Low-energy neutrino physics and neutrino mass

Among the principal concerns in neutrino physics today are the questions of whether neutrinos are massive and, if so, whether the neutrinos emitted in a weak decay are pure or mixed quantum states. The concept of mixed neutrinos has been with us for more than 20 years, having first been introduced by Maki et al (1) and by Pontecorvo (2) following demonstration in 1962 that more than one type (flavor) of neutrino existed. After having been dormant for some time, the interest in these issues was reborn in recent years with the advent of grand unified theories, which predict nonvanishing neutrino mass and which can accommodate eutrino mixing, in a natural way. Controversial experiments also refueled the excitment (and consternation) of researchers in this endeavor

Fine structure of beta decay endpoint spectrum

We note that the fine structure at the endpoint region of the beta decay spectrum is now essentially known using neutrino oscillation data, if the mass of one neutrino is specified. This may help to identify the effects of nonzero neutrino masses in future experiments. An exact treatment of phase space kinematics is used. This work is independent of theoretical models. Additional restrictions due to the assumption of a so-called "complementary ansatz" for the neutrino mass matrix are also discussed.Comment: 9 pages, 8 figure

Billy Yank On The Northern Plains: The Lives Of Union Soldiers On The Minnesota-Dakota Frontier From The Great Sioux Uprising To 1866

This thesis will tell the generally forgotten story of the Civil War era soldiers on the Minnesota-Dakota frontier who fought in the Great Sioux Uprising from 1862 to 1865. It will also compare the frontier soldiers’ campaign experience with the experiences of Bell Irvin Wiley’s Civil War ‘\u27Billy Yanks.” This thesis covers enlistment procedures, food, clothing, shelter, discipline, disease, boredom, combat, the “galvanized” Yankees, the Dakota landscape, and the role of the cavalry. This story of the frontier soldiers’ expeditions against the Sioux on the northern plains is told using direct quotations from frontier soldiers’ diaries and manuscripts, along with United States government records, the Fort Rice publication. Frontier Scout, and various secondary sources. Most frontier “Billy Yanks” enlisted to fight in the Civil War; instead, they pursued the Sioux Indians across Dakota Territory on expeditions with generals Henry H. Sibley and Alfred T. Sully. In general, the experiences of these frontier soldiers were remarkably similar to those of Civil War soldiers. Subtle differences did exist, but for the most part, frontier soldiers shared common bonds with other Civil War era fighting men, such as life at military posts, boredom, and disease. However, frontier soldiers experienced a pronounced difference from their Civil War comrades in the combat and landscape they faceu, fighting Native Americans in th

Prospects for measuring coherent neutrino-nucleus elastic scattering at a stopped-pion neutrino source

Rates of coherent neutrino-nucleus elastic scattering at a high-intensity stopped-pion neutrino source in various detector materials (relevant for novel low-threshold detectors) are calculated. Sensitivity of a coherent neutrino-nucleus elastic scattering experiment to new physics is also explored.Comment: 9 pages, 14 figures; minor modifications for publicatio

A theoretical and semiemprical correction to the long-range dispersion power law of stretched graphite

In recent years intercalated and pillared graphitic systems have come under increasing scrutiny because of their potential for modern energy technologies. While traditional \emph{ab initio} methods such as the LDA give accurate geometries for graphite they are poorer at predicting physicial properties such as cohesive energies and elastic constants perpendicular to the layers because of the strong dependence on long-range dispersion forces. `Stretching' the layers via pillars or intercalation further highlights these weaknesses. We use the ideas developed by [J. F. Dobson et al, Phys. Rev. Lett. {\bf 96}, 073201 (2006)] as a starting point to show that the asymptotic $C_3 D^{-3}$ dependence of the cohesive energy on layer spacing $D$ in bigraphene is universal to all graphitic systems with evenly spaced layers. At spacings appropriate to intercalates, this differs from and begins to dominate the $C_4 D^{-4}$ power law for dispersion that has been widely used previously. The corrected power law (and a calculated $C_3$ coefficient) is then unsuccesfully employed in the semiempirical approach of [M. Hasegawa and K. Nishidate, Phys. Rev. B {\bf 70}, 205431 (2004)] (HN). A modified, physicially motivated semiempirical method including some $C_4 D^{-4}$ effects allows the HN method to be used successfully and gives an absolute increase of about $2-3$ to the predicted cohesive energy, while still maintaining the correct $C_3 D^{-3}$ asymptotics

Predicting Neutron Production from Cosmic-ray Muons

Fast neutrons from cosmic-ray muons are an important background to underground low energy experiments. The estimate of such background is often hampered by the difficulty of measuring and calculating neutron production with sufficient accuracy. Indeed substantial disagreement exists between the different analytical calculations performed so far, while data reported by different experiments is not always consistent. We discuss a new unified approach to estimate the neutron yield, the energy spectrum, the multiplicity and the angular distribution from cosmic muons using the Monte Carlo simulation package FLUKA and show that it gives a good description of most of the existing measurements once the appropriate corrections have been applied.Comment: 8 pages, 7 figure