Download or read book Measurement of Differential Cross Sections and Cx and Cz for Gamma Photon proton Going to Kaon lambda Baryon and Gamma Photon proton Going to Kaon sigma Baryon Using CLAS at Jefferson Lab written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This work presents several observables for the reactions [gamma] p → K+[Lambda] and [gamma] p → K+[Sigma]°. In addition to measuring differential cross sections, we have made first measurements of the double polarization observables Cx and Cz. Cx and C z characterize the transfer of polarization from the incident photon to the produced hyperons. Data were obtained at Jefferson Lab using a circularly polarized photon beam at endpoint energies of 2.4, 2.9, and 3.1 GeV. Events were detected with the CLAS spectrometer. In the [Lambda] channel, the cross sections support the recent observation of new resonant structure at W = 1900 MeV. Studies of the invariant cross section, dsdd show scaling behavior suggesting that the production mechanism becomes t-channel dominated near threshold at forward kaon angles. The double polarization observables show that the recoiling [Lambda] is almost maximally polarized along the direction of the incident photon from mid to forward kaon angles. While [Sigma]o differential cross sections are of the same magnitude as the [Lambda] differential cross sections, there is evidence of different physics dominating the production mechanism. The [Sigma]° invariant cross sections do not show the same t-scaling behavior present in the [Lambda] results. The double polarization observables indicate that the [Sigma]° is not polarized as strongly as the [Lambda]. They also fail to identify one preferred polarization axis. Complete interpretation of these results will rely on model calculations. Currently available isobar models obtain varying degrees of success while attempting to predict the double polarization observables. While the models are in better agreement with the differential cross sections, discrepancies with our cross sections indicate that they must be re-optimized in light of the new data. While the data suggest that a Regge model would provide a good description of K+[Lambda] over most of the range in W, the available Regge calculation overstates the strength of the cross section and does not predict Cx and Cz correctly.
Download or read book Measurement of Differential Cross Sections and Cx and Cz for Gamma P K Lambda and Gamma P K Sigma0 Using CLAS at Jefferson Lab written by Robert K. Bradford and published by . This book was released on 2005 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement of Differential Cross Sections and Cx and Cz for p u2192 K and p u2192 K Using CLAS at Jefferson Lab written by and published by . This book was released on 2005 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work presents several observables for the reactions ? p → K+? and ? p → K+?°. In addition to measuring differential cross sections, we have made first measurements of the double polarization observables Cx and Cz. Cx and C z characterize the transfer of polarization from the incident photon to the produced hyperons. Data were obtained at Jefferson Lab using a circularly polarized photon beam at endpoint energies of 2.4, 2.9, and 3.1 GeV. Events were detected with the CLAS spectrometer. In the ? channel, the cross sections support the recent observation of new resonant structure at W = 1900 MeV. Studies of the invariant cross section, $d?/top{dt}$ show scaling behavior suggesting that the production mechanism becomes t-channel dominated near threshold at forward kaon angles. The double polarization observables show that the recoiling ? is almost maximally polarized along the direction of the incident photon from mid to forward kaon angles. While ?o differential cross sections are of the same magnitude as the ? differential cross sections, there is evidence of different physics dominating the production mechanism. The ?° invariant cross sections do not show the same t-scaling behavior present in the ? results. The double polarization observables indicate that the ?° is not polarized as strongly as the ?. They also fail to identify one preferred polarization axis. Complete interpretation of these results will rely on model calculations. Currently available isobar models obtain varying degrees of success while attempting to predict the double polarization observables. While the models are in better agreement with the differential cross sections, discrepancies with our cross sections indicate that they must be re-optimized in light of the new data. While the data suggest that a Regge model would provide a good description of K+? over most of the range in W, the available Regge calculation overstates the strength of the cross section and does not predict Cx and Cz correctly.
Download or read book Differential Cross Sections for Gamma P K Y for Lambda and Sigma0 Hyperons written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: High-statistics cross sections for the reactions? + p → K +? and? + p → K+ +?° have been measured using CLAS at Jefferson Lab for center-of-mass energies W between 1.6 and 2.53 GeV, and for -0.85
Download or read book A Measurement of the Differential Cross Section for the Reaction gamma N to pi P from Deuterium written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We report a measurement of the differential cross section for the $\gamma n \to \pi^- p$ process from the CLAS detector at Jefferson Lab in Hall B for photon energies between 1.0 and 3.5 GeV and pion center-of-mass (c.m.) angles ($\theta_{c.m.}$) between 50$^\circ$ and 115$^\circ$. We confirm a previous indication of a broad enhancement around a c.m. energy ($\sqrt{s}$) of 2.2 GeV at $\theta_{c.m.}=90^\circ$ in the scaled differential cross section, $s^7 {\frac{d\sigma}{dt}}$. Our data show the angular dependence of this enhancement as the scaling region is approached in the kinematic region from 70$^\circ$ to 105$^\circ$.
Download or read book Cross section for Elastic Scattering and Reactions Due to Protons on N15 written by Stanley Bashkin and published by . This book was released on 1958 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Differential Cross Sections for the Reactions math Display written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In high-statistics differential cross sections for the reactions [gamma] p -> p [eta] and [gamma] p -> p [eta]' the CLAS at Jefferson Lab was used to measure the center-of-mass energies from near threshold up to 2.84 GeV. The eta-prime results are the most precise to date and provide the largest energy and angular coverage. The eta measurements extend the energy range of the world's large-angle results by approximately 300 MeV. These new data, in particular the [eta]' measurements, are likely to help constrain the analyses being performed to search for new baryon resonance states.
Download or read book Compilation of Cross sections IV written by S. I. Alekhin and published by . This book was released on 1987 with total page 121 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Quasi free Cross Section Measurements at CLAS written by and published by . This book was released on 2014 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Preliminary measurements of the quasi-free differential cross sections of the gD -->pp-(p), gD --> K*(892)0L(p), and gD --> K+S*(1385)-(p) reactions are shown using data from the Jefferson Lab Hall B CLAS g13 experiment. No experimental cross section data have yet been published on gD --> K*(892)0L(p), and the only published cross section data on gD --> K+S*(1385)-(p) are at forward angles, where t-channel K+ and K*+ exchanges are predicted to dominate. These data can be used to contribute to the search for the "missing" N* resonances, some of which are predicted to have non-negligible couplings to the excited strangeness channels. These cross sections are shown to be sizable compared to the ground-state channels, indicating that it is important to include excited channels in coupled-channels analyses used to extract the N* resonances. In addition, the gD --> pp-(p) data provide a significant increase to the world statistics, and will be used to study rescattering effects within the deuteron.
Download or read book A MEASUREMENT OF THE DIFFERENTIAL CROSS SECTIONS FOR THE REACTIONS POSITIVE PION PROTON GOING TO POSITIVE KAON POSITIVE SIGMA HYPERON AND POSITIVE PION PROTON GOING TO POSITIVE KAON POSITIVE Y RESONANCE 1385 NEAR ZERO DEGREES AT 3 0 5 0 AND 7 0 GEV C written by PARVIZ KALBACI and published by . This book was released on 1971 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement of Differential Cross Sections and Spin Density Matrix Elements Along with a Partial Wave Analysis for Gamma P p Omega Using CLAS at Jefferson Lab written by Mike Williams and published by . This book was released on 2007 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cross Sections for Production of the 15 10 MeV and Other Astrophysically Significant Gamma ray Lines Through Excitation and Spallation of 12C and 16O with Protons written by and published by . This book was released on 1986 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book In beam Measurements of Inclusive Differential Cross Sections for the Production of Gamma Radiation from 30 67 5 MeV Protons on Thin Targets of Aluminum Iron Titanium and Uranium written by Guy Alton Letteer and published by . This book was released on 1988 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurements of Differential Cross Sections of Z gamma jets X Events in Proton Anti proton Collisions at S 1 2 written by and published by . This book was released on 2009 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present cross section measurements for Z/[gamma]* + jets + X production, differential in the transverse momenta of the three leading jets. The data sample was collected with the D0 detector at the Fermilab Tevatron p{bar p} collider at a center-of-mass energy of 1.96 TeV and corresponds to an integrated luminosity of 1 fb−1. Leading and next-to-leading order perturbative QCD predictions are compared with the measurements, and agreement is found within the theoretical and experimental uncertainties. We also make comparisons with the predictions of four event generators. Two parton-shower-based generators show significant shape and normalization differences with respect to the data. In contrast, two generators combining tree-level matrix elements with a parton shower give a reasonable description of the shapes observed in data, but the predicted normalizations show significant differences with respect to the data, reflecting large scale uncertainties. For specific choices of scales, the normalizations for either generator can be made to agree with the measurements.
Download or read book Differential Cross Sections and Recoil Polarizations for the Reaction math Display written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Here, high-statistics measurements of differential cross sections and recoil polarizations for the reaction $\gamma p \rightarrow K^+ \Sigma^0$ have been obtained using the CLAS detector at Jefferson Lab. We cover center-of-mass energies ($\sqrt{s}$) from 1.69 to 2.84 GeV, with an extensive coverage in the $K^+$ production angle. Independent measurements were made using the $K^{+}p\pi^{-}$($\gamma$) and $K^{+}p$($\pi^-, \gamma$) final-state topologies, and were found to exhibit good agreement. Our differential cross sections show good agreement with earlier CLAS, SAPHIR and LEPS results, while offering better statistical precision and a 300-MeV increase in $\sqrt{s}$ coverage. Above $\sqrt{s} \approx 2.5$ GeV, $t$- and $u$-channel Regge scaling behavior can be seen at forward- and backward-angles, respectively. Our recoil polarization ($P_\Sigma$) measurements represent a substantial increase in kinematic coverage and enhanced precision over previous world data. At forward angles we find that $P_\Sigma$ is of the same magnitude but opposite sign as $P_\Lambda$, in agreement with the static SU(6) quark model prediction of $P_\Sigma \approx -P_\Lambda$. This expectation is violated in some mid- and backward-angle kinematic regimes, where $P_\Sigma$ and $P_\Lambda$ are of similar magnitudes but also have the same signs. In conjunction with several other meson photoproduction results recently published by CLAS, the present data will help constrain the partial wave analyses being performed to search for missing baryon resonances.
Download or read book Differential Cross Sections and Spin Density Matrix Elements for the Reaction Gamma P P Omega written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: High-statistics differential cross sections and spin density matrix elements for the reaction gamma p -> p omega have been measured using the CLAS at Jefferson Lab for center-of-mass (CM) energies from threshold up to 2.84 GeV. Results are reported in 112 10-MeV wide CM energy bins, each subdivided into cos(theta_CM) bins of width 0.1. These are the most precise and extensive omega photoproduction measurements to date. A number of prominent structures are clearly present in the data. Many of these have not previously been observed due to limited statistics in earlier measurements.
Download or read book Differential Cross Sections and Recoil Polarizations for the Reaction p u2192 K 0 written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Here, high-statistics measurements of differential cross sections and recoil polarizations for the reaction $\gamma p \rightarrow K+̂ \Sigma0̂$ have been obtained using the CLAS detector at Jefferson Lab. We cover center-of-mass energies ($\sqrt{s}$) from 1.69 to 2.84 GeV, with an extensive coverage in the $K+̂$ production angle. Independent measurements were made using the $K{̂+}p\pi{̂-}$($\gamma$) and $K{̂+}p$($\pi-̂,\gamma$) final-state topologies, and were found to exhibit good agreement. Our differential cross sections show good agreement with earlier CLAS, SAPHIR and LEPS results, while offering better statistical precision and a 300-MeV increase in $\sqrt{s}$ coverage. Above $\sqrt{s} \approx 2.5$ GeV, $t$- and $u$-channel Regge scaling behavior can be seen at forward- and backward-angles, respectively. Our recoil polarization ($P_\Sigma$) measurements represent a substantial increase in kinematic coverage and enhanced precision over previous world data. At forward angles we find that $P_\Sigma$ is of the same magnitude but opposite sign as $P_\Lambda$, in agreement with the static SU(6) quark model prediction of $P_\Sigma \approx -P_\Lambda$. This expectation is violated in some mid- and backward-angle kinematic regimes, where $P_\Sigma$ and $P_\Lambda$ are of similar magnitudes but also have the same signs. In conjunction with several other meson photoproduction results recently published by CLAS, the present data will help constrain the partial wave analyses being performed to search for missing baryon resonances.
