Theoretical predictions are given for the light-flavor sea-quark distributions including the strange quark ones on the basis of the flavor SU(3) version of the chiral quark soliton model. Careful account is taken here of the SU(3) symmetry breaking effects due to the mass difference between the strange and nonstrange quarks. This effective mass difference ∆ms between the strange and nonstrange ...

Flavor asymmetry in the light quark sea of the proton has been well-established by experiment [1–4]. The violation of the Gottfried sum rule found by NMC [1] indicated that D ≡ ∫ 1 0 dx (d̄(x) − ū(x)) = 0.148 ± 0.039. In Drell-Yan experiments, d̄/ū was determined to be greater than 2 at x = .18 by NA51 [2], and the x-dependence of this ratio has recently been measured by E866 [3] in the region 0....

This paper is devoted to second order necessary optimality conditions for the Mayer optimal control problem when the control set U is a closed subset of R. We show that, in the absence of endpoint constraints, if an optimal control ū(·) is singular and integrable, then for almost every t such that ū(t) is in the interior of U , both the Goh and a generalized LegendreClebsch conditions hold true...

Abstract This paper provides a new explanation for the insertion of * in plural forms CVCC- nouns also formed with an external suffix, e.g. ʕabd- : ʕabad-ū- ‘servant(s)’, various Semitic languages. CVCaC-ū- pattern is usually considered to be remnant Proto-Semitic broken system Northwest Semitic, but we show that it goes back this form. Internal evidence from as well comparative Afroasiatic poi...

Abstract. The unipotent variety of a reductive algebraic group G plays an important role in the representation theory. In this paper, we will consider the closure Ū of the unipotent variety in the De Concini-Procesi compactification Ḡ of a quasisimple, adjoint group G. We will prove that Ū − U is a union of some G-stable pieces introduced by Lusztig in [L4]. This was first conjectured by Luszti...

Let ū(t) be a control that satisfies the infinite-dimensional version of Pontryagin’s maximum principle for a linear control system, and let z(t) be the costate associated with ū(t). It is known that integrability of ‖z(t)‖ in the control interval [0, T ] guarantees that ū(t) is time and norm optimal. However, there are examples where optimality holds (or does not hold) when ‖z(t)‖ is not integ...

We study the d̄− ū asymmetry of the proton in a model approach in which hadronic fluctuations of the nucleon are generated through gluon splitting and recombination mechanisms. Within this framework, it is shown that the d̄ − ū asymmetry of the proton is consistently described by including only nucleon fluctuations to |πN〉 and |π∆〉 bound states. Predictions of the model closely agree with the rec...

The function u = u(t, a) usually represents the population density of a certain specie at time t > 0 and age a > 0, so that ū(t) in equation (1.4) is the (weighted) total population independent of age. The operator A[ū](t) in equation (1.1) acts for a fixed function ū and time t as a linear (and unbounded) operator on a Banach space E0. In concrete applications, A[ū](t) plays the role of non-li...

where F : IR 7→ IR and h : [0,+∞) × IR × IR 7→ IR are smooth maps. We assume that the system (1) is strictly hyperbolic, and that each characteristic field is either linearly degenerate or genuinely nonlinear in the sense of Lax [8]. Given a piecewise Lipschitz continuous solution u = u(t, x) of (1), we shall study the behavior of first-order variations of u, by defining a suitable class of “ge...

The advantage and feasibility of using W -boson production to extract unique information on the flavor asymmetry of the ū and d̄ sea-quark distributions in the proton are examined. The W and W production cross section ratios in p + p collisions are shown to be sensitive to the d̄/ū ratios, and they are free from charge-symmetry-breaking and nuclear-binding effects. The feasibility for measuring t...