Evidence for the h_b(1P) meson in the decay Upsilon(3S) --> pi0 h_b(1P)
The BABAR Collaboration, J. P. Lees, V. Poireau, E. Prencipe, V. Tisserand, J. Garra Tico, E. Grauges, M. Martinelli, D. A. Milanes, A. Palano, M. Pappagallo, G… 展开作者
The BABAR Collaboration, J. P. Lees, V. Poireau, E. Prencipe, V. Tisserand, J. Garra Tico, E. Grauges, M. Martinelli, D. A. Milanes, A. Palano, M. Pappagallo, G. Eigen, B. Stugu, L. Sun, D. N. Brown, L. T. Kerth, Yu. G. Kolomensky, G. Lynch, I. L. Osipenkov, H. Koch, T. Schroeder, D. J. Asgeirsson, C. Hearty, T. S. Mattison, J. A. McKenna, A. Khan, V. E. Blinov, A. R. Buzykaev, V. P. Druzhinin, V. B. Golubev, E. A. Kravchenko, A. P. Onuchin, S. I. Serednyakov, Yu. I. Skovpen, E. P. Solodov, K. Yu. Todyshev, A. N. Yushkov, M. Bondioli, S. Curry, D. Kirkby, A. J. Lankford, M. Mandelkern, D. P. Stoker, H. Atmacan, J. W. Gary, F. Liu, O. Long, G. M. Vitug, C. Campagnari, T. M. Hong, D. Kovalskyi, J. D. Richman, C. A. West, A. M. Eisner, J. Kroseberg, W. S. Lockman, A. J. Martinez, T. Schalk, B. A. Schumm, A. Seiden, C. H. Cheng, D. A. Doll, B. Echenard, K. T. Flood, D. G. Hitlin, P. Ongmongkolkul, F. C. Porter, A. Y. Rakitin, R. Andreassen, M. S. Dubrovin, B. T. Meadows, M. D. Sokoloff, P. C. Bloom, W. T. Ford, A. Gaz, M. Nagel, U. Nauenberg, J. G. Smith, S. R. Wagner, R. Ayad, W. H. Toki, H. Jasper, A. Petzold, B. Spaan, M. J. Kobel, K. R. Schubert, R. Schwierz, D. Bernard, M. Verderi, P. J. Clark, S. Playfer, J. E. Watson, D. Bettoni, C. Bozzi, R. Calabrese, G. Cibinetto, E. Fioravanti, I. Garzia, E. Luppi, M. Munerato, M. Negrini, L. Piemontese, R. Baldini-Ferroli, A. Calcaterra, R. de Sangro, G. Finocchiaro, M. Nicolaci, S. Pacetti, P. Patteri, I. M. Peruzzi, M. Piccolo, M. Rama, A. Zallo, R. Contri, E. Guido, M. Lo Vetere, M. R. Monge, S. Passaggio, C. Patrignani, E. Robutti, B. Bhuyan, V. Prasad, C. L. Lee, M. Morii, A. J. Edwards, A. Adametz, J. Marks, U. Uwer, F. U. Bernlochner, M. Ebert, H. M. Lacker, T. Lueck, P. D. Dauncey, M. Tibbetts, P. K. Behera, U. Mallik, C. Chen, J. Cochran, H. B. Crawley, W. T. Meyer, S. Prell, E. I. Rosenberg, A. E. Rubin, A. V. Gritsan, Z. J. Guo, N. Arnaud, M. Davier, D. Derkach, J. Firmino da Costa, G. Grosdidier, F. Le Diberder, A. M. Lutz, B. Malaescu, A. Perez, P. Roudeau, M. H. Schune, A. Stocchi, L. Wang, G. Wormser, D. J. Lange, D. M. Wright, I. Bingham, C. A. Chavez, J. P. Coleman, J. R. Fry, E. Gabathuler, D. E. Hutchcroft, D. J. Payne, C. Touramanis, A. J. Bevan, F. Di Lodovico, R. Sacco, M. Sigamani, G. Cowan, S. Paramesvaran, A. C. Wren, D. N. Brown, C. L. Davis, A. G. Denig, M. Fritsch, W. Gradl, A. Hafner, K. E. Alwyn, D. Bailey, R. J. Barlow, G. Jackson, G. D. Lafferty, R. Cenci, B. Hamilton, A. Jawahery, D. A. Roberts, G. Simi, C. Dallapiccola, E. Salvati, R. Cowan, D. Dujmic, G. Sciolla, D. Lindemann, P. M. Patel, S. H. Robertson, M. Schram, P. Biassoni, A. Lazzaro, V. Lombardo, F. Palombo, S. Stracka, L. Cremaldi, R. Godang, R. Kroeger, P. Sonnek, D. J. Summers, X. Nguyen, P. Taras, G. De Nardo, D. Monorchio, G. Onorato, C. Sciacca, G. Raven, H. L. Snoek, C. P. Jessop, K. J. Knoepfel, J. M. LoSecco, W. F. Wang, L. A. Corwin, K. Honscheid, R. Kass, N. L. Blount, J. Brau, R. Frey, J. A. Kolb, R. Rahmat, N. B. Sinev, D. Strom, J. Strube, E. Torrence, G. Castelli, E. Feltresi, N. Gagliardi, M. Margoni, M. Morandin, M. Posocco, M. Rotondo, F. Simonetto, R. Stroili, E. Ben-Haim, M. Bomben, G. R. Bonneaud, H. Briand, G. Calderini, J. Chauveau, O. Hamon, Ph. Leruste, G. Marchiori, J. Ocariz, S. Sitt, M. Biasini, E. Manoni, A. Rossi, C. Angelini, G. Batignani, S. Bettarini, M. Carpinelli, G. Casarosa, A. Cervelli, F. Forti, M. A. Giorgi, A. Lusiani, N. Neri, E. Paoloni, G. Rizzo, J. J. Walsh, D. Lopes Pegna, C. Lu, J. Olsen, A. J. S. Smith, A. V. Telnov, F. Anulli, G. Cavoto, R. Faccini, F. Ferrarotto, F. Ferroni, M. Gaspero, L. Li Gioi, M. A. Mazzoni, G. Piredda, C. Bünger, T. Hartmann, T. Leddig, H. Schröder, R. Waldi, T. Adye, E. O. Olaiya, F. F. Wilson, S. Emery, G. Hamel de Monchenault, G. Vasseur, Ch. Yèche, M. T. Allen, D. Aston, D. J. Bard, R. Bartoldus, J. F. Benitez, C. Cartaro, M. R. Convery, J. Dorfan, G. P. Dubois-Felsmann, W. Dunwoodie, R. C. Field, M. Franco Sevilla, B. G. Fulsom, A. M. Gabareen, M. T. Graham, P. Grenier, C. Hast, W. R. Innes, M. H. Kelsey, H. Kim, P. Kim, M. L. Kocian, D. W. G. S. Leith, P. Lewis, S. Li, B. Lindquist, S. Luitz, V. Luth, H. L. Lynch, D. B. MacFarlane, D. R. Muller, H. Neal, S. Nelson, C. P. O'Grady, I. Ofte, M. Perl, T. Pulliam, B. N. Ratcliff, S. H. Robertson, A. Roodman, A. A. Salnikov, V. Santoro, R. H. Schindler, J. Schwiening, A. Snyder, D. Su, M. K. Sullivan, S. Sun, K. Suzuki, J. M. Thompson, J. Va'vra, A. P. Wagner, M. Weaver, W. J. Wisniewski, M. Wittgen, D. H. Wright, H. W. Wulsin, A. K. Yarritu, C. C. Young, V. Ziegler, X. R. Chen, W. Park, M. V. Purohit, R. M. White, J. R. Wilson, A. Randle-Conde, S. J. Sekula, M. Bellis, P. R. Burchat, T. S. Miyashita, M. S. Alam, J. A. Ernst, N. Guttman, A. Soffer, P. Lund, S. M. Spanier, R. Eckmann, J. L. Ritchie, A. M. Ruland, C. J. Schilling, R. F. Schwitters, B. C. Wray, J. M. Izen, X. C. Lou, F. Bianchi, D. Gamba, M. Pelliccioni, L. Lanceri, L. Vitale, N. Lopez-March, F. Martinez-Vidal, A. Oyanguren, H. Ahmed, J. Albert, Sw. Banerjee, H. H. F. Choi, K. Hamano, G. J. King, R. Kowalewski, M. J. Lewczuk, C. Lindsay, I. M. Nugent, J. M. Roney, R. J. Sobie, T. J. Gershon, P. F. Harrison, T. E. Latham, E. M. T. Puccio, H. R. Band, S. Dasu, Y. Pan, R. Prepost, C. O. Vuosalo, S. L. Wu
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8 pages, 4 postscript figures, submitted to Phys. Rev. D (Rapid Communications)
Using a sample of 122 million Upsilon(3S) events recorded with the BaBar detector at the PEP-II asymmetric-energy e+e- collider at SLAC, we search for the $h_b(1P)$ spin-singlet partner of the P-wave chi_{bJ}(1P) states in the sequential decay Upsilon(3S) --> pi0 h_b(1P), h_b(1P) --> gamma eta_b(1S). We observe an excess of events above background in the distribution of the recoil mass against the pi0 at mass 9902 +/- 4(stat.) +/- 2(syst.) MeV/c^2. The width of the observed signal is consistent with experimental resolution, and its significance is 3.1sigma, including systematic uncertainties. We obtain the value (4.3 +/- 1.1(stat.) +/- 0.9(syst.)) x 10^{-4} for the product branching fraction BF(Upsilon(3S)-->pi0 h_b) x BF(h_b-->gamma eta_b).
The di-electron width of an Upsilon meson is the decay rate of the Upsilon into an electron-positron pair, expressed in units of energy. We measure the di-electron width of the Upsilon(1S) meson to be 1.354 +- 0.004 +- 0.020 keV (the first uncertainty is statistical and the second is systematic), the di-electron width of the Upsilon(2S) to be 0.619 +- 0.004 +- 0.010 keV and that of the Upsilon(3S) to be 0.446 +- 0.004 +- 0.007 keV. We determine these values with better than 2% precision by integrating the Upsilon production cross-section from electron-positron collisions over their collision e…
We report a measurement of the production ratio of charged and neutral B mesons from Upsilon(4S) decays based on the ratio of efficiency-corrected yields for the charmonium modes J/psi K^+ and J/psi K^{0}_{S} with 81.9 fb^-1 of data collected with the BABAR detector on the Upsilon(4S) resonance at 10.580 GeV. We find a value of 1.006 +/- 0.036 (stat) +/- 0.031 (sys) for the ratio R^{+/0}=Gamma(Upsilon(4S) -> B^+ B^-)/Gamma(Upsilon(4S)->B^0 B^0bar).
We have performed a search for the eta_b(1S) meson in the radiative decay of the Upsilon(2S) resonance using a sample of 91.6 million Upsilon(2S) events recorded with the BABAR detector at the PEP-II B factory at the SLAC National Accelerator Laboratory. We observe a peak in the photon energy spectrum at E_gamma = 609.3 {+4.6} {-4.5} (stat) +/- 1.9 (syst) MeV, corresponding to an eta_b(1S) mass of 9394.2 {+4.8} {-4.9} (stat) +/- 2.0 (syst) MeV/c^2. The branching fraction for the decay Upsilon(2S) --> gamma eta_b(1S) is determined to be [3.9 +/-1.1 (stat) {+1.1} {-0.9} (syst)] x 10^(-4). We fin…
CDF has obtained new results on quarkonium production in p\bar{p} collisions at \sqrt{s} = 1.8 TeV. We report on measurements of Upsilon meson production, Upsilon(1S) production from Chi_b feeddown, and the production polarization of Upsilon(1S), J/Psi and Psi(2S) mesons.
Cross sections for elastic photoproduction of J/Psi and Upsilon mesons are presented. For J/Psi mesons the dependence on the photon-proton centre-of-mass energy W_gammap is analysed in an extended range with respect to previous measurements of 26<=W_gammap<= 285 GeV. The measured energy dependence is parameterized as sigma_gammap proportional W_gammap^delta with delta=0.83+-0.07. The differential cross section dsigma/dt for J/Psi mesons is derived, its dependence on W_gammap and on t is analysed and the effective trajectory (in terms of Regge theory) is determined to be alpha(t)=(1.27+-0.05)+(…
We search for invisible decays of the Upsilon(1S) meson using a sample of 91.4 x 10^{6} Upsilon(3S) mesons collected at the BaBar/PEP-II B-factory. We select events containing the decay Upsilon(3S) -> pi+ pi- Upsilon(1S) and search for evidence of an undetectable Upsilon(1S) decay recoiling against the dipion system. We set an upper limit on the branching fraction BR(Upsilon(1S) -> invisible) < 3.0 x 10^{-4} at the 90% confidence level.
Production of the Upsilon(1S) meson in association with a vector boson is a rare process in the standard model with a cross section predicted to be below the sensitivity of the Tevatron. Observation of this process could signify contributions not described by the standard model or reveal limitations with the current non-relativistic quantum-chromodynamic models used to calculate the cross section. We perform a search for this process using the full Run II data set collected by the CDF II detector corresponding to an integrated luminosity of 9.4/fb. The search considers the Upsilon(1S) to di-mu…
Using 420 pb^-1 of data collected on the Upsilon(5S) resonance with the CLEO III detector, we reconstruct B mesons in 25 exclusive decay channels to measure or set upper limits on the decay rate of Upsilon(5S) into B meson final states. We measure the inclusive B cross-section to be sigma(Y(5S)-->BB(X))=(0.176+-0.030+-0.016) nb and make the first measurements of the production rates of sigma(Y(5S)-->B*B*)=(0.131+-0.025+-0.014) nb and sigma(Y(5S)-->BB*)=(0.043+-0.016+-0.006) nb, respectively. We set 90% confidence level limits of sigma(Y(5S)-->B B-bar)<0.038 nb, sigma(Y(5S)-->B(*)B(*)(pi))<0.05…
Using data collected by the CLEO III detector at CESR, we started a series of investigations on the Upsilon(5S) resonance decay properties. The data sample used for this analysis consists of 0.42 fb-1 of data taken on the Upsilon(5S) resonance, 6.34 fb-1 of data collected on the Upsilon(4S) and 2.32 fb-1 of data taken in the continuum below the Upsilon(4S). B_s mesons are expected to decay predominantly into D_s meson, while the lighter B mesons decay into D_s only about 10% of the time. We exploit this difference to make a preliminary model dependent estimate of the ratio of B_s(*) anti-B_s(*…
We use data collected by the CLEO III detector at CESR on the Upsilon(5S) resonance to measure the inclusive yield of Ds mesons. Comparing with data taken on the Upsilon(4S), which decays into lighter B mesons, we make a model dependent estimate of the ratio of Bs(*)anti-Bs(*) to the total b anti-b quark pair production at the Upsilon(5S) energy of (16.0+/-2.6+/-5.8)%.
Pair production of Upsilon(1S) mesons is observed at the LHC in proton-proton collisions at sqrt(s) = 8 TeV by the CMS experiment in a data sample corresponding to an integrated luminosity of 20.7 inverse femtobarns. Both Upsilon(1S) candidates are fully reconstructed via their decays to mu+ mu-. The fiducial acceptance region is defined by an absolute Upsilon(1S) rapidity smaller than 2.0. The fiducial cross section for the production of Upsilon(1S) pairs, assuming that both mesons decay isotropically, is measured to be 68.8 +/- 12.7 (stat) +/- 7.4 (syst) +/- 2.8 (B) pb, where the third uncer…
Using data taken with the CLEO III detector, 1.09 fb-1 at Upsilon(1S), and 1.28 fb-1 at Upsilon(2S), branching fractions have been measured for the first time for exclusive decays of each resonance into one hundred different final states consisting of 4 to 10 light hadrons, pions, kaons, and protons. Significant strength is found in 73 decay modes of Upsilon(1S) and 17 decay modes of Upsilon(2S), with branching fractions ranging from 0.3x10^-5 to 110x10^-5. Upper limits at 90% confidence level are presented for the other decay modes.
We study transitions between Upsilon states with the emission of charged pions using 604.6/fb of data collected with the Belle detector at the KEKB asymmetric-energy e+e- collider. The measured product branching fraction is B(Upsilon(4S) -> Upsilon(1S)pi+pi-) * B(Upsilon(1S) -> mu+mu-) = = (2.11 +/- 0.30(stat.) +/- 0.14(sys.))*10^(-6) and the partial decay width is Gamma(Upsilon(4S) -> Upsilon(1S)pi+pi-) = = (1.75 +/- 0.25(stat.) +/- 0.24(sys.)) keV.
We present a measurement of the branching fraction of invisible Upsilon(1S) decays, using 1.2 fb^{-1} of data collected at the Upsilon(2S) resonance with the CLEO III detector at CESR. After subtracting expected backgrounds from events that pass selection criteria for invisible Upsilon(1S) decay in Upsilon(2S) -> pi+ pi- Upsilon(1S), we deduce a 90% C.L. upper limit of B[Upsilon(1S) -> invisible] < 0.39%.
We present measurements of decay matrix elements for hadronic transitions of the form Upsilon(nS) -> pi pi Upsilon(mS) where (n, m) = (3, 1), (2, 1), and (3, 2). We reconstruct charged and neutral pion modes with the final state Upsilon decaying to either mu+mu- or e+e-. Dalitz plot distributions for the twelve decay modes are fit individually as well as jointly assuming isospin symmetry, thereby measuring the matrix elements of the decay amplitude. We observe and account for the anomaly previously noted in the di-pion invariant mass distribution for the Upsilon(3S) -> pi pi Upsilon(1S) transi…
Using data collected with the CLEO-III detector at the CESR e+e- collider, we report on a first observation of the decay of the Upsilon(3S) to tau tau, and precisely measure the ratio of branching fractions of Upsilon(nS),n=1,2,3 to tau tau and mu mu final states, finding agreement with expectations from lepton universality. We derive absolute branching fractions for these decays, and also set a limit on the influence of a low mass CP-odd Higgs boson in the decay of the Upsilon(1S).
We study transitions between Upsilon states with the emission of charged pions using 477 fb^{-1} of data collected with the Belle detector at the KEKB asymmetric-energy e+ e- collider. We select inclusive Upsilon(4S) -> mu+ mu- pi+ pi- X events (where X represents anything) and observe a peak in the distribution of the mass difference Delta M = (M(mu+mu-pi+pi-) -M(mu+mu-)). This peak, at Delta M = (1119.2 +/- 0.4) MeV/c^2, is identified as a signal for the decay Upsilon(4S) -> Upsilon(1S) pi+ pi- with a subsequent transition Upsilon(1S) -> mu+ mu-. The measured product branching fraction BR(Up…
The ratio of charged and neutral B meson production at the Upsilon(4S), f_{+-}/f_{00}, is measured through the decays B bar -> D* l- nu_l bar, reconstructed using a partial reconstruction method where the D* is detected only through a pion daughter from the decay D* -> D pi. Using data collected by the CLEO II detector, the charged and neutral B decays are measured in such a way that their ratio is independent of decay model, limited mainly by the uncertainty in the relative efficiency for detecting neutral and charged pions. This measurement yields the ratio of production fractions times the …
We search for a low-mass scalar CP-odd Higgs boson, A0, produced in the radiative decay of the Upsilon resonance and decaying into a tau+tau- pair: Upsilon(1S)->gamma A0. The production of Upsilon(1S) mesons is tagged by Upsilon(2S)->pi+pi-Upsilon(1S) transitions, using a sample of (98.3+/-0.9) million Upsilon(2S) mesons collected by the BaBar detector. We find no evidence for a Higgs boson in the mass range 3.5 GeV<= m(A0)<=9.2 GeV, and combine these results with our previous search for the tau decays of the light Higgs in radiative Upsilon(3S) decays, setting limits on the coupling of A0 to …
In this paper we present two searches for new physics in Upsilon(3S) decays collected by the BABAR detector. We search for charged lepton-flavour violating decays of the Upsilon(3S), which are unobservable in the Standard Model but are predicted to occur in several beyond-the-Standard Model scenarios. We also search for production of a light Higgs or Higgs-like state produced in radiative decays of the Upsilon(3S) and decaying to muon pairs.
Charged lepton-flavor violating processes are extremely rare in the Standard Model, but they may occur in several beyond-the-Standard Model theories, including Supersymmetry or models with leptoquarks or compositeness. We present a search for such processes in a sample of 117M Upsilon(3S) decays recorded with the BaBar detector. We place upper limits on the branching fractions BF(Upsilon(3S) -> e tau) < 5.0e-6 and BF(Upilon(3S) -> mu tau) < 4.1e-6 at 90% confidence level. These results are used to place lower limits on the mass scale of beyond-the-Standard Model physics contributing to lepton-…
Using the CLEO III detector we report on a new study of exclusive radiative Upsilon(1S) decays into the final states gamma pi^+ pi^-, gamma K^+ K^- and gamma p anti-p. We present branching ratios for the decay modes Upsilon(1S) to gamma f_2(1270), Upsilon(1S) to gamma f_2'(1525), and Upsilon(1S) to gamma f_0(1710) with f_0(1710) to K^+ K^-.
Based on data collected by the CLEO III detector at CESR, we started a series of investigations to open the mysteries of the $Υ$(5S) resonance decay properties. $B_s$ mesons are expected to decay predominantly into $D_s$ meson, while the lighter $B$ mesons decay into $D_s$ only about 10% of the time. We exploit this difference to present the first evidence of a substantial production of $B_s$ mesons at the $Υ$(5S) resonance. We make here a preliminary model dependent estimate of the ratio of $B_s^{(*)}\bar{B}_s^{(*)}$ to the total $b\bar{b}$ quark pair production at the $Υ$(5S) energy to be $(…
Using the Belle detector operating at the KEKB e+e- storage ring, we have measured the mean multiplicity and the momentum spectrum of neutral pions from the decays of the Upsilon(4S) resonance. We measure a mean of 4.70 +/- 0.04 +/- 0.22 neutral pions per Upsilon(4S) decay.
Using data taken with the CLEO III detector at the Cornell Electron Storage Ring, we have investigated the direct photon spectrum in the decays Upsilon(1S) -> gggamma, Upsilon(2S) -> gggamma, Upsilon}(3S) -> gggamma. The latter two of these are first measurements. Our analysis procedures differ from previous ones in the following ways: a) background estimates (primarily from pi^0 decays are based on isospin symmetry rather than a determination of the pi^0 spectrum, which permits measurement of the Upsilon(2S) and Upsilon(3S) direct photon spectra without explicit corrections for pi^0 backgroun…
I present two analyses done with the CLEOIII detector at CESR. The first is a search for the Lepton Flavor Violating decay Upsilon to mu tau, with preliminary results, and the second constrains Lepton Universality in Upsilon to tau tau relative to Upsilon to mu mu. This second analysis, whose results are final, has dramatically improved uncertainties relative to other such measurements, and is also the first observation of the decay Upsilon(3S) to tau tau. A limit is also set on the involvement of a CP odd Higgs in the decay of the Upsilon(1S) to tau pairs.
Using data obtained with the CLEO~III detector, running at the Cornell Electron Storage Ring (CESR), we report on a new study of exclusive radiative Upsilon(1S) decays into the final states gamma pi^+ pi^-, gamma K^+ K^-, and gamma p pbar.. We present branching ratio measurements for the decay modes Upsilon(1S) to gamma f_2(1270), Upsilon(1S) to gamma f_2'(1525), and Upsilon(1S) to gamma K^+K^-; helicity production ratios for f_2(1270) and f_2'(1525); upper limits for the decay Upsilon(1S) to gamma f_J(2200), with f_J(2220) to pi^+ pi^-, K^+ K^-, p pbar; and an upper limit for the decay Upsilo…
We report preliminary measurements of the exclusive charmless semileptonic branching fractions of the B+ --> eta l+ nu and B+ --> eta' l+ nu decays. These measurements are based on 316 fb-1 of data collected at the Y(4S) resonance by the BABAR detector. In events in which the decay of one B meson to a hadronic final state is fully reconstructed, the semileptonic decay of the recoiling B meson is identified by the detection of a charged lepton and an eta or eta'. We measure the branching fraction BR(B+ --> eta l+ nu) = (0.84 +/- 0.27 +/- 0.21) x 10-4, where the first error is statistical and th…
Using 1.8 fb-1 of pp collisions at a center-of-mass energy of 7 TeV recorded by the ATLAS detector at the Large Hadron Collider, we present measurements of the production cross sections of Upsilon(1S,2S,3S) mesons. Upsilon mesons are reconstructed using the di-muon decay mode. Total production cross sections for p_T<70 GeV and in the rapidity interval |Upsilon|<2.25 are measured to be 8.01+-0.02+-0.36+-0.31 nb, 2.05+-0.01+-0.12+-0.08 nb, 0.92+-0.01+-0.07+-0.04 nb respectively, with uncertainties separated into statistical, systematic, and luminosity measurement effects. In addition, differenti…
Using a sample of 122 million Upsilon(3S) decays collected with the BaBar detector at the PEP-II asymmetric energy collider at the SLAC National Accelerator Laboratory, we measure the ratio R_taumu=BR(Upsilon(1S)->tau^+tau^-)/BR(Upsilon(1S)->mu^+mu^-); the measurement is intended as a test of lepton universality and as a possible search for a light pseudoscalar Higgs boson in Next to Minimal Supersymmetric Standard Model (NMSSM) scenarios. Such a boson could appear in a deviation of the ratio R_taumu from the Standard Model expectation, that is 1, except for small lepton mass corrections. The …
We search for single-photon decays of the Upsilon(1S) resonance, Upsilon->gamma+invisible, where the invisible state is either a particle of definite mass, such as a light Higgs boson A0, or a pair of dark matter particles, chi chi-bar. Both A0 and chi are assumed to have zero spin. We tag Upsilon(1S) decays with a dipion transition Upsilon(2S)->pi+pi-Upsilon(1S) and look for events with a single energetic photon and significant missing energy. We find no evidence for such processes in the mass range m_A0<=9.2 GeV and m_chi<=4.5 GeV in the sample of 98e6 Upsilon(2S) decays collected with the B…
Using the CLEO detector at the Cornell Electron Storage Ring, we have observed the Bs meson in e+e- annihilation at the Upsilon(5S) resonance. We find 14 candidates consistent with Bs decays into final states with a J/psi or a Ds(*)-. The probability that we have observed a background fluctuation is less than 8x10e-10. We have established that at the energy of the Upsilon(5S) resonance Bs meson production proceeds predominantly through the creation of Bs*Bs* pairs. We find sigma(e+e- -> Bs*Bs*) = [0.11 (+0.04-0.03)(stat.)+/-0.02(syst.)] nb, and set the following limits: sigma(e+e- -> BsBs) / s…
We present the analysis technique and preliminary results of two ongoing analyses at CLEO which put lepton universality and lepton flavor conservation to the test in Upsilon decays.
Using CLEO data, we study the production of the anti-deuteron, d-bar, in Upsilon(nS) resonance decays and the nearby continuum. The branching ratios obtained are B^dir(Upsilon(1S) --> d-bar X) = (3.36 +- 0.23 +- 0.25) x 10^-5, B(Upsilon(1S) --> d-bar X) = (2.86 +- 0.19 +- 0.21) x 10^-5, and B(Upsilon(2S) --> d-bar X) = (3.37 +- 0.50 +- 0.25) x 10^-5, where the `dir' superscript indicates that decays produced via re-annihilation of the b bbar pair to a gamma* are removed from both the signal and the normalizing number of Upsilon(1S) decays in order to isolate direct decays of the Upsilon(1S) to…
Bound upsilon states and their decays provide a unique laboratory for testing QCD, LQCD, and quarkonium potential models. I review recent results, some of which are significant improvements in precision over previous measurements and others are first-time observations. While most of the results presented are from CLEO III there are also notable contributions from BaBar and Belle who have just begun to exploit their strong capabilities for studying bound state upsilons.
Semileptonic decays of B mesons may be used in many different ways to probe the CKM matrix. Presented here are several recent results from the CLEO II experiment, all involving the analysis or utilization of semileptonic B decays.
The angular distributions of Upsilon(1S) to mu+ mu- decays are analyzed using a sample of Upsilon(1S) mesons in 2.9 fb^{-1} of data collected at sqrt{s} = 1.96TeV. The results of the one-dimensional angular analysis suggest that Upsilon(1S) may be longitudinal polarized at high transverse momentum. This observation is largely inconsistent with NRQCD prediction that predicts transverse polarization at high p_T.
We search for a light scalar particle produced in single-photon decays of the Upsilon(3S) resonance through the process Upsilon(3S) -> gamma A0, A0 -> invisible. Such an object appears in Next-to-Minimal Supersymmetric extensions of the Standard Model, where a light CP-odd Higgs boson naturally couples strongly to b-quarks. If, in addition, there exists a light, stable neutralino, decays of A0 could be preferentially to an invisible final state. We search for events with a single high-energy photon and a large missing mass, consistent with a 2-body decay of Upsilon(3S). We find no evidence for…
We search for evidence of a light scalar boson in the radiative decays of the Upsilon(2S) and Upsilon(3S) resonances: Upsilon(2S,3S)-> gamma A0, A0 -> mu^+ mu^-. Such a particle appears in extensions of the Standard Model, where a light CP-odd Higgs boson naturally couples strongly to b-quarks. We find no evidence for such processes in the mass range 0.212<= m(A0)<= 9.3 GeV in the samples of 99*10^6 Upsilon(2S) and 122*10^6 Upsilon(3S) decays collected by the BABAR detector at the PEP-II B-factory and set stringent upper limits on the effective coupling of the b quark to the A0. We also limit …
I present highlights of recent CLEO studies on the Upsilon(1S), Upsilon(2S), and Upsilon(3S). The preliminary results presented here include the first observation of a hadronic cascade in the Upsilon system not involving pions, Upsilon(3S) to gamma chi(b1,2)(2P) followed by chi(b1,2)(2P) to omega Upsilon(1S). I also present preliminary results on a search for inclusive psi production in Upsilon(1S) decays. I end with a search for nine different two body hadronic decays of the Upsilon(nS), n=1,2,3, resulting in the discovery of two such decays, and vastly improved upper limits on the branching …
Using data corresponding to an integrated luminosity of 1.3 fb^-1, we observe a narrow mass state decaying into Upsilon(1S)+gamma, where the Upsilon(1S) meson is detected by its decay into a pair of oppositely charged muons, and the photon is identified through its conversion into an electron-positron pair. The significance of this observation is 5.6 standard deviations. The mass of the state is centered at 10.551 \pm 0.014 (stat.) \pm 0.017 (syst.) GeV/c^2, which is consistent with that of the state recently observed by the ATLAS Collaboration.
We study the properties of charmed, nonstrange, $\rm D$ mesons produced in continuum $\rm {e^+}{e^-}$ annihilations. The $ \rm {e^+}{e^-}$ collisions were generated in the energy region of the $ \rm Υ(3S)$ and $ \rm Υ(4S)$ resonances by the Cornell Electron Storage Ring, and were analyzed by the CLEO detector. We make extensive study of the decay topology $\rm D^0, D^+ \rightarrow \overline{\rm K}^{_{_0}}X$, where the $\overline{\rm K}^{_{_0}}$ is observed in the final state $\rm K^{0}_{S} \rightarrow π^+π^-$. The decay $ \rm D^+ \rightarrow K^- π^+π^-$ is also considered. We analyze the hadro…
We report on a search for the radiative decay of Upsilon(1S) to the pseudoscalar mesons eta and etaprime in 21.2 +/- 0.2 times 10^6 Upsilon(1S) decays collected with the CLEO III detector at the Cornell Electron Storage Ring (CESR). The eta meson was reconstructed in the three modes eta to gamma-gamma, eta to pi+pi-pi0 and eta to 3pi0. The etaprime meson was reconstructed in the mode etaprime to pi+ pi- eta with eta decaying through any of the above three modes, and also etaprime to gamma rho, where rho decays to pi^+ pi^-. Five out of the seven sub-modes are found to be virtually background-f…
We have investigated the invariant mass spectrum of dimuons collected by the CDF experiment during the 1992-1995 run of the Fermilab Tevatron collider to improve the limit on the existence of narrow resonances set by the experiments at the SPEAR e+e- collider. In the mass range 6.3-9.0 GeV/c^2, we derive 90% upper credible limits to the ratio of the production cross section times muonic branching fraction of possible narrow resonances to that of the Y(1S) meson. In this mass range, the average limit varies from 1.7 to 0.5%. This limit is much worse at the mass of 7.2 GeV/c^2 due to an excess o…
The chi_b(nP) quarkonium states are produced in proton-proton collisions at the Large Hadron Collider (LHC) at sqrt(s) = 7 TeV and recorded by the ATLAS detector. Using a data sample corresponding to an integrated luminosity of 4.4 fb^-1, these states are reconstructed through their radiative decays to Upsilon(1S,2S) with Upsilon->mu+mu-. In addition to the mass peaks corresponding to the decay modes chi_b(1P,2P)->Upsilon(1S)gamma, a new structure centered at a mass of 10.530+/-0.005 (stat.)+/-0.009 (syst.) GeV is also observed, in both the Upsilon(1S)gamma and Upsilon(2S)gamma decay modes. Th…
Using CLEO data, we report on the confirmation of the eta_b(1S0) ground state of bottomonium in the radiative decay Upsilon(3S) -> gamma eta_b. We determine its mass to be M(eta_b) = 9391.8 +- 6.6 +- 2.1 MeV, which corresponds to the hyperfine splitting Delta M_hf(1S) = 68.5 +- 6.6 +- 2.0 MeV, and the branching fraction B(Upsilon(3S) -> gamma eta_b) = (7.1 +- 1.8 +- 1.1) x 10^-4. These results agree with those previously reported by BaBar.
We present an improved measurement of the eta' meson energy spectrum in Upsilon(1S) decays, using 1.2 fb^{-1}} of data taken at the Upsilon(1S) center-of-mass energy with the CLEO III detector. We compare our results with models of eta' gluonic form factor that have been suggested to explain the unexpectedly large B to eta' X_s rate. Models based on perturbative QCD fail to fit the data for large eta' energies, showing that Standard Model strong interaction dynamics is not likely to provide an explanation for the large rate of high energy eta' observed in B decays.
Data on e+e- -> piplus-piminus-Upsilon(1S,2S,3S) show a large increase in branching fractions near Upsilon(10860). A suggestion of Ali et al. is to interpret this as evidence for a tetraquark, Yb(10890) = b-bbar. However, it may also be interpreted in terms of Upsilon(10860) -> B-B*, B*B* and BsB*s above the open-b threshold, followed by de-excitation processes such as $BB* -> Upsilon (1S,2S,3S). In the charm sector, a hypothesis open to experimental test is that X,Y and Z peaks in the mass range 3872 to 3945 MeV may all be due to regular 3P1 and 3P2 c-cbar states (and perhaps 3P0) mixed with …
We study the Upsilon(3S,2S)->eta Upsilon(1S) and Upsilon(3S,2S)->pi+pi- Upsilon(1S) transitions with 122 million Upsilon(3S) and 100 million Upsilon(2S) mesons collected by the BaBar detector at the PEP-II asymmetric energy e+e- collider. We measure B[Upsilon(2S)->eta Upsilon(1S)]=(2.39+/-0.31(stat.)+/-0.14(syst.))10^-4 and Gamma[Upsilon(2S)->eta Upsilon(1S)]/Gamma[Upsilon(2S)-> pi+pi- Upsilon(1S)]=(1.35+/-0.17(stat.)+/-0.08(syst.))10^-3. We find no evidence for Upsilon(3S)->eta Upsilon(1S) and obtain B[Upsilon(3S)->eta Upsilon(1S)]<1.0 10^-4 and Gamma[Upsilon(3S)->eta Upsilon(1S)]/Gamma[Upsil…
I detail recent work done by the CLEO collaboration using data gathered at the CESR accelerator concerning the Upsilon system. Results include B_S production at the Upsilon(5S), decays of the Upsilon(nS) (n=1,2,3) to tau pairs, the Upsilon di-electron width, decays of the Upsilon to two hadrons and a photon, and the observation of the first di-pion transition between chi_b states.
We have searched for the bottomonium eta_b(1S) via the hindered magnetic dipole (M1) photon transition Upsilon(3S) -> gamma eta_b(1S). No evidence for such a transition is found in the data sample of 4.7 x 10^6 Upsilon(3S)'s collected with the CLEO-III detector. We set upper limits on the branching ratio from 9.30 to 9.43 GeV/c^2 of eta_b(1S) masses. These upper limits rule out many previously published phenomenological estimates of the rate for this transition.
In this Letter we describe a search for lepton flavor violation (LFV) in the bottomonium system. We search for leptonic decays of Upsilon(nS)(n=1,2, and 3) into muon and tau using the data collected with the CLEO III detector. We identify the tau lepton using its leptonic decay into electron and utilize multidimensional likelihood fitting with PDF shapes measured from independent data samples. We report our estimates of 95% CL upper limits on LFV branching fractions of Upsilon mesons. We interpret our results in terms of the exclusion plot for the energy scale of a hypothetical new interaction…
We report on a study of exclusive radiative decays of the Upsilon(1S) resonance into the final states gamma pi^0 pi^0, gamma eta eta and gamma pi^0 eta, using 1.13 inverse femto-barn of e^+ e^- annihilation data collected at sqrt(s)= 9.46 GeV with the CLEO III detector operating at the Cornell Electron Storage Ring. In the channel gamma pi^0 pi^0, we measure the branching ratio for the decay mode Upsilon(1S) to gamma f_2(1270) to be (10.5 \pm 1.6 (+ 1.9)(-1.8)) x 10^-5. We place upper limits on the product branching ratios for the isoscalar resonances f_0(1500) and f_0(1710) for the pi^0 pi^0 …
Using data collected using the CLEO III detector, we present recent results on decays of the $Υ(1S)-Υ(3S)$ resonances. We report on three analyses. They are: (1) improved measurements of the muonic branching fraction of the $Υ(1S)-Υ(3S)$, (2) precision measurements of $Υ(2S)$ and $Υ(3S)$ photonic transitions, and (3) new measurements of $Υ(1S)$ decays to charmonium final states.}]
We report results of a search for the invisible decay of the Upsilon(1S) via the Upsilon(3S)->pi+pi-Upsilon(1S) transition using a data sample of 2.9 fb^{-1} at the Upsilon(3S) resonance. The data were collected with the Belle detector at the KEKB asymmetric-energy e+e- collider. No signal is found, and an upper limit for the branching fraction at the 90% confidence level is determined to be B(Upsilon(1S)->invisible) < 2.5x10^{-3}.
Recent CLEO results on the observation of the $Υ(1D)$ state and a search for the $η_b(1S)$ state from a data sample of $4.7 \times 10^6\,Υ(3S)$ decays collected with the CLEO-III detector, and a measurement of the $η^{\prime}$ production spectrum using $1.9 \times 10^6\,Υ(1S)$ decays collected with the CLEO-II detector are described.
We search for a non-SM-like CP-odd Higgs boson (a0_1) with m(a0_1)< 2m(b) in radiative decays of the Upsilon(1S), using 21.5M Upsilon(1S) mesons directly produced in e+e- annihilation. We investigate a0_1 --> tau+tau- and a0_1 --> mu+mu- decay channels. No significant signal is found. We obtain upper limits on the product of B(Upsilon(1S)-->gamma a0_1) and B(a0_1-->tau+tau-) or B(a0_1-->mu+mu-). Our tau+tau- results are almost two orders of magnitude more stringent than previous upper limits. Our data provide no evidence for a Higgs state with a mass of 214 MeV decaying to mu+mu-. Existence of…
We report a preliminary branching fraction of (1.80 +/- 0.37(stat.) +/- 0.23(syst.)) x 10^-4 for the charmless exclusive semileptonic B+ -> pi0 l+ nu decay, where l can be either a muon or an electron. This result is based on data corresponding to an integrated luminosity of 81 fb^-1 collected at the Upsilon(4S) resonance with the BABAR detector. The analysis uses BBbar events that are tagged by a B meson reconstructed in the semileptonic B- -> D0 l- nubar (X) decays, where X can be either a gamma or a pi0 from a D* decay.
We report the results of a search for the bottomonium ground state eta_b(1S) in the photon energy spectrum with a sample of (109 +/- 1) million of Upsilon(3S) recorded at the Upsilon(3S) energy with the BABAR detector at the PEP-II B factory at SLAC. We observe a peak in the photon energy spectrum at E_gamma = 921.2 {+2.1} {-2.8} (stat) +/- 2.4(syst) MeV with a significance of 10 standard deviations. We interpret the observed peak as being due to monochromatic photons from the radiative transition Upsilon(3S) -> gamma eta_b(1S). This photon energy corresponds to an eta_b(1S) mass of $9388.9 {+…
Motivated by concerns regarding possible two-body contributions to the recently-measured inclusive Upsilon(nS)->gamma+X (n=1, 2, 3) direct photon spectra, we report on a new study of exclusive radiative decays of these narrow Upsilon(nS) resonances into two-body final states R+gamma, with R a narrow resonant hadronic state decaying into four or more charged particles. Such two-body processes are not explicitly addressed in the extant theoretical frameworks used to calculate the inclusive direct photon spectra, and must also be explicitly inserted into Monte Carlo simulations. Using data collec…
