FAMN Seminars

1 Oct 2021, 12:30 → 31 Jul 2023, 12:30 Europe/Madrid

Seminario 5ª Planta (Department of Atomic, Molecular and Nuclear Physics, Faculty of Physics, University of Seville)

Guillermo D Megias (University of Seville, Spain)

Seminars organized by the Department of Atomic, Molecular and Nuclear Physics (FAMN) at the Faculty of Physics, University of Seville.

Seminarios organizados por el Departamento de Física Atómica, Molecular y Nuclear (FAMN) de la Facultad de Física, Universidad de Sevilla.


Link to the videoconference session:

Videoconference session (Blackboard Collaborate)

Thursday 21 October

12:00 → 13:00 Impact of ground-state structure on $^{6}$Li + p reactions at sub-Coulomb energies

Abstract: The accuracy of several astrophysical models, as those describing elemental abundances in the Universe, is limited by the knowledge of cross-section for a wide number of nuclear reactions, often involving light reactants at low collision energies. An investigation on the $^{6}$Li + p $\to$ $^{3}$He + $\alpha$ reaction at energies around and below the Coulomb barrier (i.e. from 1-2 MeV down to few keV in the centre-of-mass) is here presented. It is found that the reaction dynamics can be very sensible to the details of the structure assigned to the reactants. Some recent efforts to adopt more microscopic and realistic descriptions are mentioned.

Seminar given by Salvatore Simone Perrotta, PhD fellow at University of Catania (Italy) and University of Seville (Spain).

Speaker: Mr Salvatore Simone Perrotta (Università degli Studi di Catania & Universidad de Sevilla)

Monday 22 November

12:30 → 13:30 Multi-channel experimental and theoretical study of heavy-ion direct nuclear reactions within the NUMEN project

In the last years, the search for neutrino-less double beta (0νββ) decay has attracted much interest due to the extraordinary consequences that could derive from its observation. The NUMEN project aims to provide experimental information on the nuclear matrix elements involved in the expression of 0νββ decay half-life by measuring the cross section of nuclear double charge exchange reactions. The strategies adopted in the experimental campaigns performed at INFN - Laboratori Nazionali del Sud, in Catania, will be described during the seminar. The advantages of the multi-channel approach to the NUMEN nuclear reaction data analysis will be emphasized focusing on one specific case: the $^{18}$O + $^{12}$C collision at 275 MeV incident energy. The status of the experimental and theoretical analysis for the $^{76}$Ge ↔ $^{76}$Se network of nuclear reactions will be also presented with a special attention to the elastic and inelastic scattering, single and double charge exchange reaction channels.

Seminar given by Alessandro Spatafora, PhD student at the University of Catania and INFN-LNS (Italy), and member of the NUMEN Collaboration.

Speaker: Mr Alessandro Spatafora (Università degli Studi di Catania and INFN-LNS)

Thursday 16 December

12:30 → 13:30 (Tratando de) desvelar los secretos del planeta Venus

Abstract: Si bien Venus y la Tierra son planetas gemelos en muchos aspectos, su evolución ha sido radicalmente diferente. A diferencia de la Tierra, Venus es un infierno tanto para la vida (tal y como la conocemos) como para la exploración espacial. Con una atmósfera 90 veces más densa que la Tierra, temperaturas superficiales por encima de los 450ºC, y una gruesa capa permanente de nubes de ácido sulfúrico, pocas sondas han logrado sobrevivir en su viaje hasta una superficie que no hemos explorado in situ por casi 40 años. Las recientes misiones Venus Express (ESA) y Akatsuki (JAXA) no sólo supusieron el retorno a Venus tras muchos años, sino una revolución en todo lo que creíamos saber sobre este planeta, abriendo tanto nuestro apetito por este planeta que 4 nuevas misiones van a lanzarse en los próximos 10 años.

Bio: Javier Peralta (Algeciras, 1979) es doctor en Física por la Universidad del País Vasco y trabaja como astrofísico especializado en atmósferas planetarias. Es miembro de las misiones espaciales Akatsuki (JAXA), Venus Express (ESA) y EnVision (ESA), y ha publicado 45 artículos en revistas científicas internacionales, siendo portada en dos ocasiones en Geophysical Research Letters. En la actualidad desarrolla en la Universidad de Sevilla un proyecto EMERGIA sobre la atmósfera de Venus como preparación a las misiones EnVision (ESA) y Shukrayaan-1 (ISRO, India).

Speaker: Dr Javier Peralta Calvillo (Universidad de Sevilla)

Thursday 17 February

12:30 → 13:30 Machine learning applied to the analysis of quantum phases in a quantum simulation of the Agassi model

Quantum simulations provide a fast-developing and powerful tool to realize the analysis of various physical systems of quantum nature and should be able to outperform classical computers and solve previously intractable problems. As such, many experimental setups are being proposed to validate the feasibility of the quantum simulation of different physical models. One prominent many-body quantum system is the Agassi model, which is a two-level system that includes a combination of long range monopole-monopole and short range pairing interactions. An extended Agassi model that adds a more general monopole interaction, presents a very rich quantum phase diagram that gives rise to several quantum phase transitions (QPT) of different character, making it of great interest in the field of QPTs. This study usually revolves around the computation of the system's ground state energy and can become difficult when several quantum phases are present in the system. In this talk, we will show how machine learning methods can help us extract the quantum phase of the system through easy to measure observables, without the need of computing the ground state energy of the system, and how these algorithms work.

Seminar given by Alvaro Sáiz Castillo, PhD student at the University of Seville.

Speaker: Mr Álvaro Sáiz Castillo (Universidad de Sevilla)

Tuesday 21 June

12:30 → 13:30 Collective motion in γ‐unstable nuclei within energy‐dependent Davidson potential and deformation dependent mass formalisms

In this work, we propose an exactly solvable model which is constructed by considering energy-dependent Davidson potential in the β part of the generalized version of the collective quadrupole Bohr Hamiltonian (BH) within deformation-dependent mass (DDM) formalism. Analytical expression of the energy spectra and corresponding wave functions are derived by means of the asymptotic iteration method. The combined effect of DDM and the energy dependence of the potential coupling constant is duly investigated. Also, the numerical calculations of the electric quadrupole transition ratios and energy spectrum of several nuclei undergoing a γ-unstable shape phase transition are performed and compared with experimental data as well as with other theoretical models. Besides, we investigate the correlation between both formalisms: energy-dependent potential and DDM, through solutions of BH for transition nuclei in the limit E(5) with Davidson potential.

Seminar given by Samira BAID (Cadi Ayyad University (Marrakech) and Universidad de Sevilla)

Speaker: Ms Samira BAID (Cadi Ayyad University (Marrakech) and Universidad de Sevilla)

Thursday 24 November

12:45 → 13:05 Phenomenology of Strong Interactions through Effective Models of Quantum Chromodynamics

Abstract: The discovery of the Higgs boson completed the Standard Model of elementary particle physics and its mechanism is an essential tool to explain the universe's evolution; for example, the mass origin of particles. However, the Higgs mechanism is insufficient to explain the mass of the nucleons. The explanation could be given by the Quantum Chromodynamics (QCD), the theory of the strong interactions between quarks mediated by gluons. QCD exhibits three relevant properties: color confinement, asymptotic freedom and chiral symmetry breaking. Confinement explains how quarks and gluons cannot be isolated and therefore cannot be directly observed. Instead, matter is formed by composed particles (by quarks and gluons), known as hadrons. We can explore the implications of dynamical mass generation (via the chiral symmetry breaking) through hadronic properties such as mass and structure using QCD effective models. Moreover, it is believed that under extreme conditions of density and temperature, chiral symmetry restoration occurs and therefore a modification in the properties of hadrons takes place. This will also be studied by employing the same framework slightly modified like the extended Nambu--Jona-Lasinio Model (eNJL).

Bio: Bilgai Almeida Zamora finished her B.Sc. in Physics at the University of Sonora, Mexico, in 2018. Just after that, she went to CINVESTAV, Mexico, in order to complete her postgraduate studies in Nuclear and Particle Physics which were finished in 2020; her Master thesis was entitled "Properties of pseudoscalar mesons at finite density within the extended Nambu—Jona-Lasinio model via 't Hooft determinant". Bilgai is actually a Ph.D. student, financially supported by CONACYT, at the University of Sonora under the supervision of Dr. Jesús Javier Cobos Martínez, her doctoral thesis is also co-supervised by Dr. Jorge Segovia from the University Pablo de Olavide, in Seville.

Speaker: Ms Bilgai Almeida Zamora (University of Sonora (Mexico) and University Pablo de Olavide (Spain))

Thursday 12 January

12:30 → 13:30 Microscopic description of correlated electronic systems with variational symmetry-projected approximations

Abstract: Symmetry-projected approximations, inherited from nuclear structure theory, are used to describe ground and excited states, with well-defined quantum numbers, of the two-dimensional Hubbard model with nearest-neighbor hopping and periodic boundary conditions. Results for the half-filled 2 × 4, 4 × 4, and 6 × 6 lattices as well as doped 4 × 4 systems are compared with available results, both exact and from other state-of-the-art approximations. The method allows to access dynamical properties of the Hubbard model such as spectral functions and density of states. The stability of the Hubbard gap is discussed in several examples. It is shown that, given their relatively low computational cost and the high quality of the results obtained, symmetry-projected configuration mixing strategies represent powerful tools to study correlated fermionic systems.

Bio: El Dr. Rayner R. Rodriguez Guzmán tiene 20 años de experiencia en el desarrollo de modelos teóricos e implementaciones computacionales, para describir sistemas correlacionados de muchos cuerpos en campos de investigación tales como Física de la Estructura Nuclear, Física de la Materia Condensada y Química Cuántica. Es autor de 91 artículosde investigación incluidos en la base de datos Web of Science (índice h= 32, 2578 citas) entre los que destacan publicaciones en Physical Review Letters, Physical Review A, Physical Review B, Physical Review C, Journal of Physics G, Journal of Chemical Physics, Journal of Physical Chemistry, Molecular Physics. Ha participado como investigador en proyectos nacionales e internacionales financiados por la Academia de Ciencias de Finlandia, el Departamento de Energía de los Estados Unidos, la Comisión de Energía Atómica de Francia, la Sociedad para el Avance de la Ciencia de Kuwait, el Consejo Superior de Investigaciones Científicas (CSIC), etc. Obtuvo su doctorado por la Universidad Autónoma de Madrid en 2001, y posteriormente ha realizado su labor de investigación en centros tales como el Instituto de Física Teórica de la Universidad de Tuebingen (Alemania), la Universidad de Yale (Estados Unidos), el Consejo Superior de Investigaciones Científicas (CSIC-Madrid), la Universidad de Yyvaskyla (Finlandia), el Comisariado de la Energía Atómica (Francia), la Universidad de Rice (Estados Unidos), la Universidad de Surrey (Reino Unido) y la Universidad de Kuwait. Actualmente, es investigador dentro del programa María Zambrano en la Universidad de Sevilla.

Speaker: Dr Rayner Roberto Rodríguez Guzmán (Departamento de Física Aplicada I, EPS, Universidad de Sevilla)

Monday 31 July

10:30 → 11:30 Seminar on Neutrino oscillation analyses at long-baseline facilities (TBD)

Seminar given by Dr. Stephen J. Dolan, Senior Research Fellow (EP) at CERN (Geneva, Switzerland) and member of the T2K, DUNE, HyperKamiokande and ICARUS experiments. Date to be determined.

Speaker: Dr Stephen J. Dolan (CERN (Geneva, Switzerland))

10:30 → 11:30 Seminar on Neutrino-nucleus cross sections at the T2K experiment (TBD)

Seminar given by Dr. Ciro Riccio, Research Associate at the Stony Brook University (SUNY, USA) and member of the T2K, HyperKamiokande and DUNE experiments. Date to be determined.

Speaker: Dr Ciro Riccio (Department of Physics and Astronomy • Stony Brook University, SUNY, USA)

10:30 → 11:30 Seminar on the MeV-scale physics program (supernova & solar neutrinos) of the DUNE experiment (TBD)

Seminar given by Dr. Steven Gardiner, Research Associate at Fermi National Accelerator Laboratory (FermiLab, USA) and member of the MicroBooNE and DUNE experiments. Date to be determined.

Speaker: Dr Steven Gardiner (Fermi National Accelerator Laboratory, FermiLab, USA)