Additional jet activity in dijet events is measured using Formula: see text collisions at ATLAS at a centre-of-mass energy of Formula: see text, for jets reconstructed using the Formula: see text ...algorithm with radius parameter Formula: see text. This is done using variables such as the fraction of dijet events without an additional jet in the rapidity interval bounded by the dijet subsystem and correlations between the azimuthal angles of the dijet s. They are presented, both with and without a veto on additional jet activity in the rapidity interval, as a function of the scalar average of the transverse momenta of the dijet s and of the rapidity interval size. The double differential dijet cross section is also measured as a function of the interval size and the azimuthal angle between the dijet s. These variables probe differences in the approach to resummation of large logarithms when performing QCD calculations. The data are compared to powheg, interfaced to the pythia 8 and herwig parton shower generators, as well as to hej with and without interfacing it to the ariadne parton shower generator. None of the theoretical predictions agree with the data across the full phase-space considered; however, powheg+pythia 8 and hej+ariadne are found to provide the best agreement with the data. These measurements use the full data sample collected with the ATLAS detector in Formula: see textFormula: see text collisions at the LHC and correspond to integrated luminosities of Formula: see text and Formula: see text for data collected during 2010 and 2011, respectively.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
ATLAS measurements of the azimuthal anisotropy in lead-lead collisions at Formula: see text TeV are shown using a dataset of approximately 7 Formula: see textbFormula: see text collected at the LHC ...in 2010. The measurements are performed for charged particles with transverse momenta Formula: see text GeV and in the pseudorapidity range Formula: see text. The anisotropy is characterized by the Fourier coefficients, Formula: see text, of the charged-particle azimuthal angle distribution for Formula: see text-4. The Fourier coefficients are evaluated using multi-particle cumulants calculated with the generating function method. Results on the transverse momentum, pseudorapidity and centrality dependence of the Formula: see text coefficients are presented. The elliptic flow, Formula: see text, is obtained from the two-, four-, six- and eight-particle cumulants while higher-order coefficients, Formula: see text and Formula: see text, are determined with two- and four-particle cumulants. Flow harmonics Formula: see text measured with four-particle cumulants are significantly reduced compared to the measurement involving two-particle cumulants. A comparison to Formula: see text measurements obtained using different analysis methods and previously reported by the LHC experiments is also shown. Results of measurements of flow fluctuations evaluated with multi-particle cumulants are shown as a function of transverse momentum and the collision centrality. Models of the initial spatial geometry and its fluctuations fail to describe the flow fluctuations measurements.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The AMPTE CCE Spacecraft Dassoulas, John; Margolies, Donald L.; Peterson, Max R.
IEEE transactions on geoscience and remote sensing,
05/1985, Letnik:
GE-23, Številka:
3
Journal Article
Recenzirano
The flight segment of the Active Magnetospheric Particle Tracer Explorers (AMPTE) Program consisted of three separate spacecraft which were launched "piggyback" into orbit aboard a Delta 3924 launch ...vehicle, from Cape Canaveral, FL, on August 16, 1984. The three spacecraft are the Charge Composition Explorer (CCE), built for NASA by the Applied Physics Laboratory of The Johns Hopkins University (APL/ JHU); the Ion Release Module (IRM), built in the Federal Republic of Germany; and the United Kingdom Subsatellite (UKS), built in the United Kingdom. This paper describes the CCE Spacecraft design, development, and early performance in orbit.
Forty years of space mission management Coughlin, Thomas B; Chiu, Mary C; Dassoulas, John
Johns Hopkins APL technical digest,
10/1999, Letnik:
20, Številka:
4
Journal Article
Recenzirano
Over the past 40 years, APL has developed 58 satellites using the methodology currently captured by the phrase 'faster, better, cheaper'. In so doing, a management culture evolved that allowed us to ...successfully meet technical requirements within short schedules, often below originally estimated costs. We present the basic guidelines used in our space mission management approach and illustrate how they can be applied effectively. (Author)
Stereotactic radiosurgery has been shown to afford a reasonable chance of local tumor control. However, new brain metastasis can arise following successful local tumor control from radiosurgery. This ...study evaluates the timing, number, and risk factors for development of subsequent new brain metastasis in a group of patients treated with stereotactic radiosurgery alone.
One hundred seventeen patients with histologically confirmed metastatic cancer underwent Gamma Knife surgery (GKS) to treat all brain metastases demonstrable on MR imaging. Patients were followed clinically and radiologically at approximately 3-month intervals for a median of 14.4 months (range 0.37-51.8 months). Follow-up MR images were evaluated for evidence of new brain metastasis formation. Statistical analyses were performed to determine the timing, number, and risk factors for development of new brain metastases.
The median time to development of a new brain metastasis was 8.8 months. Patients with 3 or more metastases at the time of initial radiosurgery or those with cancer histologies other than non-small cell lung carcinoma were found to be at increased risk for early formation of new brain metastasis (p < 0.05). The mean number of new metastases per patient was 1.6 (range 0-11). Those with a higher Karnofsky Performance Scale score at the time of initial GKS were significantly more likely to develop a greater number of brain metastases by the last follow-up evaluation.
The timing and number of new brain metastases developing in patients treated with GKS alone is not inconsequential. Those with 3 or more metastases at the time of radiosurgery and those with cancer histology other than non-small cell lung carcinoma were at greater risk of early formation of new brain metastasis. Frequent follow-up evaluations, such as at 3-month intervals, appears appropriate in this patient population, particularly in high-risk patients. When detected early, salvage treatments including repeat radiosurgery can be used to treat new brain metastasis.
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