121418547
Observation of pairs of charmed particles produced by high-energy photons in nuclear emulsions coupled with a magnetic spectrometer
Abstract Preliminary results of an experiment using nuclear emulsions exposed to a tagged photon beam at the CERN SPS (experiment WA58) are presented. Six events showing pairs of charmed particles have been found. One of these has been interpreted as an associated production of Λ c + and D 0 . The mean lifetime of the neutral D meson based on three events is τ 0 = (0.58 −0.2 +0.8 × 10 −13 s,, whereas a statistical analysis of eight charged charmed particles, assumed to be D mesons, leads to an estimate of the mean lifetime of τ ± ≈ 4.4 × 10 −13 s.
125281002
Photoproduction of $K \bar{K} \pi$ Final States in the Photon Energy Range From 20-{GeV} to 70-{GeV}
CERN-OMEGA PHOTON COLLABORATION. PHOTOPRODUCTION OF & lt;K AK PI& gt; FINAL STATES IN THE ENERGY RANGE 20 TO 70 GEV. NO EVIDENCE IS FOUND FOR THE PHOTOPRODUCTION OF PHIPRIME(1680).
121568291
Multiplicity distributions associated with charged hadron production over a range of transverse momentum and production angle at ISR energies
Abstract The charged multiplicity density M , associated with identified charged hadrons up to 3.0 GeV/ c in p T , is presented at ISR energies from 23.4 to 63.4 GeV and at 3 laboratory angles, as a function of pseudorapidity and azimuth.
122240842
Multiplicities associated with the production of pions, kaons or protons of high transverse momentum, at the ISR
Abstract In high-energy proton-proton collisions, the mean charged multiplicity M in the central region, associated with a high-PT hadron trigger at 90°, shows a linear dependence on both ln s and PT. M is measured to depend on the type (π ± , K ± , p or p ) of the idenfied high-PT trigger particle.
121816869
Associated photoproduction of a charmed meson and a charmed baryon
121682572
Correlations between two identified charged hadrons at the CERN ISR
Abstract We have measured the value of the correlation R (h 1 , h 2 ) between two identified charged hadrons ( h = π ± , K ± , p or p ) produced in pp collisions at the CERN ISR. One hardon was produced in the forward direction and the other at a large angle. Quantum number dependent effects have been observed.
119080021
Fermionic and bosonic stabilizing effects for type I and type II dimension bubbles
We consider two types of "dimension bubbles", which are viewed as 4d nontopological solitons that emerge from a 5d theory with a compact extra dimension. The size of the extra dimension varies rapidly within the domain wall of the soliton. We consider the cases of type I (II) bubbles where the size of the extra dimension inside the bubble is much larger (smaller) than outside. Type I bubbles with thin domain walls can be stabilized by the entrapment of various particle modes whose masses become much smaller inside than outside the bubble. This is demonstrated here for the cases of scalar bosons, fermions, and massive vector bosons, including both Kaluza-Klein zero modes and Kaluza-Klein excitation modes. Type II bubbles expel massive particle modes but both types can be stabilized by photons. Plasma filled bubbles containing a variety of massless or nearly massless radiation modes may exist as long-lived metastable states. Furthermore, in contrast to the case with a "gravitational bag", the metric for a fluid-filled dimension bubble does not exhibit a naked singularity at the bubble's center.
122066859
Superconducting strings as sources of high-energy cosmic rays
SummaryThe possibility is explored that highly charged superconducting strings and vortons ionize neutral atoms and act as high-energy charged-particle accelerators. For strings characterized by a GUT mass scale, it is roughly estimated (neglecting radiative losses) that charged particles such as protons and heavier nuclei may reach an energy scale ≥ 1021 eV.
119078909
Gauged dimension bubbles
Some of the peculiar electrodynamical effects associated with gauged ``dimension bubbles'' are presented. Such bubbles, which effectively enclose a region of 5d spacetime, can arise from a 5d theory with a compact extra dimension. Bubbles with thin domain walls can be stabilized against total collapse by the entrapment of light charged scalar bosons inside the bubble, extending the idea of a neutral dimension bubble to accommodate the case of a gauged U(1) symmetry. Using a dielectric approach to the 4d dilaton-Maxwell theory, it is seen that the bubble wall is almost totally opaque to photons, leading to a new stabilization mechanism due to trapped photons. Photon dominated bubbles very slowly shrink, resulting in a temperature increase inside the bubble. At some critical temperature, however, these bubbles explode, with a release of radiation.
119297926
Real scalar fields on manifolds
A generic theory of a single real scalar field is considered, and a simple method is presented for obtaining a class of solutions to the equation of motion. These solutions are obtained from a simpler equation of motion that is generated by replacing a set of the original coordinates by a set of generalized coordinates, which are harmonic functions in the spacetime. These ansatz solutions solve the original equation of motion on manifolds that are defined by simple constraints. These manifolds, and their dynamics, are independent of the form of the scalar potential. Some scalar field solutions, and manifolds upon which they exist, are presented for Klein–Gordon and quartic potentials as examples. Solutions existing on leaves of a foliated space may allow inferences of the characteristics expected of exact bulk solutions.
118912120
Excitation fields in a superconducting global string
SummaryA model of a straight superconducting global cosmic string is examined in a setting wherein the string supports a charge/current pulse described by a travelling wave along the string. Linearized field equations are obtained for fluctuations of the scalar and vector fields of the theory, and a set of approximate particular solutions are found for the case in which the linear charge density and the current of the string have equal magnitudes. Although the equations of motion seem to suggest that the scalar and vector excitation fields are massive inside the string core, the particular solutions show that they behave as effectively massless fields which propagate at the speed of light along the string along with the primary charge/current pulse. The effect of the mass parameter is to modulate the radial profile of the excitation fields. The vector excitation field generates radial and angular components for both the electric and magnetic fields, but the particular solutions do not describe the emission or absorption of electromagnetic radiation from the string.