Resolution of Nearly Mass Degenerate Higgs Bosons and Production of Black Hole Systems of Known Mass at a Muon Collider

The direct s-channel coupling to Higgs bosons is 40000 times greater for muons than electrons; the coupling goes as mass squared. High precision scanning of the lighter $h^0$ and the higher mass $H^0$ and $A^0$ is thus possible with a muon collider. The $H^0$ and $A^0$ are expected to be nearly mass degenerate and to be CP even and odd, respectively. A muon collider could resolve the mass degeneracy and make CP measurements. The origin of CP violation in the $K^{0}$ and $B^{0}$ meson systems might lie in the the $H^0/A^0$ Higgs bosons. If large extra dimensions exist, black holes with lifetimes of $\sim 10^{-26}$ seconds could be created and observed via Hawking radiation at the LHC. Unlike proton or electron colliders, muon colliders can produce black hole systems of known mass. This opens the possibilities of measuring quantum remnants, gravitons as missing energy, and scanning production turn on. Proton colliders are hampered by parton distributions and CLIC by beamstrahlung. The ILC lacks the energy reach.Comment: Latex, 5 pages, 2 figures, proceedings to the DPF 2004: Annual Meeting of the Division of Particles and Fields of APS, 26 August-31 August 2004, Riverside, CA, US

6D Muon Ionization Cooling with an Inverse Cyclotron

A large admittance sector cyclotron filled with LiH wedges surrounded by helium or hydrogen gas is explored. Muons are cooled as they spiral adiabatically into a central swarm. As momentum approaches zero, the momentum spread also approaches zero. Long bunch trains coalesce. Energy loss is used to inject the muons into the outer rim of the cyclotron. The density of material in the cyclotron decreases adiabatically with radius. The sector cyclotron magnetic fields are transformed into an azimuthally symmetric magnetic bottle in the center. Helium gas is used to inhibit muonium formation by positive muons. Deuterium gas is used to allow captured negative muons to escape via the muon catalyzed fusion process. The presence of ionized gas in the center may automatically neutralize space charge. When a bunch train has coalesced into a central swarm, it is ejected axially with an electric kicker pulse.Comment: Five pages. LaTeX, three postscript figure files. To appear in the AIP Conference Proceedings for COOL05: International Workshop on Beam Cooling, Galena, IL, 18-23 Sept. 200

Generic Bell correlation between arbitrary local algebras in quantum field theory

We prove that for any two commuting von Neumann algebras of infinite type, the open set of Bell correlated states for the two algebras is norm dense. We then apply this result to algebraic quantum field theory -- where all local algebras are of infinite type -- in order to show that for any two spacelike separated regions, there is an open dense set of field states that dictate Bell correlations between the regions. We also show that any vector state cyclic for one of a pair of commuting nonabelian von Neumann algebras is entangled (i.e., nonseparable) across the algebras -- from which it follows that every field state with bounded energy is entangled across any two spacelike separated regions.Comment: Third version; correction in the proof of Proposition

The role of the lateral prefrontal cortex and anterior cingulate in stimulus–response association reversals

Many complex tasks require us to flexibly switch between behavioral rules, associations, and strategies. The prefrontal cerebral cortex is thought to be critical to the performance of such behaviors, although the relative contribution of different components of this structure and associated subcortical regions are not fully understood. We used functional magnetic resonance imaging to measure brain activity during a simple task which required repeated reversals of a rule linking a colored cue and a left/right motor response. Each trial comprised three discrete events separated by variable delay periods. A colored cue instructed which response was to be executed, followed by a go signal which told the subject to execute the response and a feedback instruction which indicated whether to ‘‘hold’’ or ‘‘f lip’’ the rule linking the colored cue and response. The design allowed us to determine which brain regions were recruited by the specific demands of preparing a rule contingent motor response, executing such a response, evaluating the significance of the feedback, and reconfiguring stimulus–response (SR) associations. The results indicate that an increase in neural activity occurs within the anterior cingulate gyrus under conditions in which SR associations are labile. In contrast, lateral frontal regions are activated by unlikely/unexpected perceptual events regardless of their significance for behavior. A network of subcortical structures, including the mediodorsal nucleus of the thalamus and striatum were the only regions showing activity that was exclusively correlated with the neurocognitive demands of reversing SR associations. We conclude that lateral frontal regions act to evaluate the behavioral significance of perceptual events, whereas medial frontal–thalamic circuits are involved in monitoring and reconfiguring SR associations when necessary

Malignant Cutaneous Peripheral Nerve Sheath Tumour with Rhabdomyosarcomatous Differentiation (Triton Tumour) in a Domestic Cat

Divergent differentiation is encountered frequently within human malignant peripheral nerve sheath tumours (MPNSTs). The new component is often a rhabdomyosarcoma, but in animals this specific form of divergent differentiation within MPNSTs has only been reported once (in a dog). Incisional wedge biopsy of a locally extensive, ventral abdominal wall mass, which extended from the dermis to the subcutis, from a 12-year-old female domestic shorthaired cat, was performed. The tissue was examined with routine haematoxylin and eosin staining and immunohistochemical methods. A malignant neoplasm with spindle and polygonal cell components and progression towards a rhabdomyosarcomatous phenotype was observed. Both neoplastic cell populations exhibited strong expression of vimentin and there was multifocal expression of S100 and desmin. There was strong cytoplasmic labelling for α-sarcomeric actin and muscle actin and weak labelling for myoglobin within the cells positive for desmin. There was multifocal positive nuclear labelling for myogenin. Glial fibrillary acidic protein, α-smooth muscle actin, microphthalmia-associated transcription factor and melanoma antigen recognized by T cells were not expressed. Microscopical features, aided by immunohistochemistry, identified a MPNST with progression towards a rhabdomyosarcomatous phenotype, a so-called ‘triton tumour’. A Schwann cell component could account for the divergent patterns of growth, given the plasticity of the neural crest. Nerve sheath tumours have been reported in the skin and subcutis of cats and are a differential diagnosis of feline cutaneous spindle cell neoplasms

Theoretical Expectations For High Mass Photon Pairs in L+ L- Gamma Gamma Events at LEP/SLC

Recently, the L3 collaboration has reported the observation of four events in the reactions e+ e- --> L+ L- + (2 Photons), L = e, mu, tau, with the invariant photon pair mass near 60 GeV in a data sample collected in the L3 detector corresponding to 950,000 produced Z0's. More recently, more data from the other LEP collaborations have become available. In this paper, we use the Monte Carlo genrator YFS3 and our recent exact results on e+ e- --> L+ L- + (2 Photons) to assess the QED expectations for such L3-type high mass photon pair events in e+ e- --> L+ L- + (n Photons) near the Z0 resonance.Comment: 9 pages (LaTeX + 6 uu-encoded figures), UTHEP-93-1002 (version with corrected preprint number

A common contrast pooling rule for suppression within and between the eyes

Recent work has revealed multiple pathways for cross-orientation suppression in cat and human vision. In particular, ipsiocular and interocular pathways appear to assert their influence before binocular summation in human but have different (1) spatial tuning, (2) temporal dependencies, and (3) adaptation after-effects. Here we use mask components that fall outside the excitatory passband of the detecting mechanism to investigate the rules for pooling multiple mask components within these pathways. We measured psychophysical contrast masking functions for vertical 1 cycle/deg sine-wave gratings in the presence of left or right oblique (645 deg) 3 cycles/deg mask gratings with contrast C%, or a plaid made from their sum, where each component (i) had contrast 0.5Ci%. Masks and targets were presented to two eyes (binocular), one eye (monoptic), or different eyes (dichoptic). Binocular-masking functions superimposed when plotted against C, but in the monoptic and dichoptic conditions, the grating produced slightly more suppression than the plaid when Ci $ 16%. We tested contrast gain control models involving two types of contrast combination on the denominator: (1) spatial pooling of the mask after a local nonlinearity (to calculate either root mean square contrast or energy) and (2) "linear suppression" (Holmes & Meese, 2004, Journal of Vision 4, 1080–1089), involving the linear sum of the mask component contrasts. Monoptic and dichoptic masking were typically better fit by the spatial pooling models, but binocular masking was not: it demanded strict linear summation of the Michelson contrast across mask orientation. Another scheme, in which suppressive pooling followed compressive contrast responses to the mask components (e.g., oriented cortical cells), was ruled out by all of our data. We conclude that the different processes that underlie monoptic and dichoptic masking use the same type of contrast pooling within their respective suppressive fields, but the effects do not sum to predict the binocular case