Seminars

Thursday, Aug 24 at 3:30 PM
1300 Auditorium (FRIB Tower 3)
Qingzi Xing, Tsinghua University, China
Progress with Research on H+/H- Accelerators at Tsinghua University
Thursday, Aug 24 at 4:00 PM
1309 Seminar Room
Raghav Elayavalli, Rutgers University
Jetting through the Primordial Universe

Abstract:  The presence of the Quark Gluon Plasma (QGP) in ultra relativistic heavy ion collisions was first verified at the Relativistic Heavy Ion Collider at BNL almost fifteen years ago. Since then, heavy ion collisions at the LHC, CERN at 2.76 and 5.02 TeV center of mass energies have greatly enhanced our knowledge of this very high temperature plasma of strongly interacting and unbound quarks and gluons. An early signature of the QGP, both theorized and seen in experiments, was the aspect of ``jet quenching\" and understanding that phenomenon will be the main focus of this talk. The concept behind quenching is that a high energetic quark or gluon jet, undergoes significant energy loss due to the overall structure modifications related to its fragmentation and radiation patterns as it traverses the medium. The term jet, parameterized by a fixed lateral size or the jet radius, represents the collimated spray of particles arising from the initial hard scattered parton. Along with published results of the jet production cross sections in proton-proton, proton-lead and lead-lead collisions, we present nuclear modification factors that unequivocally confirm jet quenching. In addition, we study the inherent medium induced modifications to the jet structure by comparing experimental measurements with Monte Carlo predictions. I summarize by compiling the physics we\'ve learned thus far behind jet quenching followed by a brief description of the trend in current and future heavy ion studies.

Friday, Aug 25 at 10:00 AM
1300 Auditorium (FRIB Tower 3)
Ben Freemire, Northern Illinois University
Accelerator R&D Toward Proton Drivers for Future Particle Accelerators

Abstract:  The future Deep Underground Neutrino Experiment (DUNE), which aims to resolve the neutrino mass hierarchy and measure CP violation, relies on a 40 kton liquid argon detector and a neutrino beam delivered from a multi-MW proton driver driving the Long Baseline Neutrino Facility (LBNF), sited at Fermilab. The existing beamline has achieved 700 kW operation, with a new SRF linac and other upgrades expected to support 1.2 MW of beam power at 120 GeV. Eventual operation at 2 MW or greater is desired. Performance of the existing Linac and Booster is limited by beam loss driven by space charge. An accelerator R&D program has been started in an effort to overcome such limitations, and the Integrable Optics Test Accelerator (IOTA) is under construction with the goal of investigating space charge effects, beam halo formation, particle losses, beam instabilities, etc. The array of planned experiments will be discussed, as well as the current status of construction and commissioning.

Monday, Aug 28 at 11:00 AM
NSCL Lecture Hall 1200
Eric Lunderberg, NSCL
Subbarrier Coulomb Excitation at RaA3 - Commissioning of the SeGA-JANUS Experimental Setup

Abstract:  COMMITTEE: Alexandra Gade (Chairperson), Sean Liddick, Wayne Repko, Michael Thoennessen, Vladimir Zelevinsky. THESIS IS ON DISPLAY IN ROOM 1312 BPS BLDG. AND THE NSCL

Tuesday, Aug 29 at 10:00 AM
NSCL Lecture Hall 1200
Michael Thoennessen, Associate Director for User Relations, FRIB
10,000 days (almost) at the NSCL
Tuesday, Aug 29 at 2:00 PM
NSCL Lecture Hall 1200
Dayah Chrisman, NSCL
Unbound States in the Island of Inversion

Abstract:  COMMITTEE:Michael Thoennessen (Chairperson),S. Bogner, J. Singh, A. Spyrou, K. Tollefson

Wednesday, Sep 06 at 4:10 PM
NSCL Lecture Hall 1200
Michael Lisa, The Ohio State University
Subatomic fluid spintronics - Global hyperon polarization in heavy ion collisions at RHIC

Abstract:  In 1915, Barnett et al found that rotation of a metal cylinder can induce a magnetization in the object. This remains a rare example of a coupling between macroscopic mechanical rotation and quantum spin (though this was not the paradigm of the day). Just last year (2016), Takahashi et al discovered the first polarization of electrons induced by mechanical vorticity induced by viscous effects in a fluid; they thus heralded the new field of fluid spintronics. In 2000, first collisions at Brookhaven National Lab's Relativistic Heavy Ion Collider (RHIC) led to the surprising discovery that the deconfined quark-gluon plasma (QGP) is best described as a "nearly perfect fluid." These fluid properties remain the focus of intense study, and are providing insights into the Strong force in the non-perturbative regime. However, fundamental features of the fluid-- including its vorticity-- are largely unexplored. I will discuss recent measurements by the STAR Collaboration at RHIC, on the spin alignment, or polarization, of Lambda hyperons with the angular momentum of the collision. I will argue that a RHIC collision generates the subatomic analog of Takahashi's observation, the vorticity generated by initial viscous forces and maintained by subsequent low viscosity. These measurements allow an estimate of both the vorticity of the QGP and the magnetic field in which it evolves. Both of these quantities far surpass any known system in the universe. Furthermore, knowledge of both is crucial to recent studies that may reveal the onset of chiral symmetry restoration in QCD.

Monday, Sep 11 at 12:30 PM
Biomedical & Physical Sciences Bldg., Rm. 1400
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Title to be Announced