Electromagnetic form factor of Ds∗ meson from Nf = 2 twisted mass lattice QCD

We investigate the electromagnetic form factor of [Formula: see text] meson using [Formula: see text] twisted mass lattice quantum chromodynamics gauge configurations. The numerical simulations are carried out under twisted boundary conditions which are helpful to increase the resolution in momentum space. We determine electromagnetic form factors with more small four-momentum transfer, and further fit the charge radius for [Formula: see text] meson.

S-boson production in the reaction of Coulomb scattering of a nucleus by a proton or electron

The production cross-section of the beyond the standard model (BSM) scalar boson (S boson) have been considered it the article. Scalar boson produced via photon fusion reaction in the deep inelastic scattering of a charged particle (proton or electron) on heavy nucleus of the target. This process is one of the possible mechanisms of BSM boson production at the SHiP (Search for Hidden Particles) experiment at the CERN LHC and may be dominating among others processes due to large nuclear charge. Previously [1], the amplitude and the production cross-section of this reaction were found. The found cross-section was analyzed for the case of proton scattering on the lead nucleus and compared with the production cross-section in the decay of Ds meson. In this paper we make estimate of the process more accurate and consider also electron-nucleus scattering. It was found that the photon fusion reaction pZ \to S may be effective only in the case of massless S boson.