Olmo, G. J. (2011). Palatini approach to modified gravity: f(R) theories and beyond. Int. J. Mod. Phys. D, 20(4), 413–462.
Abstract: We review the recent literature on modified theories of gravity in the Palatini approach. After discussing the motivations that lead to consider alternatives to Einstein's theory and to treat the metric and the connection as independent objects, we review several topics that have been recently studied within this framework. In particular, we provide an in-depth analysis of the cosmic speed-up problem, laboratory and solar system tests, the structure of stellar objects, the Cauchy problem, and bouncing cosmologies. We also discuss the importance of going beyond the f(R) models to capture other phenomenological aspects related with dark matter/energy and quantum gravity.
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Oset, E., Albaladejo, M., Xie, J. J., & Ramos, A. (2014). Recent developments on hadron interaction and dynamically generated resonances. Int. J. Mod. Phys. E, 23(7), 1461008–8pp.
Abstract: In this talk I report on the recent developments in the subject of dynamically generated resonances. In particular I discuss the gamma p -> K-0 Sigma+ and gamma n -> K-0 Sigma(0) reactions, with a peculiar behavior around the K*(0)Lambda threshold, due to a 1/2(-) resonance around 2035 MeV. Similarly, I discuss a BES experiment, J/psi -> eta K*(0) (K) over bar*(0) decay, which provides evidence for a new h(1) resonance around 1830 MeV that was predicted from the vector-vector interaction. A short discussion is then made about recent advances in the charm and beauty sectors.
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Hidalgo-Duque, C., & Llanes-Estrada, F. J. (2015). Soft interactions in jet quenching. Int. J. Mod. Phys. A, 30(13), 1550067–25pp.
Abstract: We study the collisional aspects of jet quenching in a high-energy nuclear collision, especially in the final state pion gas. The jet has a large energy, and acquires momentum transverse to its axis more effectively by multiple soft collisions than by few hard scatterings (as known from analogous systems such as J/psi production at Hera). Such regime of large E and small momentum transfer corresponds to Regge kinematics and is characteristically dominated by the pomeron. From this insight we estimate the jet quenching parameter in the hadron medium (largely a pion gas) at the end of the collision, which is naturally small and increases with temperature in line with the gas density and compare it to the jet quenching parameter obtained within the quark-gluon plasma (QGP) phase in widely known perturbative approximations. The physics in the quark-gluon plasma/liquid phase is less obvious, and here we revisit a couple of simple estimates that suggest indeed that the pomeron-mediated interactions are very relevant and should be included in analysis of the jet quenching parameter. Finally, since the occasional hard collisions produce features characteristic of a Levy flight in the q(perpendicular to)(2) plane perpendicular to the jet axis, we suggest one- and two-particle q perpendicular to correlations as interesting experimental probes sensitive to the nature (softness versus hardness) of the interactions of a jet inside the QGP.
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Bordes, J., Chan, H. M., & Tsou, S. T. (2021). delta(CP) for leptons and a new take on CP physics with the FSM. Int. J. Mod. Phys. A, 36, 2150236–22pp.
Abstract: A bonus of the framed Standard Model (FSM), constructed initially to explain the mass and mixing patterns of quarks and leptons, is a solution (without axions) of the strong CP problem by cancelling the theta-angle term theta(I) Tr(H-mu v H-mu v*) in coloura by a chiral transformation on a quark zero mode which is inherent in FSM, and produces thereby a CP-violating phase in the CKM matrix similar in size to what is observed.' Extending here to flavour, one finds that there are two terms proportional to Tr(G(mu v) G(mu v)*): (a) in the action from flavour instantons with unknown coefficient, say theta(I)', (b) induced by the above FSM solution to the strong CP-problem with therefore known coefficient theta(C)'. Both terms can be cancelled in the FSM by a chiral transformation on the lepton zero mode to give a Jarlskog invariant J' in the PMNS matrix for leptons of order 10(-2), as is hinted by the experiment. But if, as suggested in Ref. 2, the term theta(I)' is to be cancelled by a chiral transformation in the predicted hidden sector to solve the strong CP problem therein, leaving only the term theta(C)' to be cancelled by the chiral transformation on leptons, then the following prediction results: J' similar to -0.012 (delta(CP)'similar to (1.11)pi) which is (i) of the right order, (ii) of the right sign and (iii) in the range favoured by the present experiment. Together with the earlier result for quarks, this offers an attractive unified treatment of all known CP physics.
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Bordes, J., Chan, H. M., & Tsou, S. T. (2021). Unified FSM treatment of CP physics extended to hidden sector giving (i) delta(CP) for leptons as prediction, (ii) new hints on the material content of the universe. Int. J. Mod. Phys. A, 36, 2150238–19pp.
Abstract: A unified treatment of CP physics for quarks and leptons in the framed Standard Model (FSM) is extended to include the predicted hidden sector giving as consequences: (i) that an earlier part estimate of the Jarlskog invariant J' for leptons is turned into a prediction for its actual value, i.e. J' similar to -0.012 (delta(CP)' similar to 1.11 pi), which is of the right order of magnitude, of the right sign, and in the range of values favoured by the present experiment, (ii) some novel twists to the effects of CP-violation on the material content of the universe.
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