Bulletin of the American Physical Society
2008 Annual Meeting of the Division of Nuclear Physics
Volume 53, Number 12
Thursday–Sunday, October 23–26, 2008; Oakland, California
Session LG: Cosmology |
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Chair: Karl van Bibber, Lawrence Livermore National Laboratory Room: Jewett Ballroom C |
Sunday, October 26, 2008 8:30AM - 8:42AM |
LG.00001: Limits on cold dark matter axions from the ADMX high resolution search Gray Rybka, Steven Asztalos, Richard Bradley, Gianpaolo Carosi, Michael Hotz, Jungseek Hwang, Darin Kinion, Leslie Rosenberg, Pierre Sikivie, David Tanner, Karl van Bibber The axion, a hypothetical particle invented to solve the strong CP problem in the Standard Model, has properties that also make it a compelling dark matter candidate. The Axion Dark Matter experiment (ADMX) looks for the conversion of nearby halo axions into nearly monochromatic microwave photons. Some theories of axion production of the early universe predict that present day axions will have velocity dispersions much smaller than they would had they been produced in thermal equilibrium. The high resolution channel in ADMX takes advantage of these low velocity dispersions to probe even pessimistic axion-to-photon couplings for these ``cold axion'' models. Additionally, the high resolution channel is sensitive to seasonal and annual changes in a cold axion signal, offering an insight into galactic dark matter distribution. This talk will cover the search for cold dark matter axions with masses of a few MeV using the ADMX high-resolution channel. [Preview Abstract] |
Sunday, October 26, 2008 8:42AM - 8:54AM |
LG.00002: Limits on thermally-distributed halo dark-matter axions from ADMX Gianpaolo Carosi, Steven Asztalos, Richard Bradley, Michael Hotz, Jungseek Hwang, Darin Kinion, Leslie Rosenberg, Gray Rybka, Pierre Sikivie, David Tanner, Karl van Bibber The Axion Dark Matter eXperiment (ADMX) at LLNL searches for dark-matter axions through their Primakoff conversion to microwave photons, resonantly enhanced in a high-Q cavity permeated by a strong magnetic field. The most general assumption is that halo axions are thermalized with the local virial velocity of the Milky Way, about 270 km/sec, which implies a spectral line-broadening of one part in a million. ADMX has set limits on halo axions for realistic models over an octave of mass range in the few microelectronvolt range. The experiment is the most sensitive spectral receiver in the world, able to detect signals in the GHz range well below a yoctowatt. This talk will outline the experimental technique, data analysis and results for the medium-resolution search. [Preview Abstract] |
Sunday, October 26, 2008 8:54AM - 9:06AM |
LG.00003: Overview, Technical Description and Future of the Axion Dark Matter eXperiment S. Asztalos, R. Bradley, G. Carosi, M. Hotz, J. Hwang, D. Kinion, L. Rosenberg, G. Rybka, P. Sikivie, D. Tanner, K. van Bibber The Axion Dark Matter eXperiment (ADMX) at LLNL searches for dark-matter axions through their Primakoff conversion to microwave photons, resonantly enhanced in a high-Q cavity permeated by a strong magnetic field. The original operations of the experiment employed conventional microwave amplifiers, using heterojunction field-effect transistor amplifiers (HFET) amplifiers; these devices had a system noise temperature around 3 K, determined by the sum of the 1.5 K physical temperature and the 1.5 K amplifier equivalent noise temperature. ADMX is the world's quietest spectral receiver in the GHz regime, capable of detecting a single RF photon per minute above the cavity blackbody and amplifier noise. ADMX has covered a frequency range of 460 to 812 MHz (1.9 - 3.4 micro-eV); over that octave of mass range axions were excluded as the Milky Way halo dark matter for well-motivated models of the coupling of the axion to two photons. An upgrade of ADMX has recently been completed, which replaced the previous HFET amplifiers with SQUID amplifiers. This talk will describe the experiment, both hardware and data analysis, the SQUID amplifier technology and recent operating experience, and discuss plans for a second-phase upgrade to further reduce the systems noise temperature to $\sim$100 mK. [Preview Abstract] |
Sunday, October 26, 2008 9:06AM - 9:18AM |
LG.00004: Measuring the radiative width of the Hoyle state Jason Burke A key rate that governs energy generation in stars is the triple alpha rate. The ratio of the radiative width to the total width of the Hoyle state represents the probability that a $^{12}$C nucleus will be formed when three alpha particles fuse together in a stellar environment. Measurements of the ratio of the radiative width to total width using an alpha particle scattering technique developed in the 1960's have been made several times. Using this technique the Hoyle state is excited via inelastic nuclear scattering and the scattered alpha particles and recoiling $^{12}$C nuclei are detected in coincidence. We have improved on this technique by using a large area highly segmented silicon detector array called STARS. During a five day run we accumulated 1500 alpha-$^{12}$C recoil coincident events over an angle range from 40 to 55 degrees in 1 degree steps. The experimental results including statistical and systematic uncertainty analysis will be presented. This work was performed under the auspices of the U.S. Department of Energy under contract numbers DE-AC52-07NA27344 (LLNL), DE-AC02-05CH11231 (LBNL) and DE-FG52-06NA26206 (UR). [Preview Abstract] |
Sunday, October 26, 2008 9:18AM - 9:30AM |
LG.00005: Astrophysical Data Transmission in Planck Units Shantilal Goradia ``Data Communication and Net Working'' by Forouzan expresses (an informatics equivalent of statistics) that $N$ (data rate or bits/second) divided by$ r$ (number of data elements per signal or log$_{2} \quad L)$ is the baud rate. For $N$ = 10$^{43}$ Planck times per second, and $L$ = 10$^{90}$, the number of photons in the universe, the baud rate is more than 10$^{40}$, so high a signal rate for the carriers of the attractive and repulsive pulses that we, the observers, would think that gravity is continuous, and not probabilistic. Any potential slight correction to the above as it may apply to the case, or its application to smaller baryon number (10$^{79})$ would not change the above implicit message, considering the order of magnitudes involved. This communicative aspect of gravity, and our postulation, slight modification to the inverse square law, in [1] that the probability of an interaction between two particles is inversely proportional to the square of their separations in integer number of Planck lengths, are mutually supplementary and complimentary, portraying two ducks that, not only walk like ducks, but also talk like ducks. Therefore, they are ducks. Refer to: [1] Goradia, Shantilal http://www.arXiv.org/pdf/physics/0210040v4. [Preview Abstract] |
Sunday, October 26, 2008 9:30AM - 9:42AM |
LG.00006: The mass, energy, space and time system theory-MEST Dayong Cao Things have their own system of mass, energy, space and time of themself. (The MEST for short thereinafter). Mass is density, energy is force, time is frequency, spac is amplitude square. There are the transmutation between space-time and mass-energy. When they get a balance, they get the inertia and eigenvalue system. The quality of microsubstance mainly is quantum space-time; The nature of the macrosubstance is mainly mass-energy. In wave-particle duality, the quality of wave mainly is quantum space-time; The nature of the particle is mainly mass-energy. New mass-energy wave equation, space-time particle equation are being put forward. With anode dark current of hole and mass wave, give a new explain to the photoelectric effect experiment; and get new mass-energy equation which equal the mass-energy relation of Einstein and Electrodynamics. And the new photoelectric conversion equation are being put forward. Consequently, it is discovered the transmutation between space-time and mass-energy. New atom and nuclear model And New speed of light theory are being put forward. There are different mass of electrons of atom. And explain the probability of wave. Deduce the new uncertainty principle, uncertainty and probability can not be divided. MEST can unites both orbit equations of nine planes and orbit equations of electrons of H and He . MEST can unites both wave equations of nine planes and particle equations of sun. We can change the orbit of asteroid who will impacted near our earth. [Preview Abstract] |
Sunday, October 26, 2008 9:42AM - 9:54AM |
LG.00007: Deeper Probing of the Fine-structure Constant Shantilal Goradia In our earlier attempt in [1] to derive fine-structure constant, one subtle reason why the natural logarithm of the age of the universe in Planck times comes out to be slightly greater than the reciprocal of the fine structure constant is that the variable $W$ in Boltzmann's expression should be the age of the universe in Planck times divided by the bit depth for our specific application. Since we cannot decode the nature's bit depth, we cannot come up with the expected value of ALPHA. For an assumed bit depth of 10, the reciprocal of ALPHA goes down by ln10 (2.3) without having a significant impact on the order of magnitude of the baud rate (baud rate = bits per second/bit depth = 10$^{43}$ (Planck time/second)/10 = 10$^{42})$. Use of terms and equations from informatics in both of author's interrelated abstracts this meeting is meant to engage a wider audience simply. [1] Goradia, Shantilal ``What is Fine-structure Constant?'' http://www.arXiv.org/pdf/physics/0210040v3. [Preview Abstract] |
Sunday, October 26, 2008 9:54AM - 10:06AM |
LG.00008: The mass, energy, space and time system of Wave, Particle and universe -MEST Dayong Cao Things have their own system of mass, energy, space and time of themself. (The MEST for short thereinafter). Mass is density, energy is force, time is frequency, spac is amplitude square. New mass-energy wave equation, space-time particle equation are being put forward. Mass, Energy, Space (Radius), Time (Period) of nine planes compose a MEST of plane; Mass(Density of sun), Energy (Gravity of sun), Space (Radius of nine planes), Time (Period of nine planes) compose other MEST of sun. MEST can unites both wave equations of nine planes and particle equations of sun. Mass, Energy, Space (Radius), Time (Period) of electron of H compose a MEST of electron; Mass, Energy (coulombic force), Space (Radius of electron), Time (Period of electron) compose other MEST of nucleon of H. MEST can unites both wave equations of electron of H and particle equations of nucleon of H. MEST can unites both wave equations of electron of H and wave equations of nine planes. Dark matter-energy is from Black hole. Because Black hole have a applied thrust to it, So its quantity that be estimated is bigger than it's in fact. There are a lot of asteroids and dark matter-energy near the orbit of Jupiter. They will impacted near our earth, when Dark matter-energy changes the orbit of these asteroids. It is a recurrent action. Because there is a interaction between back hole and the solar system. [Preview Abstract] |
Sunday, October 26, 2008 10:06AM - 10:18AM |
LG.00009: The mass, energy, space and time system of Star and Black hole -MEST Dayong Cao Things have their own system of mass, energy, space and time of themself. (The MEST for short thereinafter). Mass is density, energy is force, time is frequency, spac is amplitude square. In MEST of Star, Mass-energy condense to center, Space-time radiate to Around. An Nuclear is like the Mass-energy center while the charge cloud is like the Space-Time around. Neutron, Proton, Electron, Muon atom compose a MEST-1 of Star. Neutron, Proton, Pion meson+, Pion meson- compose a MEST-2 of Star. Electron, Muon atom, Eleneutrino, Muneutrino compose a MEST-3 of Star. Pion meson+, Pion meson-, Eleneutrino, Muneutrino compose a MEST-4 of Star. In MEST of Black hole, Space-time condense to center, Mass-energy radiate to Around. Black hole is space-time particle center while the dark matter-energy is the radiate mass-energy Wave around Black hole. The dark matter-energy is from the Black hole. MEST of the dark matter-energy reverse of MEST-1, MEST-2, MEST-3, MEST-4. Because Black hole have a applied thrust to dark matter-energy, So the quantity of mass of dark matter-energy that be estimated is bigger than it's in fact. Black hole and Dark matter-energy can reduce the frequence of the light of star. [Preview Abstract] |
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