We calculate the differential cross sections for proton elastic scattering on the exotic halo nuclei
6
He and
8
He at energies around ~0.7 GeV at the momentum transfers squared up to 0.30 (GeV/
c
)
2
...and investigate the influence of the nucleon centre-of-mass correlations on the calculated cross sections. In particular, we show that the approximate account of the centre-of-mass correlations used previously considerably overestimates the cross sections at high values of the momentum transfer.
The differential cross sections for small-angle proton elastic scattering on the
6,8,9,11Li nuclei at energies near 700 MeV/nucleon were measured in inverse kinematics using secondary nuclear beams ...at GSI Darmstadt. The hydrogen-filled ionization chamber IKAR was employed as target and recoil proton detector. For determining the nuclear matter radii and radial matter distributions, the measured cross sections have been analysed with the aid of the Glauber multiple-scattering theory. The nuclear matter distribution deduced for
11Li exhibits a very pronounced halo structure, the matter radius of
11Li being significantly larger than those of the
6,8,9Li isotopes. The data on
8,9Li are consistent with the existence of sizable neutron skins in these nuclei. The obtained data allow for a test of various theoretical model calculations of the structure of the studied neutron-rich nuclei.
New experimental method for investigation of the nucleon polarizabilities Yevetska, O.; Watzlawik, S.; Ahrens, J. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
06/2010, Letnik:
618, Številka:
1
Journal Article
Recenzirano
At the continuous wave (cw) Superconducting Darmstadt Electron Linear Accelerator S-DALINAC, a new method has been developed for the determination of the electric (
α
¯
) and magnetic (
β
¯
) ...polarizabilities of the proton and the deuteron. For that purpose the energy and angular dependence of the differential cross-section for elastic
γ
p
and
γ
d
scattering of bremsstrahlung photons in the energy range between 20 and 100
MeV is measured by detecting the recoiling proton (deuteron) in coincidence with the scattered bremsstrahlung photon.
α
¯
and
β
¯
are then found by means of a best fit to a theoretical description of the scattering cross-section with these quantities as open parameters. The experimental setup consists of a bremsstrahlung photon facility, two specially designed high pressure hydrogen (deuterium) ionization chambers which serve as targets and detectors of the recoil proton (deuteron), NaI gamma spectrometers and several additional detectors for beam diagnostics and normalization. The whole setup was tested using bremsstrahlung photon beams with endpoint energies of 60 and 79.3
MeV. The results of the test experiments show that future high-statistics measurements are feasible.
We calculate the differential cross sections for proton elastic scattering on the exotic halo nuclei sup.6He and sup.8He at energies around ~0.7 GeV at the momentum transfers squared up to 0.30 ...(GeV/c).sup.2 and investigate the influence of the nucleon centre-of-mass correlations on the calculated cross sections. In particular, we show that the approximate account of the centre-of-mass correlations used previously considerably overestimates the cross sections at high values of the momentum transfer.
This paper presents a review of studies on the spatial structure of light exotic nuclei performed by the PNPI-GSI collaboration. A series of experiments has been carried out in beams of exotic nuclei ...with an energy of 0.7 GeV/nucleon at the Helmholtz Center for Heavy Ion Research (GSI, Darmstadt), in which the differential cross sections for proton–nucleus small-angle scattering in inverse kinematics have been measured using the ionization spectrometer IKAR developed at PNPI. An analysis of the measured cross sections has allowed us to determine the nuclear matter distributions in the studied nuclei of the He, Li, Be, B, and C isotopes and also to determine the halo sizes in
6
He,
11
Li,
14
Be,
8
B, and
15
C nuclei.
(ProQuest: ... denotes formulae and/or non-USASCII text omitted) Using proton-proton collision data corresponding to an integrated luminosity of 3.0fb super(?1), recorded by the LHCb detector at ...center-of-mass energies of 7 and 8 TeV, the ... decay is observed with a statistical significance of 5.1 standard deviations. By normalizing to B super(+)arrowright D super(0)pi super(+) decays, a measurement of the branching fraction multiplied by the production rates for ... relative to B super(+) mesons in the LHCb acceptance is obtained, ... , where the first uncertainty is statistical and the second is systematic. This decay is expected to proceed predominantly through weak annihilation and penguin amplitudes, and is the first ... decay of this nature to be observed.
(ProQuest: ... denotes formulae and/or non-USASCII text omitted) A search for the B super(0)arrowrightK +K- decay is performed using pp-collision data collected by LHCb. The data set corresponds to ...integrated luminosities of 1.0 and 2.0 fb super(-1) at center-of-mass energies of 7 and 8 TeV, respectively. This decay is observed for the first time, with a significance of more than 5 standard deviations. The analysis also results in an improved measurement of the branching fraction for the ... decay. The measured branching fractions are scriptB(B super(0)arrowrightK+K-)=(7.80+ or -1.27+ or -0.81+ or -0.21) x 10 super(-8) and ... = (6.91+ or -0.54+ or -0.63+ or -0.19+ or -0.40) x 10 super(-7). The first uncertainty is statistical, the second is systematic, the third is due to the uncertainty on the B super(0)arrowrightK +pi super(-) branching fraction used as a normalization. For the ... mode, the fourth accounts for the uncertainty on the ratio of the probabilities for b quarks to hadronize into ... and B super(0) mesons.
Decays of the Xi sub()band Omega sub()bbaryons to the charmless final states ph super(-)h' super(-), where h(') denotes a kaon or pion, are searched for with the LHCb detector. The analysis is based ...on a sample of proton-proton collision data collected at center-of-mass energies radicals= 7 and 8 TeV, corresponding to an integrated luminosity of 3fb super(-1). The decay Xi sub()barrowrightpK super(-)K super(-) is observed with a significance of 8.7 standard deviations, and evidence at the level of 3.4 standard deviations is found for the XI sub()barrowrightpK super(-)pi super(-) decay. Results are reported, relative to the B super(-)arrowrightK+K-K- normalization channel, for the products of branching fractions and b-hadron production fractions. The branching fractions of Xi sub()barrowrightpK super(-)pi super(-) and Xi sub()barrowrightppi super(-)pi super(-) relative to Xi sub()barrowrightpK super(-)K super(-) decays are also measured.
(ProQuest: ... denotes formulae and/or non-USASCII text omitted) The polarization of photons produced in radiative ... decays is studied for the first time. The data are recorded by the LHCb ...experiment in pp collisions corresponding to an integrated luminosity of 3fb super(-1) at center-of-mass energies of 7 and 8 TeV. A time-dependent analysis of the ... decay rate is conducted to determine the parameter scriptA super(white triangle up), which is related to the ratio of right- over left-handed photon polarization amplitudes in barrowrightsgamma transitions. A value of ... is measured. This result is consistent with the standard model prediction within 2 standard deviations.