122344374
Predictions of unknown masses and their applications
In this paper we predict atomic masses which are not experimentally accessible by using local mass relations which connect with the proton-neutron interactions with improved accuracy. Based on our predicted masses, we investigate one-proton and one-neutron drip lines for a few regions in the nuclide chart and α-decay half-lives times for some isotopes with proton number 102 Z 106. The impact of our predicted one-neutron separation energies on astrophysical r-process nucleosynthesis is discussed within the framework of a classical r-process model.
126298012
New Geiger-Nuttall law for alpha decay of heavy 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.
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.
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.
21554167
Measurement of the muon reconstruction performance of the ATLAS detector using 2011 and 2012 LHC proton–proton collision data
This paper presents the performance of the ATLAS muon reconstruction during the LHC run with $$pp$$pp collisions at $$\sqrt{s}=7$$s=7–8 TeV in 2011–2012, focusing mainly on data collected in 2012. Measurements of the reconstruction efficiency and of the momentum scale and resolution, based on large reference samples of $${J/\psi \rightarrow \mu \mu }$$J/ψ→μμ, $$Z \rightarrow \mu \mu $$Z→μμ and $${\Upsilon \rightarrow \mu \mu }$$Υ→μμ decays, are presented and compared to Monte Carlo simulations. Corrections to the simulation, to be used in physics analysis, are provided. Over most of the covered phase space (muon $$|\eta |<2.7$$|η|<2.7 and $$5 \lesssim p_{\mathrm{T}}\lesssim 100$$5≲pT≲100 GeV) the efficiency is above $$99\,\%$$99% and is measured with per-mille precision. The momentum resolution ranges from $$1.7\,\%$$1.7% at central rapidity and for transverse momentum $$p_{\mathrm{T}}\simeq 10$$pT≃10 GeV, to $$4\,\%$$4% at large rapidity and $$p_{\mathrm{T}}\simeq 100$$pT≃100 GeV. The momentum scale is known with an uncertainty of $$0.05\,\%$$0.05% to $$0.2\,\%$$0.2% depending on rapidity. A method for the recovery of final state radiation from the muons is also presented.
118293635
Measurement of inelastic J/PSI production in deep inelastic scattering at HERA
The inelastic production of J/psi mesons in ep collisions has been studied with the ZEUS detector at HERA using an integrated luminosity of 109 pb(-1). The J/psi mesons were identified using the decay channel J/psi -> mu(+)mu(-). The measurements were performed in the kinematic range 2 < Q(2) < 80 GeV2, 50 < W < 250 GeV, 0.2 < z < 0.9 and -1.6 < Y-lab < 1.3, where Q(2) is the virtuality of the exchanged photon, W is the photon-proton centre-of-mass energy, z is the fraction of the photon energy carried by the J/psi meson in the proton rest frame and Ylab is the rapidity of the J/psi in the laboratory frame. The measured cross sections are compared to theoretical predictions within the non-relativistic QCD framework including colour-singlet and colour-octet contributions, as well as to predictions based on the k(T)-factorisation approach. Calculations of the colour-singlet process generally agree with the data, whereas inclusion of colour-octet terms spoils this agreement.
73533447
Measurement of J/ψ photoproduction at large momentum transfer at HERA
The proton-dissociative diffractive photoproduction of J/ψ mesons has been studied in ep collisions with the ZEUS detector at HERA using an integrated luminosity of 112 pb−1. The cross section is presented as a function of the photon-proton centre-of-mass energy and of the squared four-momentum transfer at the proton vertex. The results are compared to perturbative QCD calculations.
3070782
Combined inclusive diffractive cross sections measured with forward proton spectrometers in deep inelastic ep scattering at HERA
A combination of the inclusive diffractive cross section measurements made by the H1 and ZEUS Collaborations at HERA is presented. The analysis uses samples of diffractive deep inelastic ep scattering data at a centre-of-mass energy $\sqrt{s}=318~\mathrm{GeV}$ where leading protons are detected by dedicated spectrometers. Correlations of systematic uncertainties are taken into account, resulting in an improved precision of the cross section measurement which reaches 6 % for the most precise points. The combined data cover the range 2.5<Q2<200 GeV2 in photon virtuality, $0.00035 < \mbox{$x_{\mathbb{P}}$}< 0.09$ in proton fractional momentum loss, 0.09<|t|<0.55 GeV2 in squared four-momentum transfer at the proton vertex and 0.0018<β<0.816 in $\beta=x/\mbox{$x_{\mathbb{P}}$}$, where x is the Bjorken scaling variable.
5770458
Search for stop production in R-parity-violating supersymmetry at HERA
A search for stop production in R-parity-violating supersymmetry has been performed in e+p interactions with the ZEUS detector at HERA, using an integrated luminosity of 65 pb-1. At HERA, the R-parity-violating coupling λ’ allows resonant squark production, $e^+d\to\tilde{q}$. Since the lowest-mass squark state in most supersymmetry models is the light stop, $\tilde{t}$, this search concentrated on production of $\tilde{t}$, followed either by a direct R-parity-violating decay, or by the gauge decay to $b\tilde{\chi}^+_{1}$. No evidence for stop production was found and limits were set on λ’131 as a function of the stop mass in the framework of the minimal supersymmetric standard model. The results have also been interpreted in terms of constraints on the parameters of the minimal supergravity model.