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Upcoming Seminars

23. 04. 2019 at 14:00
S2 11/10

SFB Colloquium

Evan O'Connor (Stockholm University)
Core-Collapse Supernovae from 1D to 3D

Core-Collapse supernovae are triggered by the implosion and subsequent explosion of the iron core in an evolved massive star. Since the core is shrouded from us by the overlying layers of the star, numerical simulations (and the odd neutrino detection of a Galactic supernova) are our best look into this extreme engine that powers one of the most energetic events in the Universe. Nature is 3D, and it is critical to simulate core-collapse supernovae in three dimensions because of the important hydrodynamic instabilities that can be present, however they are computationally expensive. With 1D and 2D models, we are now able to perform parameterized and systematic studies across a range of stars. Furthermore, in spherical symmetry we are able to achieve excellent agreement between otherwise completely independent codes. In this talk I will present a global comparison in 1D between six core collapse codes, an exploration of parameterized 1D explosions with over 1000 simulations and the beginnings of a systematic study of core collapse in 2D and simulations where we explore fundamentally 3D phenomena. I'll also present new results on the equation of state dependence of black hole formation.

02. 05. 2019 at 14:00
S2 11/10

Theorie-Seminar

Laura Moschini (Johannes Gutenberg-Universitaet Mainz)
Solving the apparent inconsistency between GSI and RIKEN estimates of 11Be dB(E1)/dE

The breakup of 11Be, the archetypal one-neutron halo nucleus, is a particularly interesting case because, due to its short lifetime, it is one of the only ways to infer information about its structure. In that reaction, the halo neutron dissociates from the core during the collision with a target. When performed on a heavy target, like lead, the reaction is dominated by the E1 transition from the ground state. This transition is characterized by the dB(E1)/dE. This strength has been inferred from two experiments, one performed at 520AMeV at GSI [1] and the other at about 70AMeV at RIKEN [2]. Strangely the analyses of both experiments provide different E1 strengths. In this work we reanalyze them using the eikonal approximation to elucidate this discrepancy. To analyze the RIKEN data we adopt the dynamical eikonal approximation (DEA), which works well at intermediate energies; while for the GSI experiment we have developed a model for the high-energy collision properly taking into account relativistic effects, on both kinematics and dynamical aspects [3,4]. Our eikonal model includes a consistent treatment of both nuclear and Coulomb interactions at all orders. The description of the 11Be structure is provided by Halo-EFT [5,6] fitting the low- energy constants of this description onto structure observables, like the ANC of the bound states and phaseshifts in the continuum, predicted by an ab initio calculation [7]. Our cross sections for the 11Be breakup are in excellent agreement with both RIKEN and GSI data [6,8]. The dB(E1)/dE extracted from our structure model is in agreement with the RIKEN result, as well as the ab initio prediction [7]. We can conclude that the discrepancy between GSI and RIKEN E1 strengths arises from the method applied to extract this quantity from the experimental data. This new way of analyzing nuclear reactions performed to study the structure of nuclei away from stability has been extended to the case of 15C, another one-neutron halo nucleus, whose breakup has been measured at GSI and RIKEN at 605 and 68AMeV respectively [9,10]. In both cases, our reaction models have led to excellent agreement with the data [11].
[1] R. Palit et al., Phys. Rev. C 68, 054606 (2003)
[2] N. Fukuda et al., Phys. Rev. C 70, 054606 (2004)
[3] G. Satchler, Nucl. Phys. A 540, 533 (1992)
[4] A. Winther and K. Alder, Nucl. Phys. A 319, 518 (1979)
[5] H.-W. Hammer, C. Ji, D. R. Phillips, J. Phys. G 44, 103002 (2017) [6] P. Capel, D. Phillips and H. Hammer, Phys. Rev. C 98, 034610 (2018) [7] A. Calci et al., Phys. Rev. Lett. 117, 242501 (2016)
[8] L. Moschini and P. Capel, Phys. Lett. B 790, 367-371 (2019)
[9] U. Datta Pramanik et al., Phys. Lett. B 551, 63-70 (2003)
[10] T. Nakamura et al., Phys. Rev. C 79, 035805 (2009)
[11] L. Moschini, J. Yang and P. Capel, in preparation

09. 05. 2019 at 14:00
S2 11/10

Theorie-Seminar

Johannes Weber (MSU)
TBA

TBA

23. 05. 2019 at 14:00
S2 11/10

SFB Colloquium

Ann-Cecilie Larsen (University of Oslo)
TBA

TBA

06. 06. 2019 at 14:00
S2 11/10

Theorie-Seminar

Johann Haidenbauer (Juelich)
TBA

TBA

13. 06. 2019 at 14:00
S2 11/10

Theorie-Seminar

Claudia Travaglio (INAF-Astrophysical Observatory Turin)
TBA

TBA

27. 06. 2019 at 14:00
S2 11/10

SFB Colloquium

Atsushi Tamii (Osaka University)
TBA

TBA

04. 07. 2019 at 14:00
S2 11/10

Theorie-Seminar

Dominik Schwarz (Univ. Bielefeld)
TBA

TBA

Address

Technische Universität Darmstadt

Institut für Kernphysik
Theoriezentrum

S2|11
Schlossgartenstraße 2
64289 Darmstadt

Secretary

Genette Kluckner

+49 6151 16 21551
+49 6151 16 21555

Stephanie Müller

+49 6151 16 21558
+49 6151 16 21555

Next Seminar

SFB Colloquium

on 23. 04. 2019 at 14:00
(S2 11/10)
Evan O'Connor
Core-Collapse Supernovae from 1D to 3D
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