The Exact Electron Propagator in a Magnetic Field as the Sum over Landau Levels on a Basis of the Dirac Equation Exact Solutions

The exact propagator for an electron in a constant uniform magnetic field as the sum over Landau levels is obtained by the direct derivation by standard methods of quantum field theory from exact solutions of the Dirac equation in the magnetic field. The result can be useful for further development of the calculation technique of quantum processes in an external active medium, particularly in the conditions of moderately large field strengths when it is insufficient to take into account only the ground Landau level contribution.Comment: 9 pages, LaTeX; v2: 3 misprints corrected, a note and 1 reference added; to appear in Int. J. Mod. Phys.

Neural Natural Language Inference Models Enhanced with External Knowledge

Modeling natural language inference is a very challenging task. With the availability of large annotated data, it has recently become feasible to train complex models such as neural-network-based inference models, which have shown to achieve the state-of-the-art performance. Although there exist relatively large annotated data, can machines learn all knowledge needed to perform natural language inference (NLI) from these data? If not, how can neural-network-based NLI models benefit from external knowledge and how to build NLI models to leverage it? In this paper, we enrich the state-of-the-art neural natural language inference models with external knowledge. We demonstrate that the proposed models improve neural NLI models to achieve the state-of-the-art performance on the SNLI and MultiNLI datasets.Comment: Accepted by ACL 201

MS – 230: Young Men’s Christian Association of Pennsylvania College Papers, 1867-1872

In 1867, President H. L. Baugher appointed Tutor Henry Eyster Jacobs (Class of 62) to chair a student committee to draw up a constitution for an organization through which students could learn about and support Christian missions. March 16, 1867, the Young Men’s Christian Association of Pennsylvania College was formed with Edward S. Breidenbaugh (Class of 1868) as its first president. With an early membership of 40, the association meet monthly, then quickly moved to weekly programs including prayer meetings, bible study, and lectures. Over the years, they supported the work of the Y. M. C.A. of Pennsylvania, several foreign missions, conducted services in the local poorhouse, held public lectures, and worked for temperance The Y.M.C.A. was the precursor to the Student Christian Association that functioned on this campus until 1965 when it merged with the Chapel Council to become one body. Chiefly an organization for inquiry concerning missions, the Y. M. C. A. of Pennsylvania College members wrote letters to foreign missionaries requesting details of mission work. Folder 1 contains letters from missionaries in Indian, Japan, Syria, Turkey, and China, as well as a “home missionary” in St. Louis, Missouri. Some respondents wrote of the importance of the work in general and a few wrote details of their personal missionary work. The rest of the papers contain business correspondence with Executive Committee of the Y.M.C.A. of Pennsylvania and other Y.M.C.A. organizations, as well as letters from local ministers contacted to speak before the group. These records, 1867-1872, are the only extant records of the association until 1946-1965, For those papers, see Record Group 3.4 Office of the Chaplain, Series I: Student Christian Association. Special Collections and College Archives Finding Aids are discovery tools used to describe and provide access to our holdings. Finding aids include historical and biographical information about each collection in addition to inventories of their content. More information about our collections can be found on our website http://www.gettysburg.edu/special_collections/collections/.https://cupola.gettysburg.edu/findingaidsall/1196/thumbnail.jp

To be or not to Be? - First Evidence for Neutrinoless Double Beta Decay

Double beta decay is indispensable to solve the question of the neutrino mass matrix together with $\nu$ oscillation experiments. Recent analysis of the most sensitive experiment since nine years - the HEIDELBERG-MOSCOW experiment in Gran-Sasso - yields a first indication for the neutrinoless decay mode. This result is the first evidence for lepton number violation and proves the neutrino to be a Majorana particle. We give the present status of the analysis in this report. It excludes several of the neutrino mass scenarios allowed from present neutrino oscillation experiments - only degenerate scenarios and those with inverse mass hierarchy survive. This result allows neutrinos to still play an important role as dark matter in the Universe. To improve the accuracy of the present result, considerably enlarged experiments are required, such as GENIUS. A GENIUS Test Facility has been funded and will come into operation by early 2003.Comment: 16 pages, latex, 10 figures, Talk was presented at International Conference "Neutrinos and Implications for Physics Beyond the Standard Model", Oct. 11-13, 2002, Stony Brook, USA, Proc. (2003) ed. by R. Shrock, also see Home Page of Heidelberg Non-Accelerator Particle Physics Group: http://www.mpi-hd.mpg.de/non_acc