Bulletin of the American Physical Society
80th Annual Meeting of the APS Southeastern Section
Volume 58, Number 17
Wednesday–Saturday, November 20–23, 2013; Bowling Green, Kentucky
Session JB: Particle Physics II |
Hide Abstracts |
Chair: Darin Acosta, University of Florida Room: 2 |
Saturday, November 23, 2013 10:30AM - 10:42AM |
JB.00001: A Search for the Standard Model Higgs in $t\bar{t}$H, H$\rightarrow$$b\bar{b}$ decay channel at $\sqrt s$ = 8 TeV John Wood The most important goal of the Large Hadron Collider (LHC) is to elucidate the mechanism of electroweak symmetry breaking. The Standard Model(SM) Higgs Boson is thought to be a prime candidate for this. The newly discovered boson announced on July 4th, 2012, with a mass of ~125GeV, has so far been shown to be consistent with a SM Higgs. However, the final confirmation of this new particle as the SM Higgs depends on subsequent measurements of its properties. The observation of this new particle in association with top-quark pairs would allow the couplings of this particle to top and bottom quarks to be directly measured. $t\bar{t}$Higgs, Higgs to $b\bar{b}$ is an excellent channel to explore due to the dominant branching ratio of Higgs to $b\bar{b}$ and the kinematic handle the $t\bar{t}$ offers on the event. However, it presents a plethora of difficult challenges due to a low signal to background ratio and uncertainties on kinematically similar SM backgrounds. This talk describes a search for the SM Higgs boson in association with top quarks. Data to Monte Carlo comparisons are made with with the full 19.4 $fb^{-1}$ 2012 dataset of pp collisions collected by the CMS detector. [Preview Abstract] |
Saturday, November 23, 2013 10:42AM - 10:54AM |
JB.00002: Investigation of Wavelength Dependent Radiation Damage in ECAL Crystals Joseph Goodell The Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) uses a Light Monitoring Farm (LMF) to assess the behavior and response of the lead tungstate scintillating crystals and the vacuum phototriode (VPT) photodetectors. The LMF uses 440nm blue laser light, 455nm blue LED light, and 617 orange LED light to try to extract a wavelength dependence on the radiation damage to crystals and VPTs. Data from the LMF are compared with non-radiation VPT studies performed at the University of Virginia to separate whether the effects are due to radiation or to VPT performance. Combining these experimental results with radiation damage theory we compare what we expect from radiation damage to observed differences in blue and orange light response. [Preview Abstract] |
Saturday, November 23, 2013 10:54AM - 11:06AM |
JB.00003: New Singlet Positronium Bound State Horace Crater, Cheuk-Yin Wong The Two-Body Dirac equations of constraint dynamics applied to QED yield an exact Sommerfeld-like solution for the spectrum of $^{1}J_{J}$ singlet positronium states which agrees with standard perturbative results through order $\alpha ^{4}$. At short distance the bound state equation is $ (-d^{2}/dr^{2}+(J(J+1)-\alpha ^{2})/r^{2})u=0,$ and the radial part of the wave function $u=r\psi $ has two solutions with probabilities near the origin of $\psi ^{2}d^{3}r=u^{2}drd\Omega =r^{(1\pm \sqrt{(2J+1)^{2}-4a^{2}})}drd\Omega $. For $J\neq 0$ only the `$+$' sign is allowable but both signs for $J=0$ are well behaved. The `$+$' sign corresponds to ordinary positronium (with a binding energy of about 6.8 eV). The `$-$' sign corresponds to a new positronium state with a binding energy of about 300 KeV and size about a electron Compton wave length. The ordinary $1S$ positronium state decays into this new $1S$ state with a life time on the order of $10^{-3} $ seconds by two photon emission with c.m. energy of about $700$ KeV. The peculiar $1S$ state then annihilates into two photons with c.m. energy of about $300$ KeV. Thus the existence of this new positronium state would be a distinctive 4 gamma decay signature of ordinary singlet positronium. [Preview Abstract] |
Saturday, November 23, 2013 11:06AM - 11:18AM |
JB.00004: The K0TO Experiment: Undergraduate Research in High Energy Particle Physics Melissa Hutcheson The K0TO Experiment aims to discover and measure the rare decay mode of the neutral kaon, $K_L \rightarrow \pi_0 \nu \bar{\nu}$. This decay is a flavor changing neutral current process which directly violates CP symmetry and proceeds through second order weak interactions. The Standard Model predicts the branching ratio to be $2.8 \times 10^{-11}$. The goals of the experiment are to first observe the decay and then measure at least 100 events to determine the branching ratio to a higher accuracy (on the order of $10^{-12}$) which will either establish more precise limits for the Standard Model or reveal evidence of new physics. An important component of the experiment is the Data Acquisition System (DAQ System) which collects data at a rate of about 1 Terabyte per second. In order to process the data a series of trigger cuts are in place to selectively record events of interested and discard unwanted events. The high rate signals from the detector are shaped and converted from analog to digital by an ADC board. A study was conducted in order to determine the temperature dependence of the ADC pedestal values on which the accuracy of the experimental data relies heavily. [Preview Abstract] |
Saturday, November 23, 2013 11:18AM - 11:30AM |
JB.00005: The 1 + 1 Dirac equation with a linear potential Walter Jaronski The Dirac equation in one spatial dimension is studied for the case of a linear potential. Different choices are made for the Lorentz nature of the potential: vector, scalar, and pseudoscalar. The existence of bound states is explored for each choice. In the scalar and pseudoscalar cases, solutions can be found by elementary means and they are of oscillator form. The use of transformations of the Foldy-Wouthuysen type in one spatial dimension is also considered. In the scalar case and for massless particles, the free FW transformation exchanges the spatial coordinate and its conjugate momentum. [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700