Nucleon and pion structure with lattice QCD simulations at physical value of the pion mass

We present results on the nucleon scalar, axial, and tensor charges as well as on the momentum fraction, and the helicity and transversity moments. The pion momentum fraction is also presented. The computation of these key observables is carried out using lattice QCD simulations at a physical value of the pion mass. The evaluation is based on gauge configurations generated with two degenerate sea quarks of twisted mass fermions with a clover term. We investigate excited states contributions with the nucleon quantum numbers by analyzing three sink-source time separations. We find that, for the scalar charge, excited states contribute significantly and to a less degree to the nucleon momentum fraction and helicity moment. Our result for the nucleon axial charge agrees with the experimental value. Furthermore, we predict a value of 1.027(62) in the MS¯¯¯¯¯ scheme at 2 GeV for the isovector nucleon tensor charge directly at the physical point. The pion momentum fraction is found to be ⟨x⟩π±u−d=0.214(15)(+12−9) in the MS¯¯¯¯¯ at 2 GeV.

Digitization for Preservation and Access: Restoring the Usefulness of the Nitrate Negative Collections at the American Geographical Society Library

Film-based photographic collections of nitrate negatives pose major challenges to preservation and access because of unstable media and the lack of item-level indexing. Digitization offers an opportunity to capture the content of deteriorating negatives, to extend access to them, and to restore their usefulness as information resources. Digitization as a preservation strategy has been the subject of ongoing debate. This article contributes to the discussion by exploring access to and the preservation of film-based photographic collections and by presenting the digiti- zation project at the American Geographical Society Library as a case study. The project, Saving and Sharing the AGS Library’s Historic Nitrate Negative Images, was undertaken from 2010 to 2012 to preserve and provide access to over 69,000 nitrate negatives from its historic collections.

Transactions of the American Philosophical Society.

new ser.:v.2 (1825)

Transactions of the American Horticultural Society.

5

Transactions of the American Philosophical Society.

new ser.:v.16 (1890)

Transactions of the American Philosophical Society.

new ser.:v.3 (1830)

Transactions of the American Philosophical Society.

new ser.:v.10 (1853)

Transactions of the American Entomological Society

v. 47 1921

Transactions of the American Entomological Society

v. 46 1920

Reactor safety conference, jointly sponsored by American Nuclear Society, Atomic Industrial Forum [and] United States Atomic Energy Commission, New York City, October 31, 1957.

Cover title.

Transactions of the American Fisheries Society.

Nuclear science abstracts

Address at the celebration of the forty-sixth anniversary of the American Bible Society /

The Anniversary exercises were held at Irving Hall, May 8th, 1862, Heman Lincoln, Senior Vice President of the Society, in the Chair.

Proceedings of the ... session of the American Pomological Society.

Description based on: 13th (1871)