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.
120292912
Gravitational field of a superconducting global string
SummaryThe Newtonian gravitational field of a superconducting global cosmic string is investigated using the weak-field approximation, and is found to receive contributions from the global string field, the condensate field, and the electromagnetic fields. For certain parameter ranges the gravitational field in the region exterior to the string may be everywhere repulsive, everywhere attractive, or repulsive in some regions and attractive in others. For a neutral superconducting global string there can exist a particular current for which the gravitational field of the superconducting global string approximately coincides with that of a Grand Unified Theory (GUT) scale Weyl string, and, as pointed out by Widom, Srivastava, and Redington, observed asymptotic galactic rotation velocities can be roughly explained without the introduction of any further dark-matter hypothesis.
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.}
119125621
Moduli vacuum bubbles produced by evaporating black holes
We consider a model with a toroidally compactified extra dimension giving rise to a temperature-dependent 4D effective potential with one-loop contributions due to the Casimir effect, along with a 5D cosmological constant. The forms of the effective potential at low and high temperatures indicate a possibility for the formation of a domain wall bubble, formed by the modulus scalar field, surrounding an evaporating black hole. This is viewed as an example of a recently proposed black hole vacuum bubble arising from matter-sourced moduli fields in the vicinity of an evaporating black hole [D. Green, E. Silverstein, and D. Starr, Phys. Rev. D 74, 024004 (2006)]. The black hole bubble can be highly opaque to lower-energy particles and photons, and thereby entrap them within. For high-temperature black holes, there may also be a symmetry-breaking black hole bubble of false vacuum of the type previously conjectured by Moss [I. G. Moss, Phys. Rev. D 32, 1333 (1985)], tending to reflect low-energy particles from its wall. A double bubble composed of these two different types of bubble may form around the black hole, altering the hole's emission spectrum that reaches outside observers. Smaller mass black holes that have already evaporated away could have left vacuum bubbles behind that contribute to the dark matter.
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.
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.
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.
122300884
Forward electroproduction of single charged pions in the resonance region using a deuterium target
Abstract The rates for forward electroproduction of single charged pions from deutrium have been measured in the resonance region, at a virtual photon mass squared ≈−0.5( GeV/ c 2 ) 2 . Results are presented in the form of a π− to π + cross-section ratio.
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).
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.
110048496
The H1 Forward Track Detector at HERA II
In order to maintain efficient tracking in the forward region of H1 after the luminosity upgrade of the HERA machine, the H1 Forward Track Detector was also upgraded. While much of the original software and techniques used for the HERA I phase could be reused, the software for pattern recognition was completely rewritten. This, along with several other improvements in hit finding and high-level track reconstruction, are described in detail together with a summary of the performance of the detector.