On the dependence of the wave function of a bound nucleon on its momentum and the EMC effect

It is widely discussed in the literature that the wave function of the nucleon bound in a nucleus is modified due to the interaction with the surrounding medium. We argue that the modification should strongly depend on the momentum of the nucleon. We study such an effect in the case of the point-like configuration component of the wave function of a nucleon bound in a nucleus A, considering the case of arbitrary final state of the spectator A-1 system. We show that for non relativistic values of the nucleon momentum, the momentum dependence of the nucleon deformation appears to follow from rather general considerations and discuss the implications of our theoretical observation for two different phenomena: i) the search for medium induced modifications of the nucleon radius of a bound nucleon through the measurement of the electromagnetic nucleon form factors via the A(e,e'p)X process, and ii) the A-dependence of the EMC effect; in this latter case we also present a new method of estimating the fraction of the nucleus light-cone momentum carried by the photons and find that in a heavy nuclei protons loose about 2% of their momentum.Comment: 38 pages, 1 figure; changed references and text in Section I (Introduction

On stability of the neutron rich Oxygen isotopes

Stability with respect to neutron emission is studied for highly neutron-excessive Oxygen isotopes in the framework of Hartree-Fock-Bogoliubov approach with Skyrme forces Sly4 and Ska. Our calculations show increase of stability around 40O.Comment: 5 pages, 3 figure

Nuclear magnetization distribution and hyperfine splitting in Bi82+^{82+} ion

Hyperfine splitting in Bi$^{82+}$ and Pb$^{81+}$ ions was calculated using continuum RPA approach with effective residual forces. To fix the parameters of the theory the nuclear magnetic dipole moments of two one- particle and two one-hole nuclei around $^{208}$Pb were calculated using the same approach. The contribution from velocity dependent two-body spin- orbit residual interaction was calculated explicitly. Additionally, the octupole moment of $^{209}$Bi and the hfs in muonic bismuth atom were calculated as well in the same approach. All the calculated observables, except the electronic hfs in $^{209}$Bi, are in good agreement with the data. We argue for more accurate measurement of the octupole moment and the muonic hfs for $^{209}$Bi.Comment: 11 pages, 5 figure

Global Study of Nuclear Structure Functions

We present the results of a phenomenological study of unpolarized nuclear structure functions for a wide kinematical region of x and Q^2. As a basis of our phenomenology we develop a model which takes into account a number of different nuclear effects including nuclear shadowing, Fermi motion and binding, nuclear pion excess and off-shell correction to bound nucleon structure functions. Within this approach we perform a statistical analysis of available data on the ratio of the nuclear structure functions F_2 for different nuclei in the range from the deuteron to the lead. We express the off-shell effect and the effective scattering amplitude describing nuclear shadowing in terms of few parameters which are common to all nuclei and have a clear physical interpretation. The parameters are then extracted from statistical analysis of data. As a result, we obtain an excellent overall agreement between our calculations and data in the entire kinematical region of x and Q^2. We discuss a number of applications of our model which include the calculation of the deuteron structure functions, nuclear valence and sea quark distributions and nuclear structure functions for neutrino charged-current scattering.Comment: 67 pages, 18 figures (v3: updated text and references, a new section with discussion about relation between off-shell effect and modification of the nucleon size in nuclei, accepted for publication in Nucl. Phys. A

Выход судна из ледяного канала // Ship exit from an ice channel

Abstract: Материалы и методы исследования. Предпринята попытка теоретического рассмотрения выхода судна из ледяного канала и определения условий, при которых он выполним. Материалом для разработки теоретической модели служат данные натурных и модельных экспериментов. Основные результаты. Разработан метод расчета ледовых усилий, действующих на корпус судна при выполнении маневра выхода из ледяного канала. Выполнен анализ влияния параметров главных размерений и формы корпуса судна в носовой и кормовой оконечностях на возможность осуществления этого маневра. Получены оценки диапазона ширин ледяных каналов, из которых выход судна невозможен. Заключение. Предложены рекомендации по выбору скоростного режима при выполнении маневра выхода из канала. Полученные соотношения могут быть использованы для оценок возможности выхода судна из ледяного канала на ранних стадиях его проектирования. Materials and methods. This paper is an attempt of a theoretical investigation for channel exit and its feasibility conditions. The theoretical model was based upon the data of full-scale trials and model tests. Main results. The study yielded ice load calculation method for the hull of the ship performing channel exit, as well as analysed the effect of main dimensions and bow and stern lines upon the feasibility of this maneuver. The investigation yielded estimated widths of ice channels making channel exit maneuver impossible. Conclusion. This paper suggests recommendations on channel exit maneuver speed. These findings could be helpful in channel-exit capability assessments for ships at early design stages