6851820
The Effect of Reduced Spatial Symmetries on Lattice States: Results for Non-zero Linear Momentum
The irreducible representations of the cubic space group are described and used to determine the mapping of continuum states to lattice states with non-zero linear momentum. The Clebsch-Gordan decomposition is calculated from the character table for the cubic space group. These results are used to identify multiparticle states which appear in the hadron spectrum on the lattice.
3073653
Silicon detector dark matter results from the final exposure of CDMS II.
We report results of a search for weakly interacting massive particles (WIMPS) with the silicon detectors of the CDMS II experiment. This blind analysis of 140.2 kg day of data taken between July 2007 and September 2008 revealed three WIMP-candidate events with a surface-event background estimate of 0.41(-0.08)(+0.20)(stat)(-0.24)(+0.28)(syst). Other known backgrounds from neutrons and 206Pb are limited to <0.13 and <0.08 events at the 90% confidence level, respectively. The exposure of this analysis is equivalent to 23.4 kg day for a recoil energy range of 7-100 keV for a WIMP of mass 10  GeV/c2. The probability that the known backgrounds would produce three or more events in the signal region is 5.4%. A profile likelihood ratio test of the three events that includes the measured recoil energies gives a 0.19% probability for the known-background-only hypothesis when tested against the alternative WIMP+background hypothesis. The highest likelihood occurs for a WIMP mass of 8.6  GeV/c2 and WIMP-nucleon cross section of 1.9×10(-41)  cm2.
16657381
Search for millicharged particles using optically levitated microspheres.
We report results from a search for stable particles with charge ≳10^{-5}e in bulk matter using levitated dielectric microspheres in high vacuum. No evidence for such particles was found in a total sample of 1.4 ng, providing an upper limit on the abundance per nucleon of 2.5×10^{-14} at the 95% confidence level for the material tested. These results provide the first direct search for single particles with charge ≲0.1e bound in macroscopic quantities of matter and demonstrate the ability to perform sensitive force measurements using optically levitated microspheres in vacuum.
119285051
Initial systematic investigations of the landscape of low layer NAHE extensions
The discovery that the number of physically consistent string vacua is on the order of 10500 has prompted several statistical studies of string phenomenology. Contained here is one such study that focuses on the Weakly Coupled Free Fermionic Heterotic String (WCFFHS) formalism. Presented are systematic extensions of the well-known NAHE (Nanopoulos, Antoniadis, Hagelin, Ellis) set of basis vectors, which have been shown to produce phenomenologically realistic models. Statistics related to the number of U(1)’s, the specific gauge groups and their factors, non-Abelian singlets, and spacetime supersymmetries (ST SUSYs) are discussed for the full range of models produced. These findings are compared with prior results of other large-scale investigations. Statistical coupling between the gauge groups and the number of ST SUSYs is also discussed. In particular, for order-3 extensions there is a correlation between the appearance of exceptional groups and enhanced ST SUSY. Also discussed are some three-generation GUT models found among the data sets. These models are unique because they come from basis vectors which still have a geometric interpretation—there are no “rank cuts” in these models.
119293103
THE FATE OF LORENTZ FRAME IN THE VICINITY OF BLACK HOLE SINGULARITY
General Relativity (GR) is known to break down at singularities. However, it is expected that quantum corrections become important when the curvature is of the order of Planck scale avoiding the singularity. By calculating the effect of tidal forces on a freely falling inertial frame, and assuming the least possible size of the frame to be of the Planck length, we show that the Lorentz frames cease to exist at a finite distance from the singularity. Within that characteristic radius, one cannot apply GR nor Quantum Field Theory (QFT) as we know them today. Additionally, we consider other quantum length scales and impose limits on the distances from the singularity at which those theories can conceivably be applied within a Lorentz frame.
121546122
Central Hadron Calorimeter of UA1
Abstract An iron—scintillator sampling calorimeter is described, which measures hadronic energy in proton-antiproton interactions at the CERN 540 GeV SPS collider. Construction details are given of the instrumentation of the magnet pieces of the UA1 experiment and of the methods used to measure the calorimeter response and resolution. The system of lasers and quartz fibres, which allows long term monitoring of the calorimeter response, is also described.
118426859
SYSTEMATIC INVESTIGATIONS OF THE FREE FERMIONIC HETEROTIC STRING GAUGE GROUP STATISTICS: LAYER 1 RESULTS
Using software under development at Baylor University, we explicitly construct all layer 1 gauge, weakly coupled free fermionic heterotic string models up to order 22 in four large spacetime dimensions. The gauge models consist primarily of gauge content making a systematic construction process efficient. We present an overview of the model building procedure, redundancies in the process, methods used to reduce such redundancies and statistics regarding the occurrence of various combinations of gauge group factors and GUT groups. Statistics for both and models are presented.
133913420
SOME TESTS ON CIRCULAR DIAPHRAGMS OF POLYETHYLENE TEREPHTHALATE FILM