Charged Bilepton Pair Production at LHC Including Exotic Quark Contribution

The production of $W^+ W^-$ pair in hadron colliders was calculated up to loop corrections by some authors in the Electroweak standard model (SM) framework. This production was also calculated, at the tree level, in some extensions of the SM such as the vector singlet, the fermion mirror fermion and the vector doublet models by considering the contributions of new neutral gauge bosons and exotic fermions. The obtained results for $e^+ e^-$ and $pp$ collisions pointed out that the new physics contributions are quite important. This motivates us to calculate the production of a more massive charged gauge boson predicted by the ${SU (3)_C \times SU (3)_L \times U (1)_X}$ model (3-3-1 model). Thus, the aim of the present paper is to analyze the role played by of the extra gauge boson ${Z^\prime}$ and of the exotic quarks, predicted in the minimal version of the 3-3-1 model, by considering the inclusive production of a pair of bileptons ($V^\pm$) in the reaction $p + p \longrightarrow V^+ + V^- + X$, at the Large Hadron Collider (LHC) energies. Our results show that the correct energy behavior of the elementary cross section follows from the balance between the contributions of the extra neutral gauge boson with those from the exotic quarks. The extra neutral gauge boson induces flavor-changing neutral currents (FCNC) at tree level, and we have introduced the ordinary quark mixing matrices for the model when the first family transforms differently to the other two with respect to $SU(3)_L$. We obtain a huge number of heavy bilepton pairs produced for two different values of the center of mass energy of the LHC.Comment: 23 pages, 8 figures, 3 tables. To be published in Nuclear Physics

Inference of Well-Typings for Logic Programs with Application to Termination Analysis

This paper develops a method to infer a polymorphic well-typing for a logic program. One of the main motivations is to contribute to a better automation of termination analysis in logic programs, by deriving types from which norms can automatically be constructed. Previous work on type-based termination analysis used either types declared by the user, or automatically generated monomorphic types describing the success set of predicates. Declared types are typically more precise and result in stronger termination conditions than those obtained with inferred types. Our type inference procedure involves solving set constraints generated from the program and derives a well-typing in contrast to a success-set approximation. Experiments show that our automatically inferred well-typings are close to the declared types and thus result in termination conditions that are as good as those obtained with declared types for all our experiments to date. We describe the method, its implementation and experiments with termination analysis based on the inferred types

Specializing Interpreters using Offline Partial Deduction

We present the latest version of the Logen partial evaluation system for logic programs. In particular we present new binding-types, and show how they can be used to effectively specialise a wide variety of interpreters.We show how to achieve Jones-optimality in a systematic way for several interpreters. Finally, we present and specialise a non-trivial interpreter for a small functional programming language. Experimental results are also presented, highlighting that the Logen system can be a good basis for generating compilers for high-level languages

Context-sensitive multivariant assertion checking in modular programs

We propose a modular, assertion-based system for verification and debugging of large logic programs, together with several interesting models for checking assertions statically in modular programs, each with different characteristics and representing different trade-offs. Our proposal is a modular and multivariant extensión of our previously proposed abstract assertion checking model and we also report on its implementation in the CiaoPP system. In our approach, the specification of the program, given by a set of assertions, may be partial, instead of the complete specification required by raditional verification systems. Also, the system can deal with properties which cannot always be determined at compile-time. As a result, the proposed system needs to work with safe approximations: all assertions proved correct are guaranteed to be valid and all errors actual errors. The use of modular, context-sensitive static analyzers also allows us to introduce a new distinction between assertions checked in a particular context or checked in general

Independence in CLP Languages

Studying independence of goals has proven very useful in the context of logic programming. In particular, it has provided a formal basis for powerful automatic parallelization tools, since independence ensures that two goals may be evaluated in parallel while preserving correctness and eciency. We extend the concept of independence to constraint logic programs (CLP) and prove that it also ensures the correctness and eciency of the parallel evaluation of independent goals. Independence for CLP languages is more complex than for logic programming as search space preservation is necessary but no longer sucient for ensuring correctness and eciency. Two additional issues arise. The rst is that the cost of constraint solving may depend upon the order constraints are encountered. The second is the need to handle dynamic scheduling. We clarify these issues by proposing various types of search independence and constraint solver independence, and show how they can be combined to allow dierent optimizations, from parallelism to intelligent backtracking. Sucient conditions for independence which can be evaluated \a priori" at run-time are also proposed. Our study also yields new insights into independence in logic programming languages. In particular, we show that search space preservation is not only a sucient but also a necessary condition for ensuring correctness and eciency of parallel execution

Homeomorphic Embedding for Online Termination of Symbolic Methods

Well-quasi orders in general, and homeomorphic embedding in particular, have gained popularity to ensure the termination of techniques for program analysis, specialisation, transformation, and verification. In this paper we survey and discuss this use of homeomorphic embedding and clarify the advantages of such an approach over one using well-founded orders. We also discuss various extensions of the homeomorphic embedding relation. We conclude with a study of homeomorphic embedding in the context of metaprogramming, presenting some new (positive and negative) results and open problems

A Synergistic Analysis for Sharing and Groundness which traces Linearity

Accurate variable sharing information is crucial both in the automatic parallelisation and in the optimisation of sequential logic programs. Analysis for possible variable sharing is thus an important topic in logic programming and many analyses have been proposed for inferring dependencies between the variables of a program, for instance, by combining domains and analyses. This paper develops the combined domain theme by explaining how term structure, and in particular linearity, can be represented in a sharing group format. This enables aliasing behaviour to be more precisely captured; groundness information to be more accurately propagated; and in addition, refines the tracking and application of linearity. In practical terms, this permits aliasing and groundness to be inferred to a higher degree of accuracy than in previous proposals and also can speed up the analysis itself. Correctness is formally proven

RADIATIVE AND COLLISIONAL DESEXCITATION OF 1P1 AND 3P1 RESONANCE STATES IN XENON.

No abstract availabl