Distinguishing scalar from pseudoscalar Higgs production at the LHC

In this letter we examine the production channels for the scalar or pseudoscalar Higgs plus two jets at the CERN Large Hadron Collider (LHC). We identify possible signals for distinguishing between a scalar and a pseudoscalar Higgs boson.Comment: 7 pages, REVTeX4, 4 eps figures. Figure 1 and 4 replaced. Typos corrected, additional reference adde

Large Transverse Momenta in Statistical Models of High Energy Interactions

The creation of particles with large transverse momenta in high energy hadronic collisions is a long standing problem. The transition from small- (soft) to hard- parton scattering `high-pt' events is rather smooth. In this paper we apply the non-extensive statistical framework to calculate transverse momentum distributions of long lived hadrons created at energies from low (sqrt(s)~10 GeV) to the highest energies available in collider experiments (sqrt(s)~2000 GeV). Satisfactory agreement with the experimental data is achieved. The systematic increase of the non-extensivity parameter with energy found can be understood as phenomenological evidence for the increased role of long range correlations in the hadronization process. Predictions concerning the rise of average transverse momenta up to the highest cosmic ray energies are also given and discussed.Comment: 20 pages, 10 figure

Unusual morphologies and the occurrence of pseudomorphs after ikaite (CaCO3•6H2O) in fast growing, hyperalkaline speleothem

Unusual speleothem, associated with hyperalkaline (pH>12) groundwaters have formed within a shallow, abandoned railway tunnel at Peak Dale, Derbyshire, UK. The hyperalkaline groundwaters are produced by the leaching of a thin layer (<2 m) of old lime kiln waste above the soil-bedrock surface above the tunnel by rainwater. This results in a different reaction and chemical process to that more commonly associated with the formation of calcium carbonate speleothems from Ca-HCO3-type groundwaters and degassing of CO2. Stalagmites within the Peak Dale tunnel have grown rapidly (averaging 33 mm y-1), following the closure of the tunnel 70 years ago. They have an unusual morphology comprising a central sub-horizontally-laminated column of micro- to nano-crystalline calcium carbonate encompassed by an outer sub-vertical assymetric ripple laminated layer. The stalagmites are largely composed of secondary calcite forming pseudomorphs (<1 mm) which we believe to be predominantly after the ‘cold climate’ calcium carbonate polymorph, ikaite (calcium carbonate hexahydrate: CaCO3•6H2O), with minor volumes of small (<5 μm) pseudomorphs after vaterite. The tunnel has a near constant temperature of 8-9°C which is slightly above the previously published crystallisation temperatures for ikaite (<6°C). Analysis of a stalagmite actively growing at the time of sampling, and preserved immediately within a dry nitrogen cryogenic vessel, indicates that following crystallisation of ikaite, decomposition to calcite occurs rapidly, if not instantaneously. We believe this is the first occurrence of this calcium carbonate polymorph observed within speleothem

Scalar and Pseudoscalar Higgs Boson Plus One Jet Production at the LHC and Tevatron

The production of the Standard Model (SM) Higgs boson (H) in association with a jet is compared with that of the lightest scalar Higgs boson (h^0) and the pseudoscalar Higgs boson (A^0) of the Minimal Supersymmetric Model (MSSM) at both the CERN Large Hadron Collider (LHC) and the Fermilab Tevatron. We include both top and bottom quark loops to lowest order in QCD and investigate the limits of zero quark mass and infinite quark mass.Comment: 14 pages, REVTeX4, 14 eps figures v2: Version accepted for publication in PR

Interactions between Simulant Vitrified Nuclear Wastes and high pH solutions: A Natural Analogue Approach

This study details the characterization of a glass sample exposed to hyperalkaline water and calcium-rich sediment for an extended time period (estimated as 2-70 years) at a lime (CaO) waste site in the UK. We introduce this site, known as Peak Dale, in reference to its use as a natural analogue for nuclear waste glass dissolution in the high pH environment of a cementitious engineered barrier of a geological disposal facility. In particular, a preliminary assessment of alteration layer chemistry and morphology is described and the initiation of a long-term durability assessment is outlined

Effects of erythropoietin therapy on the lipid profile in end-stage renal failure

Effects of erythropoietin therapy on the lipid profile in end-stage renal failure. To evaluate the effects of erythropoietin (EPO) therapy on the lipid profile in end-stage renal failure, we undertook a prospective study in patients on both hemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD). One hundred and twelve patients (81 HD, 31 CAPD) were enrolled into the study. Lipid parameters [that is, total cholesterol and the LDL and HDL subfractions, triglycerides, lipoprotein (a), apoproteins A and B], full blood count, iron studies, B12, folate, blood urea, aluminium and serum parathyroid hormone were measured prior to commencement of EPO therapy. Ninety-five patients were reassessed 5.2 ± 0.3 (mean ± SEM) months later and 53 patients underwent a further assessment 13.1 ± 0.6 months after the commencement of EPO, giving an overall follow-up of 10.0 ± 0.6 months in 95 patients. As expected, EPO treatment was associated with an increase in hemoglobin (7.7 ± 0.1 vs. 9.9 ± 0.2 g/dl; P < 0.001) and a decrease in ferritin (687 ± 99 vs. 399 ± 69 µg/liter; P < 0.01). A significant fall in total cholesterol occurred (5.8 ± 0.1 vs. 5.4 ± 0.2 mmol/liter; P < 0.05) in association with a fall in apoprotein B (1.15 ± 0.04 vs. 1.04 ± 0.06; P < 0.05) and serum triglycerides (2.26 ± 0.14 vs. 1.99 ± 0.21; P < 0.05) during the course of the study. Other lipid parameters did not change, although there was a trend towards improvement. These changes correlated with the increase in Hb (P < 0.001 in each case), and the reduction in ferritin for total cholesterol (P < 0.02), LDL cholesterol (P < 0.03), and to a lesser extent apoprotein B (P < 0.07). No difference was observed in patients using maintenance HD or CAPD, and similar trends were observed in male and female patients. Improvements in the lipid profile occurred independently of the time on dialysis prior to the commencement of EPO. We conclude that EPO treatment is associated with alterations in the lipid profile which may suggest a long-term improvement in the vascular morbidity of chronic renal failure. The causes of the improved lipids are not addressed by this study and may be equally due to a direct or secondary benefit of EPO therapy

Axial vector form factor of nucleons in a light-cone diquark model

The nucleon axial vector form factor is investigated in a light-cone quark spectator diquark model, in which Melosh rotations are applied to both the quark and vector diquark. It is found that this model gives a very good description of available experimental data and the results have very little dependence on the parameters of the model. The relation between the nucleon axial constant and the anomalous magnetic moment of nucleons is also discussed.Comment: 8 pages, Revtex4, 1 figure, version to be published in Phys. Rev.

Interference-induced gain in Autler-Townes doublet of a V-type atom in a cavity

We study the Autler-Townes spectrum of a V-type atom coupled to a single-mode, frequency-tunable cavity field at finite termperature, with a pre-selected polarization in the bad cavity limit, and show that, when the mean number of thermal photons $N\gg 1$ and the excited sublevel splitting is very large (the same order as the cavity linewidth), the probe gain may occur at either sideband of the doublet, depending on the cavity frequency, due to the cavity-induced interference.Comment: Minor changes are mad

Mirror Symmetry and Other Miracles in Superstring Theory

The dominance of string theory in the research landscape of quantum gravity physics (despite any direct experimental evidence) can, I think, be justified in a variety of ways. Here I focus on an argument from mathematical fertility, broadly similar to Hilary Putnam's 'no miracles argument' that, I argue, many string theorists in fact espouse. String theory leads to many surprising, useful, and well-confirmed mathematical 'predictions' - here I focus on mirror symmetry. These predictions are made on the basis of general physical principles entering into string theory. The success of the mathematical predictions are then seen as evidence for framework that generated them. I attempt to defend this argument, but there are nonetheless some serious objections to be faced. These objections can only be evaded at a high (philosophical) price.Comment: For submission to a Foundations of Physics special issue on "Forty Years Of String Theory: Reflecting On the Foundations" (edited by G. `t Hooft, E. Verlinde, D. Dieks and S. de Haro)