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71.
Search for production of single top quarks via tcg and tug flavor-changing-neutral-current couplings
Abazov VM Abbott B Abolins M Acharya BS Adams M Adams T Aguilo E Ahn SH Ahsan M Alexeev GD Alkhazov G Alton A Alverson G Alves GA Anastasoaie M Ancu LS Andeen T Anderson S Andrieu B Anzelc MS Arnoud Y Arov M Askew A Asman B Assis Jesus AC Atramentov O Autermann C Avila C Ay C Badaud F Baden A Bagby L Baldin B Bandurin DV Banerjee P Banerjee S Barberis E Barfuss AF Bargassa P Baringer P Barnes C Barreto J Bartlett JF Bassler U Bauer D Beale S Bean A Begalli M Begel M Belanger-Champagne C 《Physical review letters》2007,99(19):191802
We search for the production of single top quarks via flavor-changing-neutral-current couplings of a gluon to the top quark and a charm (c) or up (u) quark. We analyze 230 pb{-1} of lepton+jets data from pp[over] collisions at a center of mass energy of 1.96 TeV collected by the D0 detector at the Fermilab Tevatron Collider. We observe no significant deviation from standard model predictions, and hence set upper limits on the anomalous coupling parameters kappa{g}{c}/Lambda and kappa{g}{u}/Lambda, where kappa{g} define the strength of tcg and tug couplings, and Lambda defines the scale of new physics. The limits at 95% C.L. are kappa{g}{c}/Lambda<0.15 TeV-1 and kappa{g}{u}/Lambda<0.037 TeV-1. 相似文献
72.
Abazov VM Abbott B Abolins M Acharya BS Adams M Adams T Aguilo E Ahn SH Ahsan M Alexeev GD Alkhazov G Alton A Alverson G Alves GA Anastasoaie M Ancu LS Andeen T Anderson S Andrieu B Anzelc MS Arnoud Y Arov M Askew A Asman B Assis Jesus AC Atramentov O Autermann C Avila C Ay C Badaud F Baden A Bagby L Baldin B Bandurin DV Banerjee P Banerjee S Barberis E Barfuss AF Bargassa P Baringer P Barreto J Bartlett JF Bassler U Bauer D Beale S Bean A Begalli M Begel M Belanger-Champagne C Bellantoni L 《Physical review letters》2007,99(24):241801
We report a study of the decay Bs(0)-->Ds(*)Ds(*) using a data sample corresponding to 1.3 fb(-1) of integrated luminosity collected by the D0 experiment in 2002-2006 during run II of the Fermilab Tevatron collider. One Ds(*) meson was partially reconstructed in the decay Ds-->phi mu nu, and the other Ds(*) meson was identified using the decay Ds-->phi pi where no attempt was made to distinguish Ds and Ds(*) states. For the branching fraction Br(Bs(0)-->Ds(*)Ds(*)) we obtain a 90% C.L. range [0.002,0.080] and central value 0.039(-0.017)(+0.019)(stat)(-0.015)(+0.016)(syst). This was subsequently used to make the most precise estimate of the width difference DeltaGamma(s)CP in the Bs(0)-Bs(0) system: DeltaGamma(s)CP/Gamma(s)=0.079(-0.035)(+0.038)(stat)(-0.030)(+0.031)(syst). 相似文献
73.
Abazov VM Abbott B Abolins M Acharya BS Adams M Adams T Aguilo E Ahn SH Ahsan M Alexeev GD Alkhazov G Alton A Alverson G Alves GA Anastasoaie M Ancu LS Andeen T Anderson S Andrieu B Anzelc MS Arnoud Y Arov M Arthaud M Askew A Asman B Assis Jesus AC Atramentov O Autermann C Avila C Ay C Badaud F Baden A Bagby L Baldin B Bandurin DV Banerjee S Banerjee P Barberis E Barfuss AF Bargassa P Baringer P Barreto J Bartlett JF Bassler U Bauer D Beale S Bean A Begalli M Begel M Belanger-Champagne C 《Physical review letters》2007,99(17):172001
This Letter presents the first strong evidence for the resolution of the excited B mesons B(1) and B(2)* as two separate states in fully reconstructed decays to B(+)(*)pi(-). The mass of B(1) is measured to be 5720.6+/-2.4+/-1.4 MeV/c(2) and the mass difference DeltaM between B(2)* and B(1) is 26.2+/-3.1+/-0.9 MeV/c;{2}, giving the mass of the B(2)* as 5746.8+/-2.4+/-1.7 MeV/c(2). The production rate for B(1) and B(2)* mesons is determined to be a fraction (13.9+/-1.9+/-3.2)% of the production rate of the B+ meson. 相似文献
74.
Victor E. Asadchikov Andrey V. Butashin Alexey V. Buzmakov Alexander N. Deryabin Vladimir M. Kanevsky Igor A. Prokhorov Boris S. Roshchin Yuri O. Volkov Denis A. Zolotov Atefeh Jafari Pavel Alexeev Angelica Cecilia Tilo Baumbach Dimitrios Bessas Andreas N. Danilewsky Ilya Sergueev Hans‐Christian Wille Raphaël P. Hermann 《Crystal Research and Technology》2016,51(4):290-298
We report on the growth and characterization of sapphire single crystals for X‐ray optics applications. Structural defects were studied by means of laboratory double‐crystal X‐ray diffractometry and white‐beam synchrotron‐radiation topography. The investigations confirmed that the main defect types are dislocations. The best quality crystal was grown using the Kyropoulos technique. Therein the dislocation density was 102–103 cm−2 and a small area with approximately 2*2 mm2 did not show dislocation contrast in many reflections. This crystal has suitable quality for application as a backscattering monochromator. A clear correlation between growth rate and dislocation density is observed, though growth rate is not the only parameter impacting the quality. 相似文献
75.
V. A. Alexeev V. D. Gorin G. K. Ustinova 《Bulletin of the Russian Academy of Sciences: Physics》2013,77(5):520-522
Meteorite data on monitoring the variations in GCR gradients at 2–4 AU from the Sun over the period 1957–2010 demonstrate the effect of the inversion of solar magnetic fields (SMFs) during the solar maximum periods of 11-year solar cycles on the depth of GCR modulation in the heliosphere. 相似文献
76.
Using computational modeling, we design nano-structured surfaces able to selectively regulate interactions between microchannel walls and flowing colloid-polymer suspensions. Depending on the geometry of nanoscopic posts lining internal channel surfaces, suspended nanoparticles and polymeric chains can be either hydrodynamically attracted to channel walls or repelled to the bulk fluid. 相似文献
77.
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 Andeen T Anderson S Andrieu B Anzelc MS Arnoud Y Arov M Askew A Asman B Jesus AC Atramentov O Autermann C Avila C Ay C Badaud F Baden A Bagby L Baldin B Bandurin DV Banerjee P Banerjee S Barberis E Bargassa P Baringer P Barnes C Barreto J Bartlett JF Bassler U Bauer D Bean A Begalli M Begel M Belanger-Champagne C Bellantoni L Bellavance A 《Physical review letters》2006,97(11):111801
We present a search for supersymmetry in the R-parity violating resonant production and decay of smuons and muon sneutrinos in the channels mu-->chi(1)(0)mu, mu-->chi(2,3,4)(0)mu, and nu(mu)-->chi(1,2)(+/-)mu. We analyzed 0.38 fb(-1) of integrated luminosity collected between April 2002 and August 2004 with the D0 detector at the Fermilab Tevatron Collider. The observed number of events is in agreement with the standard model expectation, and we calculate 95% C.L. limits on the slepton production cross section times branching fraction to gaugino plus muon, as a function of slepton and gaugino masses. In the framework of minimal supergravity, we set limits on the coupling parameter lambda(211)('), extending significantly previous results obtained in Run I of the Tevatron and at the CERN LEP collider. 相似文献
78.
By integrating mesoscale models for hydrodynamics and micromechanics, we examine fluid-driven motion of vesicles on compliant surfaces. The vesicles, modeled as fluid-filled elastic shells, represent biological cells or polymeric microcapsules. Focusing on nonspecific interactions between these vesicles and synthetic substrates, we isolate mechanically and topographically patterned surfaces that transmit stop and go instructions, causing the vesicles to halt at specific locations, and with an increase in the flow velocity, to resume moving. For surfaces containing arrays of compliant posts, the substrates also affect the vesicles' gait, causing them to "crawl," "walk," or "jump." The latter behavior could promote the intermixing of reactants that are encapsulated within the microcapsules. Such control over vesicle dynamics can facilitate various biological assays and fabrication of arrays of mobile microreactors. 相似文献
79.
Alexeev Alexander A. Nurieva Evgeniya V. Lyssenko Konstantin A. Grishin Yuri K. Zefirova Olga N. 《Structural chemistry》2019,30(2):473-479
Structural Chemistry - In an attempt to synthesize 4-thia-6-azatricyclo[5.3.1.13,9]dodecan-5-imine as putative antihypotensive agent with prolonged effect, a reaction of... 相似文献
80.
B. M. Abramov P. N. Alexeev Yu. A. Borodin S. A. Bulychjov K. K. Gudima I. A. Dukhovskoy A. P. Krutenkova V. V. Kulikov M. A. Martemianov M. A. Matsyuk E. N. Turdakina A. I. Khanov 《Physics of Atomic Nuclei》2018,81(3):330-337
The differential cross sections for the yields of nuclear fragments at an angle of 3.5? in the fragmentation of carbon nuclei with energy 0.95 GeV per nucleon on a beryllium target were measured in the FRAGM experiment at the ITEP TWA heavy-ion accelerator. The momentum spectra of fragments were used to test the following four models of ion–ion interactions: BC, INCL++, LAQGSM03.03, and QMD. For light fragments, the slope parameters of the kinetic-energy spectra were obtained in the cumulative region. 相似文献