Search results for "Elementary particles"
showing 10 items of 60 documents
Análisis de las colisiones elásticas entre nucleos de la capa S-d a energías próximas a la barrera de Coulomb
1987
Estudio y test de detectores silicio para la reconstrucción de trazas en la zona de bajo ángulo del detector de atlas de LHC del CERN
1999
Extensión de CHPT a energías superiores
1998
Análisis de la estructura de corrientes Cargadas y Neutras a partir de procesos Nucleares Semileptonicos
1983
Asimetría de carga en la colisión de Leptones Positivos y Negativos con Núcleos : Efecto del intercambio de dos Fotones
1984
μ-e conversion in nuclei and Z' physics
1993
Together with the existence of new neutral gauge bosons, models based on extended gauge groups (rank > 4) often predict also new charged fermions. A mixing of the known fermions with new states with exotic weak-isospin assignments (left-handed singlets and right-handed doublets) will induce tree level flavour changing neutral interactions mediated by Z exchange, while if the mixing is only with new states with ordinary weak-isospin assignments, the flavour changing neutral currents are mainly due to the exchange of the lightest new neutral gauge boson Z'. We show that the present experimental limits on μ-e conversion in nuclei give a nuclear-model-independent bound on the Z-e-μ vertex which…
Search for quarks in proton-proton interactions at √s = 52.5 GeV
1978
The results of an experiment to search for quarks in pp collisions, at a total centre-of-mass energy √s = 52.5 GeV, are reported. The experiment was sensitive to fractionally charged particles with 0.035e ⩽ |Q| ⩽ 0.67e,β =v/c ⩾ 0.1, and masses up to 21 GeV/c2. The 90% confidence level on the ratio «quark flux/charged-particle flux» is 5.11 · 10−11 for |Q| = 1/3e. This value holds true for particles produced with a mean transverse momentum of 0.4 GeV/c.
Parity violation correlations in light muonic atoms
1989
The 2 S -1 S transition in light muonic atoms is very sensitive to parity violation correlations induced via neutral currents. Observables depending on these transitions such as the photon polarization and the angular correlation between the emitted radiation and the atom polarization are a clear signal of weak neutral currents in atoms. We find the relation between the lepton and quark couplings and these observables emphasizing the effect of the nuclear spin. The results expected in muonic, atoms μ- 4 He and μ- 3 He are given.
Search for ultrahigh energy neutrinos in highly inclined events at the Pierre Auger Observatory
2011
Erratum: Phys. Rev. D 85, 029902(E) (2012) [http://dx.doi.org/10.1103/PhysRevD.85.029902]
Study of Two-Photon Exchange via the Beam Transverse Single Spin Asymmetry in Electron-Proton Elastic Scattering at Forward Angles over a Wide Energy…
2020
We report on a new measurement of the beam transverse single spin asymmetry in electron-proton elastic scattering, $A^{ep}_{\perp}$, at five beam energies from 315.1 MeV to 1508.4 MeV and at a scattering angle of $30^{\circ} < \theta < 40^{\circ}$. The covered $Q^2$ values are 0.032, 0.057, 0.082, 0.218, 0.613 (GeV/c)$^2$. The measurement clearly indicates significant inelastic contributions to the two-photon-exchange (TPE) amplitude in the low-$Q^2$ kinematic region. No theoretical calculation is able to reproduce our result. Comparison with a calculation based on unitarity, which only takes into account elastic and $\mathrm{\pi N}$ inelastic intermediate states, suggests that there are ot…