High Energy Physics - Lattice
Conventional lattice formulations of $\theta$ vacua in the $1+1$-dimensional $\text{O}(3)$ nonlinear sigma model suffer from a sign problem. Here, we construct the first sign-problem-free regularization for arbitrary $\theta$. Using…
We study the application of $\mathrm{SU}(3)$ gauge field smoothing methods to $\mathrm{Z}(3)$-projected center-vortex gauge fields. Due to the proportionality of the vortex links to the identity, naive applications of these methods are…
I make some simple observations about the calculation of weighted averages over energy of Minkowski space spectral densities from weighted averages over time of Euclidean space correlation functions, measured in latice simulations. The…
We present a lattice calculation of the charged/neutral pion mass difference $M_{\pi^{+}}-M_{\pi^{0}}$ at order $\mathcal{O}(\alpha_{em})$ using the gauge configurations produced by the Extended Twisted Mass Collaboration with $N_{f}=2+1+1$…
We consider the $Sp(4)$ gauge theory coupled to $N_f=2$ fundamental and $n_f=3$ antisymmetric flavours of Dirac fermions in four dimensions. This theory serves as the microscopic origin for composite Higgs models with $SU(4)/Sp(4)$ coset,…
In this work, we introduce some new $U(1)$ symmetry groups of the free fermionic action in euclidean space-time, which are a consequence of parity and time-reversal symmetries. Afterwards, we discuss how the introduction of a gauge…
We study the scaling behavior of the (2+1)-flavor QCD crossover region towards the chiral limit with smaller-than-physical light quark mass gauge ensembles, generated using the HISQ fermion discretization. At zero chemical potential, we…
Using effective-range expansion for the two-body amplitudes may generate spurious sub-threshold poles outside of the convergence range of the expansion. In the infinite volume, the emergence of such poles leads to the inconsistencies in the…
The two-dimensional Schwinger model is used to explore how lattice fermion operators perceive the global topological charge $q \in \mathbb{Z}$ of a given background gauge field. We focus on Karsten-Wilczek and Borici-Creutz fermions, which…
We derive the on-shell form of amplitudes containing two external currents with a single hadron in the initial state and two hadrons in the final state, denoted as $1+\mathcal{J}\to 2+\mathcal{J}$. This class of amplitude is relevant in…
Bosonic quantum field theories, even when regularized using a finite lattice, possess an infinite dimensional Hilbert space and, therefore, cannot be simulated in quantum computers with a finite number of qubits. A truncation of the Hilbert…
An $N=\infty$ equivalence among quenched $U(N)$ models on finite lattice tori of $V$ sites is proven to all orders in planar perturbation theory by putting circulant lattice momenta together with group indices on 't Hooft's double lines.…
We present a lattice calculation of the leading corrections to the masses of nucleons and $\Delta$ resonances. These are obtained in QCD+QED at $1$st order in the Isospin Breaking parameters $\alpha_{EM}$, the electromagnetic coupling, and…
We present the first lattice study of pion-pion scattering with varying number of colors, $N_\text{c}$. We use lattice simulations with four degenerate quark flavors, $N_\text{f}=4$, and $N_\text{c}=3-6$. We focus on two scattering channels…
We present a lattice calculation of the mass difference between neutron and proton, for which we find $ M_n - M_p = 1.73(69) \, \text{MeV}$. This is obtained at 1st order in the $QED$ coupling $\alpha_{EM}$ and in the mass difference…
In commonly used Monte Carlo algorithms for lattice gauge theories the integrated autocorrelation time of the topological charge is known to be exponentially-growing as the continuum limit is approached. This…
Interesting lattice QCD simulations at high temperature in QCD and particular truncated studies have shown the emergence of an unexpected group symmetry, so called \textit{chiralspin}. However this is not a symmetry of the QCD action for…
In this paper, we look how to construct in Minkowski space-time a new type of \textit{chiralspin} group transformation of the spinor fields, similar to the one discovered by recent works of \textit{Glozman et al.} in the context of high…
The isovector axial form factor of the nucleon plays a key role in interpreting data from long-baseline neutrino oscillation experiments. We perform a lattice-QCD based calculation of this form factor, introducing a new method to directly…
We initiate the studies on the structural physics of the tower of stable large-$N_c$ mesons through a first computation of the collinear quark-structure of a large-$N_c$ pion using lattice Monte-Carlo methods. We adapt the large-$N_c$…