Alvarez, A., Cepedello, R., Hirsch, M., & Porod, W. (2022). Temperature effects on the Z(2) symmetry breaking in the scotogenic model. Phys. Rev. D, 105(3), 035013–8pp.
Abstract: It is well known that the scotogenic model for neutrino mass generation can explain correctly the relic abundance of cold dark matter. There have been claims in the literature that an important part of the parameter space of the simplest scotogentic model can be constrained by the requirement that no Z(2)-breaking must occur in the early universe. Here we show that this requirement does not give any constraints on the underlying parameter space at least in those parts, where we can trust perturbation theory. To demonstrate this, we have taken into account the proper decoupling of heavy degrees of freedom in both the thermal potential and in the RGE evolution.
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Coogan, A., Bertone, G., Gaggero, D., Kavanagh, B. J., & Nichols, D. A. (2022). Measuring the dark matter environments of black hole binaries with gravitational waves. Phys. Rev. D, 105(4), 043009–22pp.
Abstract: Large dark matter overdensities can form around black holes of astrophysical and primordial origin as they form and grow. This “dark dress” inevitably affects the dynamical evolution of binary systems and induces a dephasing in the gravitational waveform that can be probed with future interferometers. In this paper, we introduce a new analytical model to rapidly compute gravitational waveforms in the presence of an evolving dark matter distribution. We then present a Bayesian analysis determining when dressed black hole binaries can be distinguished from GR-in-vacuum ones and how well their parameters can be measured, along with how close they must be to be detectable by the planned Laser Interferometer Space Antenna (LISA). We show that LISA can definitively distinguish dark dresses from standard binaries and characterize the dark matter environments around astrophysical and primordial black holes for a wide range of model parameters. Our approach can be generalized to assess the prospects for detecting, classifying, and characterizing other environmental effects in gravitational wave physics.
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Balbinot, R., & Fabbri, A. (2022). Quantum correlations across the horizon in acoustic and gravitational black holes. Phys. Rev. D, 105(4), 045010–20pp.
Abstract: We investigate, within the framework of quantum field theory in curved space, the correlations across the horizon of a black hole in order to highlight the particle-partner pair creation mechanism at the origin of Hawking radiation. The analysis concerns both acoustic black holes, formed by Bose-Einstein condensates, and gravitational black holes. More precisely, we have considered a typical acoustic black hole metric with two asymptotic homogeneous regions and the Schwarzschild metric as describing a gravitational black hole. By considering equal-time correlation functions, we find a striking disagreement between the two cases: the expected characteristic peak centered along the trajectories of the Hawking particles and their partners seems to appear only for the acoustic black hole and not for the gravitational Schwarzschild one. The reason for that is the existence of a quantum atmosphere displaced from the horizon as the locus of origin of Hawking radiation together, and this is the crucial aspect, with the presence of a central singularity in the gravitational case swallowing everything is trapped inside the horizon. Correlations, however, are not absent in the gravitational case; to see them, one simply has to consider correlation functions at unequal times, which indeed display the expected peak.
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Lopez-Ibañez, M. L., Melis, A., Jay Perez, M., Rahat, M. H., & Vives, O. (2022). Constraining low-scale flavor models with (g-2)(mu) and lepton flavor violation. Phys. Rev. D, 105(3), 035021–21pp.
Abstract: We present here two concrete examples of models where a sub-TeV scale breaking of their respective T-13 and A(5) flavor symmetries is able to account for the recently observed discrepancy in the muon anomalous magnetic moment, (g – 2)(mu). Similarities in the flavor structures of the charged-lepton Yukawa matrix and dipole matrix yielding (g – 2)(mu) give rise to strong constraints on low-scale flavor models when bounds from lepton flavor violation (LFV) are imposed. These constraints place stringent limits on the off- diagonal Yukawa structure, suggesting a mostly (quasi)diagonal texture for models with a low flavor breaking scale A(f). We argue that many of the popular flavor models in the literature designed to explain the fermion masses and mixings are not suitable for reproducing the observed discrepancy in (g – 2)(mu), which requires a delicate balance of maintaining a low flavor scale while simultaneously satisfying strong LFV constraints.
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Magalhaes, R. B., Crispino, L. C. B., & Olmo, G. J. (2022). Compact objects in quadratic Palatini gravity generated by a free scalar field. Phys. Rev. D, 105(6), 064007–15pp.
Abstract: We study the correspondence that connects the space of solutions of general relativity (GR) with that of Ricci-based gravity theories (RBGs) of the f(R, Q) type in the metric-affinc formulation, where Q = R(mu nu)R(mu nu). We focus on the case of scalar matter and show that when one considers a free massless scalar in the GR frame, important simplifications arise that allow one to establish the correspondence for arbitrary f (R, Q) Lagrangian. We particularize the analysis to a quadratic f (R, Q) theory and use the spherically symmetric, static solution of Jannis-Newman-Winicour as seed to generate new compact objects in our target theory. We find that two different types of solutions emerge, one representing naked singularities and another corresponding to asymmetric wormholes with bounded curvature scalars everywhere. The latter solutions, nonetheless, are geodesically incomplete.
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Antusch, S., Figueroa, D. G., Marschall, K., & Torrenti, F. (2022). Characterizing the postinflationary reheating history: Single daughter field with quadratic-quadratic interaction. Phys. Rev. D, 105(4), 043532–36pp.
Abstract: We study the evolution of the energy distribution and equation of state of the Universe from the end of inflation until the onset of either radiation domination (RD) or a transient period of matter domination (MD). We use both analytical techniques and lattice simulations. We consider two-field models where the inflaton (/) has a monomial potential after inflation V((/)) proportional to i(/) – vip (p 4, and of order similar to 50% for p 4. The system goes to MD at late times for p = 2, while it goes to RD for p > 2. In the later case, we can calculate exactly the number of e-folds until RD as a function of g2, and hence predict accurately inflationary observables like the scalar tilt ns and the tensor-to-scalar ratio r. In the scenario (ii), the energy is always transferred completely to X for p > 2, as long as its effective mass m2X = g2((/) – v)2 is not negligible. For p = 2, the final ratio between the energy densities of X and (/) depends strongly on g2. For all p > 2, the system always goes to MD at late times.
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Perez-Ramos, R., Sanchis-Lozano, M. A., & Sarkisyan-Grinbaum, E. K. (2022). Searching for hidden matter with long-range angular correlations at e(+)e(-) colliders. Phys. Rev. D, 105(5), 053001–8pp.
Abstract: The analysis of azimuthal correlations in multiparticle production can be useful to uncover the existence of new physics beyond the Standard Model, e.g., Hidden Valley, in e(+)e(-) annihilation at high energies. In this paper, based on previous theoretical studies and using the PYTHIA8 event generator, it is found that both azimuthal and rapidity long-range correlations are enhanced due to the presence of a new stage of matter on top of the QCD partonic cascade. Ridge structures, similar to those observed in hadronic collisions at the LHC, show up providing a possible signature of new physics at future e(+)e(-) colliders.
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Ikeno, N., Molina, R., & Oset, E. (2022). Zcs states from the D*s over bar D* and J=psi K* coupled channels: Signal in B+ -> J=psi phi K+ decay. Phys. Rev. D, 105(1), 014012–13pp.
Abstract: We study the D*s over bar D* system in connection with the J=psi K* in coupled channels and observe that, within reasonable values of the cutoff used to regularize the loops, the system does not develop a bound state. However, the JP = 2+ channel has enough attraction to create a strong cusp structure that shows up in the J=psi K+ invariant mass distribution in the B+ -> J=psi phi K+ decay at the D*s over bar D* threshold. Such structure is results should stimulate further measurements around this region, given the fact that cusp effects provide as valuable information on hadron dynamics as resonances themselves.
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de Anda, F. J., Medina, O., Valle, J. W. F., & Vaquera-Araujo, C. A. (2022). Scotogenic Majorana neutrino masses in a predictive orbifold theory of flavor. Phys. Rev. D, 105(5), 055030–12pp.
Abstract: The use of extra space-time dimensions provides a promising approach to the flavor problem. The chosen compactification of a 6-dimensional orbifold implies a remnant family symmetry A4. This makes interesting predictions for quark and lepton masses, for neutrino oscillations and neutrinoless double beta decay, providing also a very good global description of all flavor observables. Due to an auxiliary Z4 symmetry, we implement a scotogenic Majorana neutrino mass generation mechanism with a viable WIMP dark matter candidate.
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Bruschini, R., & Gonzalez, P. (2022). Is chi(c1)(3872) generated from string breaking? Phys. Rev. D, 105(5), 054028–6pp.
Abstract: We show, from a diabatic analysis of lattice results for string breaking, that mixing of Q (Q) over bar with open-flavor meson-meson configurations may be expressed through a mixing potential which is order 1/m(Q). A relation between the minimum string breaking energy gap and the string tension comes out naturally. Using this relation, and matching the energy gap for b (b) over bar with lattice QCD data, we study the mixing in the c (c) over bar case without any additional parameter. A 1(++) bound state very close below the D-0(D) over bar*(0) threshold, in perfect correspondence with chi(c1)(3872), is predicted.
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