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21.
P. Granet M. Loret L. Mosca J. Saudraix J.C. Scheuer C. Dujardin J. Laurent J. Schlesinger R. Windmolders J.J. Dumoni S. Tavernier F. Verbeure H. Blumenfeld K. Dziunikowska I.V. Ajinenko P.V. Chliapnikov L.N. Guerdyukov B.A. Manyukov O.G. Tchikilev 《Physics letters. [Part B]》1976,62(3):350-352
Elastic scattering of 32.1 GeV/c K+ on protons has been measured in a bubble chamber experiment. Results are presented in the momentum transfer interval 0.06–1.40 GeV2 and compared with data at different energies. An effective Regge trajectory is calculated using K+p elastic data from 10 to 175 GeV/c. 相似文献
22.
Acosta D Affolder T Albrow MG Ambrose D Amidei D Anikeev K Antos J Apollinari G Arisawa T Artikov A Ashmanskas W Azfar F Azzi-Bacchetta P Bacchetta N Bachacou H Badgett W Barbaro-Galtieri A Barnes VE Barnett BA Baroiant S Barone M Bauer G Bedeschi F Behari S Belforte S Bell WH Bellettini G Bellinger J Benjamin D Beretvas A Bhatti A Binkley M Bisello D Bishai M Blair RE Blocker C Bloom K Blumenfeld B Bocci A Bodek A Bolla G Bolshov A Bortoletto D Boudreau J Bromberg C Brubaker E Budagov J 《Physical review letters》2005,94(17):171802
We report the first largely model independent measurement of charged particle multiplicities in quark and gluon jets, Nq and Ng, produced at the Fermilab Tevatron in pp collisions with a center-of-mass energy of 1.8 TeV and recorded by the Collider Detector at Fermilab. The measurements are made for jets with average energies of 41 and 53 GeV by counting charged particle tracks in cones with opening angles of theta(c) = 0.28, 0.36, and 0.47 rad around the jet axis. The corresponding jet hardness Q = Ejet theta c varies in the range from 12 to 25 GeV. At Q = 19.2 GeV, the ratio of multiplicities r = Ng/Nq is found to be 1.64+/-0.17, where statistical and systematic uncertainties are added in quadrature. The results are in agreement with resummed perturbative QCD calculations. 相似文献
23.
Abulencia A Acosta D 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 Bachacou H 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 Ben-Haim E Benjamin D Beretvas A Beringer J Berry T Bhatti A Binkley M Bisello D Bishai M 《Physical review letters》2005,95(22):221805
We report on a search for B0(s) --> mu+ mu- and B0(d) --> mu + mu- decays in pp collisions at square root(s) = 1.96 TeV using 364 pb(-1) of data collected by the CDF II detector at the Fermilab Tevatron Collider. After applying all selection requirements, we observe no candidates inside the B0(s) or B0(d) mass windows. The resulting upper limits on the branching fractions are B(B0(s) --> mu+ mu-) < 1.5 x 10(-7) and B(B0(d) --> mu+ mu-) < 3.9 x 10(-8) at 90% confidence level. 相似文献
24.
Acosta D 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 Arisawa T Arguin JF Artikov A Ashmanskas W Attal A Azfar F Azzi-Bacchetta P Bacchetta N Bachacou H Badgett W Barbaro-Galtieri A Barker GJ Barnes VE Barnett BA Baroiant S Bauer G Bedeschi F Behari S Belforte S Bellettini G Bellinger J Belloni A Ben-Haim E Benjamin D Beretvas A Bhatti A Binkley M Bisello D Bishai M Blair RE Blocker C Bloom K Blumenfeld B 《Physical review letters》2005,95(7):071801
We present a search for long-lived doubly charged Higgs bosons (H(+/- +/-)), with signatures of high ionization energy loss and muonlike penetration. We use 292 pb(-1) of data collected in pp collisions at sqrt[s] = 1.96 TeV by the CDF II detector at the Fermilab Tevatron. Observing no evidence of long-lived doubly charged particle production, we exclude H(+/- +/-)(L) and H(+/- +/-)(R) bosons with masses below 133 GeV/c(2) and 109 GeV/c(2), respectively. In the degenerate case we exclude H(+/- +/-) mass below 146 GeV/c(2). All limits are quoted at the 95% confidence level. 相似文献
25.
Acosta D Affolder T Akimoto T Albrow MG Ambrose D Amerio S Amidei D Anastassov A Anikeev K Annovi A Antos J Aoki M Apollinari G Arisawa T Arguin JF Artikov A Ashmanskas W Attal A Azfar F Azzi-Bacchetta P Bacchetta N Bachacou H Badgett W Barbaro-Galtieri A Barker GJ Barnes VE Barnett BA Baroiant S Barone M Bauer G Bedeschi F Behari S Belforte S Bellettini G Bellinger J Benjamin D Beretvas A Bhatti A Binkley M Bisello D Bishai M Blair RE Blocker C Bloom K Blumenfeld B Bocci A Bodek A Bolla G 《Physical review letters》2004,93(22):221802
We present the results of a search for doubly charged Higgs bosons (H+/-+/-) decaying to dileptons (ll(')) using approximately 240 pb(-1) of pp collision data collected by the CDF II experiment at the Fermilab Tevatron. In our search region, given by same-sign ll(') mass m(ll('))>80 GeV/c(2) (100 GeV/c(2) for ee channel), we observe no evidence for H+/-+/- production. We set limits on sigma(pp -->H++H---->l(+)l('+)l(-)l('-)) as a function of the mass of the H+/-+/- and the chirality of its couplings. Assuming exclusive same-sign dilepton decays, we derive lower mass limits on H(+/-+/-)(L) of 133, 136, and 115 GeV/c(2) in the ee, mumu, and emu channels, respectively, and a lower mass limit of 113 GeV/c(2) on H(+/-+/-)(R) in the mumu channel, all at the 95% confidence level. 相似文献
26.
Acosta D Affolder T Akimoto H Albrow MG Ambrose D Amidei D Anikeev K Antos J Apollinari G Arisawa T Artikov A Asakawa T Ashmanskas W Azfar F Azzi-Bacchetta P Bacchetta N Bachacou H Badgett W Bailey S de Barbaro P Barbaro-Galtieri A Barnes VE Barnett BA Baroiant S Barone M Bauer G Bedeschi F Behari S Belforte S Bell WH Bellettini G Bellinger J Benjamin D Bensinger J Beretvas A Berryhill J Bhatti A Binkley M Bisello D Bishai M Blair RE Blocker C Bloom K Blumenfeld B Blusk SR Bocci A Bodek A 《Physical review letters》2004,92(5):051803
We present the results of a search for pair production of scalar top quarks (t(1)) in an R-parity violating supersymmetry scenario in 106 pb(-1) of pp collisions at square root of s=1.8 TeV collected by the Collider Detector at Fermilab. In this mode each t(1) decays into a tau lepton and a b quark. We search for events with two tau's, one decaying leptonically (e or mu) and one decaying hadronically, and two jets. No candidate events pass our final selection criteria. We set a 95% confidence level lower limit on the t(1) mass at 122 GeV/c(2) for Br(t(1)-->tau b)=1. 相似文献
27.
Acosta D Affolder T Ahn MH Akimoto T Albrow MG Ambrose D Amidei D Anastassov A Anikeev K Annovi A Antos J Aoki M Apollinari G Arguin JF Arisawa T Artikov A Asakawa T Ashmanskas W Attal A Azfar F Azzi-Bacchetta P Bacchetta N Bachacou H Badgett W Bailey S Barbaro-Galtieri A Barker G Barnes VE Barnett BA Baroiant S Barone M Bauer G Bedeschi F Behari S Belforte S Bell WH Bellettini G Bellinger J Benjamin D Beretvas A Bhatti A Binkley M Bisello D Bishai M Blair RE Blocker C Bloom K Blumenfeld B 《Physical review letters》2003,91(24):241804
We report on measurements of differential cross sections dsigma/dp(T) for prompt charm meson production in ppmacr; collisions at sqrt[s]=1.96 TeV using 5.8+/-0.3 pb(-1) of data from the CDF II detector at the Fermilab Tevatron. The data are collected with a new trigger that is sensitive to the long lifetime of hadrons containing heavy flavor. The charm meson cross sections are measured in the central rapidity region |y|=1 in four fully reconstructed decay modes: D0-->K-pi(+), D(*+)-->D0pi(+), D+-->K-pi(+)pi(+), D(+)(s)-->phipi(+), and their charge conjugates. The measured cross sections are compared to theoretical calculations. 相似文献
28.
Boutreau L Léon E Salpin JY Amekraz B Moulin C Tortajada J 《European journal of mass spectrometry (Chichester, England)》2003,9(4):377-390
The analytical distinction of the most common isomeric underivatized hexoses was investigated by means of mass spectrometry experiments. Electrospray ionization and tandem mass spectrometry were used in the analysis of silver and copper-coordinated monosaccharides (D-glucose, D-galactose, D-fructose, O-methyl-alpha-D-glucose and O-methyl-beta-D-glucose). The results show that cationization by Ag(+) allows the differentiation of the three first monosaccharides while the complexes formed by association of Cu(+) with these three monosacharides display a similar reactivity that prevents stereoisomer distinction. Unlike copper, silver adduct-ions of both alpha and beta anomeric O-methyl-D-glucoses exhibit specific decomposition patterns (i.e. a loss of methanol for the alpha-anomer and a loss of silver hydride for the beta-anomer), which allow an easy characterization. A theoretical survey of selected complexes, based on the use of DFT calculations were carried out on both anomers in order to rationalize the experimental findings. 相似文献
29.
Affolder T Akimoto H Akopian A Albrow MG Amaral P Amendolia SR Amidei D Anikeev K Antos J Apollinari G Arisawa T Asakawa T Ashmanskas W Azfar F Azzi-Bacchetta P Bacchetta N Bailey MW Bailey S de Barbaro P Barbaro-Galtieri A Barnes VE Barnett BA Baroiant S Barone M Bauer G Bedeschi F Belforte S Bell WH Bellettini G Bellinger J Benjamin D Bensinger J Beretvas A Berge JP Berryhill J Bevensee B Bhatti A Binkley M Bisello D Bishai M Blair RE Blocker C Bloom K Blumenfeld B Blusk SR Bocci A Bodek A 《Physical review letters》2001,86(15):3233-3238
We present the first measurement of the ratio of branching fractions R identical withB(t-->Wb)/B(t-->Wq) from p_p collisions at sqrt[s] = 1.8 TeV. The data set corresponds to 109 pb(-1) of data recorded by the Collider Detector at Fermilab during the 1992-95 Tevatron run. We measure R = 0.94(+0.31)(-0.24)(stat+syst) or R>0.61 (0.56) at 90% (95)% C.L., in agreement with the standard model predictions. This measurement yields a limit on the Cabibbo-Kobayashi-Maskawa quark mixing matrix element /V(tb)/ under the assumption of three generations and unitarity. 相似文献
30.
Affolder T Akimoto H Akopian A Albrow MG Amaral P Amidei D Anikeev K Antos J Apollinari G Arisawa T Artikov A Asakawa T Ashmanskas W Azfar F Azzi-Bacchetta P Bacchetta N Bachacou H Bailey S de Barbaro P Barbaro-Galtieri A Barnes VE Barnett BA Baroiant S Barone M Bauer G Bedeschi F Belforte S Bell WH Bellettini G Bellinger J Benjamin D Bensinger J Beretvas A Berge JP Berryhill J Bhatti A Binkley M Bisello D Bishai M Blair RE Blocker C Bloom K Blumenfeld B Blusk SR Bocci A Bodek A Bokhari W 《Physical review letters》2001,87(13):131802
We report on a measurement of the mass dependence of the forward-backward charge asymmetry, A(FB), and production cross section d sigma/dM for e(+)e(-) pairs with mass M(ee)>40 GeV/c(2). The data sample consists of 108 pb(-1) of pp macro collisions at square root of s = 1.8 TeV taken by the Collider Detector at Fermilab during 1992-1995. The measured asymmetry and d sigma/dM are compared with the predictions of the standard model and a model with an extra Z' gauge boson. 相似文献