Department of Physics and Astronomy

Nuclear, Astro and Particle Physics Seminars

These lectures feature speakers from around the country and globe. Each seminar lasts about an hour and takes a closer look at more specialized fields in various realms of physics and astronomy.

Many seminars will be held in a hybrid format and a recurring Zoom link is provided to access the virtual format.

The talks will be on Wednesdays at 4PM in the Rogers Room (Jones PSC 409).

Upcoming Seminars (Spring 2023):

Title of Seminar Talk

Wednesday, February 22, 2023
4:00 pm
Jones PSC #409
Dr. Bulat Farkhtdinov
Institute for Nuclear Research
Moscow, Russia

TBA

Recent Seminars:

Dr. Ethan Cline, Postdoctoral Fellow
Department of Physics and Astronomy - Massachusetts Institute of Technology (Cambridge, MA)
Department of Physics and Astronomy - Stony Brook University (Stony Brook, NY)
Research Profile

Abstract:
The search for a dark photon holds considerable interest in the physics community. Such a force carrier would begin to illuminate the dark sector. Many experiments have searched for such a particle, but, so far, it has proven elusive. In recent years, the concept of a low mass dark photon has gained popularity in the physics community. Of particular recent interest is the ^8Be and ^4He anomaly, which could be explained by a 17 MeV mass dark photon. The proposed Darklight experiment would search for this potential low mass force carrier at ARIEL in the 10-20 MeV e^+e  ^ - invariant mass range. This talk will focus on the experimental design and physics case of the Darklight experiment.

Visiting Professor at Harvard University  (Cambridge, MA)
Laboratoire de Physique Théorique et Hautes Énergies - Sorbonne Université (Paris, France)
Research Profile

Abstract:
I will first review the properties of the cosmological constant in supergravity. I will then describe the difficulties for obtaining de Sitter vacua in string theory and present a new mechanism of moduli stabilisation based on perturbative quantum corrections that behave logarithmically at large volumes. This framework leads to vacua with positive tuneable energy at weak coupling, as well as to new models of small field inflation compatible with observations.

Dr. Gil Paz, Associate Professor
Department of Physics and Astronomy
Wayne State University
Detroit, MI
Research Profile

Abstract:
For over 12 years now, we have been facing the proton radius puzzle, the difference between the proton charge radius extractions using electrons and muons. After reviewing some of the theoretical work on electron-proton scattering and muonic hydrogen spectroscopy, I will present new effective field theory tools that aim to directly connect muonic hydrogen spectroscopy and muon-proton scattering. This effective field theory is relevant for MUSE, the new muon-proton scattering experiment.

In particular, I will present the determination of the Wilson coefficients of the four- fermion contact interactions at ${\cal O}(Z^2\alpha^2)$ and power $1/m_p^2$. Surprisingly, we found that the coefficient of the spin-independent interaction vanishes, implying that MUSE will be sensitive mostly to the proton charge radius and not spin-independent two-photon exchange effects.

Dr. Shmuel Nussinov, Professor Emeritus
School of Physics and Astronomy
Tel Aviv University
Tel Aviv, Israel
Research Profile

Abstract:
Some interesting features of detection via collisions with nuclei of WIMP (Weakly Interacting Massive Particles) and some other DM (Dark Matter) types will be discussed. Separately, I'll discuss analogs of nuclei of a variety of masses in the dark sector and, in particular, some versions where the dark sector is a "mirror image" of our sector. DM grains and clouds of various sizes, masses, and compositions as well as their possible impacts will be briefly discussed.

Dr. Bob Bernstein, Scientist II
Fermi National Accelerator Facility
Batavia, IL
Research Profile

Abstract:
The Mu2e Experiment at Fermilab will search for coherent, neutrinoless conversion of muons into electrons in the field of a nucleus with a sensitivity improvement of a factor of 10,000 over previous experiments. Such a charged lepton flavor-violating reaction probes new physics at a scale inaccessible with direct searches at either present or planned high energy colliders. The experiment both complements and extends the current search for muon decay to electron+gamma at MEG and searches for new physics at the LHC. We will present the physics motivation for Mu2e, the novel design of the muon beamline and the detector, and the current status of the experiment.

Department of Physics and Astronomy
Mississippi State University
Starkville, MS

Abstract:
The E12-10-002 (F2) experiment ran in Hall C at Jefferson Lab to extract the F2 structure functions from inclusive H(e ,e ′ ) and D(e ,e ′ ) reactions at high x Bjorken region. These extractions allow constraining the PDF (especially at large Bjorken x), facilitate the study of Quark Hadron Duality, and contribute to the calculation of non-singlet moments as a test of LQCD. F2 experiment measurements cover a large kinematic range in x from 0.2 to 1.0, and in Q2 from 4 to 16 GeV2.

While the proton F2 structure function has been studied extensively through inelastic electron-proton scattering, much less is known about neutron structure due to the unavailability of high density, free neutron targets. The BONuS12 experiment was proposed to measure the neutron F2 on a nearly free neutron within a weakly bound Deuteron target via the spectator tagging method. Tagging the slow backward moving spectator protons minimizes both off-shell and final-state interaction effects with the measured proton momentum used to correct for the initial-state momentum of the struck neutron. The recoil detector used to detect spectator protons with momenta 70 < Ps < 150 MeV/c and the CEBAF Large Acceptance Spectrometer (CLAS12) to detect the scattered electrons.
Mr. Matthew Nicol, Doctoral Researcher
University of York
York, England, United Kingdom

Abstract:
Exotics, particles not allowed in the quark model, provide a fantastic opportunity to study possible hadron structures, the limitations of QCD, and get a broader picture of the strong interaction. My research approaches this topic from several different perspectives by observing possible states produced from excitations within hadrons and also by replacing valence quarks. My first project explores the topic of dibaryons, specifically, genuine hexaquarks for which experimental evidence was produced in recent years. I focus on searching for a very strange hexaquark (dsss), producing the first ever constraints on this particle with an upper limit on the cross section. Finding exotics such as this can prove very difficult, for example, only seven hyperons have been discovered in the last 20 years, this is why I am also producing the first ever scaling behaviour of strangeness. By comparing strange production of S=-1,-2,-3 on different targets, we will be able to identify possible energy regimes for enhanced strange exotic production. Lastly, looking at exotic hybrid mesons, where excited gluon fields contribute to the overall properties of a meson and can lead to quantum numbers not allowed in the quark model. I have determined the moments for resonances that produce a K + K - pair, these will be used to extract their quantum numbers and see what mesons have been observed and if any of them are exotic.