Glueball Masses in Relativistic Potential Model

The problem of glueball mass spectra using the relativistic Dirac equation is studied. Also the Breit-Fermi approach used to obtaining hyperfine splitting in glueballs. Our approach is based on the assumption, that the nature and the forces between two gluons are the short-range. We were to calculate the glueball masses with used screened potential.Comment: 7 pages, LaTe

Kinetically constrained freezing transition in a dipole-conserving system

We study a stochastic lattice gas of particles in one dimension with strictly finite-range interactions that respect the fracton-like conservation laws of total charge and dipole moment. As the charge density is varied, the connectivity of the system's charge configurations under the dynamics changes qualitatively. We find two distinct phases: Near half filling the system thermalizes subdiffusively, with almost all configurations belonging to a single dynamically connected sector. As the charge density is tuned away from half filling there is a phase transition to a frozen phase where locally active finite bubbles cannot exchange particles and the system fails to thermalize. The two phases exemplify what has recently been referred to as weak and strong Hilbert space fragmentation, respectively. We study the static and dynamic scaling properties of this weak-to-strong fragmentation phase transition in a kinetically constrained classical Markov circuit model, obtaining some conjectured exact critical exponents.Comment: 12 pages, 7 figures, 1 table; added new Appendix and additional results in v2; added new Appendix and clarified explanations in v3; published in Physical Review

BB and BcB_c mesons with NRQCD and Clover actions

We present preliminary results from our study of the heavy-light spectrum and decay constants. For the heavy quark, we use NRQCD at various masses around and above the $b$ quark mass. For the first time, the heavy quark action and the heavy-light current consistently include corrections at second order in the non-relativistic expansion, as well as the leading finite $a$ corrections. The light quarks are simulated using a tadpole-improved Clover action at various masses in the strange and $c$ quark region.Comment: 6 Pages LaTex. Axis files of figures included. Joint writeup of two talks presented at LATTICE96(heavy quarks

The glueball spectrum from an anisotropic lattice study

The spectrum of glueballs below 4 GeV in the SU(3) pure-gauge theory is investigated using Monte Carlo simulations of gluons on several anisotropic lattices with spatial grid separations ranging from 0.1 to 0.4 fm. Systematic errors from discretization and finite volume are studied, and the continuum spin quantum numbers are identified. Care is taken to distinguish single glueball states from two-glueball and torelon-pair states. Our determination of the spectrum significantly improves upon previous Wilson action calculations.Comment: 14 pages, 8 figures, uses REVTeX and epsf.sty (final version published in Physical Review D

Renormalization-group study of the many-body localization transition in one dimension

Using a new approximate strong-randomness renormalization group (RG), we study the many-body localized (MBL) phase and phase transition in one-dimensional quantum systems with short-range interactions and quenched disorder. Our RG is built on those of Zhang $\textit{et al.}$ [1] and Goremykina $\textit{et al.}$ [2], which are based on thermal and insulating blocks. Our main addition is to characterize each insulating block with two lengths: a physical length, and an internal decay length $\zeta$ for its effective interactions. In this approach, the MBL phase is governed by a RG fixed line that is parametrized by a global decay length $\tilde{\zeta}$, and the rare large thermal inclusions within the MBL phase have a fractal geometry. As the phase transition is approached from within the MBL phase, $\tilde{\zeta}$ approaches the finite critical value corresponding to the avalanche instability, and the fractal dimension of large thermal inclusions approaches zero. Our analysis is consistent with a Kosterlitz-Thouless-like RG flow, with no intermediate critical MBL phase.Comment: 9 pages, 4 figures; published in Physical Review

Status of Inclusive Educational Placement for Students with Extensive and Pervasive Support Needs

Reauthorization of IDEA in 2004 established procedural mandates and accountability requirements ensuring all students with disabilities participate and progress in general education curriculum. Broadly speaking, improvements toward greater access have been found for many students with disabilities, however the extent to which this holds true for students with extensive and pervasive support needs is not evident. Past research associated with LRE for students with extensive and pervasive support needs was considered when replicating previous research using the cumulative placement rate to analyze LRE data for students with extensive and pervasive support needs (autism, intellectual disability, deaf blindness, and multiple disabilities). Results indicate that student with extensive and pervasive support needs have substantially less positive LRE placement trends over the past 15 years with most placed in separate classrooms and settings. Recommendations for transforming federal and state policies and procedures are shared

Inclusive Education National Research Advocacy Agenda: A Call to Action

The TASH Inclusive Education National Committee responded to Horner and Dunlap’s (2012) call to ensure that future research integrates inclusive values with strong science by developing an inclusive education (IE) national research agenda. Qualitative methods were implemented to answer three questions: (a) What is the state of IE research? (b) What research still must be done? and (c) What are recommendations for a national IE research advocacy agenda? The findings include 15 areas organized within three domains advocating for continued research across systems level capacity building and support, building and classroom capacity for inclusive education, and student learning and development. Implications for research and policy reform are discussed

On the glueball spectrum in O(a)-improved lattice QCD

We calculate the light `glueball' mass spectrum in N_f=2 lattice QCD using a fermion action that is non-perturbatively O(a) improved. We work at lattice spacings a ~0.1 fm and with quark masses that range down to about half the strange quark mass. We find the statistical errors to be moderate and under control on relatively small ensembles. We compare our mass spectrum to that of quenched QCD at the same value of a. Whilst the tensor mass is the same (within errors), the scalar mass is significantly smaller in the dynamical lattice theory, by a factor of ~(0.84 +/- 0.03). We discuss what the observed m_q dependence of this suppression tells us about the dynamics of glueballs in QCD. We also calculate the masses of flux tubes that wind around the spatial torus, and extract the string tension from these. As we decrease the quark mass we see a small but growing vacuum expectation value for the corresponding flux tube operators. This provides clear evidence for `string breaking' and for the (expected) breaking of the associated gauge centre symmetry by sea quarks.Comment: 33pp LaTeX. Version to appear in Phys. Rev.

Universality classes of thermalization for mesoscopic Floquet systems

We identify several distinct phases of thermalization that can occur in periodically driven mesoscopic or intermediate-scale quantum chaotic systems. In doing so, we also identify a new Floquet thermal ensemble, the ``ladder ensemble", that is qualitatively distinct from the ``featureless infinite-temperature" state that has long been assumed to be the appropriate equilibrium ensemble for driven systems. The phases we find can be coarsely classified by (i) whether or not the system irreversibly exchanges energy of order $\omega$ with the drive, i.e., Floquet thermalizes, and (ii) the Floquet thermal ensemble describing the final equilibrium in systems that do Floquet thermalize. These phases are representative of regimes of behavior in mesoscopic systems, but they are sharply defined in a particular large-system limit where the drive frequency $\omega$ scales up with system size $N$ as the $N\to\infty$ limit is taken: we examine frequency scalings ranging from a weakly $N$-dependent $\omega(N) \sim \log N$, to stronger scalings ranging from $\omega(N) \sim \sqrt{N}$ to $\omega(N) \sim N$. We show that the transition where Floquet thermalization breaks down happens at an extensive drive frequency and, beyond that, systems that do not Floquet thermalize are distinguished based on the presence or absence of rare resonances across Floquet zones. We produce a thermalization phase diagram that is relevant for numerical studies of Floquet systems and experimental studies on intermediate-scale quantum simulators, both of which are limited to finite-size systems that lack a clean separation of scales between $N$ and $\omega$. A striking prediction of our work is that certain experimentally observable quench protocols from simple initial states can show Floquet thermalization to a novel type of Schrodinger-cat state that is a global superposition of states at distinct temperatures.Comment: 17 pages, 8 figure