# 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, March 22, 2023
4:00 pm
Online
Dr. Georgios Karananas
Ludwig-Maximilians-Universität München
Munich, Germany

Conformal Symmetry in the Standard Model and its
Symbiosis with Gravity
Wednesday, April 05, 2023
4:00 pm
Jones PSC #409
Dr. Gael Finauri
Technical University Munich
Munich, Germany

Light-cone Distribution Amplitudes of Energetic Heavy Mesons
Wednesday, April 12, 2023
4:00 pm
Jones PSC #409
Dr. Jure Zupan
Department of Physics
University of Cincinnati
Cincinnati, OH

TBA
Wednesday, April 19, 2023
4:00 pm
Jones PSC #409
Dr. André De Gouvea
Department of Physics and Astronomy
Northwestern University
Evanston, IL

TBA
Wednesday, April 26, 2023
4:00 pm
Jones PSC #409
Dr. Baha Balantekin
Department of Physics

TBA

### Recent Seminars:

Dr. Gael Finauri
Technical University Munich
Munich, Germany
Research Profile

Abstract:
Light-cone distribution amplitudes (LCDAs) frequently arise in factorization theorems involving light and heavy mesons.
The QCD LCDA for heavy mesons includes short-distance physics at energy scales of the heavy quark mass.
In this talk I will explain how to achieve the separation of this perturbative scale from the purely hadronic effects by expressing the QCD LCDA as a convolution of a perturbative jet" function with the universal, quark-mass independent HQET LCDA.
This factorization allows to efficiently resum large logarithms between Lambda QCD and m_Q  as well as between m_Q and the scale of the hard process in the production of boosted heavy mesons at colliders.
As an application I will present updated theoretical predictions for the brancing ratio of W -> B \gamma.
Dr. Georgios Karananas
Ludwig-Maximilians-Universität München
Munich, Germany
Research Profile

Abstract:
I will discuss how (broken) conformal symmetry can be used as a guiding principle to construct viable minimalistic extensions of the Standard Model. I will highlight the central role gravity (and its incarnations) plays in these considerations, with an emphasis on the Einstein-Cartan formulation. I will show that an inflationary epoch driven by the Higgs field is automatically incorporated. Moreover, the inflationary predictions may in principle be related to the electroweak physics, thus creating an intricate link between the primordial and late Universe. Finally, I will comment on the self-consistency of these constructions.
Dr. Bulat Farkhtdinov
Institute for Nuclear Research
Moscow, Russia

Abstract:
We compute the probability of producing  n>>1 particles from few colliding particles in the (3+1)-dimensional λϕ^4 theory with no spontaneous symmetry breaking. To this end, we numerically implement the semiclassical method of singular solutions, which works at n≫1 in the weakly coupled regime λ≪1. For the first time, we obtain reliable results in the region of exceptionally large final state multiplicities λn>>1 where the probability decreases exponentially with n. The exponent depends on multiplicity linearly and its tilt depends on the mean kinetic energy ε of produced particles. In the opposite case λn<<1 our data match well-known tree-level results, and they interpolate between the two limits at λn~1. Overall, this proves exponential suppression of the multiparticle production probability at n≫1 and arbitrary ε in the unbroken theory. In the talk, I will cover both the numerical implementation of the method and obtained results.
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.