Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Experimental results on a search for charmed particle production in proton-proton collisions at the center of mass energy (.sqrt.s) of 53 GeV are presented. Evidence of cidences, a signature of charmed particle production, was sought. The inclusive e/.pi. ratio was measured with a magnetic spectrometer located at 32° from Beam 1 of Intersection I6 of the CERN Intersecting Storage Rings (ISR). The e/.pi. ratio from direct (unknown) sources was found to rise from 1.06 x 10−4 at p/sub perpendicular to/ = 1.5 GeV/c to 5.53 x 10−4 at p/sub perpendicular to/ = 0.25 GeV/c. One possible source for this signal is the semi-leptonic decay of charmed particles (e.g., D .-->. K° e.nu.). If so, then electron-strange particle (e.g., .lambda.°, K°) coincidences are expected. The charged decay products of .lambda.° and K° were detected in a multiparticle spectrometer surrounding Beam 1 downstream of the intersection. To determine if there is an electron-strange particle correlation, the number of .lambda.°'s (K°'s) in coincidence with an electron in the 32° spectrometer was compared with the number of .lambda.'s (K°'s) in coincidence with a hadron in the same kinematic range. No evidence for an enhanced production of strange particles with electrons relative to hadrons was found. However, given the acceptance of the apparatus, the absence of a signal is consistent with current models of charmed particle production and decay. 40 references, 51 figures, 20 tables.
Search for Charmed Particle Production in Proton-proton Collisions at the CERN-ISR. [53 GeV (c. M.)].
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Experimental results on a search for charmed particle production in proton-proton collisions at the center of mass energy (.sqrt.s) of 53 GeV are presented. Evidence of cidences, a signature of charmed particle production, was sought. The inclusive e/.pi. ratio was measured with a magnetic spectrometer located at 32° from Beam 1 of Intersection I6 of the CERN Intersecting Storage Rings (ISR). The e/.pi. ratio from direct (unknown) sources was found to rise from 1.06 x 10−4 at p/sub perpendicular to/ = 1.5 GeV/c to 5.53 x 10−4 at p/sub perpendicular to/ = 0.25 GeV/c. One possible source for this signal is the semi-leptonic decay of charmed particles (e.g., D .-->. K° e.nu.). If so, then electron-strange particle (e.g., .lambda.°, K°) coincidences are expected. The charged decay products of .lambda.° and K° were detected in a multiparticle spectrometer surrounding Beam 1 downstream of the intersection. To determine if there is an electron-strange particle correlation, the number of .lambda.°'s (K°'s) in coincidence with an electron in the 32° spectrometer was compared with the number of .lambda.'s (K°'s) in coincidence with a hadron in the same kinematic range. No evidence for an enhanced production of strange particles with electrons relative to hadrons was found. However, given the acceptance of the apparatus, the absence of a signal is consistent with current models of charmed particle production and decay. 40 references, 51 figures, 20 tables.
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Experimental results on a search for charmed particle production in proton-proton collisions at the center of mass energy (.sqrt.s) of 53 GeV are presented. Evidence of cidences, a signature of charmed particle production, was sought. The inclusive e/.pi. ratio was measured with a magnetic spectrometer located at 32° from Beam 1 of Intersection I6 of the CERN Intersecting Storage Rings (ISR). The e/.pi. ratio from direct (unknown) sources was found to rise from 1.06 x 10−4 at p/sub perpendicular to/ = 1.5 GeV/c to 5.53 x 10−4 at p/sub perpendicular to/ = 0.25 GeV/c. One possible source for this signal is the semi-leptonic decay of charmed particles (e.g., D .-->. K° e.nu.). If so, then electron-strange particle (e.g., .lambda.°, K°) coincidences are expected. The charged decay products of .lambda.° and K° were detected in a multiparticle spectrometer surrounding Beam 1 downstream of the intersection. To determine if there is an electron-strange particle correlation, the number of .lambda.°'s (K°'s) in coincidence with an electron in the 32° spectrometer was compared with the number of .lambda.'s (K°'s) in coincidence with a hadron in the same kinematic range. No evidence for an enhanced production of strange particles with electrons relative to hadrons was found. However, given the acceptance of the apparatus, the absence of a signal is consistent with current models of charmed particle production and decay. 40 references, 51 figures, 20 tables.
Search for Charmed Particle Production in Proton-proton Collisions at the CERN-ISR
Author: William Leigh Marsh
Publisher:
ISBN:
Category : Nuclear physics
Languages : en
Pages : 326
Book Description
Publisher:
ISBN:
Category : Nuclear physics
Languages : en
Pages : 326
Book Description
A Search for Charmed Meson Production in Proton-proton Collisions at the CERN-ISR
Author: Gordon John VanDalen
Publisher:
ISBN:
Category : Nuclear physics
Languages : en
Pages : 436
Book Description
Publisher:
ISBN:
Category : Nuclear physics
Languages : en
Pages : 436
Book Description
Energy Research Abstracts
Scientific and Technical Aerospace Reports
A Search for Charmed Particles in Neutrino Induced Reactions and a Study of Light-ion Collisions at Very High Energy
Energy Research Abstracts
Nuclear Science Abstracts
A Proposal to Search for Charmed Particles Originating from the Interactions of 400 GeV
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
There has been much recent discussion of the possibility of the existence of 'charmed' particles, hadrons which possess non-zero values of 'charm', a further additive quantum number. These particles may be generated either in the three triplet model of Han and Nambu or by the postulate of a fourth, charm-bearing quark. On the assumption that charm, like strangeness, is conserved in strong and electromagnetic interactions (the opposite assumption would necessitate charmed particles coupling strongly to ordinary hadrons and the existence of yet undiscovered states, e.g. Z*s) but not conserved in weak interactions one might expect their production either singly in neutrino interactions or in pairs in associated production in high energy hadron collisions, to be followed by their subsequent, relatively slow, decay into 'uncharmed' particles. Various estimates as to mass, lifetime, production cross-sections and decay modes have been made for these particles. However their failure to appear as di-lepton events among the neutrino interactions of the Brookhaven A.G.S. and CERN P.S. experiments might suggest that their masses are in excess of 2 GeV/c2 the other hand, such particles would have been expected to have been observed directly in bubble chamber studies at FNAL had their lifetimes been greater than 10−11s as suggested by some authors. This proposal, which may be thought of as complementary to that of Burhop et al, is for a straightforward exposure of a stack of emulsions to a 400 GeV/c proton beam to look for evidence of the pair production of charmed particles. The spatial resolution of the emulsion technique is about one micron with the consequence that the decays of particles of mean lives in the range 10−11 to 10−14 s should be readily observable.
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
There has been much recent discussion of the possibility of the existence of 'charmed' particles, hadrons which possess non-zero values of 'charm', a further additive quantum number. These particles may be generated either in the three triplet model of Han and Nambu or by the postulate of a fourth, charm-bearing quark. On the assumption that charm, like strangeness, is conserved in strong and electromagnetic interactions (the opposite assumption would necessitate charmed particles coupling strongly to ordinary hadrons and the existence of yet undiscovered states, e.g. Z*s) but not conserved in weak interactions one might expect their production either singly in neutrino interactions or in pairs in associated production in high energy hadron collisions, to be followed by their subsequent, relatively slow, decay into 'uncharmed' particles. Various estimates as to mass, lifetime, production cross-sections and decay modes have been made for these particles. However their failure to appear as di-lepton events among the neutrino interactions of the Brookhaven A.G.S. and CERN P.S. experiments might suggest that their masses are in excess of 2 GeV/c2 the other hand, such particles would have been expected to have been observed directly in bubble chamber studies at FNAL had their lifetimes been greater than 10−11s as suggested by some authors. This proposal, which may be thought of as complementary to that of Burhop et al, is for a straightforward exposure of a stack of emulsions to a 400 GeV/c proton beam to look for evidence of the pair production of charmed particles. The spatial resolution of the emulsion technique is about one micron with the consequence that the decays of particles of mean lives in the range 10−11 to 10−14 s should be readily observable.