Journal of High Energy Physics最新文献

We investigated the influence of the massive scalar field on the information degradation concerning the Unruh-DeWitt (UDW) detectors. In this conjecture, we adopted a system with a finite and large interaction time. To accomplish our purpose, one examines the quantum coherence of a uniformly accelerated qubit and the probability of finding the detector in the ground state. In this framework, we consider a quantum interferometric circuit to obtain the probability, visibility, and coherence. Naturally, these measurements provide us with wave-like information. Besides, one modifies the circuit to describe the path distinguishability and the particle-like information. These results are promising, as they allow us to understand the influence of the Unruh effect on the wave-particle duality. Thus, our findings announce that the increase in the scalar field mass induces a decrease in information degradation. Finally, we noted that the information concerning the Unruh effect remains preserved when m ≥ Ω. Therefore, the detector cannot absorb particles with mass equal to or greater than its energy gap. These results indicate that the scalar field mass is a protective factor against information degradation for systems under high acceleration conditions.

Collinear emission of W bosons off a high-energy muon induces a large muon-neutrino component among the Parton Distribution Functions (PDFs) of a muon. In this paper we study the phenomenology related to the ν_μ PDF at future high-energy muon colliders. We examine total rates and differential distributions of the ( e{overline{nu}}_e ) and Wγ production processes, which receive a large, and often dominant, contribution from this PDF, allowing for a detailed experimental study. As a demonstration of the impact the ν_μ PDF could have for searches of new physics, we study the charged-current pair production of a couple of heavy states, components of a SU(2)_L doublet. In both ( e{overline{nu}}_e ) production and charged-current pair production of heavy states, we compare results obtained using PDFs with those of a fixed-order simulation.

In the framework of AdS/CFT duality, we consider the semiclassical problem in general quadratic theory of gravity. We construct asymptotically global AdS and hyperbolic (topological) AdS black hole solutions with non-trivial quantum hair in 4 and 5-dimensions by perturbing the maximally symmetric AdS solutions to the holographic semiclassical equations. We find that under certain conditions, our semiclassical solution of hyperbolic AdS black holes can be dynamically unstable against linear perturbations. In this holographic semiclassical context, we also study the thermodynamic instability of the hairy solutions in the 5-dimensional Gauss-Bonnet theory by computing the free energy and show that depending on the parameter of the Gauss-Bonnet theory, the free energy can be smaller than that of the background maximally symmetric AdS solution in both the global AdS and hyperbolic AdS black hole cases.

We derive a lower bound on the sensitivity of generic mechanical and electromagnetic gravitational wave detectors. We consider both classical and quantum detection schemes, although we focus on the former. Our results allow for a simple reproduction of the sensitivities of a variety of experiments, including optical interferometers, resonant bars, optomechanical sensors, and electromagnetic conversion experiments. In the high-frequency regime, all detection schemes we consider can be characterised by their stored electromagnetic energy and the signal transfer function, which we provide. We discuss why high-frequency gravitational wave searches are especially difficult and primordial gravitational wave backgrounds might not be detectable above the sensitivity window of existing interferometers.

We present minimally supersymmetric AdS₄ flux vacua derived from massive type IIA compactified on T⁶/ℤ₃ × ℤ₃ orbifold, characterized by unconstrained fluxes with general scalings. We discover anisotropic scaling solutions in which scale separation is realized in the supergravity limit, and the subvolumes of the internal space become large and anisotropic in this limit. Additionally, we identify further regimes in which subvolumes either shrink or remain constant, while scale separation is either broken or realized for large values of the unconstrained fluxes. Then, we employ a probe D4-brane to interpolate between vacua, finding that it interpolates through the regimes we previously identified. Finally, we utilize an open string modulus of the D4-brane to calculate the distance between anisotropic vacua for the regime where scale separation is realized in the supergravity limit. We show the dependence of both the geodesic distance and the Distance Conjecture parameter on the unconstrained flux scalings.

Dense neutrino gases can exhibit collective flavor instabilities, triggering large flavor conversions that are driven primarily by neutrino-neutrino refraction. One broadly distinguishes between fast instabilities that exist in the limit of vanishing neutrino masses, and slow ones, that require neutrino mass splittings. In a related series of papers, we have shown that fast instabilities result from the resonant growth of flavor waves, in the same way as turbulent electric fields in an unstable plasma. Here we extend this framework to slow instabilities, focusing on the simplest case of an infinitely homogeneous medium with axisymmetric neutrino distribution. The relevant length and time scales are defined by three parameters: the vacuum oscillation frequency ω_E = δm²/2E, the scale of neutrino-neutrino refraction energy ( mu =sqrt{2}{G}_{textrm{F}}left({n}_{nu }+{n}_{overline{nu}}right) ), and the ratio between lepton and particle number ( epsilon =left({n}_{nu }-{n}_{overline{nu}}right)/left({n}_{nu }+{n}_{overline{nu}}right) ). We distinguish between two very different regimes: (i) For ω_E ≪ μϵ², instabilities occur at small spatial scales of order (μϵ)⁻¹ with a time scale of order ( epsilon {omega}_E^{-1} ). This novel branch of slow instability arises from resonant interactions with neutrinos moving along the axis of symmetry. (ii) For μϵ² ≪ ω_E ≪ μ, the instability is strongly non-resonant, with typical time and length scales of order ( 1/sqrt{omega_Emu } ). Unstable modes interact with all neutrino directions at once, recovering the characteristic scaling of the traditional studies of slow instabilities. In the inner regions of supernovae and neutron-star mergers, the first regime may be more likely to appear, meaning that slow instabilities in this region may have an entirely different character than usually envisaged.

We investigate the fermionic perturbations of the asymptotically AdS background known as holographic neutron star, which represents a highly degenerate state of strongly coupled fermions on a sphere at finite temperature. We calculate the two-point correlator of a fermionic operator and obtain its scaling properties as we approach the critical region of the phase diagram.

We show that near the edges of the conformal window of supersymmetric SU(N_c) QCD, perturbed by Anomaly Mediated Supersymmetry Breaking (AMSB), chiral symmetry can be broken depending on the initial conditions of the RG flow. We do so by perturbatively expanding around Banks-Zaks fixed points and taking advantage of Seiberg duality. Interpolating between the edges of the conformal window, we predict that non-supersymmetric QCD breaks chiral symmetry up to N_f ≤ 3N_c − 1, while we cannot say anything definitive for N_f ≥ 3N_c at this moment.

We investigate multi-lepton jet events from the decay of the 125 GeV Higgs boson (h) into quadruple new gauge bosons (Z′) at the LHC. Such an exotic decay is realized via the process of h → ϕϕ → Z′Z′Z′Z′ with new scalar boson ϕ in models with an additional U(1) gauge symmetry. Charged leptons coming from the Z′ decay tend to be observed as lepton-jets rather than isolated leptons when the masses of Z′ and ϕ are smaller than ( mathcal{O} )(10) GeV, because of the highly-boosted effects. Performing the signal and background analyses, we find that the branching ratio of h → 4Z′ is maximally constrained to be smaller than of order 10⁻⁶ (10⁻⁷) by using the muonic-lepton jets assuming the integrated luminosity of 140 fb⁻¹ (3000 fb⁻¹) at LHC. For lighter Z′ (< 2m_μ), we can use the electronic-lepton jets instead of the muon-jets, by which the upper limit on the branching ratio is obtained to be of order 10⁻⁶–10⁻⁵. These bounds can be converted into the constraint on model parameters such as a mixing angle between h and ϕ. It is shown that stronger bounds on the mixing angle are obtained in the dark photon case as compared with the previous constraints given by flavor experiments and the Higgs decay h → Z′Z′ in the mass range of ( {m}_{Z^{prime }} ) ≲ 10 GeV.

Near the horizon of extremal charged black holes, an accidental symmetry is known to act on zero-temperature perturbations, transforming them into finite-temperature ones. In this paper, we uncover the corresponding accidental symmetry of the vacuum Einstein equation near the horizon of extremal spinning black holes. To do so, we first devise a new method of deriving the symmetry near the AdS₂ × S² near-horizon geometry of extreme Reissner-Nordström, using a new scaling coordinate transformation that unifies the near-horizon limits of extremal and near-extremal black holes in a way that is regular at zero temperature. We use our new method to obtain the accidental symmetry in the near-horizon of extreme Kerr (NHEK). We show that accidental symmetries combine neatly with the near-horizon isometries inside a Virasoro algebra.