11,999 research outputs found
A study of the f0(1370), f0(1500), f0(2000) and f2(1950) observed in the centrally produced 4pi final states
The production and decay properties of the f0(1370), f0(1500), f0(2000) and
f2(1950) have been studied in central pp interactions at 450 GeV/c. The dPT,
phi and |t| distributions of these resonances are presented. For the J = 0
states, the f0(1370) and f0(2000) have similar dPT and phi dependences. These
are different to the dPT and phi dependences of the f0(980), f0(1500) and
f0(1710). For the J = 2 states the f2(1950) has different dependences to the
f2(1270) and f2'(1520). This shows that the dPT and phi dependences are not
just J phenomena.Comment: 14 pages, Latex, 4 Figure
Experimental evidence for a vector-like behaviour of Pomeron exchange
Evidence is presented that the Pomeron act as a non-conserved vector current.
A study has been made of the azimuthal angle phi, which is defined as the angle
between the pT vectors of the two outgoing protons, in the reaction pp ->
pp(X0) for those resonances (X0) which are compatible with being produced by
double Pomeron exchange. These distributions have been compared with a model
which describes the Pomeron as a non-conserved vector current and a qualitative
agreement is found. In addition, when one of the particles exchanged is known
to have spin 0, namely pi-Pomeron exchange, the phi distribution is flat.Comment: 13 pages, Latex, 4 Figure
A coupled channel analysis of the centrally produced K+K- and pi+pi- final states in pp interactions at 450 GeV/c
A coupled channel analysis of the centrally produced K+K- and pi+pi- final
states has been performed in pp collisions at an incident beam momentum of 450
GeV/c. The pole positions and branching ratios to pipi and KK of the f0(980),
f0(1370), f0(1500) and f0(1710) have been determined. A systematic study of the
production properties of all the resonances observed in the pi+pi- and K+K-
channels has been performed.Comment: 16 pages, Latex, 5 Figure
A search for charmonium states produced in central pp interactions at 450 GeV/c
A search for centrally produced charmonium states has been presented. There
is no significant evidence for any charmonium production. An upper limit of 2
nb is found for the cross section of chic production using the decay chic(1P)->
J/psi gamma.Comment: 10 pages, Latex, 4 Figure
The role of secondary Reggeons in central meson production
We estimate the contribution of f_2 trajectory exchange to the central \eta
and \eta^\prime production. It is shown that secondary Reggeons may give a
large contribution to processes of double diffractive meson production at high
energy.Comment: 7 pages, Latex, 5 figure
A model for the spatiotemporal organization of DNA replication in Saccharomyces cerevisiae
DNA replication in eukaryotes is considered to proceed according to a precise program in which each chromosomal region is duplicated in a defined temporal order. However, recent studies reveal an intrinsic temporal disorder in the replication of yeast chromosome VI. Here we provide a model of the chromosomal duplication to study the temporal sequence of origin activation in budding yeast. The model comprises four parameters that influence the DNA replication system: the lengths of the chromosomes, the explicit chromosomal positions for all replication origins as well as their distinct initiation times and the replication fork migration rate. The designed model is able to reproduce the available experimental data in form of replication profiles. The dynamics of DNA replication was monitored during simulations of wild type and randomly perturbed replication conditions. Severe loss of origin function showed only little influence on the replication dynamics, so systematic deletions of origins (or loss of efficiency) were simulated to provide predictions to be tested experimentally. The simulations provide new insights into the complex system of DNA replication, showing that the system is robust to perturbation, and giving hints about the influence of a possible disordered firing
Theory and experiment of the ESR of Co in Zn % (OH)PO and Mg(OH)AsO
Experiments of Electron Spin Resonance (ESR) were performed on Co
substituting Zn or Mg in powder samples of Zn(OH)PO and
Mg(OH)AsO. The observed resonances are described with a theoretical
model that considers the departures from the two perfect structures. It is
shown that the resonance in the penta-coordinated complex is allowed, and the
crystal fields that would describe the resonance of the Co in the two
environments are calculated. The small intensity of the resonance in the
penta-coordinated complex is explained assuming that this site is much less
populated than the octahedral one; this assumption was verified by a molecular
calculation of the energies of the two environments, with both Co and Zn as
central ions in Zn(OH)PO.Comment: 43 pages, LaTex file, 6 figures, EPS. submitted to Journal of Physics
Condens
Systematization of tensor mesons and the determination of the glueball
It is shown that new data on the -resonances in the mass
range MeV support the linearity of the -trajectories,
where is the radial quantum number of quark--antiquark state. In this way
all vacancies for the isoscalar tensor -mesons in the range up to 2450
MeV are filled in. This allows one to fix the broad -state with
MeV and MeV as the lowest tensor glueball. PACS
numbers: 14.40.-n, 12.38.-t, 12.39.-MkComment: 10 pages, 1 figur
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