D. Ugolini
A5053921287- Pulsars and Gravitational Waves Research
- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- Gamma-ray bursts and supernovae
- Geophysics and Gravity Measurements
- Astrophysical Phenomena and Observations
- High-Energy Particle Collisions Research
- Cosmology and Gravitation Theories
- Dark Matter and Cosmic Phenomena
- Geophysics and Sensor Technology
- Astrophysics and Cosmic Phenomena
- Neutrino Physics Research
- Atomic and Subatomic Physics Research
- Seismic Waves and Analysis
- Advanced Frequency and Time Standards
- Radio Astronomy Observations and Technology
- Astronomical Observations and Instrumentation
- Statistical and numerical algorithms
- High-pressure geophysics and materials
- Superconducting Materials and Applications
- Black Holes and Theoretical Physics
- Particle Accelerators and Free-Electron Lasers
- Computational Physics and Python Applications
- Cold Atom Physics and Bose-Einstein Condensates
- Magnetic confinement fusion research
Trinity University
2013-2024
University of California, Berkeley
2014
Lawrence Berkeley National Laboratory
2014
California Institute of Technology
1998-2011
Cardiff University
2011
Carleton College
2011
Andrews University
2011
Australian National University
2011
Charles Sturt University
2011
LIGO Scientific Collaboration
2011
We report on a study of the invariant mass spectrum hadronic system in decay ${\ensuremath{\tau}}^{\ensuremath{-}}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{0}{\ensuremath{\nu}}_{\ensuremath{\tau}}.$ This was performed with data obtained CLEO II detector operating at CESR ${e}^{+}{e}^{\ensuremath{-}}$ collider. present fits to phenomenological models which resonance parameters associated $\ensuremath{\rho}(770)$ and $\ensuremath{\rho}(1450)$ mesons are...
In a sample of 19 million produced B mesons, we have observed the decays -> eta K* and improved our previous measurements eta'K. The branching fractions measure for these decay modes are BR(B+ K*+) = (26.4 +9.6-8.2 +- 3.3) x $10^{-6}$, BR(B0 K*0) (13.8 +5.5-4.6 1.6) eta' K+) (80 +10-9 7) $10^{-6}$ K0) (89 +18-16 9) $10^{-6}$. We searched with comparable sensitivity related report upper limits fractions.
We report results of searches for charmless hadronic B meson decays to pseudoscalar( pi(+/-), K+/-, pi(0), or K(0)(S))-vector( rho, K(*), omega) final states. By using 9.7x10(6) BB pairs collected with the CLEO detector, we first observation B(-)--->pi(-)rho(0), B(0)-->pi(+/-)rho(-/+), and B(-)-->pi(-)omega, which are expected be dominated by b-->u transitions. The measured branching fractions (10.4(+3.3)(-3.4)+/-2.1)x10(-6), (27.6(+8.4)(-7.4)+/-4.2)x10(-6), (11.3(+3.3)(-2.9)+/-1. 4)x10(-6),...
We search for CP-violating charge asymmetries (alpha(CP)) in the B meson decays to K(+/-)pi(-/+), K(+/-)pi(0), K(0)(S)pi(+/-), K(+/-)eta('), and omega pi(+/-). Using 9.66 million upsilon(4S) collected with CLEO detector, statistical precision on alpha(CP) is range of +/-0.12 +/-0.25 depending decay mode. While up +/-0.5 are possible within standard model, measured consistent zero all five modes studied.
We have studied charmless hadronic decays of $B$ mesons into two-body final states with kaons and pions observe three new processes the following branching fractions: $B(B\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}})\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}({4.3}_{\ensuremath{-}1.4}^{+1.6}\ifmmode\pm\else\textpm\fi{}0.5)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$,...
The resonant structure of the four pion final state in decay →τ3ππ0ντ has been analyzed using 4.27 million τ+τ− pairs collected by CLEO II experiment at Cornell Electron Storage Ring. A partial wave analysis performed; spectral decomposition system is dominated ωπ and a1π states. mass width ρ′ resonance have extracted from a fit to →τωπντ function. We searched for second class currents spin-parity established an upper limit on non-vector current contribution.Received 30 September...
We present an update of the search for lepton family number violating decay $\stackrel{\ensuremath{\rightarrow}}{\ensuremath{\tau}}\ensuremath{\mu}\ensuremath{\gamma}$ using 12.6 million ${\ensuremath{\tau}}^{+}{\ensuremath{\tau}}^{\ensuremath{-}}$ pairs collected with CLEO detector. No evidence a signal has been found and corresponding upper limit is...
In a sample of $9.66\times 10^6 B\bar{B}$ pairs collected with the CLEO detector we make first observation B decays to an $\eta_c$ and kaon. We measure branching fractions $BR(B^+\to\eta_c K^+) = (0.69 + 0.26 - 0.21 +- 0.08 0.20)\times 10^{-3}$ $BR(B^0\to\eta_c K^0) (1.09 0.55 0.42 0.12 0.31)\times 10^{-3}$, where error is statistical, second systematic third from fraction uncertainty. From these extract decay constant in factorization approximation, $f_{\eta_c} 335 75$ MeV. also search for...
Using the CLEO detector at Cornell Electron Storage Ring, we have made a measurement of R=sigma(e+e- ->hadrons)/sigma(e+e- ->mu+mu-) =3.56+/-0.01+/-0.07 ECM=10.52 GeV. This implies value for strong coupling constant alpha_s(10.52 GeV)=0.20+/-0.01+/-0.06, or alpha_s(M_Z)=0.13+/-0.005+/-0.03.
We have searched for two-body charmless decays of B mesons to purely hadronic exclusive final states including $\omega$ or $\phi$ using data collected with the CLEO II detector. With this sample $6.6 \times 10^6$ we observe a signal $\omega K^+$ state, and measure branching fraction B($B^+ \to \omega K^+$) = 1.5 +0.7 -0.6 +-0.2 $\times 10^{-5}$. also some evidence $\phi K^*$ upper limits are given 22 other decay modes. These results provide opportunity studies theoretical models physical parameters.
Using data taken with the CLEO II detector at Cornell Electron Storage Ring, we present first full angular analysis in color-suppressed modes B0→J/ψK*0 and B+→J/ψK*+. This leads to a complete determination of decay amplitudes these including longitudinal polarization γL/γ=0.52±0.07±0.04 P wave component |P|2=0.16±0.08±0.04. In addition, update branching fractions for B→J/ψK B→J/ψK∗.Received 24 February 1997DOI:https://doi.org/10.1103/PhysRevLett.79.4533©1997 American Physical Society
We report the first observation of $B\to \eta' X$ transitions with high momentum $\eta'$ mesons. observe $39.0\pm 11.6$ B decay events $2.0< p_{\eta'} < 2.7$ GeV/c, region where background from $b\to c$ processes is suppressed. discuss physical interpretation signal, including possibility that it due to s g^*$ transitions. Given interpretation, we find ${\cal B}(B\to X_s) = (6.2 \pm 1.6(stat) 1.3(sys)^{+0.0}_{-1.5}(bkg))\times 10^{-4} $ for $2.0<p_{\eta'}<2.7$ GeV/c.
We report the first observation of two narrow charmed strange baryons decaying to $\Xi_c^+\gamma$ and $\Xi_c^0\gamma$, respectively, using data from CLEO II detector at CESR. interpret observed signals as $\Xi_c^{+\prime}(c{su})$ $\Xi_c^{0\prime}(c{sd})$, symmetric partners well-established antisymmetric $\Xi_c^+(c[su])$ $\Xi_c^0(c[sd])$. The mass differences $M(\Xi_c^{+\prime})-M(\Xi_c^+)$ $M(\Xi_c^{0\prime})-M(\Xi_c^0)$ are measured be $107.8\pm 1.7\pm 2.5$ $107.0\pm 1.4\pm 2.5 MeV/c^2$,...
Using data recorded by the CLEO-II detector at CESR, we report evidence of a pair excited charmed baryons, one decaying into Λ+cπ+ and other Λ+cπ−. The doubly charged state has measured mass difference M(Λ+cπ+)−M(Λ+c) 234.5±1.1±0.8 MeV/c2 width 17.9+3.8−3.2±4.0MeV/c2, neutral M(Λ+cπ−)−M(Λ+c) 232.6±1.0±0.8 13.0+3.7−3.0±4.0MeV/c2. We interpret these as Σ*++c Σ*0c, spin 32+ excitations Σc baryons.Received 26 September 1996DOI:https://doi.org/10.1103/PhysRevLett.78.2304©1997 American Physical Society
We have searched for the effective FCNC decays b->s l+l- using an inclusive method. set upper limits on branching ratios B(b->s e+e-) < 5.7 10^{-5}, mu+mu-) 5.8 and e+-mu-+) 2.2 10^{-5} (at 90 %\ C.L.). Combining di-electron di-muon decay modes we find: l+l-) 4.2 %
We have studied semileptonic B meson decays with a p-wave charm in the final state using 3.29×106 BB¯ events collected CLEO II detector at Cornell Electron-Positron Storage Ring. find value for exclusive product branching fraction B(B−→D10ℓ−ν¯ℓ)B(D10→D*+π−)=(0.373±0.085±0.052±0.024)% and an upper limit B(B−→D2*0ℓ−ν¯ℓ)B(D2*0→D*+π−)<0.16% (90% C.L.). Furthermore, we present first measurement of q2 spectrum B−→D10ℓ−ν¯ℓ.Received 18 August 1997DOI:https://doi.org/10.1103/PhysRevLett.80.4127©1998...
A search for the lepton-family-number-violating decays τ→eγ and τ→μγ has been performed using CLEO II data. No evidence of a signal found corresponding upper limits are B(τ→eγ)<2.7×10−6 B(τ→μγ)<3.0×10−6 at 90% C.L.Received 12 November 1996DOI:https://doi.org/10.1103/PhysRevD.55.R3919©1997 American Physical Society
We have observed new channels for τ decays with an η in the final state. study 3-prong tau decays, using η→γγ and η→3π0 decay modes 1-prong two π0's channel. The measured branching fractions are B(τ−→π−π−π+ηντ)=(3.4−0.5+0.6±0.6)×10−4 B(τ−→π−2π0ηντ)=(1.4±0.6±0.3)×10−4. observe clear evidence f1→ηππ substructure measure B(τ−→f1π−ντ)=(5.8−1.3+1.4±1.8)×10−4. also searched η′(958) production obtain 90% C.L. upper limits B(τ−→π−η′ντ)<7.4×10−5 B(τ−→π−π0η′ντ)<8.0×10−5.Received 25 June...
Using a sample of 4.7/fb integrated luminosity accumulated with the CLEO-II detector at Cornell Electron Storage Ring (CESR), we have measured branching fractions tau lepton into $K^- h^+ \pi^- \nu_\tau$ and K^+ relative to $h^- h^- \nu_\tau; K^- \pi^0\nu_\tau$ \pi^0 \nu_\tau$. The are: (5.16+-0.20+-0.50)*$10^{-2}$, (1.52+-0.14+-0.29)*$10^{-2}$, (2.54+-0.44+-0.39)*$10^{-2}$ $<0.0154$ 95% C.L., respectively. Coupled additional experimental information, use our results extract information on...
We have observed the decay ${B}^{+}\ensuremath{\rightarrow}{\overline{D}}^{0}{K}^{+}$, using $3.3\ifmmode\times\else\texttimes\fi{}{10}^{6}$ $B\overline{B}$ pairs collected with CLEO II detector at Cornell Electron Storage Ring. find ratio of branching fractions...
We report new measurements of the differential and total branching ratios for inclusive B decay to D^0, D^+ D^{*+} first measurement same quantities $D^{*0}$. Here is mixture B_d B_u from $\Upsilon(4S)$ decay. Furthermore, since more than one charm particle (or antiparticle) kind can be produced in decay, here ``inclusive ratio'' used mean average number particles their antiparticles a certain species obtain following results (the error statistical, second systematic this analysis, third...
The branching fractions for $\ensuremath{\tau}\ensuremath{\rightarrow}e\ensuremath{\nu}{\ensuremath{\nu}}_{\ensuremath{\tau}},$ $\ensuremath{\mu}\ensuremath{\nu}{\ensuremath{\nu}}_{\ensuremath{\tau}},$ and $h{\ensuremath{\nu}}_{\ensuremath{\tau}}$ are measured using data collected with the CLEO detector at CESR ${e}^{+}{e}^{\ensuremath{-}}$ collider: ${\mathcal{B}}_{e}$=0.1776$\ifmmode\pm\else\textpm\fi{}$0.0006$\ifmmode\pm\else\textpm\fi{}$0.0017,...
Using data taken with the CLEO II detector at Cornell Electron Storage Ring, we have determined ratio of branching fractions: ${R}_{\ensuremath{\gamma}}\ensuremath{\equiv}\ensuremath{\Gamma}(\ensuremath{\Upsilon}(1S)\ensuremath{\rightarrow}\ensuremath{\gamma}\mathrm{gg})/\ensuremath{\Gamma}(\ensuremath{\Upsilon}(1S)\ensuremath{\rightarrow}\mathrm{ggg})=[2.75\ifmmode\pm\else\textpm\fi{}0.04(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.15(\mathrm{syst})]%$. From this ratio, QCD scale parameter...
We present new measurements of photon energies and branching fractions for the radiative transitions Υ(2S)→γχb(J=0,1,2)(1P). The masses χb states are determined from measured energies. ratio mass splittings between substates, r≡(MJ=2−MJ=1)/(MJ=1−MJ=0), with M mass, provides information on nature b¯b confining potential. find r(1P)=0.542±0.022±0.024. This value is somewhat lower than previous world average, but more consistent theoretical expectation that r(1P)<r(2P); i.e., this splitting...
Using data collected with the CLEO II detector at Cornell Electron Storage Ring, we determine ratio R(chrg) for mean charged multiplicity observed in Upsilon(1S)->gggamma events, to e+e- -> qqbar gamma events. We find R(chrg)=1.04+/-0.02+/-0.05 jet-jet masses less than 7 GeV.