120927641
A parameterization forSO(3) Yang-Mills-Higgs systems
SummaryA model consisting of anSO(3) gauge field interacting with an isovector Higgs field is investigated. The gauge fields and field tensors are parameterized by the Higgs field directionality and a gauge field structure function in terms of which the magnetic field and magnetic charge density of a 't Hooft-Polyakov magnetic monopole can be simply expressed. An isovector Debye potential for a 't Hooft-Polyakov gauge field is written in terms of the gauge field structure function.
118565299
Short note on the stabilty of a dilatonic wall
A nontopological soliton solution of dilaton–Maxwell theory describes a domain wall-like solution which confines magnetic flux in its core (Gibbons and Wells, Class Quant Grav 11:2499, 1994). Since the solution is not stabilized by a nontrivial topology of the vacuum manifold, it is interesting to see if the static solution is stable against small fluctuations. We consider the stability of the solution in response to small fluctuations in the scalar and magnetic fields. It is determined that the ansatz solution does indeed exhibits stability.
29278740
Domain defects in strings and walls.
A type of model is considered where the Witten mechanism allows the breaking of a discrete symmetry within the core of a cosmic string or a domain wall. The formation of a real scalar field condensate results in the creation of different, but energetically degenerate, domains which are separated by massive domain defects. The defects within strings (domain kinks) are particlelike states, whereas the defects within walls (domain ribbons) resemble stringlike states. Relativistic kink-antikink pairs annihilate after their initial formation, with the release of boson radiation, and kink-antikink pairs can be created through string intercommutations. Ribbons and antiribbons can be either infinite in extent or form closed loops. Ribbon loops can be involved in fission or fusion processes producing boson radiation, and oscillating ribbon loops decay mainly through the production of boson radiation, with a negligible fraction of the released energy being emitted in the form of gravitational radiation.
8897328
Supersymmetry breaking and Fermi balls.
A simple model is presented where the disappearance of domain walls and the associated production of {open_quote}{open_quote}Fermi balls,{close_quote}{close_quote} which have been proposed as candidates for cold dark matter, are features which arise rather naturally in response to softly broken supersymmetry. {copyright} {ital 1996 The American Physical Society.}
119203809
Chameleon gravity and satellite geodesy
We consider the possibility of the detection of a chameleon effect by an earth orbiting satellite such as LAGEOS, and possible constraints that might be placed on chameleon model parameters. Approximate constraints presented here result from using a simple monopole approximation for the gravitational field of the earth, along with results from the Khoury-Weltman chameleon model, solar system constraints obtained from the Cassini mission, and parameter bounds obtained from the LAGEOS satellite. It is furthermore suggested that a comparison of ground-based and space-based multipole moments of the geopotential could reveal a possible chameleon effect.
119206581
Dilatonic effects on a falling test mass in scalar-tensor theory
Effects of a 4d dilaton field on a falling test mass are examined from the Einstein frame perspective of scalar-tensor theory. Results are obtained for the centripetal acceleration of particles in circular orbits, and the radial acceleration for particles with pure radial motion. These results are applied to the specific case of nonrelativistic motion in the weak field approximation of Brans–Dicke theory, employing the exact Xanthopoulos–Zannias solutions. For a given parameter range, the results obtained from Brans–Dicke theory are qualitatively dramatically different from those of general relativity. Comments are made concerning a comparison with the general relativistic results in the limit of an infinite Brans–Dicke parameter.
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.
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).
120611016
Nuclear photoproduction of rho mesons
Abstract Targets of Be, C, Al, Cu, Ag and Au were exposed to a tagged photon beam in the 2.75 to 4.35 GeV energy range and cross sections are presented for the reaction γA → Aϱ0. Optical spark chambers were used to examine charged particles and γ rays from the targets, so that the data are believed to be free from inelastic contamination. The results are analysed both in terms of total cross sections σ(Aγ → ϱA), and in terms of forward differential cross sections ( d σ d t ) θ=0 (γ A → ϱ A ) . From the A dependence of these cross sections we determine the total rho-nucleon cross section, σϱN, to be (22.5 ± 2.7) mb, and the absolute values of the cross sections determine the forward photoproduction cross section from a nucleon ( d σ d t ) θ=0 (γ p → ϱ p ) = (72.7 ± 8) μ b/GeV 2 . These values correspond to an assumed value αϱN = −0.2 for the ratio of the real to imaginary part of the ϱ nucleon forward scattering amplitude. The corresponding value of the photon-rho coupling constant γ ϱ 2 4π =0.65±0.16 .
22405819
A search for narrow resonances in proton-proton collisions at 53 GeV centre-of-mass energy
Abstract A search for narrow resonances produced in pp collisions at the CERN ISR has been carried out using two magnetic spectrometers to measure and identify two-final-state charged hadrons. The resultant two-particle invariant mass spectra show no strong structure suggesting any new narrow resonance. The statistical significance of various enhancements seen in the data is discussed, and upper limits on the cross section times branching ratio for new particle production are presented.
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.