Testing Nucleon Strangeness in Polarization Effects for n+p→d+η

1998 ◽  
Vol 07 (01) ◽  
pp. 139-145
Author(s):  
H. Koru ◽  
M. P. Rekalo
Keyword(s):  
Strong Interaction ◽  
Spin Structure ◽  
Production Angle ◽  
Charge Symmetry ◽  
Polarization Effects ◽  
Relative Value ◽  
Polarization Observables ◽  
Text Component

Charge symmetry of strong interaction results in a simplified spin structure of amplitude for n+p→d+η in "orthogonal" kinematics, where the η-production angle is equal to 90° in CMS. The presence of singlet and triplet amplitudes in such kinematics induces a rich set of different polarization observables, sensitive to the relative value of these amplitudes. This can be used to test a hypothesis of singlet enhancement of η-production in NN- and [Formula: see text]-collisions, due to a nonperturbative [Formula: see text]-component of the nucleon with special polarization properties.

Test of the Isospin Invariance Using Polarization Effects in Slow Antiproton Annihilation, $\bar p+ p(n)\rightarrow P+V$

1997 ◽  
Vol 12 (07) ◽  
pp. 479-487
Author(s):  
C. Yalçin ◽  
M. P. Rekalo ◽  
H. Koru
Keyword(s):  
Density Matrix ◽  
Strong Interaction ◽  
Spin Structure ◽  
Charge Conjugation ◽  
P Wave ◽  
Antiproton Annihilation ◽  
Polarization Effects ◽  
Symmetry Properties

The spin structure of the amplitudes for antiproton annihilation at rest, [Formula: see text], P=π, η;V=ρ, ω, ϕ, is established. The relation between symmetry properties of strong interaction (isospin invariance and the invariance relative to charge conjugation) and the polarization effects in such reactions are derived. It is demonstrated that the simplest polarization effects in [Formula: see text], namely, the elements of V-meson density matrix, are sensitive to possible violation of the isospin invariance and C-invariance. The analysis of the spin structure of P-wave annihilation amplitudes is also presented.

scholarly journals MOMENTS OF SPIN STRUCTURE FUNCTIONS: SUM RULES AND POLARIZABILITIES

2010 ◽  
Vol 19 (10) ◽  
pp. 1893-1921 ◽  
Author(s):  
J.-P. CHEN
Keyword(s):  
Momentum Transfer ◽  
Strong Interaction ◽  
Spin Structure ◽  
Sum Rules ◽  
Structure Functions ◽  
Operator Product ◽  
Nucleon Structure ◽  
Free Region ◽  
Wide Range ◽  
Spin Structure Functions

Nucleon structure study is one of the most important research areas in modern physics and has challenged us for decades. Spin has played an essential role and often brought surprises and puzzles to the investigation of the nucleon structure and the strong interaction. New experimental data on nucleon spin structure at low to intermediate momentum transfers combined with existing high momentum transfer data offer a comprehensive picture in the strong region of the interaction and of the transition region from the strong to the asymptotic-free region. Insight into some aspects of the theory for the strong interaction, Quantum Chromodynamics (QCD), is gained by exploring lower moments of spin structure functions and their corresponding sum rules (i.e., the Bjorken, Burkhardt–Cottingham, Gerasimov–Drell–Hearn (GDH), and the generalized GDH). These moments are expressed in terms of an operator-product expansion using quark and gluon degrees of freedom at moderately large momentum transfers. The higher-twist contributions have been examined through the evolution of these moments as the momentum transfer varies from higher to lower values. Furthermore, QCD-inspired low-energy effective theories, which explicitly include chiral symmetry breaking, are tested at low momentum transfers. The validity of these theories is further examined as the momentum transfer increases to moderate values. It is found that chiral perturbation theory calculations agree reasonably well with the first moment of the spin structure function g1 at low momentum transfer of 0.05–0.1 GeV2 but fail to reproduce some of the higher moments, noticeably, the neutron data in the case of the generalized polarizability δLT. The Burkhardt–Cottingham sum rule has been verified with good accuracy in a wide range of Q2 assuming that no singular behavior of the structure functions is present at very high excitation energies.

Talk or Walk? Gait Speed over Self-Report in Association with Cognitive Speed in Healthy Older Adults

GeroPsych ◽  
2019 ◽  
Vol 32 (1) ◽  
pp. 41-52
Author(s):  
Matthew C. Costello ◽  
Shane J. Sizemore ◽  
Kimberly E. O’Brien ◽  
Lydia K. Manning
Keyword(s):  
Older Adults ◽  
Older Adult ◽  
Gait Speed ◽  
Well Being ◽  
Self Report ◽  
Subjective Report ◽  
Healthy Older Adults ◽  
Relative Value ◽  
Cognitive Speed ◽  
Age Range

Abstract. This study explores the relative value of both subjectively reported cognitive speed and gait speed in association with objectively derived cognitive speed. It also explores how these factors are affected by psychological and physical well-being. A group of 90 cognitively healthy older adults ( M = 73.38, SD = 8.06 years, range = 60–89 years) were tested in a three-task cognitive battery to determine objective cognitive speed as well as measures of gait speed, well-being, and subjective cognitive speed. Analyses indicated that gait speed was associated with objective cognitive speed to a greater degree than was subjective report, the latter being more closely related to well-being than to objective cognitive speed. These results were largely invariant across the 30-year age range of our older adult sample.

Guilty Pleasure No More

2017 ◽  
Vol 29 (3) ◽  
pp. 126-136 ◽  
Author(s):  
Robin L. Nabi ◽  
Debora Pérez Torres ◽  
Abby Prestin
Keyword(s):  
Stress Management ◽  
Perceived Stress ◽  
Media Use ◽  
Well Being ◽  
Breast Cancer Patients ◽  
Positive Role ◽  
Individual Difference Variables ◽  
Relative Value ◽  
Management Techniques ◽  
Managing Stress

Abstract. Despite the substantial attention paid to stress management in the extant coping literature, media use has been surprisingly overlooked as a strategy worthy of close examination. Although media scholars have suggested media use may be driven by a need to relax, related research has been sporadic and, until recently, disconnected from the larger conversation about stress management. The present research aimed to determine the relative value of media use within the broader range of coping strategies. Based on surveys of both students and breast cancer patients, media use emerged as one of the most frequently selected strategies for managing stress across a range of personality and individual difference variables. Further, heavier television consumers and those with higher perceived stress were also more likely to use media for coping purposes. Finally, those who choose media for stress management reported it to be an effective tool, although perhaps not as effective as other popular strategies. This research not only documents the centrality of media use in the corpus of stress management techniques, thus highlighting the value of academic inquiry into media-based coping, but it also offers evidence supporting the positive role media use can play in promoting psychological well-being.

Enhanced polarization effects in chiral composites

1994 ◽  
Vol 4 (12) ◽  
pp. 2601-2607 ◽  
Author(s):  
A. H. Sihvola
Keyword(s):  
Polarization Effects
Sign in / Sign up

Export Citation Format

Share Document