Search results

Within Chiral Perturbation Theory (CHPT) we compute the form factors A, V and γ = A/V in the π → lνγ decay to O(p6). A and γ obtain corrections of order 25%.

We present technical details of the evaluation of the elastic ππ scattering amplitude to two loops in chiral perturbation theory. In particular, we elaborate on the renormalization procedure at the two-loop order and on the evaluation of the relevant Feynman diagrams that can all be expressed in terms of elementary functions. For the sake of clarity, we discuss these matters both in the N-componen

We discuss the vector meson masses within the context of chiral perturbation theory performing an expansion in terms of the momenta, quark masses and 1/Nc. We extend the previous analysis to include isospin breaking effects and also include up to order p4. We discuss vector meson chiral perturbation theory in some detail and present a derivation from a relativistic Lagrangian. The unknown coeffici

Chiral perturbation theory relates the |S|=2 matrix element K0|(sd)V-A×(sd)V-A|K0 to the |S|=1 matrix element +0|(sd)V-A(uu)V-A+(su)V- A×(ud)V-A-(sd)V-A(dd)V-A|K+. The latter matrix element is measured in K++0 decay and the former matrix element is relevant for the predictions that the standard model makes for CP nonconservation in K0-K0 mixing. In this paper the corrections of order mK4 lnmK2 to

We discuss hyperon decays and hyperon magnetic moments using a chiral lagrangian where the baryons appear as solitons. Some relations are derived using the semiclassical approximation.

The contribution of electromagnetic "Penguin"-type diagrams to ε{lunate}′/ε{lunate} is examined in the standard six-quark model.

The predictions of chiral perturbation theory for the weak non-leptonic decays of hyperons are examined beyond the leading order. For the S-wave amplitudes we find that the leading corrections to lowest order chiral perturbation theory preserve the vanishing of the Σ+ → nπ+ amplitude. However, the Lee-Sugawara relation gets a large correction indicating a breakdown of chiral perturbation theory fo

A new scenario accounting for the production of monojets with large missing transverse energy is described and a specific model implementing it is constructed. The production rate for monojets is calculated.

Models are considered which have no small Yukawa couplings unrelated to symmetry. This situation is generic in higher dimensional unification where Yukawa couplings are predicted to have a strength similar to the gauge couplings. Generations have then to be differentiated by symmetry properties and the structure of fermion mass matrices is given in terms of quantum numbers alone. Possible symmetri

We investigate unified models where all small quantities in the fermion mass matrices are given in terms of one small ratio of symmetry breaking scales. We describe for a U(1) generation symmetry how the size of masses and mixings is determined, including possible contributions from heavy mirror quarks and leptons. This can be used for computerized model scanning. We search for realistic mass patt

This chapter discusses the question of mind in space. It aims to lay the ground for an emerging research field, astrocognition, studying the origin, evolution, and distribution of intelligence in the universe. The first section concerns terrestrial intelligence, the cognitive phenomena involved in human search for extraterrestrial life and intelligence. Intelligence could be explained as a cogniti

The last decades have seen a noticeable increase in cognitive science studies that have changed the understanding of human thinking. Its relevance for historical research cannot be overlooked any more. Cognitive history could be explained as the study of how humans in history used their cognitive abilities in order to understand the world around them and to orient themselves in it, but also how th

Euclid completed his geometrical proofs in the Elements (c. 300BC) with the abbreviation “QED” (quod erat demonstrandum). This phrase was not only used in mathematics in the early modern period, but also in deductive proofs in physics, astronomy, philosophy, and ethics. This chapter is a cognitive- historical interpretation of the axiomatic-deductive ideal that consists of some widely accepted pro

Long follow up is needed in prospective cohort study evaluation of plasma biomarkers for incident peripheral arterial disease (PAD) Middle-aged PAD-free individuals from the cardiovascular cohort of the Malmö Diet and Cancer study (n = 5550; 1991–94) were followed prospectively for a median time of 23.4 years. The plasma biomarkers lipoprotein-associated phospholipase A2 (Lp-PLA 2 ) activity and

The response of childhood acute lymphoblastic leukemia (ALL) to dexamethasone predicts the long-term remission outcome. To explore the mechanisms of dexamethasone resistance in B cell ALL (B-ALL), we generated dexamethasone-resistant clones by prolonged treatment with dexamethasone. Using RNA-sequencing and high-throughput screening, we found that dexamethasone-resistant cells are dependent on rec

The bedrock of Skåne, the southernmost province of Sweden, has been targeted for geothermal feasibility studies since the late 1970s. An exploration project concerning the geothermal potential in the Romeleåsen Fault Zone was launched outside the town of Lund in 2001. Besides geophysical imaging of the thrust fault zone, the investigations included drilling and investigations of a 3701.8-m-deep e