

Quantum interferometric probe of neutron--hidden neutron oscillations

The nature of dark matter remains an outstanding problem in particle physics and cosmology. Hidden-sector extensions of the Standard Model predict a neutral partner of the neutron, whose weak mixing with ordinary neutrons induces oscillations between visible and dark baryonic states. We show that macroscopic quantum interferometry provides a direct and experimentally accessible probe of this phenomenon. In particular, a Mach--Zehnder interferometer with very cold neutrons converts neutron--hidden neutron oscillations into measurable phase-dependent intensity modulations. By combining controlled phase shifts with tunable magnetic fields and material potentials, the setup enables a resonant exploration of the hidden-sector parameter space. We find that existing cold-neutron facilities can probe mixing amplitudes down to $\epsilon_{nn'} \sim 10^{-14}\,\mathrm{eV}$ for mass splittings $\delta m \sim 10^{-9}\,\mathrm{eV}$, accessing a previously unexplored region of parameter space relevant to baryonic dark matter scenarios. These results establish neutron interferometry as a precision laboratory tool for testing hidden-sector physics.

hep-ph

Particle mixing and quantum reference frames

We discuss the role of quantum reference frames in providing a viable definition of rest frame for mixed particles. We then analyze the related concept of frame-dependent entanglement and its impact on the phenomenology of neutral mesons and neutrinos.

hep-ph

Vector-field spontaneous baryogenesis with Lorentz invariance violation

We extend spontaneous baryogenesis by considering the spontaneous breaking of $U(1)_B$ through a complex vector field. This field interacts with baryons and leptons via a vector-current coupling and, by construction, acquires a nonzero vacuum expectation value. Accordingly, the theory also exhibits a spontaneous violation of Lorentz invariance, effectively realizing a Bumblebee model. In this picture, the pseudo-Nambu-Goldstone boson arising from spontaneous breaking of the $U(1)_B$ global symmetry is the global phase of the Bumblebee vector and, in the broken phase, it results minimally coupled with the baryonic current, guaranteeing the violation of the baryon number. Consequently, we assume that the pseudo-Nambu-Goldstone, arising from spontaneous breaking of $U(1)_B$, plays the role of the inflaton, leading to baryogenesis across the entire inflationary stage, up to when the inflaton decays into baryon-antilepton and antibaryon-lepton pairs through a CP-violating interaction that also violates the Lorentz symmetry. Afterwards, we address the issue of flavor oscillations among baryon and lepton fields, including the oscillation probability in the calculation of the baryon asymmetry. Remarkably, our framework predicts a non-null mixing factor even for massless fermions. This mixing acts on the spatial momenta rather than on the masses of the produced fermions, allowing larger values of the coupling constant even guaranteeing the production of light fermions. The net baryon asymmetry results accordingly modified, and may also reproduce the experimental data for allowed values of the coupling constant.

hep-ph

Quantized Dirac Fields in torsionful gravity: cosmological implications and links with the dark universe

We consider a classical field in square torsion theory as a source of torsion for a quantum fermion field in FLRW metric. In the framework of QFT, we obtain vacuum contributions to the energy-momentum tensor and to the axial current that modify the dynamics of the classical field and the field equations as back-reaction. These contributions lead to a modified classical field and therefore to a modified torsion term $L^\mu$ and expectation value of energy-momentum tensor $T^{\mu\nu}$ on the quantum vacuum, altering the field equations in an interative process. We consider the first step of this process and we find that the vacuum condensate could affect the inflationary phase of the Universe. Higher order terms could impact the dark Universe.

hep-th

A Breakdown Case Study of the Lindblad Approach via Entanglement and Purity

The Lindblad master equation is widely used to describe the reduced dynamics of open quantum systems under Markovian assumptions. Here, we investigate its ability to reproduce the reduced evolution emerging from a microscopic many-body model in which two interacting two-level subsystems are embedded in a larger environment and evolve under fully unitary dynamics. The exact evolution exhibits a clear separation of timescales. At short times, decoherence arises from environmentally induced dephasing, leading to a Gaussian suppression of coherences and a quadratic decay of purity. At intermediate times, collective decoherence channels saturate and a slower, still Gaussian, decay driven by relative environmental fluctuations dominates. At later times the system settles in a complete decohered state. The first two behaviors cannot be reproduced by a Lindblad dynamics with constant coefficients, which always results in an exponential decay: Our work provides a simple example of the breakdown of the effective description relevant in many realistic settings.

quant-ph

Impact of flavor condensate dark matter on accretion disk luminosity in spherical spacetimes

We investigate the impact of dark matter condensates on the emission and thermodynamic properties of accretion disks, in a spherically-symmetric and static background. We focus on a class of models where dark matter originates from a genuine mass mixing among neutrino fields and compute the corrections to the dark matter's potential within galactic halo. We find a corresponding Yukawa correction induced by the dark matter energy-momentum tensor over the Newtonian potential. In so doing, employing Schwarzschild coordinates, and adopting the Novikov-Thorne formalism, we compute the geodesic structure and the corresponding disk-integrated luminosity profiles. Assuming a constant mass accretion rate, constituted solely by baryonic matter, we find non-negligible deviations in both the disk structure and radiative output, as compared to the standard Schwarzschild case. Afterwards, we discuss physical consequences of our Yukawa correction, comparing it with recent literature, predicting similar potentials, albeit derived from extended theories of gravity. Accordingly, we thus speculate to use our results to distinguish among candidates of dark matter. Indeed, our findings suggest that incoming high-precision observations of accretion disk spectra may provide a tool to probe dark matter's nature under the form of particles, extended theories of gravity or condensates.

gr-qc

Single arm interferometry to probe the scalar field dark matter

We analyse the interaction of photons with a scalar dark matter field \phi and we propose to use a single arm interferometer to reveal this interaction and constrain the parameters of the scalar dark matter model. By considering a beam of coherent light and two spatially separated squeezing operations, we show that the interaction of photons with scalar dark matter leads to an observable deviation in the outgoing light state, with respect to free evolution. Therefore the single arm interferometer may yield a novel revelation method for scalar dark matter.

hep-ph

Searching for mirror neutrons and dark matter with cold neutron interferometry

We report a novel neutron interferometry scheme aimed at probing the potential existence of mirror neutrons, which have been proposed as viable dark matter candidates. Our theoretical analysis demonstrates that if mirror neutrons exist, ordinary neutrons would acquire a measurable geometric phase as a result of their mixing with these mirror counterparts.

hep-ph

Quantum reference frames and particle mixing

We discuss the necessity and the emergence of quantum reference frames when attempting to define a rest frame for mixed particles. We analyze the corresponding concept of frame dependent entanglement and how it could affect measurements on mixed mesons and neutrinos.

hep-ph

Missing matter in galaxies as a neutrino mixing effect

We show that, in the framework of quantum field theory in curved spacetime, the semiclassical energy-momentum tensor of the neutrino flavor vacuum fulfills the equation of state of dust and cold dark matter. We consider spherically symmetric spacetimes, and we demonstrate that, within the weak field approximation, the flavor vacuum contributes as a Yukawa correction to the Newtonian potential. This corrected potential may account for the flat rotation curves of spiral galaxies. In this perspective, neutrino mixing could contribute to dark matter

hep-ph

The impact of the X17 boson on particle physics anomalies: muon anomalous magnetic moment, Lamb shift, W mass and dark charges

We show that the X17 vector boson, introduced to explain the ^8 Be anomalous decay, could play a crucial role in the explanation of the muon's (electron's) anomalous magnetic moment and the muonic Lamb shift. We further constrain the possible kinetic mixing with the U(1)_Y boson of the Standard Model by using the latest available data on the W boson mass.

hep-ph

Probing Mirror Neutrons and Dark Matter through Cold Neutron Interferometry

We propose a novel neutron interferometry setup to explore the potential existence of mirror neutrons, a candidate for dark matter. Our work demonstrates that if mirror neutrons exist, neutrons will acquire an observable geometric phase due to mixing with these mirror counterparts. This geometric phase, detectable through our interferometric setup, could serve as a direct probe for the presence of mirror matter particles. Additionally, this investigation could shed light on unresolved issues in particle physics, such as the neutron lifetime puzzle. We discuss the setup's versatility and limitations, showing its capability to explore a wide range of parameters in neutron interferometry and potentially uncover new physics.

hep-ph