Elementary Particles and Fields and String Theory Commons^™

Superluminal Propagation On A Moving Braneworld, Brian Greene, Daniel Kabat, Janna Levin, Arjun S. Menon

Publications and Research

We consider a braneworld scenario in the simplest setting, M₄ × S¹, with a four-dimensional (4D) Minkowski metric induced on the brane, and establish the possibility of superluminal propagation. If the brane is at rest, the 4D Lorentz symmetry of the brane is exact, but if the brane is in motion, it is broken globally by the compactification. By measuring bulk fields, an observer on the brane sees a slice through a higher-dimensional field profile, which carries an imprint of the extra dimensions even when the brane is at rest. If the brane is in motion, we …

Quark And Gluon Entanglement In The Proton On The Light Cone At Intermediate X, Adrian Dumitru, Eric Kolbusz

Publications and Research

In QCD with $N_c$ colors the antisymmetric valence quark color space singlet state $\sim \epsilon_{i_1\cdots i_{N_c}} |i_1,\cdots, i_{N_c}\rangle$ of the proton corresponds to the reduced density matrix $\rho_{ij}=(1/N_c) \delta_{ij}$ for a single color degree of freedom. Its degenerate spectrum of eigenvalues, $\lambda_i=1/N_c$, the purity $\tr \rho^2 = 1/N_c$, and the von Neumann entropy $S_\mathrm{vN}=\log(N_c)$ all indicate maximal entanglement of color. On the other hand, for $N_c\to\infty$ the spatial wave function of the proton factorizes into valence quark wave functions determined by a mean field [E. Witten, Nucl. Phys. B160, 57 (1979)] where there is no entanglement of spatial degrees of …

The Octagon At Large M, Riccardo Argurio, Matteo Bertolini, Sebastían Franco, Eduardo García-Valdecasas, Shani Meynet, Antoine Pasternak, Valdo Tatitscheff

Publications and Research

Recently, the first instance of a model of D-branes at Calabi-Yau singularities where supersymmetry is broken dynamically into stable vacua has been proposed. This construction was based on a system of N regular and M = 1 fractional branes placed at the tip of the so-called (orientifolded) Octagon singularity. In this paper we show that this model admits a large M generalization, having the same low energy effective dynamics. This opens up the possibility that the effect on geometry is smooth, and amenable to describing the gauge theory all along the RG flow, including the deep IR, in terms of …

Non-Perturbative Processes In Standard Model \& New Physics: From Standard Calculations To Machine Learning, Cody Michael Grant

Wayne State University Dissertations

I calculated non-perturbative processes to study the Standard Model and probe areas of new physics. I found that invisible decays of heavy mesons are not dominated by the leading order contribution in the Standard Model. I argue that this affects neutrino mass constraints and avenues for discovering new physics, such as dark photons. In addition to this, I used a novel approach to approximate a semileptonic form factor with an artificial neural network (ANN). Comparing the results from the ANN to common phenomenological parameterizations, and using it to set a lower bound constraint on the CKM matrix element, $V_{cd}$. Finally, …

Aspects On The Quantum Dynamics Of A System Coupled To A Bosonic Environment, Qidong Xu

Dartmouth College Ph.D Dissertations

In this work we study various aspects of the quantum dynamics for a system coupled to a Bosonic environment, which is described by a collection of quantum harmonic oscillators or a quantum field. We first consider two quantum mechanical oscillator system-bath models obtained by dimensionally truncating linearized gravity coupled to a massive scalar field and scalar QED, and we show that they separately map onto the phase damped oscillator model and the oscillator system subject to two-photon damping. The phase damped oscillator model also corresponds to the optomechanical system with an acoustic field environment, and we study the acoustic environment …

Machine Learning-Based Event Generator For Electron-Proton Scattering, Y. Alanazi, P. Ambrozewicz, M. Battaglieri, A.N. Hiller Blin, M. P. Kuchera, Y. Li, T. Liu, R. E. Mcclellan, W. Melnitchouk, E. Pritchard, M. Robertson, N. Sato, R. Strauss, L. Velasco

Computer Science Faculty Publications

We present a new machine learning-based Monte Carlo event generator using generative adversarial networks (GANs) that can be trained with calibrated detector simulations to construct a vertex-level event generator free of theoretical assumptions about femtometer scale physics. Our framework includes a GAN-based detector folding as a fast-surrogate model that mimics detector simulators. The framework is tested and validated on simulated inclusive deep-inelastic scattering data along with existing parametrizations for detector simulation, with uncertainty quantification based on a statistical bootstrapping technique. Our results provide for the first time a realistic proof of concept to mitigate theory bias in inferring vertex-level event …

Generally Covariant Theory Of Multipole Moment Conserving Quasiparticles, Gavin Eric Riley

Honors Theses and Capstones

This report represents the creation of a field theory which is capable of describing quasiparticle excitations that preserve 2^k -pole moments. These quasiparticles exhibit certain ’semidynamic’ properties such as individual particle immobility but free movement of bound 2^L-tuples. We provide a review of work done on dipole conserving fractons and their dynamics [1] and expand upon it to describe higher moment conserving systems with global quadratic (and higher) phase symmetry. This requires the selection of the temporal and spatial directions. The selection of a temporal direction is done with a foliation defined by an anisotropic scaling of space and time, …

Several Problems In Nonlinear Schrödinger Equations, Tim Van Hoose

Masters Theses

“We study several different problems related to nonlinear Schrödinger equations….

We prove several new results for the first equation: a modified scattering result for both an averaged version of the equation and the full equation, as well as a set of Strichartz estimates and a blowup result for the 3d cubic problem.

We also present an exposition of the classical work of Bourgain on invariant measures for the second equation in the mass-subcritical regime”--Abstract, page iv.

Spin(7) Orientifolds And 2d N = (0, 1) Triality, Sebastían Franco, Alessandro Mininno, Ángel M. Uranga, Xingyang Yu

Publications and Research

We present a new, geometric perspective on the recently proposed triality of 2d N = (0, 1) gauge theories, based on its engineering in terms of D1-branes probing Spin(7) orientifolds. In this context, triality translates into the fact that multiple gauge theories correspond to the same underlying orientifold. We show how Spin(7) orientifolds based on a particular involution, which we call the universal involution, give rise to precisely the original version of N = (0, 1) triality. Interestingly, our work also shows that the space of possibilities is significantly richer. Indeed, general Spin(7) orientifolds extend triality to theories that can …

Fano 3-Folds, Reflexive Polytopes And Brane Brick Models, Sebastían Franco, Rak-Kyeong Seong

Publications and Research

Reflexive polytopes in n dimensions have attracted much attention both in mathematics and theoretical physics due to their connection to Fano n-folds and mirror symmetry. This work focuses on the 18 regular reflexive polytopes corresponding to smooth Fano 3-folds. For the first time, we show that all 18 regular reflexive polytopes have corresponding 2d (0, 2) gauge theories realized by brane brick models. These 2d gauge theories can be considered as the worldvolume theories of D1-branes probing the toric Calabi-Yau 4-singularities whose toric diagrams are given by the associated regular reflexive polytopes. The generators of the mesonic moduli …

Deeply Learning Deep Inelastic Scattering Kinematics, Markus Diefenthaler, Abdullah Farhat, Andrii Verbytskyi, Yuesheng Xu

Mathematics & Statistics Faculty Publications

We study the use of deep learning techniques to reconstruct the kinematics of the neutral current deep inelastic scattering (DIS) process in electron–proton collisions. In particular, we use simulated data from the ZEUS experiment at the HERA accelerator facility, and train deep neural networks to reconstruct the kinematic variables Q² and x. Our approach is based on the information used in the classical construction methods, the measurements of the scattered lepton, and the hadronic final state in the detector, but is enhanced through correlations and patterns revealed with the simulated data sets. We show that, with the appropriate selection …

Searching For Anomalous Extensive Air Showers Using The Pierre Auger Observatory Fluorescence Detector, Andrew Puyleart

Dissertations, Master's Theses and Master's Reports

Anomalous extensive air showers have yet to be detected by cosmic ray observatories. Fluorescence detectors provide a way to view the air showers created by cosmic rays with primary energies reaching up to hundreds of EeV . The resulting air showers produced by these highly energetic collisions can contain features that deviate from average air showers. Detection of these anomalous events may provide information into unknown regions of particle physics, and place constraints on cross-sectional interaction lengths of protons. In this dissertation, I propose measurements of extensive air shower profiles that are used in a machine learning pipeline to distinguish …

Positivity And Renormalization Of Parton Densities, John Collins, Ted C. Rogers, Nobuo Sato

Physics Faculty Publications

There have been recent debates about whether MS parton densities exactly obey positivity bounds (including the Soffer bound) and whether the bounds should be applied as a constraint on global fits to parton densities and on nonperturbative calculations. A recent paper [Candido et al., Can MS parton distributions be negative?, J. High Energy Phys. 11 (2020) 129] appears to provide a proof of positivity in contradiction with earlier work by other authors. We examine their derivation and find that its primary failure is in the apparently uncontroversial statement that bare parton density (or distribution) function (pdfs) are always …

Measuring Recoiling Nucleons From The Nucleus With The Future Electron Ion Collider, Florian Hauenstein, A. Jentsch, J. R. Pybus, A. Kiral, M. D. Baker, Y. Furletova, O. Hen, D. W. Higinbotham, Charles Hyde, V. Morozov, D. Romanov, Lawrence B. Weinstein

Physics Faculty Publications

Short range correlated nucleon-nucleon (NN) pairs are an important part of the nuclear ground state. They are typically studied by scattering an electron from one nucleon in the pair and detecting its spectator correlated partner (“spectator-nucleon tagging”). The Electron Ion Collider (EIC) should be able to detect these nucleons, since they are boosted to high momentum in the laboratory frame by the momentum of the ion beam. To determine the feasibility of these studies with the planned EIC detector configuration, we have simulated quasielastic scattering for two electron and ion beam energy configurations: 5 GeV e− and 41 …

Polarized Gluon Pseudodistributions At Short Distances, Ian Balitsky, Wayne Morris, Anatoly Radyushkin

Physics Faculty Publications

We formulate the basic points of the pseudo-PDF approach to the lattice calculation of polarized gluon PDFs. We present the results of our calculations of the one-loop corrections for the bilocal G_μα(z)G̃_λβ(0) correlator of gluonic fields. Expressions are given for a general situation when all four indices are arbitrary, and also for specific combinations of indices corresponding to three matrix elements that contain the twist-2 invariant amplitude related to the polarized PDF. We study the evolution properties of these matrix elements, and derive matching relations between Euclidean and light-cone Ioffe-time distributions. These relations are necessary for …

Experimental Study Of The Behavior Of The Bjorken Sum At Very Low Q², A. Deur, J. P. Chen, S. E. Kuhn, C. Peng, M. Ripani, V. Sulkosky, K. Adhikari, M. Battaglieri, V. D. Burkert, G. D. Cates, R. De Vita, G.E. Dodge, L. El Fassi, F. Garibaldi, H. Kang, M. Osipenko, J. T. Singh, K. Slifer, J. Zhang, X. Zheng

Physics Faculty Publications

We present new data on the Bjorken sum ^-Γ ^p-n₁ (Q²) at 4-momentum transfer 0.021 ≤ Q² ≤ 0.496 GeV². The data were obtained in two experiments performed at Jefferson Lab: EG4 on polarized protons and deuterons, and E97110 on polarized ³He from which neutron data were extracted. The data cover the domain where chiral effective field theory (χEFT), the leading effective theory of the Strong Force at large distances, is expected to be applicable. We find that our data and the predictions from χEFT are only in marginal …

Spectroscopic Study Of A Possible Λ𝑛𝑛 Resonance And A Pair Of (E, E'K⁺) Reaction With A Tritium Target, Hall A Collaboration, B. Pandey, L. Tang, T. Gogami, Florian Hauenstein, Charles Hyde, Z. Ye, J. Zhang, X. Zheng, Et Al.

Physics Faculty Publications

A mass spectroscopy experiment with a pair of nearly identical high-resolution spectrometers and a tritium target was performed in Hall A at Jefferson Lab. Utilizing the (e,e′K⁺) reaction, enhancements, which may correspond to a possible Λnn resonance and a pair of ΣNN states, were observed with an energy resolution of about 1.21 MeV (σ), although greater statistics are needed to make definitive identifications. An experimentally measured Λnn state may provide a unique constraint in determining the Λn interaction, for which no scattering data exist. In addition, although bound A = 3 and 4 Σ hypernuclei have …

Determination Of The Argon Spectral Function From (E, E'P) Data, Jefferson Lab Hall A Collaboration, L. Jiang, A.M. Ankowski, D. Abrams, Florian Hauenstein, Charles Hyde, S. Wood, Z. Ye, J. Zhang, Et Al.

Physics Faculty Publications

The E12-14-012 experiment, performed in Jefferson Lab Hall A, has measured the (e,e′p) cross section in parallel kinematics using a natural argon target. Here, we report the full results of the analysis of the data set corresponding to beam energy 2.222 GeV, and spanning the missing momentum and missing energy range 15 ≲ pm ≲ 300  MeV /c and 12 ≲ Em ≲ 80  MeV. The reduced cross section, determined as a function of p_m and E_m with ≈ 4% accuracy, has been fitted using the results of Monte Carlo simulations involving a model spectral function and …

Cooling Performance In A Dual Energy Storage Ring Cooler, B. Dhital, Y. S. Derbenev, D. Douglas, G. A. Krafft, H. Zhang, F. Lin, V. S. Morozov, Y. Zhang

Physics Faculty Publications

The longitudinal and transverse emittance growth in hadron beams due to intra-beam scattering (IBS) and other heating sources deteriorate the luminosity in a collider. Hence, a strong hadron beam cooling is required to reduce and preserve the emittance. The cooling of high energy hadron beam is challenging. We propose a dual energy storage ring-based electron cooler that uses an electron beam to extract heat away from hadron beam in the cooler ring while the electron beam is cooled by synchrotron radiation damping in the high energy damping ring. In this paper, we present a design of a dual energy storage …

Quark Spin-Orbit Correlations In The Proton, M. Engelhardt, J. Green, N. Hasan, T. Izubuchi, C. Kallidonis, S. Krieg, S. Liuti, S. Meinel, J. Negele, A. Pochinsky, A. Rajan, G. Silvi, S. Syritsyn

Physics Faculty Publications

Generalized transverse momentum-dependent parton distributions (GTMDs) provide a comprehensive framework for imaging the internal structure of the proton. In particular, by encoding the simultaneous distribution of quark transverse positions and momenta, they allow one to directly access longitudinal quark orbital angular momentum, and, moreover, to correlate it with the quark helicity. The relevant GTMD is evaluated through a lattice calculation of a proton matrix element of a quark bilocal operator (the separation in which is Fourier conjugate to the quark momentum) featuring a momentum transfer (which is Fourier conjugate to the quark position), as well as the Dirac structure appropriate …

Cebaf Injector Model For KL Beam Conditions, Sunil Pokharel, Geoffrey A. Krafft, A. S. Hofler, R. Kazimi, M. Bruker, J. Grames, S. Zhang

Physics Faculty Publications

The Jefferson Lab KL experiment will run at the Continuous Electron Beam Accelerator Facility with a much lower bunch repetition rate (7.80 or 15.59 MHz) than nominally used (249.5 or 499 MHz). While the proposed average current of 2.5 - 5.0 µA is relatively low compared to the maximum CEBAF current of approximately 180 µA, the corresponding bunch charge is atypically high for CEBAF injector operation. In this work, we investigated the evolution and transmission of low-rep-rate, high-bunch-charge (0.32 to 0.64 pC) beams through the CEBAF injector. Using the commercial software General Particle Tracer, we have simulated and analyzed the …

Existence And Non-Existence Of Doubly Heavy Tetraquark Bound States, M. Pflaumer, Luka Leskovec, S. Meinel, M. Wagner

Physics Faculty Publications

In this work we investigate the existence of bound states for doubly heavy tetraquark systems Q¯Q¯′qq′ in a full lattice-QCD computation, where heavy bottom quarks are treated in the framework of non-relativistic QCD. We focus on three systems with quark content b¯b¯ud, b¯b¯us and b¯c¯ud. We show evidence for the existence of b¯b¯ud and b¯b¯us bound states, while no binding appears to be present for b¯c¯ud. For the bound four-quark states we also discuss the importance of various creation operators and give an estimate of the meson-meson and diquark-antidiquark percentages.

Combining Nonperturbative Transverse Momentum Dependence With Tmd Evolution, J.O. Gonzalez-Hernandez, T. C. Rogers, N. Sato

Physics Faculty Publications

Central to understanding the nonperturbative, intrinsic partonic nature of hadron structure are the concepts of transverse momentum dependent (TMD) parton distribution and fragmentation functions. A TMD factorization approach to the phenomenology of semi-inclusive processes that includes evolution, higher orders, and matching to larger transverse momentum is ultimately necessary for reliably connecting with phenomenologically extracted nonperturbative structures, especially when widely different scales are involved. In this paper, we will address some of the difficulties that arise when phenomenological techniques that were originally designed for very high energy applications are extended to studies of hadron structures, and we will solidify the connection …

Perturbative Unitarity And Nec Violation In Genesis Cosmology, Yong Cai, Ji Xu, Shuai Zhao, Siyi Zhou

Physics Faculty Publications

Explorations of the violation of null energy condition (NEC) in cosmology could enrich our understanding of the very early universe and the related gravity theories. Although a fully stable NEC violation can be realized in the “beyond Horndeski” theory, it remains an open question whether a violation of the NEC is allowed by some fundamental properties of UV-complete theories or the consistency requirements of effective field theory (EFT). We investigate the tree-level perturbative unitarity for stable NEC violations in the contexts of both Galileon and “beyond Horndeski” genesis cosmology, in which the universe is asymptotically Minkowskian in the past. We …

Study Of ⋀N Fsi With ⋀ Quasi-Free Productions On The ³H (E, E'K⁺) X Reaction At Jlab, K. Itabashi, K. N. Suzuki, B. Pandey, K. Okuyama, T. Gogami, S. Nagao, S. N. Nakamura, L. Tang, D. Abrams, T. Akiyama, D. Androic, K. Aniol, C. Ayerbe Gayoso, J. Bane, S. Barcus, J. Barrow, V. Bellini, H. Bhatt, D. Bhetuwal, D. Biswas, A. Camsonne, J. Castellanos, J.-P. Chen, J. Chen, S. Covrig, D. Chrisman, R. Cruz-Torres, R. Das, E. Fuchey, K. Gnanvo, F. Garibaldi, T. Gautam, J. Gomez, P. Gueye, T. J. Hague, O. Hansen, W. Henry, F. Hauenstein, D. W. Higinbotham, C. E. Hyde, M. Kaneta, C. Keppel, T. Kutz, N. Lashley-Colthirst, S. Li, H. Liu, J. Mammei, P. Markowitz, R. E. Mcclellan, F. Meddi, D. Meekins, R. Michaels, M. Milhovilovic, A. Moyer, D. Nguyen, M. Nycz, V. Owen, C. Palatchi, S. Park, T. Petkovic, S. Premathilake, P. E. Reimer, J. Reinhold, S. Riordan, V. Rodriguez, C. Samanta, S. N. Santiesteban, B. Sawatzky, S. Širca, K. Slifer, T. Su, Y. Tian, Y. Toyama, K. Uehara, G. M. Urciuoli, D. Votaw, J. Williamson, B. Wojtsekhowski, S. A. Wood, B. Yale, Z. Ye, J. Zhang, X. Zheng

Physics Faculty Publications

An nnΛ is a neutral baryon system with no charge. The study of the pure Λ-neutron system such as nnΛ gives us information on the Λn interaction. The nnΛ search experiment (E12-17-003) was performed at JLab Hall A in 2018. In this article, the Λn FSI was investigated by a shape analysis of the ³H(e, e′K⁺)X missing mass spectrum, and a preliminary result for the Λn FSI study is given.

Magnetic Structure Of Few-Nucleon Systems At High Momentum Transfers In A Chiral Effective Field Theory Approach, A. Gnech, R. Schiavilla

Physics Faculty Publications

The five low-energy constants (LECs) in the electromagnetic current derived in chiral effective field theory (χEFT) up to one loop are determined by a simultaneous fit to the A=2−3 nuclei magnetic moments and to the deuteron magnetic form factor and threshold electrodisintegration at backward angles over a wide range of momentum transfers. The resulting parametrization then yields predictions for the ³He/³H magnetic form factors in excellent accord with the experimental values for momentum transfers ranging up to ≈0.8 GeV/c, beyond the expected regime of validity of the χEFT approach. The calculations are based on last-generation two-nucleon interactions …

Study Of The Λ/Σ⁰ Electroproduction In The Low-Q² Region At Jlab, K. Okuyama, K. Itabashi, S. Nagao, S. N. Nakamura, K. N. Suzuki, T. Gogami, B. Pandey, L. Tang, D. Abrams, T. Akiyama, D. Androic, K. Aniol, C. Ayerbe Gayoso, J. Bane, S. Barcus, J. Barrow, V. Bellini, H. Bhatt, D. Bhetuwal, D. Biswas, A. Camsonne, J. Castellanos, J.- P. Chen, J. Chen, S. Covrig, D. Chrisman, R. Cruz-Torres, R. Das, E. Fuchey, K. Gnanvo, F. Garibaldi, T. Gautam, J. Gomez, P. Gueye, T. J. Hague, O. Hansen, W. Henry, Florian Hauenstein, D. W. Higinbotham, Charles E. Hyde, M. Kaneta, C. Keppel, T. Kutz, N. Lashley-Colthirst, S. Li, H. Liu, J. Mammei, P. Markowitz, R. E. Mcclellan, F. Meddi, D. Meekins, R. Michaels, M. Mihovilovic, A. Moyer, D. Nguyen, M. Nycz, V. Owen, C. Palatchi, S. Park, T. Petkovic, S. Premathilake, P. E. Reimer, J. Reinhold, S. Riordan, V. Rodriguez, C. Samanta, S. N. Santiesteban, B. Sawatzky, S. Širca, K. Slifer, T. Su, Y. Tian, Y. Toyama, K. Uehara, G. M. Urciuoli, D. Votaw, J. Williamson, B. Wojtsekhowski, S. A. Wood, B. Yale, Z. Ye, J. Zhang, X. Zheng

Physics Faculty Publications

We performed an experiment using tritium and hydrogen cryogenic gas targets at Thomas Jefferson National Accelerator Facility (JLab) in 2018 (E12-17-003)[1, 2]. In this article, we discuss the Λ/Σ⁰ hyperon electroproduction from hydrogen target. Elementary Λ/Σ⁰ hyperon production processes are important not only for an absolute mass scale calibration in our experiment, but also for the study of the electroproduction mechanisms themselves. In this article, we reported the results of the differential cross section for the p(e, e’K⁺)Λ/Σ⁰ reaction at Q² ∼ 0.5 (GeV/c)².

𝒯, 𝒫-Odd Effects In The Luoh⁺ Cation, Daniel E. Maison, Leonid V. Skripnikov, Gleb Penyazkov, Matt Grau, Alexander N. Petrov

Physics Faculty Publications

The LuOH⁺ cation is a promising system to search for manifestations of time reversal and spatial parity violation effects. Such effects in LuOH⁺ induced by the electron electric dipole moment eEDM and the scalar-pseudoscalar interaction of the nucleus with electrons, characterized by k_s constant, in LuOH⁺ are studied. The enhancement factors, polarization in the external electric field, hyperfine interaction, and rovibrational structure are calculated. The study is required for the experiment preparation and extraction of the eEDM and k_s values from experimental data.

Collinear Factorization At Subasymptotic Kinematics And Validation In A Diquark Spectator Model, Juan V. Guerrero, Alberto Accardi

Physics Faculty Publications

We revisit the derivation of collinear factorization for Deep Inelastic Scattering at subasymptotic values of the four-momentum transfer squared, where the masses of the particles participating in the interaction cannot be neglected. By using an inclusive jet function to describe the scattered quark final state, we can restrict the needed parton kinematic approximations just to the four-momentum conservation of the hard scattering process, and explicitly expand the rest of the diagram in powers of the unobserved parton transverse momenta rather than neglecting those. This procedure provides one with more flexibility in fixing the virtuality of the scattered and recoiling partons …

X17 Boson And The ³H(P, E⁺E⁻) ⁴He And ³He(N,E⁺E⁻) ⁴He Processes: A Theoretical Analysis, M. Viviani, E. Filandri, C. Gustavino, A. Kievsky, L. E. Marcucci, Rocco Schiavilla

Physics Faculty Publications

The present work deals with e⁺−e⁻ pair production in the four-nucleon system. We first analyze the process as a purely electromagnetic one in the context of a state-of-the-art approach to nuclear strong-interaction dynamics and nuclear electromagnetic currents, derived from chiral effective field theory (χEFT). Next, we examine how the exchange of a hypothetical low-mass boson would impact the cross section for such a process. We consider several possibilities, that this boson is either a scalar, pseudoscalar, vector, or axial particle. The ab initio calculations use exact hyperspherical-harmonics methods to describe the bound state and low-energy spectrum of …