### Conveners

#### QCD, Hadron Spectroscopy, and Exotics: Parallel 2 — Heavy Spectroscopy

- Seamus Riordan (Argonne National Laboratory)

#### QCD, Hadron Spectroscopy, and Exotics: Parallel 5 — γ–γ | Form Factors at High q²

- Seamus Riordan (Argonne National Laboratory)

#### QCD, Hadron Spectroscopy, and Exotics: Parallel 8 — Light Spectroscopy | Perturbative QCD

- Seamus Riordan (Argonne National Laboratory)

Dr
Henry Lamm
(University of Maryland)

5/29/18, 4:10 PM

QCDHS

Parallel

LHCb has recently presented a measurement of $R(J/\psi)=\mathcal{BR}(B_c^+\rightarrow J/\Psi \tau^+\bar\nu_\tau)/\mathcal{BR}(B_c^+\rightarrow J/\Psi \mu^+\bar\nu_\mu)$. The value, $R(J/\psi)=0.71\pm 0.17\pm 0.18$ is in mild tension with the range of model predictions 0.25-0.28. The model transition form factors dominate the systematic uncertainty of the measurement and limit the predictions...

Dr
Meng-Lin DU
(Helmholtz-Institut f\"ur Strahlen- und Kernphysik and Bethe Center for Theoretical Physics, Universit\"at Bonn)

5/29/18, 4:30 PM

QCDHS

Parallel

For a long time, the quark model has served as an ordering scheme and brought systematics into the hadron zoo. However, many new hadrons that were observed since 2003, including the lowest-lying positive-parity charm-strange mesons $D_{s0}^\star$(2317) and $D_{s1}$(2460), do not conform with quark model expectations. Various modifications to the quark model and alternative approaches have been...

Prof.
Abner Soffer
(Tel Aviv University)

5/29/18, 5:00 PM

QCDHS

Parallel

We measure the mass difference, $\Delta m_+$, between the $D^\star (2010)^+$ and the $D^+$, using the decay chain $D^\star (2010)^+\to D^+ \pi^0$ with $D^+\to K^- \pi^+ \pi^+$. The data were recorded with the BaBar detector at center-of-mass energies at and near the $\Upsilon$(4S) resonance, and correspond to an integrated luminosity of approximately 468 fb$^{-1}$. We measure $\Delta m_+ =...

Dr
Shinya Gongyo
(RIKEN Nishina Center, RIKEN)

5/29/18, 5:20 PM

QCDHS

Parallel

In recent years, there is a renewed interest in the dibaryons due to exclusive measurements in hadron reactions as well as the direct measurement in relativistic heavy-ion collisions. In this talk, we will present the result of the dibaryon searches from lattice QCD. Particularly we focus on the study of "Most strange dibaryon", which is composed of two $\Omega$ baryons. First, we will show...

Prof.
Nikolaos Kidonakis
(Kennesaw State University)

5/29/18, 5:50 PM

QCDHS

Parallel

I present high-order calculations for single-top production in the Standard Model and in models with anomalous top-quark couplings. Theoretical results are presented for total cross sections and top-quark transverse momentum and rapidity distributions for the $t$ and $s$ single-top channels as well as for the associated production of a top quark with a $W$-boson in the Standard Model....

Shankar Adhikari
(Florida International University)

5/29/18, 6:10 PM

QCDHS

Parallel

Spin observables are important to understand the production mechanisms of hyperons, as well as the contribution of intermediate baryon resonances. $\Lambda$ polarization observables have been studied extensively in the recent decades using the reaction $\gamma + p \to K^+ + \Lambda$. This talk presents the measurement of transferred polarization coefficients $C_x$ and $C_z$, and the induced...

Prof.
Marc Vanderhaeghen
(University Mainz)

5/31/18, 2:00 PM

QCDHS

Parallel

In view of the proton radius puzzle and the precision currently achieved in extracting the proton radius from muonic Hydrogen spectroscopy, the two-photon exchange (TPE) corrections between the lepton and hadron are at present the largest source of hadronic uncertainty. I present an overview on recent work within a dispersion relation framework to estimate such TPE corrections both in elastic...

Prof.
Andrew Puckett
(University of Connecticut)

5/31/18, 2:40 PM

QCDHS

Parallel

The electromagnetic form factors (EMFFs) of the nucleon, measured in elastic electron-nucleon scattering, are among the simplest and most well-defined measurable dynamical properties of the nucleon, and serve as important benchmarks for the testing of theoretical models and $\textit{ab initio}$ lattice QCD calculations of nucleon structure. They also provide stringent, model-independent...

Dr
Vladimir Pascalutsa
(University of Mainz)

5/31/18, 3:10 PM

QCDHS

Parallel

Talk 169:
I would like to present a first partial wave-analysis (PWA) of the experimental cross sections of Compton scattering on the proton [1]. The resulting solutions reveal an appreciable sensitivity to small refinements of the experimental database, which could explain the discrepancies among the various extractions of proton polarizabilities (see e.g. [3] for review). The database...

Dr
Alexander Austregesilo
(Jefferson Lab)

6/1/18, 4:10 PM

QCDHS

Parallel

The GlueX experiment at Jefferson Lab aims to study the light-quark meson spectrum with an emphasis on the search for hybrid mesons. The $\eta\pi^0$ and $\eta^{^{_/}}\pi^0$ final states are promising channels for this search. Several experiments have observed a contribution with exotic quantum numbers in these channels in the past, but the resonance interpretation is not well established....

Prof.
John Bulava
(CP3-Origins, U. of Southern Denmark)

6/1/18, 4:40 PM

QCDHS

Parallel

Given recent progress in the determination of scattering amplitudes from lattice QCD calculations, systematic errors due to the finite lattice spacing and simulation volume must now be controlled in order to provide quantitative QCD predictions for the properties of excited hadrons. To this end, I will present a calculation of the pion-pion scattering amplitude near the $\rho$(770) resonance,...

Dr
Luka Leskovec
(University of Arizona)

6/1/18, 5:10 PM

QCDHS

Parallel

We present a lattice QCD study of the $\rho$ resonance with $N_f=2+1$ clover fermions at a pion mass of approximately 320 MeV and lattice size 3.6 fm. We study two processes involving the $\rho$. The first process is scattering of two pions in P-wave with isospin 1 where by using the Luescher method we determine the strong scattering phase shift, from which we determine the $\rho$ resonance...

Dr
Christoph Florian Redmer
(Institute for Nuclear Physics, Johannes Gutenberg-University Mainz)

6/1/18, 5:35 PM

QCDHS

Parallel

The two-photon physics program of the BESIII Collaboration is mainly motivated by the large uncertainty of the contribution of hadronic light-by-light scattering (hLBL) to the Standard Model calculations of the anomalous magnetic moment of the muon $a_\mu$. Here, electromagnetic transition form factors (TFF) can serve as experimental input to improve the calculations. Data acquired with the...

Dr
Alessandro Pilloni
(Jefferson Lab)

6/1/18, 6:00 PM

QCDHS

Parallel

Last decade witnessed a proliferation of new exotic states, in particular in the heavy quark sector. A comprehensive picture of all these states remains an unsettled topic. We discuss our recent developments in amplitude analysis, in particular related to the identification of exotic states.