w Simple model calculations indicate that instanton estimates of high-energy scattering amplitudes are unreliable when the number of final state particles becomes large. This casts doubt on recent claims that the cross section for baryon number violation becomes large at high energy.

We discuss how higher-point QCD amplitudes may be constructed from lower point ones by imposing the factorization constraints in the limits as external momenta become collinear. As a particular example, the all-n gluon one-loop amplitude with maximal helicity violation is presented. We also discuss the necessary collinear behavior of the n-gluon amplitudes.

Kaufmann has recently argued that the thesis according to which the probability of an indicative conditional equals the conditional probability of the consequent given the antecedent under certain specifiable circumstances deviates from intuition. He presents a method for calculating the probability of a conditional that does seem to give the intuitively correct result under those circumstances...

Alin Bostan, Shaoshi Chen, Frédéric Chyzak, Ziming Li, Guoce Xin INRIA, Palaiseau, 91120, (France) Department of Mathematics, NCSU, Raleigh, 27695-8025, (USA) KLMM, AMSS, Chinese Academy of Sciences, Beijing 100190, (China) Department of Mathematics, Capital Normal University, Beijing 100048, (China) [email protected], {alin.bostan, frederic.chyzak}@inria.fr [email protected], [email protected]

We consider on-shell recursion relations for all Born QCD amplitudes. This includes amplitudes with several pairs of quarks and massive quarks. We give a detailed description on how to shift the external particles in spinor space and clarify the allowed helicities of the shifted legs. We proof that the corresponding meromorphic functions vanish at z → ∞. As an application we obtain compact expr...

Researchers in the field of psychology studying subjects’ reasoning abilities and decision-making processes have identified certain common errors that are made, particularly on probability questions standard in introductory statistics courses. In addition, they have identified modifications to problems and training that promote normative reasoning in laboratory subjects. This study attempts to ...

In order to support concept-creation, we focus on handwriting assuming that it should contain the information on the process toward insight. As a result of intensive analysis of handwriting in concept creation process, one observation is that pen speed gets faster on insight after the period in which pen speed is relatively slow or time gaps get increased. Another observation is that pen pressu...

It is shown that the study of the imaginary part and of the corresponding dispersion relations of Feynman graph amplitudes within the differential equations method can provide a powerful tool for the solution of the equations, especially in the massive case. The main features of the approach are illustrated by discussing the simple cases of the 1-loop selfmass and of a particular vertex amplitu...

Various decay processes that are forbidden in the vacuum by a combination of requirements such as angular momentum conservation and Lorentz invariance, can occur if the decaying particle is propagating in a medium, even if the medium is homogeneous and isotropic. Here we consider specifically the decay of a neutrino into another neutrino and a graviton, in a thermal background of electrons. The...

The structure of tree–level open and closed superstring amplitudes is analyzed. For the open superstring amplitude we find a striking and elegant form, which allows to disentangle its α–expansion into several contributions accounting for different classes of multiple zeta values. This form is bolstered by the decomposition of motivic multiple zeta values, i.e. the latter encapsulate the α–expan...