120478740
Theoretical study on parity-violating electron scattering off isotonic nuclei
Abstract The parity-violating electron scattering off isotonic nuclei has been investigated in various nuclear models by the partial wave method. The sensitivities ϵ R n of A pv to neutron radius R n and statistical errors Δ R n / R n of isotonic nuclei in PVS experiments are studied. The parity-violating asymmetries A pv of isotonic nuclei are calculated with a large sample of nuclear mean field models and presented as a function of neutron skin thickness R n − R p . It can be observed that there is high linear dependence between A pv and neutron skin thickness R n − R p . By comparing the linear fit formula of A pv and R n − R p of isotonic nuclei, we can deduce the neutron RMS radius of isotonic nuclei and study the influences of protons on neutron density distributions.
122795101
Relativistic eikonal approaches to parity violating electron-nucleus scattering
The Coulomb electron scattering on even-even nuclei and the magnetic electron scattering on odd-$A$ nuclei have been investigated in the relativistic eikonal approximation and in the plane wave Born approximation, respectively. In this article, we generalize the relativistic eikonal approximation to the parity violating electron scattering on even-even nuclei. The parity violating asymmetries at electron energy of 850 MeV are calculated for three typical cases: Ca isotopes, $N=50$ isotones, and $N=Z$ doubly magic nuclei. In calculations the proton and neutron densities are obtained from the relativistic mean-field theory. The parity violating asymmetries are analyzed by comparing both the form factors and the densities of neutrons and protons. It is found that the parity violating asymmetries are sensitive to the differences between neutron and proton densities. Our results provide useful references for the parity violating electron-nucleus scattering experiments in the future.
121588345
Coupled-channels study of fine structure in the {alpha} decay of well deformed nuclei
We formulate a theoretical model for the {alpha} decay of well-deformed even-even nuclei based on the coupled-channel Schroedinger equation. The {alpha}-decay half-lives and fine structures observed in {alpha} decay are well described by the five-channel microscopic calculations. Since the branching ratios to high-spin states are hard to understand in the traditional {alpha}-decay theories, this success could be important to interpret future observations of heavier nuclei. It is also found that the {alpha} transition to high-spin states is a powerful tool to probe the energy spectrum and deformation of daughter nuclei.
119699060
β-decay half-lives including first-forbidden contributions for neutron-rich Zn isotopes in the extended QRPA with neutron-proton pairing
The β decays of neutron-rich Zn isotopes are investigated within the extended quasiparticle random-phase approximation, where neutron-neutron, proton-proton, and neutron-proton pairing correlations are considered in the similar manner. The Bruckner G-matrix obtained with the charge-dependent Bonn nucleon-nucleon force is used for the residual particle-particle and particle-hole interactions in addition to the pairing interactions. Contributions from both allowed Gamow-Teller and first-forbidden transitions are considered, and β-decay half-lives together with β-delayed neutron emission probabilities are calculated. The calculated results are found to agree well with the available experimental data.
121943751
Theoretical study of nuclear charge densities with elastic electron scattering
The calculated cross sections for elastic Coulomb electron scattering from the phase-shift analysis method and the eikonal approximation are compared. It is shown that the phase-shift analysis method can reproduce the experimental data very well for both light and heavy nuclei. Then the phase-shift analysis is used to investigate elastic electron scattering along the O and S isotopic chains, where the charge densities are obtained from relativistic mean-field theory. Results show that the minima of the differential cross section shift inward and upward with the increase of the neutron number.
126298012
New Geiger-Nuttall law for alpha decay of heavy nuclei
115149287
Search for new phenomena in photon + jet events collected in proton-proton collisions at s=8 TeV with the ATLAS detector
This Letter describes a model-independent search for the production of new resonances in photon + jet (gamma + jet) events using 20 fb(-1) of proton-proton LHC data recorded with the ATLAS detector ...
53982386
Measurement of charged current deep inelastic scattering cross sections with a longitudinally polarised electron beam at HERA
Measurements of the cross sections for charged current deep inelastic scattering in e−p collisions with longitudinally polarised electron beams are presented. The measurements are based on a data sample with an integrated luminosity of 175 pb−1 collected with the ZEUS detector at HERA at a centre-of-mass energy of 318 GeV. The total cross section is given for positively and negatively polarised electron beams. The differential cross-sections dσ/dQ2, dσ/dx and dσ/dy are presented for Q2>200 GeV2. The double-differential cross-section d2σ/dxdQ2 is presented in the kinematic range 280<Q2<30 000 GeV2 and 0.015<x<0.65. The measured cross sections are compared with the predictions of the Standard Model.
16324397
An NLO QCD analysis of inclusive cross-section and jet-production data from the ZEUS experiment
The ZEUS inclusive differential cross-section data from HERA, for charged and neutral current processes taken with e(+) and e(-) beams, together with differential cross-section data on inclusive jet production in e+ p scattering and dijet production in gamma p scattering, have been used in a new NLO QCD analysis to extract the parton distribution functions of the proton. The input of jet-production data constrains the gluon and allows an accurate extraction of alpha(s)( M-Z) at NLO;alpha(s)( M-Z) = 0.1183 +/- 0.0028( exp.) +/- 0.0008( model).An additional uncertainty from the choice of scales is estimated as +/- 0.005. This is the first extraction of as( M-Z) from HERA data alone.
119256577
Measurement of high-Q2 neutral current deep inelastic e−p scattering cross sections with a longitudinally polarised electron beam at HERA
AbstractMeasurements of the neutral current cross sections for deep inelastic scattering in e−p collisions at HERA with a longitudinally polarised electron beam are presented. The single-differential cross-sections dσ/dQ2, dσ/dx and dσ/dy and the double-differential cross sections in Q2 and x are measured in the kinematic region y<0.9 and Q2>185 GeV2 for both positively and negatively polarised electron beams and for each polarisation state separately. The measurements are based on an integrated luminosity of 169.9 pb−1 taken with the ZEUS detector in 2005 and 2006 at a centre-of-mass energy of 318 GeV. The structure functions 
$x\tilde{F_{3}}$ 
and xF3γZ are determined by combining the e−p results presented in this paper with previously measured e+p neutral current data. The asymmetry parameter A− is used to demonstrate the parity violating effects of electroweak interactions at large spacelike photon virtuality. The measurements agree well with the predictions of the Standard Model.
119312790
Study of taupair production at HERA
A study of events containing two tau leptons with high transverse momentum has been performed with the ZEUS detector at HERA, using a data sample corresponding to an integrated luminosity of 0.33 fb−1. The tau candidates were identified from their decays into electrons, muons or hadronic jets. The number of tau-pair candidates has been compared with the prediction from the Standard Model, where the largest contribution is expected from Bethe-Heitler processes. The total visible cross section was extracted. Standard Model expectations agree well with the measured distributions, also at high invariant mass of the tau pair.