4,441 research outputs found
Thermal Upsilon(1s) and chi_b1 suppression in sqrt(s_NN)=2.76 TeV Pb-Pb collisions at the LHC
I compute the thermal suppression of the Upsilon(1s) and chi_b1 states in
sqrt(s_NN)=2.76 TeV Pb-Pb collisions. Using the suppression of each of these
states I estimate the total R_AA for the Upsilon(1s) state as a function of
centrality, rapidity, and transverse momentum. I find less suppression of the
chi_b1 state than would be traditionally assumed; however, my final results for
the total Upsilon(1s) suppression are in good agreement with recent preliminary
CMS data.Comment: 4 pages, 4 figures; v4: published versio
Bulk Properties of a Fermi Gas in a Magnetic Field
We calculate the number density, energy density, transverse pressure, longitudinal pressure and magnetization of an ensemble of spin one-half particles in the presence of a homogeneous background magnetic field. The magnetic field direction breaks spherical symmetry causing the pressure parallel to it. We present explicit formulae appropriate at zero and finite temperature for both charged and uncharged particles including the effect of the anomalous magnetic moment. We demonstrate that the resulting expressions satisfy the canonical relations, omega = -PII and Pperpendicular = PII- MB with M = (delta)(omega)/(delta)(beta) being the magnetization of the system. We numerically calculate the resulting pressure anisotropy for a gas of protons and a gas of neutrons and demonstrate that the inclusion of the anomalous magnetic increase the level of pressure anisotropy in both cases
Planning assistance for the NASA 30/20 GHz program. Network control architecture study.
Network Control Architecture for a 30/20 GHz flight experiment system operating in the Time Division Multiple Access (TDMA) was studied. Architecture development, identification of processing functions, and performance requirements for the Master Control Station (MCS), diversity trunking stations, and Customer Premises Service (CPS) stations are covered. Preliminary hardware and software processing requirements as well as budgetary cost estimates for the network control system are given. For the trunking system control, areas covered include on board SS-TDMA switch organization, frame structure, acquisition and synchronization, channel assignment, fade detection and adaptive power control, on board oscillator control, and terrestrial network timing. For the CPS control, they include on board processing and adaptive forward error correction control
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