We present our results on transverse momentum fluctuations, multiplicity fluctuations and transverse momentum distributions
for baryons and mesons in the framework of the clustering of color sources. We determine under what conditions the initial
state configurations can lead to color connection, and more specifically, if variations of the initial state can lead to a
transition from disconnected to connected color clusters, modifying the number of effective sources. We find that beyond a
critical point, one has a condensate, containing interacting and hence color-connected sources. This point thus specifies
the onset of color deconfinement. We show that the transverse momentum and multiplicity distributions are related to each
other in a defined way. We obtain a non-monotonic dependence of the pT and multiplicity fluctuations with the number of participants. We present our results for the fluctuations and the transverse
momentum distributions at RHIC energies compared to the existing experimental data and our predictions for LHC energies. 相似文献
Let \(\pi {:}\, P\rightarrow M\) be a principal bundle and p an invariant polynomial of degree r on the Lie algebra of the structure group. The theory of Chern–Simons differential characters is exploited to define a homology map \(\chi ^{k} {:}\, H_{2r-k-1}(M)\times H_{k}({\mathcal {F}}/{\mathcal {G}})\rightarrow {\mathbb {R}}/{\mathbb {Z}}\), for \(k<r-1\), where \({\mathcal {F}} /{\mathcal {G}}\) is the moduli space of flat connections of \(\pi \) under the action of a subgroup \({\mathcal {G}}\) of the gauge group. The differential characters of first order are related to the Dijkgraaf–Witten action for Chern–Simons theory. The second-order characters are interpreted geometrically as the holonomy of a connection in a line bundle over \({\mathcal {F}}/{\mathcal {G}}\). The relationship with other constructions in the literature is also analyzed.
Let
be the bundles of linear frames and Riemannian metrics of a manifold M, respectively. The existence of a unique Diff M-invariant connection form on
, which is Riemannian with respect to the universal metric on
, is proved. Applications to the construction of universal Pontryagin and Euler forms, are given.
Authors’ addresses: R. Ferreiro Pérez, Departamento de Economía Financiera y Contabilidad I, UCM, Campus de Somosaguas, 28223
Madrid, Spain; J. Mu?oz Masqué, Insituto de Física Aplicada, CSIC, C/Serrano 144, 28006 Madrid, Spain 相似文献
A projectile ion-recoil ion coincidence technique has been employed to study the multiple ionization and the charge transfer
processes in collisions of 60–120 MeV Siq+ (q = 4−14) ions with neutral argon atoms. The relative contribution of different ionization channels, namely; direct ionization,
electron capture and electron loss leading to the production of slow moving multiply charged argon recoil ions have been investigated.
The data reported on the present collision system result from a direct measurement in the considered impact energy for the
first time. The total ionization cross-sections for the recoil ions are shown to scale as q1.7/Ep0.5
, where Ep is the energy in MeV of the projectile and q its charge state. The recoil fractions for the cases of total- and direct ionizations are found to decrease with increasing
recoil charge state j. The total ionization fractions of the recoils are seen to depend on q and to show the presence of a ‘shell-effect’ of the target. Further, the fractions are found to vary as 1/j2 upto j = 8+. The average recoil charge state 〈j〉 increases slowly with q and with the number of lost or captured electrons from or into the projectile respectively. The projectile charge changing
cross-sections σqq′ are found to decrease with increasing q for loss ionization and to increase with q for direct-and capture ionization processes respectively. The physics behind various scaling rules that are found to follow
our data for different ionization processes is reviewed and discussed. 相似文献
Large enhancements have been observed in the sub-barrier fusion cross sections for Ti+Ni systems in our previous studies.
Coupled channel calculations incorporating couplings to 2+ and 3− states failed to explain these enhancements completely. A possibilty of transfer channels contributing to the residual enhancements
had been suggested. In order to investigate the role of relevant transfer channels, measurements of one- and two-nucleon transfer
were carried out for 46,48Ti+61Ni systems. The present paper gives the results of these studies. 相似文献
This research paper presents a preliminary thermodynamic study of an innovative power plant operating under a Rankine cycle fed by an external combustion system with turbo-blower (TB). The power plant comprises an external combustion system for natural gas, where the combustion gases yield their thermal energy, through a heat exchanger, to a carbon dioxide Rankine cycle operating under supercritical conditions and with quasi-critical condensation. The TB exploits the energy from the pressurised exhaust gases for compressing the combustion air. The study is focused on the comparison of the combustion system’s conventional technology with that of the proposed. An energy analysis is carried out and the effect of the flue gas pressure on the efficiency and on the heat transfer in the heat exchanger is studied. The coupling of the TB results in an increase in efficiency and of the convection coefficient of the flue gas with pressure, favouring a reduced volume of the heat exchanger. The proposed innovative system achieves increases in efficiency of around 12 % as well as a decrease in the heat exchanger volume of 3/5 compared with the conventional technology without TB. 相似文献
The inclusion of string fusion in Dual Parton Model results in the appearance of diquark-antidiquark pairs in the sea with comparatively large Feynman-x. Such antidiquarks can fragment into fast antibaryons, thus increasing several times the corresponding yields in high energy pp collisions for xF ~ 0.8 ÷ 0.9. String fusion also results in an unusual dependence of inclusive spectra on the multiplicity of secondaries. Some numerical estimations are presented. 相似文献
Ab initio and DFT methods were used in combination with various basis sets in order to examine the [4 + 2] Diels–Alder cycloaddition reactions of ethene with 1,3-butadiene, 1,2,4-pentatriene, and 1,2,4,5-hexatetraene with a view to elucidating the role of the allene group in this type of pericyclic reaction. Based on the calculations, the insertion of an allene group decreases the activation energy and increases the exothermal character of the reaction. The decrease is even more marked in the presence of two allene groups, particularly with regard to the reaction enthalpy, which exhibits an additive effect. 相似文献