Nuclear and Particle Physics
Our group has studied the internal sub-structure of the proton with the PHENIX detector using transversely polarized proton collisions. We conducted detailed measurements of the transverse single spin asymmetries (AN) of electromagnetic clusters and eta mesons using the PHENIX Muon Piston Calorimeter, which sits at pseudo-rapidities of 3.1<\eta>
In addition, we are collaborating on development of an advanced multi-gap Resistive Plate Chamber for a time-of-flight measurement capable of better than 20 picosecond resolution. This detector will enable particle identification capabilities which are almost ten times better than is possible with current technology.
Our group is also working on low energy nuclear physics projects. It is accepted and understood that relativity has an effect on nuclear physics scattering collisions from 100 Mev. We seek to address when these relativistic effects should be considered . In particular, we intend to find at what energy is there a phase shift and cross section difference between a non relativistic Schrodinger equation solution and several different relativistic corrective models.
There are many examples of astrophysical objects that have been found to behave as one would expect of black holes. However, it remains quite difficult to examine the characteristics of horizons themselves. So called “event horizons” are the surfaces that contrast black holes from other black objects that develop a trapping surface that is not light-like. The simplest of black holes have regions of exotic energy densities, and even singularities where the laws of physics break down. We are developing non-singular dynamic black objects and black holes which nowhere involve exotic energy densities. In such geometries, there will be no observers unable to perform experiments that locally satisfy all laws of physics, eliminating certain paradoxes associated with the singular or exotic nature of the energy densities that form the black objects.
Quantum gravity and cosmology
We have several ongoing efforts in gravitation and cosmology. The canonical proper time formulation of relativistic systems is particularly useful for expressing the dynamics of gravitating systems using the proper time of those systems as the temporal parameter, along with other coordinates (like momentum) described by often non-inertial observers (like fiducial observers in general relativity). The equations allow solutions in quantum gravity using techniques from atomic physics.
Another effort is developing a quantum coherent initial state cosmology whose zero-point behaviors generate the expected scale of fluctuations consistent with those observed in the cosmic microwave background. We continue to explore this type of early inflation due to the dissolution of global quantum coherence, which of itself solves the horizon problem.
Several of our students and associates continue to develop skills in constructing Penrose diagrams for characterizing the global causal structure of various relevant dynamic geometries. Such diagrams are quite useful for identifying characteristic parameters for describing space-like quantum states, as well as establishing causal relationships between component co-gravitating systems in a dynamic geometry.
Finally, work continues on demonstrating the viability of linear spinor fields as a mechanism for unifying the structure of gravitational interactions with interactions mediated using gauge fields, consistent with the principle of equivalence. The formulation allows massless particles of finite transverse mass to mix along differing light-like affine parameters, despite the equivalence of the phase i p.x for all massless particles. An intriguing characteristic of the fundamental representation of the group is that the number of additional internal hermitian generators is precisely the same as that in SU(3) x SU(2) x U(1).
The completion of the Human Genome Project in 2003 introduced a new knowledge-base for decoding biology and defining human populations based on the science of information encoded in DNA sequence variation. We are examining the human genome as a dynamic living information and communication system. One of our major efforts models the information content encoded in whole genome single nucleotide polymorphisms (SNPs) whose variations reach homeostasis within a given environment. The extraction of meaningful information from complex SNP data depends crucially upon the lens through which the data are examined. Our approach develops biophysical parameters that characterize genome-environment interactions in population genomics using state variables analogous to those in thermodynamics and statistical physics. This ‘genodynamics’ approach offers a new way of looking at SNPs and thinking about the interrelationship and integration of genome variation, population diversity, and epidemiology in population genetics. We have found that not only is life an emergent property of a type of physical system, but in addition, the haplotype structures associated with various populations are emergent characteristics dependent upon environmental characteristics.
Another effort examines the micro-informatics of individual genomic sequences, for individual humans as well as “simpler” organisms such as bacterial phages, etc. We are developing portable information metrics that can be used to classify sequence data, as well as map the informatics along the genome. This is particularly useful in examining the relationships between asexual organism whose genomes are difficult to compare. In addition, our approach examines whole genome dynamics, beyond the local gene or regulatory function on a genome.
The research focus of this proposal is based on Dr. Paul Butler’s project to find a significant number of Solar System analogs and terrestrial mass planets around nearby stars.
This project may be compared to the NASA Kepler mission. The Kepler project has a fairly straight forward mission – to find out what fraction of stars have potentially habitable planets. Since Kepler target stars are typically more than a thousand light-years distant, these stars can not be followed up. In contrast the precision Doppler velocity surveys that Dr. Butler is carrying out are focused on the very nearest stars, the only possible targets for next generation astrometry, direct imaging, and spectroscopy missions.
In order to carry out this ongoing research, ground based telescope observations are made at Keck, AAT, Magellan,and APT. The data are analyzed with improved software developed in part by Dr. Butler and his collaborators.
Our group made history when our in-flight research project was launched into space on June 26, from NASA’s Wallops Flight Facility in Virginia. The project collected atmospheric samples near the highest point of the flight to test for the presence of microorganisms. Data from the samples will be used to develop a bio-signature that can help look for life on Earth-like, extra-solar planets.
The Terrier-Improved Orion sounding rocket was launched at 7:21 a.m. EST and flew to a height of 73.3 miles. It landed in the Atlantic Ocean 43.9 miles from Wallops Flight Facility, 12.16 minutes after launch. It contained several other student-built experiments.
The project was part of the RockSat-C 2014 Program which provides an opportunity for students to design and build a sounding rocket payload, and launch the payload on a rocket. Student teams, like Howard’s, had been steadily working since the fall to design, plan, and build a payload that would perform an in-flight experiment.