Nuclear Physics Seminar

semester, 2018


Friday, January 19th 2018
10:10 am:
Nuclear Physics Seminar in Tate 201-20
To be announced.

Tuesday, January 23rd 2018
2:30 pm:
Speaker: Chun Shen, Brookhaven National Laboratory
Subject: Going with the flow— the nuclear phase diagram at the highest temperatures and densities

Nuclear matter has a complex phase structure, with a deconfined Quark-Gluon Plasma (QGP) expected to be present under conditions of extreme pressure and temperature. The hot QGP filled the universe about few microseconds after the Big Bang. This hot nuclear matter can be generated in the laboratory via the collision of heavy atomic nuclei at high energy. I will review recent theoretical progress in studying the transport properties the QGP at almost zero baryon density. The recent beam energy scan experiments at the Relativistic Heavy-Ion Collider (RHIC) offer a unique opportunity to study the nuclear phase diagram in a hot and baryon-rich environment. I will focus on the development of a comprehensive framework that is able to connect the fundamental theory of strong interactions with the RHIC experimental observations. This dynamical framework paves the way for quantitative characterization of the QGP and for locating the critical point in the nuclear phase diagram. These studies will advance our understanding of strongly interacting many-body systems and build interconnections with other areas of physics, including string theory, cosmology, and cold atomic gases.


Friday, January 26th 2018
10:10 am:
Nuclear Physics Seminar in Tate 201-20
There will be a special nuclear physics seminar on Tuesday this week.

Friday, February 2nd 2018
10:10 am:
Nuclear Physics Seminar in Tate 201-20
There will be no seminar this week.

Tuesday, February 6th 2018
2:30 pm:
Speaker: David Radice, Princeton University
Subject:  Multimessenger astrophysics with numerical relativity
Candidate for the Nucear Theory Assistant Professor position

How are neutron stars formed and what is inside them? What is the
engine powering short gamma-ray bursts? What is the astrophysical site
of production of heavy elements? Multimessenger observations of
compact binary coalescence and core-collapse supernovae might provide
us with the key to answer these and other important open questions in
theoretical astrophysics. However, multimessenger astronomy also poses
new challenges to the theorists who need to develop models for the
joint interpretation of all data channels. In this talk, I will
present recent theoretical results. I will review the landmark
multimessenger observation of merging neutron stars, and I will
discuss its interpretation and implication in the light of results
from first-principles simulations. Finally, I will discuss future
challenges and prospective for this nascent field.


Friday, February 9th 2018
10:10 am:
Nuclear Physics Seminar in Tate 201-20
There will be a special nuclear physics seminar on Tuesday this week.

Friday, February 16th 2018
10:10 am:
Nuclear Physics Seminar in Tate 201-20
There will be no seminar this week.

Tuesday, February 20th 2018
2:30 pm:
Speaker:  Jorge Noronha, Universidade de Sao Paulo
Subject: Unveiling the secrets of nature's primordial liquid
Candidate for the Nucear Theory Assistant Professor position

Microseconds after the Big Bang, the Universe cooled into an exotic phase of matter. There the fundamental building blocks of Quantum Chromodynamics (QCD), known as quarks and gluons, were not confined inside the core of atomic nuclei. Tiny specks of this early Universe matter, called the Quark-Gluon Plasma (QGP), are now being copiously produced in heavy ion collisions at both RHIC and the LHC. These experiments provide overwhelming evidence that the QGP flows like a nearly frictionless strongly coupled liquid over distance scales not much larger than the size of a proton. Thus, the QGP formed in particle colliders is the hottest, smallest, densest, most perfect liquid known to humanity. Yet, the theoretical underpinnings behind the liquid-like behavior of QCD matter remain elusive.

In this talk I will present first principles calculations performed within string theory and relativistic kinetic theory that have shed new light on the emergence of hydrodynamic behavior in QCD and challenged the very foundations of fluid dynamics. New techniques to determine the real time, far-from-equilibrium dynamics of QCD in the large baryon density regime will also be discussed to lead current experimental efforts to discover critical phenomena in the fundamental theory of strong interactions.


Friday, February 23rd 2018
10:10 am:
Nuclear Physics Seminar in Tate 201-20
There will be no seminar this week.

Friday, March 2nd 2018
10:10 am:
Nuclear Physics Seminar in Tate 201-20
There will be no seminar this week.

Tuesday, March 6th 2018
2:30 pm:
Speaker: Jennifer Barnes, Columbia University
Subject: Nuclear Physics with Multi-Messenger Astronomy
Candidate for the Nucear Theory Assistant Professor position

The first detection in August 2017 of a binary neutron star merger in gravitational and electromagnetic waves marked the beginning of the era of multi-messenger astronomy. Future detections of neutron star-neutron star (NSNS) and neutron star-black hole (NSBH) mergers will allow astrophysicists to understand these systems in unprecedented detail, and test key theories about these exotic events. Two questions are especially interesting from a nuclear physics standpoint. First, what is the structure of ultra-dense neutron stars? Second, what is mergers' role in seeding the Universe with heavy elements synthesized via rapid neutron capture (the r-process)?
I will discuss how observations of mergers can help us answer these questions.
I will focus particularly on the radioactive transients that accompany mergers (the so-called "kilonovae"), and explain how recent theoretical advances allow us to use kilonova observations to constrain open questions in nuclear astrophysics.


Friday, March 9th 2018
10:10 am:
Nuclear Physics Seminar in Tate 201-20
There will be a special nuclear physics seminar on Tuesday this week.

Wednesday, March 21st 2018
2:30 pm:
Speaker: Aleksey Cherman, University of Washington
Subject: Symmetries, order parameters, and the phase diagram of nuclear matter
Candidate for the Nucear Theory Assistant Professor position

The phases of matter at extreme temperatures and densities are essentially determined by strong nuclear interactions. But for most temperatures and densities, we lack the theoretical tools to efficiently study QCD, the quantum field theory describing the strong nuclear force. For instance, in much of the phase diagram of QCD, there are very few well-defined order parameters to label its phases. I will describe recent advances in understanding the symmetries and order parameters of QCD, with a focus on the implications for understanding the phase diagram of nuclear matter as a function of temperature and density.


Friday, March 23rd 2018
10:10 am:
Nuclear Physics Seminar in Tate 201-20
There will be a special nuclear physics seminar on Wednesday this week.

Friday, March 30th 2018
10:10 am:
Nuclear Physics Seminar in Tate 201-20
There will be no seminar this week.

Friday, April 6th 2018
10:10 am:
Nuclear Physics Seminar in Tate 201-20
There will be no seminar this week.

Friday, April 13th 2018
10:10 am:
Nuclear Physics Seminar in Tate 201-20
There will be no seminar this week.

Friday, April 20th 2018
10:10 am:
Nuclear Physics Seminar in Tate 201-20
There will be no seminar this week.

Friday, April 27th 2018
10:10 am:
Nuclear Physics Seminar in Tate 201-20
To be announced.

Friday, May 4th 2018
10:10 am:
Nuclear Physics Seminar in Tate 201-20
There will be no seminar this week.

Friday, May 11th 2018
10:10 am:
Nuclear Physics Seminar in Tate 201-20
There will be no seminar this week.

Tuesday, September 11th 2018
11:15 am:
Nuclear Physics Seminar in Tate 301-20
Subject: Organizational Meeting
Note the change of time, day and room from the previous calendar announcement. This is the time slot for the seminar for the rest of the semester.

Tuesday, September 18th 2018
11:15 am:
Nuclear Physics Seminar in Tate 301-20
There will be no seminar this week.

Tuesday, September 25th 2018
11:15 am:
Nuclear Physics Seminar in Tate 301-20
Speaker: Rafid Mahbub, University of Minnesota
Subject: Primordial Black Hole formation in Inflation models

Primordial black holes form in the early universe when over-dense regions gravitationally collapse upon horizon reentry. While there are many proposed formation mechanisms, inflation is an attractive candidate due to curvature perturbations that are generated. Inflation models that exhibit an inflection point in their potentials are seen to give rise to enhancements in the power spectrum during horizon exit, which can produce PBHs, that are long-lived, at sufficient abundances- while also satisfying observational constraints. Lastly, if not all, a fraction of current dark matter content may be comprised of PBHs.


Tuesday, October 2nd 2018
11:15 am:
Nuclear Physics Seminar in Tate 301-20
Speaker: Aleksey Cherman, University of Minnesota
Subject: Patricle vortex systems and the nature of cold quark matter.

It is believed that cold dense quark matter is a "color-superconducting" state of matter. What does that mean? Is this sharply different from a standard "confirmed" nuclear superfluid? I'll give a basic overview of recent progress on these formal questions, with a warm up discussion of standard electromagnetic aupercondtivity the answers to the above questions have interesting physical consequences for the quantization of angular momentum of quasiparticle excitations in dense quark matter.


Tuesday, October 9th 2018
11:15 am:
Nuclear Physics Seminar in Tate 301-20
Speaker: Andre Sieverding, University of Minnesota
Subject: Neutrinos in core-collapse supernova nucleosynthesis

Supernova explosions of massive stars provide an important
contribution to the chemical enrichment of the galaxy and neutrinos
and their interactions with nuclei play a crucial role in that
environment. I will give an overview of the role of neutrinos for
supernova explosions and present recent progress in nucleosynthesis
calculations for the neutrino process, that combine state-of-the art
nuclear models and astrophysical modelling.


Tuesday, October 16th 2018
11:15 am:
Nuclear Physics Seminar in Tate 301-20
Speaker: Aleksey Cherman, University of Minnesota
Subject: Effective actions for topologically-enriched superfluids

Cold dense quark matter is a superfluid, but not quite the
familiar one we learned about in textbooks. Instead, it is a
"topologically-enriched" superfluid. I'll explain how to derive a
local effective action for this gapless phase of matter, which
involves coupling the superfluid to a topological quantum field theory
(TQFT). Along the way we'll talk about continuum "BF" actions for
four-dimensional discrete gauge theories, as well certain peculiar
five-dimensional cousins of these TQFTs relevant for our superfluids.
This talk is a more technical follow-up to a talk from two weeks ago,
but will be aimed to be followable by people who didn't attend the
first talk.


Tuesday, October 23rd 2018
11:15 am:
Nuclear Physics Seminar in Tate 301-20
Speaker: Ermal Rrapaj, University of Minnesota & University of California, Berkeley
Subject: Supernovae and neutron stars: Constraining dark matter through nuclear interactions

Tuesday, October 30th 2018
11:15 am:
Nuclear Physics Seminar in Tate 301-20
To be announced

Tuesday, November 6th 2018
11:15 am:
Nuclear Physics Seminar in Tate 301-20
There will be no seminar this week.

Tuesday, November 13th 2018
11:15 am:
Nuclear Physics Seminar in Tate 301-20
There will be no seminar this week.

Tuesday, November 20th 2018
11:15 am:
Nuclear Physics Seminar in Physics 301-20 Tate
Speaker: Mauricio Martinez Guerrero, North Caroline State University
Subject: Hydrodynamic Fluctuations and Lower Bounds of the Transport Coefficients

In this talk I will discuss the effects of hydrodynamic
fluctuations in non-relativistic and relativistic setups. Within the
framework of stochastic hydrodynamics I obtain a number of model
independent results, including the long-time tail of different
transport coefficients, and the leading non-analyticity of the
correlators of energy, momentum and particle density in
non-relativistic and relativistic setups. The presence of hydrodynamic
fluctuations induce lower bounds on the transport coefficients by
analyzing the low frequency limit of different correlation functions.
I determine the lower bounds of the bulk viscosity over entropy ratio
in a cold Fermi gas near unitarity. When extending this analysis to
the case of a U(1) conformal relativistic expanding fluid we observe
that the values of the shear viscosity and heat conductivity are
bounded from below. In both setups, non-relativistic and relativistic
one, the lower bounds on the transport coefficients are weakly
dependent on assumptions regarding the range of applicability of fluid
dynamics.


Tuesday, November 27th 2018
11:15 am:
Nulear Physics Seminar in Physics 301-20 Tate
Speaker: Fabian Rennecke, Brookhaven National Laboratory
Subject: Strangeness Neutrality and the Phase Structure of QCD

Since the incident nuclei in heavy-ion collisions do not
carry strangeness, the global net strangeness of the detected hadrons
has to vanish. We show that there is an intimate relation between
strangeness neutrality and baryon-strangeness correlations. In the
context of heavy-ion collisions, the former is a consequence of quark
number conservation of the strong interactions while the latter are
sensitive probes of the character of QCD matter. We investigate the
sensitivity of baryon-strangeness correlations on the freeze-out
conditions of heavy-ion collisions by studying their dependence on
temperature, baryon- and strangeness chemical potential. The impact of
strangeness neutrality on the QCD equation of state at finite chemical
potentials will also be discussed. We model the low-energy sector of
QCD by an effective Polyakov loop enhanced quark-meson model with 2+1
dynamical quark flavors and use the functional renormalization group
to account for the non-perturbative quantum fluctuations of hadrons.


Tuesday, December 4th 2018
11:15 am:
Nuclear Physics Seminar in Tate 301-20
Speaker: Jackson Olsen, University of Minnesota
Subject: Detecting Neutrinos from Supernovae

During a supernova vast numbers of neutrinos are released.
The energy of this neutrino emission dwarfs that of the light from the
explosion, yet the neutrinos are much more difficult to detect. I will
provide an overview of supernova neutrino detection techniques, and
discuss some of the information that might be learned from such a
detection.


Tuesday, December 11th 2018
11:15 am:
Nuclear Physics Seminar in Tate 301-20
There will be no seminar this week.

Tuesday, December 18th 2018
11:15 am:
Nuclear Physics Seminar in Tate 301-20
There will be no seminar this week.

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