Xiao, C. W. (2015). States generated in the K-multi-rho interactions. Phys. Rev. D, 92(5), 054011–16pp.
Abstract: In the present work, we use three-body interaction formalism to investigate the K-multi-rho interactions. First, we reproduce the resonances f(2)(1270) and K-1(1270) in the rho rho and rho K two-body interactions, respectively, as the clusters of the fixed-center approximation. Then, we study the three-body K-rho rho(f(2)) and rho-rho K(K-1) interactions with the fixed-center approximation of the Faddeev equations. Furthermore, we extrapolate the formalism to study the four-body, five-body, and six-body systems containing one K meson and multiple rho mesons. In our research, without introducing any free parameters, we generate the K-2(1770) state in the three-body interaction with the mass of 1707 MeV and a width about 113 MeV, which are consistent with the experiments. We also find a clear resonant structure in our results of the five-body interaction, with a mass 2505 MeV and a width about 32 MeV or more, which is associated with the K-4(2500) state, where we obtain consistent results with the experimental findings. Furthermore, we predict some new states in the other many-body interactions, K-3(2080), K-5(2670) (isospin I = 1/2), and K-4(2640) (isospin I = 3/2), with uncertainties.
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Campanario, F., Czyz, H., Gluza, J., Jelinski, T., Rodrigo, G., Tracz, S., et al. (2019). Standard model radiative corrections in the pion form factor measurements do not explain the a(mu) anomaly. Phys. Rev. D, 100(7), 076004–5pp.
Abstract: In this paper, we address the question of whether the almost four standard deviations difference between theory and experiment for the muon anomalous magnetic moment a(mu) can be explained as a higher-order Standard Model perturbation effect in the pion form factor measurements. This question has, until now, remained open, obscuring the source of discrepancies between the measurements. We calculate the last radiative corrections for the extraction of the pion form factor, which were believed to be potentially substantial enough to explain the data within the Standard Model. We find that the corrections are too small to diminish existing discrepancies in the determination of the pion form factor for different kinematical configurations of low-energy BABAR, BES-III and KLOE experiments. Consequently, they cannot noticeably change the previous predictions for a(mu) and decrease the deviations between theory and direct measurements. To solve the above issues, new data and better understanding of low-energy experimental setups are needed, especially as new direct a(mu) measurements at Fermilab and J-PARC will provide new insights and substantially shrink the experimental error.
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Vijande, J., Valcarce, A., & Richard, J. M. (2012). Stability of hexaquarks in the string limit of confinement. Phys. Rev. D, 85(1), 014019–6pp.
Abstract: The stability of systems containing six quarks or antiquarks is studied within a simple string model inspired by the strong-coupling regime of quantum chromodynamics and used previously for tetraquarks and pentaquarks. We discuss both six-quark (q(6)) and three-quark-three-antiquark (q(3)($) over bar (3)) states. The quarks are assumed to be distinguishable and thus not submitted to antisymmetrization. It is found that the ground state of (q(6)) is stable against dissociation into two isolated baryons. For the case of (q(3)($) over bar (3)), our results indicate the existence of a bound state very close to the threshold. The investigations are extended to (q(3)Q(3)) and (Q(3) ($) over bar (3)) systems with two different constituent masses, and their stability is discussed as a function of the mass ratio.
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Babichev, E., & Fabbri, A. (2014). Stability analysis of black holes in massive gravity: A unified treatment. Phys. Rev. D, 89(8), 081502–5pp.
Abstract: We consider the analytic solutions of massive (bi) gravity which can be written in a simple form using advanced Eddington-Finkelstein coordinates. We analyze the stability of these solutions against radial perturbations. First we recover the previously obtained result on the instability of the bidiagonal bi-Schwarzschild solutions. In the nonbidiagonal case (which contains, in particular, the Schwarzschild solution with Minkowski fiducial metric), we show that generically there are physical spherically symmetric perturbations, but no unstable modes.
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Mazumdar, A., & Morisi, S. (2012). Split neutrinos, two Majorana and one Dirac, and implications for leptogenesis, dark matter, and inflation. Phys. Rev. D, 86(4), 045031–6pp.
Abstract: We propose a simple framework to split neutrinos with a slight departure from tribimaximal-where two of the neutrinos are Majorana type which provide thermal leptogenesis. We propose a model based on S-3 flavor symmetry. The Dirac neutrino with a tiny Yukawa coupling explains primordial inflation and the cosmic microwave background radiation, where the inflaton is the gauge invariant flat direction. The observed baryon asymmetry, and the scale of inflation are intimately tied to the observed reactor angle sin theta(13), which can be further constrained by the LHC and the 0 nu beta beta experiments. The model also provides the lightest right-handed sneutrino as a part of the inflaton to be the dark matter candidate.
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Barenboim, G., & Park, W. I. (2015). Spiral inflation with Coleman-Weinberg potential. Phys. Rev. D, 91(6), 063511–5pp.
Abstract: We apply the idea of spiral inflation to the Coleman-Weinberg potential and show that inflation matching our observations well is allowed for a symmetry-breaking scale ranging from an intermediate scale to a grand unified theory (GUT) scale even if the quartic coupling lambda is of O(0.1). The tensor-to-scalar ratio can be of O(0.01) in the case of GUT-scale symmetry breaking.
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Figueroa, D. G., Florio, A., Loayza, N., & Pieroni, M. (2022). Spectroscopy of particle couplings with gravitational waves. Phys. Rev. D, 106(6), 063522–8pp.
Abstract: We discuss the possibility to measure particle couplings with stochastic gravitational wave backgrounds (SGWBs). Under certain circumstances a sequence of peaks of different amplitude and frequency-a stairway-emerges in a SGWB spectrum, with each peak probing a different coupling. The detection of such signature opens the possibility to reconstruct couplings (spectroscopy) of particle species involved in high energy phenomena generating SGWBs. Stairwaylike signatures may arise in causally produced backgrounds in the early Universe, e.g., from preheating or first order phase transitions. As a proof of principle we study a preheating scenario with an inflaton 0 coupled to multiple daughter fields f chi jg with different coupling strengths. As a clear stairway signature is imprinted in the SGWB spectrum, we reconstruct the relevant couplings with various detectors.
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Palomares-Ruiz, S., Vincent, A. C., & Mena, O. (2015). Spectral analysis of the high-energy IceCube neutrinos. Phys. Rev. D, 91(10), 103008–28pp.
Abstract: A full energy and flavor-dependent analysis of the three-year high-energy IceCube neutrino events is presented. By means of multidimensional fits, we derive the current preferred values of the high-energy neutrino flavor ratios, the normalization and spectral index of the astrophysical fluxes, and the expected atmospheric background events, including a prompt component. A crucial assumption resides on the choice of the energy interval used for the analyses, which significantly biases the results. When restricting ourselves to the similar to 30 TeV-3 PeV energy range, which contains all the observed IceCube events, we find that the inclusion of the spectral information improves the fit to the canonical flavor composition at Earth, (1: 1: 1)(circle plus), with respect to a single-energy bin analysis. Increasing both the minimum and the maximum deposited energies has dramatic effects on the reconstructed flavor ratios as well as on the spectral index. Imposing a higher threshold of 60 TeV yields a slightly harder spectrum by allowing a larger muon neutrino component, since above this energy most atmospheric tracklike events are effectively removed. Extending the high-energy cutoff to fully cover the Glashow resonance region leads to a softer spectrum and a preference for tau neutrino dominance, as none of the expected electron (anti) neutrino induced showers have been observed so far. The lack of showers at energies above 2 PeV may point to a broken power-law neutrino spectrum. Future data may confirm or falsify whether the recently discovered high-energy neutrino fluxes and the long-standing detected cosmic rays have a common origin.
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del Rio, A., & Navarro-Salas, J. (2014). Spacetime correlators of perturbations in slow-roll de Sitter inflation. Phys. Rev. D, 89(8), 084037–7pp.
Abstract: Two-point correlators and self-correlators of primordial perturbations in quasi-de Sitter spacetime backgrounds are considered. For large separations two-point correlators exhibit nearly scale invariance, while for short distances self-correlators need standard renormalization. We study the deformation of two-point correlators to smoothly match the self-correlators at coincidence. The corresponding angular power spectrum is evaluated in the Sachs-Wolfe regime of low multipoles. Scale invariance is maintained, but the amplitude of C(l)could change in a nontrivial way.
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De Romeri, V., Hirsch, M., & Malinsky, M. (2011). Soft masses in supersymmetric SO(10) GUTs with low intermediate scales. Phys. Rev. D, 84(5), 053012–15pp.
Abstract: The specific shape of the squark, slepton and gaugino mass spectra, if measured with sufficient accuracy, can provide invaluable information not only about the dynamics underpinning their origin at some very high scale such as the unification scale M(G), but also about the intermediate scale physics encountered throughout their renormalization group equations evolution down to the energy scale accessible for the LHC. In this work, we study general features of the TeV scale soft supersymmetry breaking parameters stemming from a generic mSugra configuration within certain classes of supersymmetry SO(10) GUTs with different intermediate symmetries below M(G). We show that particular combinations of soft masses show characteristic deviations from the mSugra limit in different models and thus, potentially, allow to distinguish between these, even if the new intermediate scales are outside the energy range probed at accelerators. We also compare our results to those obtained for the three minimal seesaw models with mSugra boundary conditions and discuss the main differences between those and our SO(10) based models.
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