CFT - Artículos
http://hdl.handle.net/10486/129147
2020-07-03T21:42:51ZTestable axion-like particles in the minimal linear σ model
http://hdl.handle.net/10486/691442
Testable axion-like particles in the minimal linear σ model
Alonso-González, J.; Merlo, L.; Pobbe, F.; Rigolin, S.; Sumensari, O.
Axion and axion-like particle models are typically affected by a strong fine-tuning problem in conceiving the electroweak and the Peccei-Quinn breaking scales. Within the context of the Minimal Linear σ Model, axion-like particle constructions are identified where this hierarchy problem is solved, accounting for a TeV Peccei-Quinn breaking scale and a pseudoscalar particle with a mass larger than 10 MeV. Potential signatures at colliders and B-factories are discussed
2020-01-01T00:00:00ZThe modified D1M interactions: New gogny forces adapted for neutron star calculations
http://hdl.handle.net/10486/691423
The modified D1M interactions: New gogny forces adapted for neutron star calculations
Viñas, X.; Gonzalez-Boquera, C.; Centelles, M.; Mondal, C.; Robledo, L. M.
The symmetry energy of the D1 family of Gogny interactions, which describe finite nuclei properties in good agreement with experimental data, shows too soft a behaviour above saturation density. As a consequence, the D1 family of Gogny forces often cannot describe the properties of neutron stars when extrapolated to the high-density region. To overcome this limitation, we have proposed reparametrizations of the D1M interaction with very minimal changes. The modified interactions retain the quality of the original force for dealing with finite nuclei and, at the same time, are able to describe the neutron star physics with a quality similar to the one provided by the Skyrme SLy4 force, which was specially designed for this purpose
2019-01-01T00:00:00ZInstantons and infinite distances
http://hdl.handle.net/10486/691363
Instantons and infinite distances
Marchesano, Fernando; Wiesner, Max
We consider geodesics of infinite length and with constant 4d dilaton in the (classical) hypermultiplet moduli space of type II Calabi-Yau compactifications. When approaching such infinite distance points, a large amount of D-instantons develop an exponentially suppressed action, substantially modifying the moduli space metric. We consider a particular large volume/strong coupling trajectory for which, in the corrected metric, the path length becomes finite. The instanton effects also modify the cllassical 4d dilaton such that, in order to keep the 4d Planck mass finite, the string scale has to be lowered. Our results can be related, via the c-map, to the physics around points of infinite distance in the vector multiplet moduli space where the Swampland Distance Conjecture and the Emergence Proposal have been discussed, and provide further evidence for them
2019-08-01T00:00:00ZOff-shell unimodular N = 1, d = 4 supergravity
http://hdl.handle.net/10486/691361
Off-shell unimodular N = 1, d = 4 supergravity
Anero, Jesus; Martin, Carmelo P.; Santos-Garcia, Raquel
We formulate a unimodular N = 1, d = 4 supergravity theory off shell. We see that the infinitesimal Grassmann parameters defining the unimodular supergravity trans- formations are constrained and show that the conmutator of two infinitesinal unimodular supergravity transformations closes on transverse diffeomorphisms, Lorentz transforma- tions and unimodular supergravity transformations. Along the way, we also show that the linearized theory is a supersymmetric theory of gravitons and gravitinos. We see that de Sitter and anti-de Sitter spacetimes are non-supersymmetric vacua of our unimodular supergravity theory
2020-01-01T00:00:00Z