Few-neutron removal from "2"3"8U at relativistic energies

As part of a comprehensive study of uranium fragmentation at relativistic energies at the GSI projectile fragment separator, FRS, inclusive neutron-removal cross sections have been measured for several xn channels at projectile energies of 600 and 950 A MeV using targets of Al, Cu and Pb. The variation of the experimental cross sections with target nuclear charge is used to disentangle nuclear and electromagnetic contributions. The electromagnetic cross sections agree surprisingly well with a simple harmonic oscillator calculation of giant dipole resonances based on measured photonuclear cross sections and do not require an extra enhancement of the two-phonon giant dipole excitation as concluded from similar measurements with "1"9"7Au. (orig.)Available from TIB Hannover: RO 801(95-19) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Production and identification of heavy Ni isotopes: Evidence for the doubly magic nucleus "7"8_2_8Ni Short note

We report the first observation of the doubly magic nucleus "7"8Ni_5_0 and the heavy isotopes "7"7Ni, "7"3","7"4","7"5Co, "8"0Cu. The isotopes were produced by nuclear fission in collisions of 750 A.MeV projectiles of "2"3"8U on Be target nuclei. The fully-stripped fission products were separated in-flight by the fragment separator FRS and identified event-by-event by measuring the magnetic rigidity, the trajectory, the energy deposit, and the time of flight. Production cross-sections and fission yields for the new Ni-isotopes are given. (orig.)Available from TIB Hannover: RO 801(95-35) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Fragmentation of a 500 MeV/nucleon "8"6Kr beam, investigated at the GSI projectile fragment separator

Production cross-sections and longitudinal momentum distributions have been investigated for reactions between a 500 MeV/nucleon "8"6Kr beam and beryllium, copper and tantalum targets. Fragments in a wide A/Z range were studied at the projectile-fragment separator FRS at GSI. The experimental production cross-sections have been used for testing the predictions obtained from a semi-empirical parameterization, a statistical abrasion model and an intranuclear-cascade model. The present study allows to extrapolate the production cross-sections towards very neutron-rich isotopes such as the doubly magic nucleus "7"8Ni. For fragments close to the projectile the measured longitudinal momentum distributions agrees qualitatively with a semi-empirical parameterization, which is based on the two-step picture of the fragmentation process. The momentum widths of lighter fragments, however, show deviations from this simple picture. (orig.)Available from TIB Hannover: RO 801(93-74) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Longitudinal momenta and production cross-sections of isotopes formed by fragmentation of a 500 A x MeV "8"6Kr beam

At the projectile-fragment separator FRS at GSI, longitudinal momentum distributions and production cross-sections were investigated for reactions between a 500 A x MeV "8"6Kr beam and beryllium, copper and tantalum targets. Fragments in a wide A/Z range were studied. For fragments close to the projectile the measured longitudinal momentum distributions agree qualitatively with a semi-empirical parametrization. Deviations from this simple picture are found, however, for the momentum widths of light fragments and for the momentum transfer to those fragments that differ in their N/Z ratio from the most probable value. The experimental data on production cross-sections are used for testing the predictions obtained from a semi-empirical parameterization, a geometrical abrasion model and an intranuclear-cascade model. The cross-section for the formation of the doubly magic nucleus "7"8Ni in "8"6Kr fragmentation is estimated to be 17 pb. (orig.)Available from TIB Hannover: RO 801(94-29) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

First spatial isotopic separation of relativistic uranium projectile fragments

Spatial isotopic separation of relativistic uranium projectile fragments has been achieved for the first time. The fragments were produced in peripheral nuclear collisions and spatially separated in-flight with the fragment separator FRS at GSI. A two-fold magnetic-rigidity analysis was applied exploiting the atomic energy loss in specially shaped matter placed in the dispersive central focal plane. Systematic investigations with relativistic projectiles ranging from oxygen up to uranium demonstrate that the FRS is a universal and powerful facility for the production and in-flight separation of monoisotopic, exotic secondary beams of all elements up to Z=92. This achievement has opened a new area in heavy-ion research and applications. (orig.)Available from TIB Hannover: RO 801(94-41) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

The GSI projectile fragment separator (FRS) - a versatile magnetic system for relativistic heavy ions

Available from TIB Hannover: RO 801(91-46) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Observation of B-s(0) -> chi(c1)phi decay and study of B-0 -> chi K-c1,K-2*(0) decays

The first observation of the decay B-s(0) -> chi(c1)phi and a study of B-0 -> chi K-c1,K-2*(0) decays are presented. The analysis is performed using a dataset, corresponding to an integrated luminosity of 1.0 fb(-1), collected by the LHCb experiment in pp collisions at a centre-of-mass energy of 7 TeV. The following ratios of branching fractions are measured: B(B-s(0) -> chi(c1)phi)/B(B-s(0) -> J/psi phi) = (18.9 +/- 1.8 (stat) +/- 1.3 (syst) +/- 0.8(B)) x 10(-2), B(B-0 -> chi K-c1*(0))//B(B-0 -> J/psi K*(0)) = (19.8 +/- 1.1 (stat) +/- 1.2 (syst) +/- 0.9(B)) x 10(-2), B(B-0 -> chi K-c2*(0))//B(B-0 -> chi K-c1*(0)) = (17.1 +/- 5.0 (stat) +/- 1.7 (syst) +/- 1.1(B)) x 10(-2), where the third uncertainty is due to the limited knowledge of the branching fractions of chi(c) -> J/psi gamma modes

First measurement of time-dependent CP violation in Bs0→K+K− B_s^0\to K^+K^- decays

Direct and mixing-induced CP-violating asymmetries in B-s(0) -> K+K- decays are measured for the first time using a data sample of p p collisions, corresponding to an integrated luminosity of 1.0 fb(-1), collected with the LHCb detector at a centre-of-mass energy of 7 TeV. The results are C-KK = 0.14 +/- 0.11 +/- 0.03 and S-KK = 0.30 +/- 0.12 +/- 0.04, where the first uncertainties are statistical and the second systematic. The corresponding quantities are also determined for B-0 -> pi(+)pi(-) decays to be C-pi pi = -0.38 +/- 0.15 +/- 0.02 and S-pi pi = -0.71 +/- 0.13 +/- 0.02, in good agreement with existing measurements

Measurement of the flavour-specific CP-violating asymmetry a(sl)(s) in B-s(0) decays

The CP-violating asymmetry a(sl)(s), is studied using semileptonic decays of B-s(0) and (B) over bar (0)(s) mesons produced in pp collisions at a centre-of-mass energy of 7 TeV at the LHC, exploiting a data sample corresponding to an integrated luminosity of 1.0 fb(-1). The reconstructed final states are D-s(+/-)mu(+/-)(s), with the D-s(+/-) particle decaying in the phi pi(+/-) mode. The D-s(+/-)mu(+/-)(s) yields are summed over B-s(0) and (B) over bar (0)(s) initial states, and integrated with respect to decay time. Data-driven methods are used to measure efficiency ratios. We obtain a(sl)(s) = (-0.06 +/- 0.50 +/- 0.36)%, where the first uncertainty is statistical and the second systematic

Measurement of the charge asymmetry in B-+/- -> phi K +/- and search for B-+/- -> phi pi(+/-) decays

The CP-violating charge asymmetry in B-+/- -> phi K-+/- decays is measured in a sample of pp collisions at 7 TeV centre-of-mass energy, corresponding to an integrated luminosity of 1.0 fb-1 collected by the LHCb experiment. The result is A(CP)(B-+/- -> phi K-+/-) = 0.022 +/- 0.021 +/- 0.009, where the first uncertainty is statistical and the second systematic. In addition, a search for the B-+/- -> phi pi(+/-) decay mode is performed, using the B-+/- -> phi K-+/- decay rate for normalization. An upper limit on the branching fraction B(B-+/- -> phi pi(+/-)) < 1.5 x 10(-7) is set at 90% confidence level. (C) 2013 The Authors. Published by Elsevier B.V. All rights reserved