Download or read book Preliminary Measurement of Prompt D sup and D sup Meson Production and D sup Spin Alignment in Hadronic Z sup 0 Decays written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors have measured the production rates as a function of scaled energy x of prompt charmed pseudoscalar D[sup[+-]] and vector D*[sup[+-]] mesons in hadronic Z[sup 0] decays. The prompt signal components were isolated from the background of D mesons from B hadron decays using impact parameters of reconstructed D[sup[+-]][yields] K[sup[minus-plus]][pi][sup[+-]][pi][sup[+-]] and D*-daughter D[sup 0][yields] K[sup[minus]][pi][sup+] and D[sup 0][yields] K[sup[minus]][pi][sup+][pi][sup[minus]][pi][sup+] candidates. Using the combined meson production rates the authors have measured the fraction of hadronic Z[sup 0] decays into c[bar c], R[sub c]= 0.182[+-] 0.027 (stat.)[+-] 0.012 (syst.) (Preliminary). Comparison of the D*[sup[+-]] and D[sup[+-]] rates gives a direct probe of vector (V) vs. pseudoscalar (P) meson production for charmed quarks, and for x> 0.4 they have measured P[sub V]= V/(V+ P)= 0.65[+-] 0.09(stat.)[+-] 0.03(syst.)[+-] 0.03 (BR) (Preliminary). They have measured the degree of spin alignment of the D*[sup[+-]] mesons along their flight direction and find it to be consistent with zero. They compared the latter two results with QCD- and model-based predictions of charm-quark jet fragmentation.
Download or read book Preliminary Measurement of Prompt D sup and D sup Meson Production and D sup Spin Alignment in Hadronic Z Decays written by and published by . This book was released on 1997 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors have measured the production rates as a function of scaled energy x of prompt charmed pseudoscalar D{sup ±} and vector D*{sup ±} mesons in hadronic Z° decays. The prompt signal components were isolated from the background of D mesons from B hadron decays using impact parameters of reconstructed D{sup ±} → K{sup {minus_plus}}?{sup ±}?{sup ±} and D*-daughter D° → K−? and D° → K−?+?−?+ candidates. Using the combined meson production rates the authors have measured the fraction of hadronic Z° decays into c{bar c}, R{sub c} = 0.182 {+-} 0.027 (stat.) {+-} 0.012 (syst.) (Preliminary). Comparison of the D*{sup {+-}} and D{sup {+-}} rates gives a direct probe of vector (V) vs. pseudoscalar (P) meson production for charmed quarks, and for x> 0.4 they have measured P{sub V} = V/(V + P) = 0.65 {+-} 0.09(stat.) {+-} 0.03(syst.) {+-} 0.03 (BR) (Preliminary). They have measured the degree of spin alignment of the D*{sup {+-}} mesons along their flight direction and find it to be consistent with zero. They compared the latter two results with QCD- and model-based predictions of charm-quark jet fragmentation.
Download or read book Preliminary Measurement of D sup D Production and D sup Spin Alignment at the Z sup 0 Resonance written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: USING HADRONIC Z[sup 0] DECAYS RECORDED BY THE SLD EXPERIMENT AT SLAC, WE HAVE MEASURED THE VECTOR/(VECTOR+PSEUDOSCALAR) PRODUCTION RATIO, V/(V+ P), FOR THE PROMPT CHARMED MESONS D[sup*+] AND D[sup+]. USING THE CHANNELS D[sup*+][yields] D[sup 0][pi][sup+][sub S], D[sup 0][yields] K[sup -][pi][sup+], AND D[sup 0][yields] K[sup -][pi][sup+][pi][sup -][pi][sup+], AS WELL AS D[sup+][yields] K[sup -][pi][sup+][pi][sup -], WE FIND V/(V+ P)= 0.61+/- 0.09(STAT.)+/- 0.03(BR), WHICH DISFAVORS THE EXPECTATION OF 0.75 FROM NAIVE SPIN COUNTING. WE HAVE ALSO MEASURED THE DEGREE OF D[sup*+] SPIN ALIGNMENT ALONG THE FLIGHT DIRECTION AND FIND IT TO BE CONSISTENT WITH ZERO FOR D[sup*+] FRACTIONAL MOMENTA x= E[sub D*]/E[sub BEAM][gt] 0.2. We compare these results with QCD model predictions.
Download or read book Preliminary Measurement of D sup D Production and D sup Spin Alignment at the Z Resonance written by and published by . This book was released on 1996 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: USING HADRONIC Z° DECAYS RECORDED BY THE SLD EXPERIMENT AT SLAC, WE HAVE MEASURED THE VECTOR/(VECTOR+PSEUDOSCALAR) PRODUCTION RATIO, V/(V + P), FOR THE PROMPT CHARMED MESONS D{sup *+} AND D. USING THE CHANNELS D{sup *+} → D°?+{sub S}, D° → K−?+, AND D° → K−?+?−?+, AS WELL AS D+ → K−?+?−, WE FIND V/(V + P) = 0.61 +/- 0.09(STAT.) +/- 0.03(BR), WHICH DISFAVORS THE EXPECTATION OF 0.75 FROM NAIVE SPIN COUNTING. WE HAVE ALSO MEASURED THE DEGREE OF D{sup *+} SPIN ALIGNMENT ALONG THE FLIGHT DIRECTION AND FIND IT TO BE CONSISTENT WITH ZERO FOR D{sup *+} FRACTIONAL MOMENTA x = E{sub D*}/E{sub BEAM}
Download or read book Preliminary Measurement of D D Production and D Spin Alignment at the Z Resonance written by and published by . This book was released on 1996 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: Using hadronic Z° decays recorded by the SLD experiment at SLAC, we have measured the vector/(vector+pseudoscalar) production ratio, V/(V+P), for the prompt charmed mesons, D{sup *+} and D. Using the channels D{sup *+}→D°?+{sub s}, D°→ K−?+, and D°→ K{sup - }?+?−?+, as well as D+??2192? K−?+?−, we find V/(V+P) = 0.57 ± 0.07 ({ital stat})± 0.02({ital BR}), which disfavors the expectations of 0.75 from naive spin counting. We have also measured the degree of D{sup *+} spin alignment along the flight direction and find it to be consistent with the zero for D{sup *+} fractional momenta? {triple_bond} E{sub D{sup *}}/D{sub {ital beam}}
Download or read book Preliminary Measurements of Production Of sup plus minus K sup plus minus P K And in Hadronic Z Decays written by and published by . This book was released on 1996 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: We have measured production of?{sup {+-}},?{sup {+-}}, {ital p}/{ital {bar p}},?° and?°/{bar?}° as a function of momentum in inclusive hadronic {ital Z}° decay events and separately in events containing primary light-({ital uds}) and {ital b}-quarks. The SLD Cherenkov Ring Imaging Detector was used to identify charged pions, kaons, and protons over most of the available momentum range 0.8>{ital p}>33 GeV/c. The neutral?°{sub s} and {Lambda}° were reconstructed using the??− and {ital p}?− decay modes, respectively. We present the first comparisons of momentum of charged tracks measured in the SLD Vertex Detector. Substantial differences are observed, consistent with the kinematics of {ital B}-hadron production in Z° decays and the properties of {ital B}-hadron decays as measured at lower energies.
Download or read book Preliminary Measurements of Production Of pi sup plus minus K sup plus minus P K sup 0 And Lambda sup 0 in Hadronic Z sup 0 Decays written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We have measured production of[pi][sup[+-]], [Kappa][sup[+-]], [ital p]/[ital[bar p]], [Kappa][sup 0] and[Lambda][sup 0]/[bar[Lambda]][sup 0] as a function of momentum in inclusive hadronic[ital Z][sup 0] decay events and separately in events containing primary light-([ital uds]) and[ital b]-quarks. The SLD Cherenkov Ring Imaging Detector was used to identify charged pions, kaons, and protons over most of the available momentum range 0.8[lt][ital p][lt]33 GeV/c. The neutral[Kappa][sup 0][sub s] and[Lambda][sup 0] were reconstructed using the[pi][sup+][pi][sup -] and[ital p][pi][sup -] decay modes, respectively. We present the first comparisons of momentum of charged tracks measured in the SLD Vertex Detector. Substantial differences are observed, consistent with the kinematics of[ital B]-hadron production in Z[sup 0] decays and the properties of[ital B]-hadron decays as measured at lower energies.
Download or read book Preliminary Measurement of Leading Particle Effects in Hadronic Z sup 0 Decays written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present preliminary evidence for leading particle production in hadronic decays of the Z[sup 0] to light quark pairs using 150,000 events recorded in the SLD experiment at SLAC. The highly polarized electron beam produced by the SLC is used to tag quark and antiquark jets, and a signed impact parameter technique is employed to reject heavy flavor events. Charged hadrons are identified in the SLD Cherenkov Ring Imaging Detector (CRID) and[Lambda]/[bar[Lambda]] are reconstructed using their charged decay modes. In a high purity sample of quark jets, the baryon momentum spectrum is harder that that of the antibaryon, and conversely for a sample of antiquark jets, supporting the hypothesis that the faster particles in jets are more likely to carry the primary quark or antiquark from the Z[sup 0] decay. Similarly, more high momentum K[sup -] that K[sup+] are observed in quark jets and conversely for antiquark jets, consistent with the hypothesis that leading K[sup[+-]] are produced predominantly in s[bar s] events rather than[ital u][bar[ital u]] events.
Download or read book Measurements of Spin sensitive Quantities in Hadronic Decays of Z sup 0 Bosons Produced in E sup e sup minus Annihilations written by and published by . This book was released on 1992 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: In 1992 the SLD experiment at SLAC collected over 11,000 hadronic decay events of Z[sup 0] bosons produced in collisions of polarised electrons with unpolarised positrons delivered by the SLC. Preliminary experimental results are presented on tests of the value of the gluon spin involving events containing three hadronic jets measured in the final state. A leading order QCD prediction is found to be in agreement with the data, whilst a model including scalar gluons is clearly excluded. Effects of the electron beam polarisation upon the orientation of the three-jet event plane are discussed.
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1989-02 with total page 604 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hadronic Decays of the D sub S Meson and a Model independent Determination of the Branching Fraction for the D sub S Decay of to Phi Pi written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: During the running periods of the years 1992, 1993, 1994 the BES experiment at the Beijing Electron Positron Collider (BEPC) collected 22.9[plus-minus] 0.7 pb[sup[minus]1] of data at an energy of 4.03 GeV, which corresponds to a local peak for e[sup+]e[sup[minus]][yields] D[sub s][sup+]D[sub s][sup[minus]] production. Four D[sub s] hadronic decay modes were tagged: D[sub s][yields][phi][pi];[phi][yields] K[sup+]K[sup[minus]]; D[sub s][yields][bar K]*(892)[sup o]K;[bar K]*[sup o](892)[yields] K[sup[minus]][pi][sup+]; D[sub s][bar K][sup o]K;[bar K][sub s][sup o][yields][pi][sup+][pi][sup[minus]]; D[sub s][yields][bar K]*(892)[sup o]K*;[bar K]*[sup o](892)[yields] K[sup[minus]][pi][sup+]; K*(892)[yields] K[sup o][pi][sup+]; K[sub s][sup o][yields][pi][sup+][pi][sup[minus]]. Using the method of double-tagging, BES performed the first model-independent measurement of BrD[sub s[yields][phi][pi]]. Our result was Br[sub D[sub s][yields][phi][pi]]= 3.4[sub[minus]1.7-0.7][sup+4.8+1.3].
Download or read book Measurements of Hadronic Decays of Z sup 0 Bosons written by and published by . This book was released on 1992 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: Z[degrees] bosons have been produced by collisions of longitudinally polarized electrons with unpolarized positrons at the SLAC Linear Collider and their decays have been recorded by the SLD experiment. We present preliminary measurements of the properties of the resulting Z[degrees] decays into multi-hadronic final states. We find good agreement with the predictions of perturbative QCD and fragmentation models.
Download or read book Graduel de Lyon written by and published by . This book was released on 1780 with total page 739 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement of Orbitally Excited D mesons at CDF II written by Igor V. Gorelov and published by . This book was released on 2004 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: Results of the first measurement of {sup 3}P orbitally excited neutral D-meson states, D*{sub 2}{sup 0} and D{sub 1}{sup 0}, produced in hadron collisions at the Tevatron are presented. Using data from the displaced track trigger, CDF II collects a large sample of these states in decay modes D*{sup +} {pi}{sup -}, D{sup +} {pi}{sup -}. Masses and widths of both states have been measured with precision better than or comparable to that of the world average.
Download or read book The Production of pi sup P Ksup 0 and Lambdasup 0 in Hadronic Zsup 0 Decays written by and published by . This book was released on 1995 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hadron Fragmentation Functions and Leading Particle Effects in Hadronic Z sup 0 Decays New Results from SLD written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors have measured the differential cross sections for the production of[pi][sup[+-]], K[sup[+-]], K[sup 0], K*(892), [phi](1,020), p and[Lambda] in hadronic Z[sup 0] decays and in subsets of flavor-tagged Z[sup 0][yields] light quark (u[anti u], d[anti d], or s[anti s]), Z[sup 0][yields] c[anti c] and Z[sup 0][yields] b[anti b] events. Charged hadrons were identified with the SLD Cherenkov ring imaging detector. The vertex detector was employed to select flavor enriched samples and the polarized electron beam from SLC was used to tag quark and anti-quark jets. The authors observe a flavor dependence in the hadron fragmentation functions. The authors present evidence for leading particle production in hadronic decays of the Z[sup 0] boson to light-flavor jets and a direct measurement of the strangeness suppression factor[gamma][sub s].
Download or read book Recent Results on Hadronic D sub S and D Meson Decays from the Mark III written by and published by . This book was released on 1989 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
