The independent cross section ratio for production of nuclei from 197Au targets irradiated with 4 GeV deuterons have been measured by off-line gamma-spectroscopy. On the basis of the measured independent cross section ratio of 198m, gAu the average intrinsic angular momentum of the primary nucleus was estimated by means of a simple statistical-model analysis based on the formalism developed by Huizenga and Vandenbosch.
The cross sections of 110 radioactive nuclide with mass numbers 22 < A < 198 amu from the interaction of 2.2 GeV/nucleon deuterons from the Nuclotron of the Laboratory of High Energies (LHE), Joint Institute for Nuclear Research (JINR) at Dubna with a 197Au target are investigated using induced activity method. The results including charge and mass distributions are parameterized in terms of 3-parameter equation in order to complete the real isobaric distribution. Using data from charge distribution total mass-yield distribution was obtained. The analysis of the mass-yield distribution allows to suppose existence of different channels of the interaction such as spallation, deep spallation, fission-like and multifragmentation processes.
The recoil properties of fragments produced by the interaction of 4.4 GeV deuteron with 197Au target have been studied. New experimental data on recoil properties for 90 nuclei, varying from 24Na to 198Au, were obtained. The technique applied was the {thick-target thick-catcher} and induced activity method. The deuteron beam was obtained from the Nuclotron of the Laboratory of High Energies (LHE), Joint Institute for Nuclear Research (JINR), Dubna. The experimental data were analyzed on the basis of the standard two-step vector model formalism. From this analysis we could find evidence to support the existence of several different mechanisms, such as spallation, fission and fragmentation, in the reaction investigated. Fission contributed appreciably to the formation of products in the mass region of 65 < A < 120. The kinematic characteristics of residual nuclei formed in the present deuteron-induced reaction have been compared to those from proton-induced reactions with gold target.
We present transverse momentum (p_T) spectra of charged hadrons measured in deuteron-gold and nucleon-gold collisions at sqrts = 200 GeV for four centrality classes. Nucleon-gold collisions were selected by tagging events in which a spectator nucleon was observed in one of two forward rapidity detectors. The spectra and yields were investigated as a function of the number of binary nucleon-nucleon collisions, u, suffered by deuteron nucleons. A comparison of charged particle yields to those in p+p collisions show that the yield per nucleon-nucleon collision saturates with u for high momentum particles. We also present the charged hadron to neutral pion ratios as a function of p_T.
Jet production rates are measured in $p$$+$$p$ and $d$$+$Au collisions at $sqrt{s_{NN}}$=200 GeV recorded in 2008 with the PHENIX detector at the Relativistic Heavy Ion Collider. Jets are reconstructed using the $R=0.3$ anti-$k_{t}$ algorithm from energy deposits in the electromagnetic calorimeter and charged tracks in multi-wire proportional chambers, and the jet transverse momentum ($p_T$) spectra are corrected for the detector response. Spectra are reported for jets with $12<p_T<50$ GeV/$c$, within a pseudorapidity acceptance of $left|etaright|<0.3$. The nuclear-modification factor ($R_{d{rm Au}}$) values for 0%--100% $d$$+$Au events are found to be consistent with unity, constraining the role of initial state effects on jet production. However, the centrality-selected $R_{d{rm Au}}$ values and central-to-peripheral ratios ($R_{rm CP}$) show large, $p_T$-dependent deviations from unity, which challenge the conventional models that relate hard-process rates and soft-particle production in collisions involving nuclei.
The total cross sections were measured for coherent double neutral-pion photoproduction on the deuteron at incident energies below 0.9 GeV for the first time. No clear resonance-like behavior is observed in the excitation function for $W_{gamma d}=2.38$--2.61 GeV, where the $d^*(2380)$ dibaryon resonance observed at COSY is expected to appear. The measured excitation function is consistent with the existing theoretical calculation for this reaction. The upper limit of the total cross section is found to be $0.034$~$mu$b for the dibaryon resonance at $W_{gamma d}=2.37$~GeV (90% confidence level) in the $gamma d to pi^0pi^0 d$ reaction.
A. R. Balabekyan
,N. A. Demekhina
,G. S. Karapetyan
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(2014)
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"Production of isomeric states in the deuteron-induced reaction of gold at incident energy 4 GeV"
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Gayane Karapetyan
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