共查询到20条相似文献,搜索用时 15 毫秒
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《Zeitschrift fur Physik C Particles and Fields》1997,73(4):601-612
A sample of 3.6 million hadronic Z decays recorded between 1991 and 1995 with the ALEPH detector at LEP is used to investigate semileptonic decays of B mesons into final states involving orbitally excited charm mesons. Topological vertex criteria are used to search for decays involving narrow D** states as well as wide D** resonances and non-resonant D(*)π final states. The sum of the branching ratios for these processes is measured to be ${? Br}({?erline {? B}}?ghtarrow {? D}? ?l^{-}{?erline v}) + {? Br}({?erline {? B}}?ghtarrow {? D}^{?t}? ?l^{-}{?erline v})?op =(2.26 pm 0.29({? stat}) pm 0.33({? syst}))%,$which accounts for a significant fraction of the deficit between inclusive measurements and the sum of exclusive semileptonic B decay modes. 相似文献
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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》2008,100(8):082002
We report the direct observation of the excited L=1 state B_(s2)(*) in fully reconstructed decays to B+K-. The mass of the B_(s2)(*) meson is measured to be 5839.6+/-1.1(stat)+/-0.7(syst) MeV/c(2), and its production rate relative to the B+ meson is measured to be [1.15+/-0.23(stat)+/-0.13(syst)]%. 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 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):1717-1720
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Muyang Chen 《中国物理C(英文版)》2021,45(12):123104-123104-6
In this study, the first radial excited heavy pseudoscalar and vector mesons (\begin{document}$\eta_c(2S)$\end{document} ![]()
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, \begin{document}$\psi(2S)$\end{document} ![]()
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, \begin{document}$B_c(2S)$\end{document} ![]()
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, \begin{document}$B^*_c(2S)$\end{document} ![]()
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, \begin{document}$\eta_b(2S)$\end{document} ![]()
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, and \begin{document}$\varUpsilon(2S)$\end{document} ![]()
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) are investigated using the Dyson-Schwinger equation and Bethe-Salpeter equation approach. It is shown that the effective interactions of the radial excited states are harder than those of the ground states. With the interaction well determined by fitting the masses and leptonic decay constants of \begin{document}$\psi(2S)$\end{document} ![]()
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and \begin{document}$\varUpsilon(2S)$\end{document} ![]()
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, the first radial excited heavy mesons could be quantitatively described in the rainbow ladder approximation. The masses and leptonic decay constants of \begin{document}$\eta_c(2S)$\end{document} ![]()
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, \begin{document}$B_c(2S)$\end{document} ![]()
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, \begin{document}$B^*_c(2S)$\end{document} ![]()
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, and \begin{document}$\eta_b(2S)$\end{document} ![]()
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are predicted. 相似文献
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The spectrum of D s mesons is systematically studied in a semi-classic mass loaded flux tube model.D s in D-wave multiplets is predicted to have lower masses in comparison with most theoretical predictions.D sJ (2632) +,D s1 (2700) ±,D sJ (2860) + and D sJ (3040) + are interpreted in the constituent quark model. 相似文献
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The spectrum of D s mesons is systematically studied in a semi-classic mass loaded flux tube model.D s in D-wave multiplets is predicted to have lower masses in comparison with most theoretical predictions.D sJ (2632) +,D s1 (2700) ±,D sJ (2860) + and D sJ (3040) + are interpreted in the constituent quark model. 相似文献
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Aubert B Bona M Boutigny D Karyotakis Y Lees JP Poireau V Prudent X Tisserand V Zghiche A Tico JG Grauges E Lopez L Palano A Pappagallo M Eigen G Stugu B Sun L Abrams GS Battaglia M Brown DN Button-Shafer J Cahn RN Groysman Y Jacobsen RG Kadyk JA Kerth LT Kolomensky YG Kukartsev G Lopes Pegna D Lynch G Mir LM Orimoto TJ Osipenkov IL Ronan MT Tackmann K Tanabe T Wenzel WA del Amo Sanchez P Hawkes CM Watson AT Held T Koch H Pelizaeus M Schroeder T Steinke M Walker D Asgeirsson DJ 《Physical review letters》2008,101(9):091801
Using 383 x 10(6) BBover pairs from the BABAR data sample, we report results for branching fractions of six charged B-meson decay modes, where a charged kaon recoils against a charmless resonance decaying to KKover* or etapipi final states with mass in the range (1.2-1.8) GeV/c2. We observe a significant enhancement at the low KKover* invariant mass which is interpreted as B+-->eta(1475)K+, find evidence for the decay B+-->eta(1295)K+, and place upper limits on the decays B+-->eta(1405)K+, B+-->f1(1285)K+, B+-->f1(1420)K+, and B+-->phi(1680)K+. 相似文献
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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 Blair RE 《Physical review letters》2006,97(21):211802
We search for decays of the type B(s)0-->h+ h'- (where h,h' = K or pi) in 180 pb(-1) of pp collisions collected at the Tevatron by the upgraded Collider Detector at Fermilab. We report the first observation of the new mode B(s)0-->K+ K- with a yield of 236+/-32 events, corresponding to (fs/fd) x B(B(s)0-->K+ K-)/B(B0-->K+ pi-) = 0.46+/-0.08stat+/-0.07syst, where fs/fd is the ratio of production fractions of B(s)0 and B0. We find results in agreement with world averages for the B0 modes, and set the following new limits at 90% C.L.: B(B(s)0-->K- pi+) < 5.6 x 10(-6) and B(B(s)0-->pi+ pi-) < 1.7 x 10(-6). 相似文献
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Battle M Ernst J Kroha H Kwon Y Roberts S Sparks K Thorndike EH Wang CH Dominick J Sanghera S Shelkov V Skwarnicki T Stroynowski R Volobouev I Zadorozhny P Artuso M He D Goldberg M Horwitz N Kennett R Moneti GC Muheim F Mukhin Y Playfer S Rozen Y Stone S Thulasidas M Vasseur G Zhu G Bartelt J Csorna SE Egyed Z Jain V Sheldon P Akerib DS Barish B Chadha M Chan S Cowen DF Eigen G Miller JS O'Grady C Urheim J Weinstein AJ Acosta D Athanas M Masek G Paar H Bean A Gronberg J Kutschke R Menary S 《Physical review letters》1993,71(24):3922-3926
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《Physics letters. [Part B]》1988,202(2):251-256
Recent results from the Crystal Ball spectrometer show no evidence for two-photon production of the pseudoscalar resonances π(1300), η(1275) or η(1440). We give a simple theoretical argument showing that the two-photon couplings to excited SU(3) pseudoscalars are naturally suppressed by chiral symmetry in QCD. Effects of the spontaneous chiral symmetry breaking nevertheless give a finite contribution to the two-photon coupling, even in the limit of zero quark mass. We construct an effective chiral meson lagrangian that incorporates these qualitative properties, and use it to estimate the two-photon couplings in the chiral limit. The results are well compatible with experiment. 相似文献
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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
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Motivated by the recent discovery at Orsay of ?′ (1680), we study the strong interaction decays of radially excited vector mesons within the framework of the3 P 0 quark pair creation model. We stress the relative importance of phase space, algebraic spinflavor couplings, and spatial overlaps. Quite a few features of the data can be will understood by the presence of a node in the spatial wave function, but the detailed structure of the modes ρ′→4π remains a serious challenge. 相似文献
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M. Stanoiu M. Belleguic Zs. Dombrádi D. Sohler F. Azaiez B. A. Brown M. J. Lopez-Jimenez M. G. Saint-Laurent O. Sorlin Yu.-E Penionzhkevich N. L. Achouri J. C. Angélique C. Borcea C. Bourgeois J. M. Daugas F. De Oliveira-Santos Z. Dlouhy C. Donzaud J. Duprat S. Grévy D. Guillemaud-Mueller S. Leenhardt M. Lewitowicz S. M. Lukyanov W. Mittig M. G. Porquet F. Pougheon P. Roussel-Chomaz H. Savajols Y. Sobolev C. Stodel J. Timár 《The European Physical Journal A - Hadrons and Nuclei》2004,22(1):5-8
The structure of the A/Z = 3 nucleus 15B has been investigated using the in-beam
-spectroscopy technique with a fragmentation reaction of a 36S beam on a 9Be target at 77.5
. The fragments were identified and selected by their energy loss and time of flight using the SPEG spectrograph.
-ray energies and intensities have been measured in coincidence with the projectile-like fragments. From this information as well as from the
-coincidence relationships a level scheme is proposed for 15B up to the neutron separation energy. The experimental results have been interpreted using shell model calculations in the psd valence space. Effects of the weakly bound nature of the valence neutrons have been observed.Received: 4 May 2004, Revised: 2 September 2004, Published online: 19 October 2004PACS:
25.70.Mn Projectile and target fragmentation - 23.20.Lv
transitions and level energies - 27.20. + n
- 21.60.Cs Shell model 相似文献
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Adams GS Anderson M Cummings JP Danko I Hu D Moziak B Napolitano J He Q Insler J Muramatsu H Park CS Thorndike EH Yang F Artuso M Blusk S Khalil S Li J Menaa N Mountain R Nisar S Randrianarivony K Sia R Skwarnicki T Stone S Wang JC Bonvicini G Cinabro D Dubrovin M Lincoln A Asner DM Edwards KW Naik P Briere RA Ferguson T Tatishvili G Vogel H Watkins ME Rosner JL Adam NE Alexander JP Cassel DG Duboscq JE Ehrlich R Fields L Gibbons L Gray R Gray SW Hartill DL Heltsley BK Hertz D Jones CD 《Physical review letters》2007,99(19):191805
Using data collected near the D{s}{*+}D{s}{-} peak production energy E_{cm}=4170 MeV by the CLEO-c detector, we study the decays of D{s}{+} mesons to two pseudoscalar mesons. We report on searches for the singly Cabibbo-suppressed D{s}{+} decay modes K{+}eta, K{+}eta', pi{+}K{S}{0}, K{+}pi{0}, and the isospin-forbidden decay mode D{s}{+}-->pi{+}pi{0}. We normalize with respect to the Cabibbo-favored D{s}{+} modes pi{+}eta, pi{+}eta', and K{+}K{S}{0}, and obtain ratios of branching fractions: B(D{s}{+}-->K{+}eta)/B(D{s}{+}-->pi{+}eta)=(8.9+/-1.5+/-0.4)%, B(D{s}{+}-->K{+}eta')/B(D{s}{+}-->pi{+}eta')=(4.2+/-1.3+/-0.3)%, B(D{s}{+}-->pi{+}K{S}{0})/B(D{s}{+}-->K{+}K{S}{0})=(8.2+/-0.9+/-0.2)%, B(D{s}{+}-->K{+}pi{0})/B(D{s}{+}-->K{+}K{S}{0})=(5.5+/-1.3+/-0.7)%, and B(D{s}{+}-->pi{+}pi{0})/B(D{s}{+}-->K{+}K{S}{0})<4.1% at 90% C.L., where the uncertainties are statistical and systematic, respectively. 相似文献