|
|
Ferreira, M. N., & Papavassiliou, J. (2023). Gauge Sector Dynamics in QCD. Particles, 6(1), 312–363.
Abstract: The dynamics of the QCD gauge sector give rise to non-perturbative phenomena that are crucial for the internal consistency of the theory; most notably, they account for the generation of a gluon mass through the action of the Schwinger mechanism, the taming of the Landau pole, the ensuing stabilization of the gauge coupling, and the infrared suppression of the three-gluon vertex. In the present work, we review some key advances in the ongoing investigation of this sector within the framework of the continuum Schwinger function methods, supplemented by results obtained from lattice simulations.
|
|
|
|
Abreu, L. M., Wang, W. F., & Oset, E. (2023). Traces of the new alpha(0)(1780) resonance in the J/Psi ->phi K+ K-(K-0 K_(0)) reaction. Eur. Phys. J. C, 83(3), 243–11pp.
Abstract: We study the J/Psi ->phi K+ K- decay, looking for differences in the production rates of K+K- or K-0 K-(0) in the region of 1700-1800 MeV, where two resonances appear dynamically generated from the vector-vector interaction. Two resonances are known experimentally in that region, the f(0)(1710) and a new resonance reported by the BABAR and BESIII collaborations. The K K should be produced with I = 0 in that reaction, but due to the different K*(0) and K*(+) masses some isospin violation appears. Yet, due to the large width of the K*, the violation obtained is very small and the rates of K+K- or K-0 K-0 production are equal within 5%. However, we also find that due to the step needed to convert two vectors into K K, a shape can appear in the K K mass distribution that can mimic the a0 production around the K* K* threshold, and is simply a threshold effect.
|
|
|
|
De La Torre Luque, P., Gaggero, D., Grasso, D., Fornieri, O., Egberts, K., Steppa, C., et al. (2023). Galactic diffuse gamma rays meet the PeV frontier. Astron. Astrophys., 672, A58–11pp.
Abstract: The Tibet AS gamma and LHAASO collaborations recently reported the observation of a gamma-ray diffuse emission with energy up to the PeV level from the Galactic plane.Aims. We discuss the relevance of non-uniform cosmic-ray transport scenarios and the implications of these results for cosmic-ray physics.Methods. We used the DRAGON and HERMES codes to build high-resolution maps and spectral distributions of that emission for several representative models under the condition that they reproduce a wide set of local cosmic-ray data up to 100 PeV.Results. We show that the energy spectra measured by Tibet AS gamma, LHAASO, ARGO-YBJ, and Fermi-LAT in several regions of interest in the sky can all be reasonably described in terms of the emission arising by the Galactic cosmic-ray “sea”. We also show that all our models are compatible with IceTop gamma-ray upper limits.Conclusions. We compare the predictions of conventional and space-dependent transport models with those data sets. Although the Fermi-LAT, ARGO-YBJ, and LHAASO preliminary data slightly favor this scenario, due to the still large experimental errors, the poorly known source spectral shape at the highest energies, the potential role of spatial fluctuations in the leptonic component, and a possible larger-than-expected contamination due to unresolved sources, a solid confirmation requires further investigations. We discuss which measurements will be most relevant in order to resolve the remaining degeneracy.
|
|
|
|
Ikeno, N., Bayar, M., & Oset, E. (2023). Molecular states of D*D*Kbar* nature. Phys. Rev. D, 107(3), 034006–12pp.
Abstract: We study the interaction of two D* and a over bar K* by using the fixed center approximation to the Faddeev equations to search for bound states of the three-body system. Since the D*D* interaction is attractive and gives a bound state, and so is the case of the D* over bar K* interaction, where the JP = 0+ bound state is identified with the X0(2900), the D*D* over bar K* system leads to manifestly exotic bound states with ccs open quarks. We obtain bound states of isospin I = 1=2, negative parity and total spin J = 0, 1, 2. For J = 0 we obtain one state, and for J = 1, 2 we obtain two states in each case. The binding energies range from 56 to 152 MeV and the widths from 80 to 100 MeV.
|
|
|
|
Giare, W., Renzi, F., Mena, O., Di Valentino, E., & Melchiorri, A. (2023). Is the Harrison-Zel'dovich spectrum coming back? ACT preference for n(s) similar to 1 and its discordance with Planck. Mon. Not. Roy. Astron. Soc., 521(2), 2911–2918.
Abstract: The Data Release 4 of the Atacama Cosmology Telescope (ACT) shows an agreement with an Harrison-Zel'dovich primordial spectrum (n(s) = 1.009 +/- 0.015), introducing a tension with a significance of 99.3 per cent Confidence Level (CL) with the results from the Planck satellite. The discrepancy on the value of the scalar spectral index is neither alleviated with the addition of large scale structure information nor with the low multipole polarization data. We discuss possible avenues to alleviate the tension relying on either neglecting polarization measurements from ACT or in extending different sectors of the theory.
|
|
