121361611
Some general properties of projectile fragments in 40Ar interactions in nuclear emulsions at 1.8 A GeV
An analysis of projectile fragments has been performed using 40Ar-emulsion interactions at 1.8 A GeV. The interaction mean free path of 40Ar nuclei was obtained on the basis of 4600 events which enabled one to calculate the total inelastic cross section. Correlations between the multiplicity of different charged particles were studied extensively to get an insight into the reaction mechanism. The average number of interacting nucleons of the projectile was calculated and compared with results from other experiments. Events with projectile fragments were divided into various reaction channels and several parameters like average emission angle and target particle multiplicities were studied as a function of target mass in different reaction channels. The projectile fragmentation properties were found to be independent of the target for peripheral collisions.
122669680
Charged Particles Multiplicity in Interactions of 3.7 A GeV 28Si with Light and Heavy Target Nuclei in Nuclear Emulsions
Results from measurement of multiplicity of different charged particles emitted from the interactions of 3.7 A GeV 28 Si with different target groups in nuclear emulsion and correlations among them are presented. The nature of the dependence of multiplicities of charged particles on the impact parameter is examined. Analysis of data in terms of specific multiplicity for different target groups is performed and the results are discussed in the light of superposition model.
54934681
Cross section and double helicity asymmetry for eta mesons and their comparison to neutral pion production in p+p collisions at sqrt(s)=200 GeV
Measurements of double-helicity asymmetries in inclusive hadron production in polarized p+p collisions are sensitive to helicity-dependent parton distribution functions, in particular to the gluon helicity distribution, {Delta}g. This study focuses on the extraction of hte double-helicity asymmetry in {eta} production (p+p{yields}{eta}+X), the {eta} cross section, and the {eta}/{pi}{sup 0} cross section ratio. The cross section and ratio measurements provide essential input for the extraction of fragmentation functions that are needed to acess the helicity-dependent parton distribution functions.
121070748
Integral frequency distribution of projectile alpha fragments in nuclear multifragmentations at intermediate and high energies
The integral frequency distributions of the numbers of projectile alpha fragments produced in nuclear multifragmentations at intermediate and high energies are studied by a simple two-source model. The calculated results are approximately in agreement with the experimental data of 16 O, 40 Ar, 56 Fe, 84 Kr, 139 La, and 197 Au multifragmentations in nuclear emulsions at 2.00 A , 1.80 A , 1.80 A , 0.08–1.70 A , 0.60–0.99 A , and 0.60–0.99 A GeV, respectively. The initial energy of nuclear limiting fragmentation is expected to be at or lower than 0.08 A GeV. Two correlations between the mean multiplicity of projectile alpha fragments ( 〈 n α 〉 ) and the projectile mass number, as well as 〈 n α 〉 and the maximum multiplicity of projectile alpha fragments are observed.
121122740
PSEUDORAPIDITY DISTRIBUTION OF SHOWER PARTICLES IN 28Si-EMULSION INTERACTIONS AT 4.5 A GeV/c PER NUCLEON
Pseudorapidity density distributions of relativistic charged particles produced in 28Si-induced interactions in nuclear emulsion at JINR Synchrophasotron have been measured. The particle distributions in minimum-bias events exhibit a pronounced forward asymmetry with respect to the peak in the pseudorapidity spectra. The effect of intranuclear collisions on the mean pseudorapidity distribution versus the shower particles (ns) or the grey particles is discussed and compared with similar studies of 28Si and 32S at BNL AGS and CERN SPS energies respectively.
60626146
ILC Reference Design Report: ILC Global Design Effort and World Wide Study
120483275
Role of high ℓ values in the onset of incomplete fusion
A particle-$\ensuremath{\gamma}$-coincidence experiment is performed to investigate the role of high $\ensuremath{\ell}$ values in the production of direct-$\ensuremath{\alpha}$-emitting channels (associated with incomplete fusion) in $^{12}\mathrm{C}+^{169}\mathrm{Tm}$ system. Spin distributions of various $\mathit{xn}/\mathit{pxn}/\ensuremath{\alpha}\mathit{xn}/2\ensuremath{\alpha}\mathit{xn}$ channels are measured at ${E}_{\mathrm{lab}}=5.6A$ and $6.5A$ MeV. Entirely different de-excitation patterns are observed in direct-$\ensuremath{\alpha}$-emitting channels and fusion-evaporation channels. The fusion-evaporation channels are found to be strongly fed over a broad spin range. While narrow range feeding for only high-spin states was observed in the case of direct-$\ensuremath{\alpha}$-emitting channels, in the present work, incomplete fusion is shown to be a promising tool to populate high-spin states in final reaction products. To have better insight into the associated $\ensuremath{\ell}$ values in different reaction channels, the present data are compared with similar data obtained in $^{16}\mathrm{O}({E}_{\mathrm{lab}}\ensuremath{\approx}5.6A \mathrm{MeV}) + ^{169}\mathrm{Tm}$ system. The mean driving angular momenta involved in the production of direct-$\ensuremath{\alpha}$-emitting channels are found to be higher than those involved in the production of fusion-evaporation channels. Direct-$\ensuremath{\alpha}$ multiplicity in the forward cone increases with driving angular momenta, which indicates the origin of direct-$\ensuremath{\alpha}$-emitting channels at high $\ensuremath{\ell}$ values in noncentral interactions.