Departamento de Física Teórica
http://hdl.handle.net/10486/129146
2019-07-15T20:07:53ZVariation of α from a dark matter force
http://hdl.handle.net/10486/687672
Variation of α from a dark matter force
Davoudiasl, Hooman; Giardino, Pier Paolo
We consider a long range scalar force that mainly couples to dark matter and unstable Standard Model states, like the muon, with tiny strength. Probing this type of force would present a challenge to observations. We point out that the dependence of the induced background scalar field on dark matter number density can cause the mass of the unstable particles to have spatial and temporal variations. These variations, in turn, leave an imprint on the value of the fine structure constant α through threshold corrections, that could be detected in astronomical and cosmological measurements. Our mechanism can accommodate the mild preference of the Planck data for such a deviation, (αCMB−αpresent)/αpresent=(−3.6±3.7)×10−3. In this case, the requisite parameters typically imply that violations of Equivalence Principle may be within reach of future experiments
2019-01-10T00:00:00ZIsomer spectroscopy in odd–even Ti isotopes: Approaching n = 40
http://hdl.handle.net/10486/687668
Isomer spectroscopy in odd–even Ti isotopes: Approaching n = 40
Recchia, F.; Wimmer, K.; Lenzi, S. M.; Riccetto, S.; Davinson, T.; Estrade, A.; Griffin, C.; Nishimura, S.; Nowacki, Frédéric; Phong, V.; Poves, Alfredo; Söderström, P. A.; Aktas, O.; Alaqueel, M.; Ando, T.; Baba, H.; Bae, S.; Choi, S.; Doornenbal, P.; Ha, J.; Harkness-Brennan, L.; Isobe, T.; John, P. R.; Kahl, D.; Kiss, G.; Labiche, M.; Matsui, K.; Momiyama, S.; Napoli, D. R.; Niikura, M.; Nita, C.; Saito, Y.; Sakurai, H.; Schrock, P.; Stahl, C.; Sumikama, T.; Werner, V.; Witt, W.
All Rights Reserved. Our understanding of the evolution of the shell structure in nuclei far from stability is based on the study of some key nuclei. Nuclei at or next to double shell closures play a special role in this. Presently, a lot of discussion is concentrated on the neutron-rich calcium isotopes, which provide a rich testing ground for various nuclear models with several traditional and new magic numbers. 60 Ca is now almost within reach with the most advanced radioactive beam facilities. In order to investigate the evolution of the shell gap at N = 40, the configuration of states in the odd–even titanium isotopes up to N = 37 ( 59 Ti) have been studied. In order to experimentally access the shell gap at N = 40, it is nowadays within the reach of the most advanced facility the investigation of neutron hole configuration states in odd–even titanium isotopes up to N = 37, in the 59 Ti nucleus. Such states correspond to relatively simple configurations that constitute a challenging testing ground for effective nuclear interactions. The new data obtained in our experiment allows to place the present predictions concerning the shell closure at N = 40 in the calcium region on a more solid ground
2019-03-01T00:00:00ZMeasurement of inclusive double-differential νμ charged-current cross section with improved acceptance in the T2K off-axis near detector
http://hdl.handle.net/10486/687580
Measurement of inclusive double-differential νμ charged-current cross section with improved acceptance in the T2K off-axis near detector
Abe, K.; T2K Collaboration; Labarga, Luis
Published by the American Physical Society. We report a measurement of the flux-integrated cross section for inclusive muon neutrino charged-current interactions on carbon. The double-differential measurements are given as a function of the muon momentum and angle. Relative to our previous publication on this topic, these results have an increased angular acceptance and higher statistics. The data sample presented here corresponds to 5.7×1020 protons on target. The total flux-integrated cross section is measured to be (6.950±0.662)×10-39 cm2 nucleon-1 and is consistent with our simulation
Artículo realizado en colaboración por numerosos autores. Solo mencionados el primero, el grupo de colaboración y el autor perteneciente a la UAM
2018-07-30T00:00:00ZNon-abelian lattice gauge theory with a topological action
http://hdl.handle.net/10486/687575
Non-abelian lattice gauge theory with a topological action
Nogradi, Daniel; Szikszai, Lorinc; Varga, Zoltan
SU(2) gauge theory is investigated with a lattice action which is insensitive to small perturbations of the lattice gauge fields. Bare perturbation theory can not be defined for such actions at all. We compare non-perturbative continuum results with that obtained by the usual Wilson plaquette action. The compared observables span a wide range of interesting phenomena: zero temperature large volume behavior (topological susceptibility), finite temperature phase transition (critical exponents and critical temperature) and also the small volume regime (discrete β-function or step-scaling function). In the continuum limit perfect agreement is found indicating that universality holds for these topological lattice actions as well.
2018-08-08T00:00:00Z