共查询到20条相似文献,搜索用时 31 毫秒
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Gabyshev N Abe K Abe K Adachi I Aihara H Asano Y Aulchenko V Aushev T Bahinipati S Bakich AM Balagura V Barberio E Bartel W Bay A Bedny I Bitenc U Bizjak I Bondar A Bozek A Bracko M Browder TE Chen A Chen WT Cheon BG Chistov R Choi Y Chuvikov A Cole S Dalseno J Danilov M Dash M Drutskoy A Eidelman S Garmash A Gershon T Gokhroo G Golob B Haba J Hayasaka K Hayashii H Hazumi M Hokuue T Hoshi Y Hou S Hou WS Hsiung YB Ikado K Imoto A Inami K Itoh R Iwasaki M Iwasaki Y Kang JH Kawasaki T Khan HR 《Physical review letters》2006,97(20):202003
We report the first measurements of the doubly charmed baryonic B decays B --> Lambda c+ Lambda c- K. The B+ --> Lambda c+ Lambda c- K+ decay is observed with a branching fraction of (6.5(-0.9)(+1.0)+/-1.1+/-3.4)x10(-4) and a statistical significance of 15.4sigma. The B0 --> Lambda c+ Lambda c- K0 decay is observed with a branching fraction of (7.9(-2.3)(+2.9)+/-1.2+/-4.1)x10(-4) and a statistical significance of 6.6sigma. The branching fraction errors are statistical, systematic, and the error resulting from the uncertainty of the Lambda c+ --> pK- pi+ decay branching fraction. The analysis is based on 357 fb(-1) of data accumulated at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+ e- collider. 相似文献
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Abulencia A Adelman J Affolder T Akimoto T Albrow MG Ambrose D Amerio S Amidei D Anastassov A Anikeev K Annovi A Antos J Aoki M Apollinari G Arguin JF Arisawa T Artikov A Ashmanskas W Attal A Azfar F Azzi-Bacchetta P Azzurri P Bacchetta N Badgett W Barbaro-Galtieri A Barnes VE Barnett BA Baroiant S Bartsch V Bauer G Bedeschi F Behari S Belforte S Bellettini G Bellinger J Belloni A Benjamin D Beretvas A Beringer J Berry T Bhatti A Binkley M Bisello D Blair RE Blocker C Blumenfeld B Bocci A 《Physical review letters》2007,98(12):122001
We report a measurement of the Lambda b0 lifetime in the exclusive decay Lambda b0-->J/psi Lambda 0 in pp collisions at square root s=1.96 TeV using an integrated luminosity of 1.0 fb-1 of data collected by the CDF II detector at the Fermilab Tevatron. Using fully reconstructed decays, we measure tau(Lambda b0)=1.593(-0.078)(+0.083)(stat)+/-0.033(syst) ps. This is the single most precise measurement of tau(Lambda b0) and is 3.2sigma higher than the current world average. 相似文献
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Félix J Berisso MC Christian DC Gara A Gottschalk EE Gutiérrez G Hartouni EP Knapp BC Kreisler MN Lee S Markianos K Moreno G Reyes MA Sosa M Wang MH Wehmann A Wesson D 《Physical review letters》2002,88(6):061801
We report results from a study of Lambda(0) polarization in the exclusive reaction pp --> p(f)(Lambda0K+) at 800-GeV/c. We observe a dependence of the polarization on the Lambda0K+ invariant mass with large (+71%) positive polarization at small mass (1.63-GeV/c(2)) and large (-43%) negative polarization at large mass (2.75-GeV/c(2)). This observation confirms the result of the CERN ISR R608 experiment and extends the range over which the effect is observed. The strong dependence of the polarization on the Lambda0K+ invariant mass suggests that the origin of the polarization is closely related to the production dynamics of the diffractively produced Lambda0K+ system. 相似文献
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Bhadra S Appel JA Bartlett DF Denby BH Biel J Bintinger D Bharadwaj VK Blodgett DE Bracker SB Bronstein J Daum C Duncan AL Eisner AM Elliott JR Estabrooks P Hartner GF Kalbfleisch GR Kennett RG Kumar BR Losty MJ Lu A Luste GJ Mantsch PM Martin JF Morrison RJ Nash T Nauenberg U Pinfold J Robertson M Schmidke W Shahbazian KK Sheperd RA Sliwa K Sokoloff MD Spalding WJ Stacey J Stanfield KC Streetman M Summers DJ Willis SE Witherell MS Yellin SJ Zorn CJ 《Physical review letters》1985,55(25):2749-2751
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Abulencia A Adelman J Affolder T Akimoto T Albrow MG Ambrose D Amerio S Amidei D Anastassov A Anikeev K Annovi A Antos J Aoki M Apollinari G Arguin JF Arisawa T Artikov A Ashmanskas W Attal A Azfar F Azzi-Bacchetta P Azzurri P Bacchetta N Badgett W Barbaro-Galtieri A Barnes VE Barnett BA Baroiant S Bartsch V Bauer G Bedeschi F Behari S Belforte S Bellettini G Bellinger J Belloni A Benjamin D Beretvas A Beringer J Berry T Bhatti A Binkley M Bisello D Blair RE Blocker C Blumenfeld B Bocci A 《Physical review letters》2007,98(12):122002
We present the first observation of the baryon decay Lambda b0-->Lambda c+pi- followed by Lambda c+-->pK-pi+ in 106 pb-1 pp collisions at square root s=1.96 TeV in the CDF experiment. In order to reduce systematic error, the measured rate for Lambda b0 decay is normalized to the kinematically similar meson decay B0-->D+pi- followed by D+-->pi+K-pi+. We report the ratio of production cross sections (sigma) times the ratio of branching fractions (B) for the momentum region integrated above pT>6 GeV/c and pseudorapidity range |eta|<1.3: sigma(pp-->Lambda b0X)/sigma(pp-->B0X)xB(Lambda b0-->Lambda c+pi-)/B(B0-->D+pi-)=0.82+/-0.08(stat)+/-0.11(syst)+/-0.22[B(Lambda c+-->pK-pi+)]. 相似文献
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Abe F Amidei D Anway-Wiese C Apollinari G Atac M Auchincloss P Azzi P Baden AR Bacchetta N Badgett W Bailey MW Bamberger A de Barbaro P Barbaro-Galtieri A Barnes VE Barnett BA Bauer G Baumann T Bedeschi F Behrends S Belforte S Bellettini G Bellinger J Benjamin D Benlloch J Bensinger J Beretvas A Berge JP Bertolucci S Biery K Bhadra S Binkley M Bisello D Blair R Blocker C Bodek A Bolognesi V Booth AW Boswell C Brandenburg G Brown D Buckley-Geer E Budd HS Busetto G Byon-Wagner A Byrum KL 《Physical review D: Particles and fields》1993,47(7):R2639-R2643
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Abazov VM Abbott B Abolins M Acharya BS Adams M Adams T Agelou M Agram JL Ahn SH Ahsan M Alexeev GD Alkhazov G Alton A Alverson G Alves GA Anastasoaie M Anderson S Andrieu B Arnoud Y Askew A Asman B Atramentov O Autermann C Avila C Badaud F Baden A Baldin B Balm PW Banerjee S Barberis E Bargassa P Baringer P Barnes C Barreto J Bartlett JF Bassler U Bauer D Bean A Beauceron S Begel M Bellavance A Beri SB Bernardi G Bernhard R Bertram I Besançon M Beuselinck R Bezzubov VA Bhat PC Bhatnagar V 《Physical review letters》2005,94(10):102001
We present measurements of the Lambda(0)(b) lifetime in the exclusive decay channel Lambda(0)(b)--> J/psiLambda(0), with J/psi--> mu(+)mu(-) and Lambda(0)--> ppi(-), the B0 lifetime in the decay B0-->J/psiK(0)(S) with J/psi--> mu(+)mu(-) and K(0)(S)-->pi(+)pi(-), and the ratio of these lifetimes. The analysis is based on approximately 250 pb(-1) of data recorded with the D0 detector in pp collisions at sqrt[s] = 1.96 TeV. The Lambda(0)(b) lifetime is determined to be tau(Lambda(0)(b)) = 1.22(+0.22)(-0.18)(stat) +/- 0.04(syst) ps, the B0 lifetime tau(B0) = 1.40(+0.11)(-0.10)(stat) +/- 0.03(syst) ps, and the ratio tau(Lambda(0)(b))/tau(B0) = 0.87(+0.17)(-0.14)(stat) +/- 0.03(syst). In contrast with previous measurements using semileptonic decays, this is the first determination of the Lambda(0)(b) lifetime based on a fully reconstructed decay channel. 相似文献
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J. Ellis A. Kotzinian D.V. Naumov 《The European Physical Journal C - Particles and Fields》2002,25(4):603-613
We propose a model for the longitudinal polarization of baryons produced in deep-inelastic lepton scattering at any , based on static SU(6) quark-diquark wave functions and polarized intrinsic strangeness in the nucleon associated with individual valence quarks.
The free parameters of the model are fixed by fitting NOMAD data on the longitudinal polarization of hyperons in neutrino collisions. Our model correctly reproduces the observed dependences of the polarization on the kinematic variables. Within the context of our model, the NOMAD data imply that the intrinsic strangeness
associated with a valence quark has anticorrelated polarization. We also compare our model predictions with results from the
HERMES and E665 experiments using charged leptons. Predictions of our model for the COMPASS experiment are also presented.
Received: 25 May 2002 / Revised version: 8 June 2002 / Published online: 7 October 2002 相似文献
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The longitudinal polarization, the transverse polarization, and the forward-backward asymmetry of baryons, have been measured using a sample of 4.34 million hadronic decays collected with the OPAL detector at LEP between 1990 and 1995. These results are important as an aid to the understanding
of hadronization mechanisms. Significant longitudinal polarization has been observed at intermediate and high momentum. For
( 0.3, the longitudinal polarization has been measured to be (stat) 5.2 (syst)%. We have observed no transverse polarization. A significant forward-backward asymmetry has been measured and
can be described by a JETSET model.
Received: 30 July 1997 相似文献
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Anjos JC Appel JA Bean A Bracker SB Browder TE Cremaldi LM Elliott JR Escobar CO Estabrooks P Gibney MC Hartner GF Karchin PE Kumar BR Losty MJ Luste GJ Mantsch PM Martin JF McHugh S Menary SR Morrison RJ Nash T Nauenberg U Ong P Pinfold J Punkar G Purohit MV Raab JR Santoro AF Sidhu JS Sliwa K Sokoloff MD Souza MH Spalding WJ Streetman ME Stundia AB Witherell MS 《Physical review letters》1989,62(15):1721-1723
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Fajfer S. Ilakovac A. Tadic D. Suruliz K. 《Zeitschrift fur Physik C Particles and Fields》1994,61(3):421-423
Zeitschrift für Physik C Particles and Fields - Available phase space suppresses the decay $\Lambda _c^ + \to p\overline {K^0 } \pi ^ + \pi ^ - $ in comparison with the decay $\Lambda _c^ +... 相似文献
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Avery P Freyberger A Rodriguez J Stephens R Yelton J Cinabro D Henderson S Kinoshita K Liu T Saulnier M Wilson R Yamamoto H Ong B Selen M Sadoff AJ Ammar R Ball S Baringer P Coppage D Copty N Davis R Hancock N Kelly M Kwak N Lam H Kubota Y Lattery M Nelson JK Patton S Perticone D Poling R Savinov V Schrenk S Wang R Alam MS Kim IJ Nemati B O'Neill JJ Romero V Severini H Sun CR Zoeller MM Crawford G Daubenmier CM Fulton R Fujino D Gan KK Honscheid K Kagan H Kass R Lee J Malchow R Morrow F 《Physical review letters》1993,71(15):2391-2395