Physics - Bachelor's degree
http://hdl.handle.net/1721.1/7696
Sat, 24 Mar 2018 07:59:01 GMT2018-03-24T07:59:01ZAnalyzing the large-scale curvature of interplanetary shocks
http://hdl.handle.net/1721.1/114134
Analyzing the large-scale curvature of interplanetary shocks
Vogt, Marissa Farland
The 3-dimensional structure of interplanetary shock surfaces are analyzed using observations from the Wind and ACE spacecraft. Events seen by both spacecraft were selected from the available data and used to calculate the radius of curvature R, of the shock surface. The surface structure was examined within the ecliptic plane, and evidence of large-scale curvature was seen when the spacecraft separation was sufficiently large. A simulation was run to test the effects of small errors in the shock normal, and showed that these errors could affect R, calculations at small separation. The radius of curvature was studied as a function of shock strength to look for evidence of ripples on the shock surface, though no correlation was found.
Thesis: S.B., Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences, 2006.; Thesis: S.B., Massachusetts Institute of Technology, Department of Physics, 2006.; Cataloged from PDF version of thesis.; Includes bibliographical references (pages 36-37).
Sun, 01 Jan 2006 00:00:00 GMThttp://hdl.handle.net/1721.1/1141342006-01-01T00:00:00ZHeavy nuclides in cosmic radiation.
http://hdl.handle.net/1721.1/112599
Heavy nuclides in cosmic radiation.
Hallock, Geoffrey Gaddis
Massachusetts Institute of Technology. Dept. of Physics. Thesis. 1969. B.S.; Bibliography: leaf 41.
Wed, 01 Jan 1969 00:00:00 GMThttp://hdl.handle.net/1721.1/1125991969-01-01T00:00:00ZCalculation of the axial charge of a heavy nucleon in Lattice QCD
http://hdl.handle.net/1721.1/111890
Calculation of the axial charge of a heavy nucleon in Lattice QCD
Pefkou, Dimitra Anastasia
In this thesis, we aim to calculate the non-renormalized axial charge gA of a heavy nucleon made out of quarks at the physical mass of the strange quark. We present the framework of Lattice QCD which makes the calculation of such observables attainable from first principles. The data used for the estimation of gA were obtained on a 243 x64 hypercubic lattice with lattice spacing a ~ 0.12 fm and pion mass m[pi] = 0.450 GeV. Three different source-sink seperations were used, tsink = [12a, 14a, 16a]. For each timeslice seperation signal we perform a correlated x2 fit and obtain the following values for gA: 0.551, 0.564 and 0.556. The unrenormalized value value for gA is extracted taking the limit as tsink --> [infinity] and is shown to be gA = 0.558. We discuss how the accuracy of this result is compromised by the small number of tsink values, by excited state contamination and by the increase of statistical noise with time.
Thesis: S.B., Massachusetts Institute of Technology, Department of Physics, 2016.; Cataloged from PDF version of thesis.; Includes bibliographical references (pages 55-57).
Fri, 01 Jan 2016 00:00:00 GMThttp://hdl.handle.net/1721.1/1118902016-01-01T00:00:00ZStudy of a short distance top mass with a cross-section at NNLL + NNLO
http://hdl.handle.net/1721.1/111889
Study of a short distance top mass with a cross-section at NNLL + NNLO
Bachu, Brad
We consider top-quarks produced at large energy in e+e- collisions and address the question of what top-mass can be measured from reconstruction. The production process is characterized by the center-of-mass energy, Q, the top mass, m, the top decay width, It, and also AQCD. These scales are well separated and can be disentangled with effective theory methods such as the Heavy-Quark Effective Theory and Soft-Collinear Effective Theory. We compute a top mass observable for future e+e- colliders to next-to-next-to-leading-logarithmic order + [Omicron] [alpha] 2/[sigma](NNLL+NNLO), which goes beyond previous next-to-leading-logarithmic + [Omicron] [alpha] 2/[sigma] (NLL+NLO) analysis. We use the two-loop heavy quark jet-function, [Omicron] [alpha] 2/[sigma] corrections to the partonic hemisphere soft function, and hard matching for boosted tops at two loops. We find that the higher order corrections exhibit good convergence and reduced uncertainty in this cross section.
Thesis: S.B., Massachusetts Institute of Technology, Department of Physics, 2017.; Cataloged from PDF version of thesis.; Includes bibliographical references (pages 49-51).
Sun, 01 Jan 2017 00:00:00 GMThttp://hdl.handle.net/1721.1/1118892017-01-01T00:00:00Z