Alejandro Vaquero Avilés-Casco

Disconnected quark loop contributions to nucleon observables using

We compute the disconnected quark loops contributions entering the determination of nucleon observables, by using a

N_f=2

N_f = 2

twisted clover fermions at the physical value of the light quark mass

ensemble of twisted mass fermions with a clover term at a pion mass

Nucleon electromagnetic form factors using lattice simulations at the physical point

m_\pi = 133

Nucleon spin and quark content at the physical point

MeV. We employ exact deflation and implement all calculations in GPUs, enabling us to achieve large statistics and a good signal.

Disconnected diagrams with twisted-mass fermions

We present results for the nucleon electromagnetic form factors using an ensemble of maximally twisted mass clover-improved fermions with pion mass of about 130 MeV. We use multiple sink-source separations and three analysis methods to probe ground-state dominance. We evaluate both the connected and disconnected contributions to the nucleon matrix elements. We find that the disconnected quark loop contributions to the isoscalar matrix elements are small, giving an upper bound of up to 2% of the connected and smaller than its statistical error. We present results for the isovector and isoscalar electric and magnetic Sachs form factors and the corresponding proton and neutron form factors. By fitting the momentum dependence of the form factors to a dipole form or to the

Implementation of the twisted mass fermion operator in the QUDA library

z

Computation of disconnected contributions to nucleon observables

expansion, we extract the nucleon electric and magnetic radii, as well as the magnetic moment. We compare our results to experiment as well as to other recent lattice QCD calculations.

A QUDA-branch to compute disconnected diagrams in GPUs

We present results on the spin and quark content of the nucleon using

Connected and disconnected contributions to nucleon axial form factors using

N_f=2