### Glueball spins in D = 3 Yang-Mills

*Journal of High Energy Physics*Springer

**2019:10**(2019) 175

### Pfaffian particles and strings in SO(2N) gauge theories

*Journal of High Energy Physics*Springer Berlin Heidelberg

**2019:1**(2019) 136

#### Abstract:

We introduce (generalised) Pfaffian operators into our lattice calculations of the mass spectra and confining string tensions of SO(2N) gauge theories, complementing the conventional trace operators used in previous lattice calculations. In SO(6) the corresponding ‘Pfaffian’ particles match the negative charge conjugation particles of SU(4), thus resolving a puzzle arising from the observation that SO(6) and SU(4) have the same Lie algebra. The same holds true (but much more trivially) for SO(2) and U(1). For SO(4) the Pfaffian particles are degenerate with, but orthogonal to, those obtained with the usual single trace operators. That is to say, there is a doubling of the spectrum, as one might expect given that the Lie algebra of SO(4) is the same as that of SU(2)×SU(2). Additional SO(8) and SO(10) calculations of the Pfaffian spectrum confirm the naive expectation that these masses increase with N, so that they cease to play a role in the physics of SO(N) gauge theories as N → ∞. We also calculate the energies of Pfaffian ‘strings’ in these gauge theories. Although all our lattice calculations are for gauge theories in D = 2 + 1, similar conclusions should hold for D = 3 + 1.### On the spectrum and string tension of U(1) lattice gauge theory in 2+1 dimensions

*Journal of High Energy Physics*Springer Verlag

**2019:1**(2019) 63

#### Abstract:

We calculate the low-lying spectra of glueballs and confining flux tubes in the U(1) lattice gauge theory in 2 + 1 dimensions. We see that up to modest lattice spacing corrections, the glueball states are consistent with being multiparticle states composed of non-interacting massive JPC = 0− − particles. We observe that the ag2 → 0 limit is, as expected, unconventional, and follows the well-known saddle-point analysis of Polyakov to a good approximation. The spectrum of closed (winding) flux tubes exhibits the presence of a massive world-sheet excitation whose mass is consistent with that of the bulk screening mass. These U(1) calculations are intended to complement existing lattice calculations of the properties of SU(N ≥ 2) and SO(N ≥ 3) gauge theories in D = 2 + 1.### Spinorial flux tubes in SO(N) gauge theories in 2+1 dimensions

*Journal of High Energy Physics*Springer Verlag

**2018:11**(2018) 132

#### Abstract:

We investigate whether one can observe in SO(3) and SO(4) (lattice) gauge theories the presence of spinorial flux tubes, i.e. ones that correspond to the fundamental representation of SU(2); and similarly for SO(6) and SU(4). We do so by calculating the finite volume dependence of the Jp = 2+ glueball in 2 + 1 dimensions, using lattice simulations. We show how this provides strong evidence that these SO(N) gauge theories contain states that are composed of (conjugate) pairs of winding spinorial flux tubes, i.e. ones that are in the (anti)fundamental of the corresponding SU(N′) gauge theories. Moreover, these two flux tubes can be arbitrarily far apart. This is so despite the fact that the fields that are available in the SO(N) lattice field theories do not appear to allow us to construct operators that project onto single spinorial flux tubes.### SO(N) gauge theories in 2+1 dimensions: Glueball spectra and confinement

*Journal of High-Energy Physics*Springer

**2017**(2017) 22