D. J. Lange
A5030492607- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Particle Detector Development and Performance
- Neutrino Physics Research
- Dark Matter and Cosmic Phenomena
- Computational Physics and Python Applications
- Medical Imaging Techniques and Applications
- Particle Accelerators and Free-Electron Lasers
- Atomic and Subatomic Physics Research
- Distributed and Parallel Computing Systems
- Cosmology and Gravitation Theories
- Black Holes and Theoretical Physics
- Radiation Detection and Scintillator Technologies
- Superconducting Materials and Applications
- Nuclear physics research studies
- Advanced Data Storage Technologies
- Scientific Computing and Data Management
- Astrophysics and Cosmic Phenomena
- Nuclear Physics and Applications
- Parallel Computing and Optimization Techniques
- Muon and positron interactions and applications
- Stochastic processes and statistical mechanics
- Radiation Therapy and Dosimetry
- Particle accelerators and beam dynamics
Princeton University
2017-2025
Institute of High Energy Physics
2017-2024
A. Alikhanyan National Laboratory
2022-2024
University of Antwerp
2024
Paul Scherrer Institute
2023
Lawrence Livermore National Laboratory
2011-2022
University of Bologna
2022
Istituto Nazionale di Fisica Nucleare, Sezione di Bologna
2022
Lund University
2021
Lawrence Livermore National Security
2008-2014
Using the CLEO II detector, we have measured differential cross sections for exclusive two-photon production of light pseudoscalar mesons ${\ensuremath{\pi}}^{0},$ \ensuremath{\eta}, and ${\ensuremath{\eta}}^{\ensuremath{'}}.$ From our measurements obtained form factors associated with electromagnetic transitions ${\ensuremath{\gamma}}^{*}\stackrel{\ensuremath{\rightarrow}}{\ensuremath{\gamma}}\mathrm{meson}.$ We these in momentum transfer ranges from 1.5 to 9, 20, $30{\mathrm{GeV}}^{2}$...
Many models of physics beyond the Standard Model predict existence new Abelian forces with gauge bosons mediating interactions between "dark sectors" and Model. We report a search for dark boson Z' coupling only to second third generations leptons in reaction e+e- -> mu+mu- Z', using 514 fb-1 data collected by BABAR experiment. No significant signal is observed masses range 0.212 - 10 GeV. Limits on parameter g' as low 7x10^-4 are derived, leading improvements bounds compared those...
We search for the rare flavor-changing neutral current process $B^{+}\rightarrow K^{+}τ^{+}τ^{-}$ using data from BABAR experiment. The sample, collected at center-of-mass energy of $Υ{(4S)}$ resonance, corresponds to a total integrated luminosity 424 fb$^{-1}$ and 471 million $B\overline{B}$ pairs. reconstruct one $B$ meson, produced in $Υ{(4S)}\rightarrow B^{+} B^{-}$ decay, many hadronic decay modes activity compatible with K^{+} τ^{+}τ^{-}$ rest event. Each $τ$ lepton is required...
Based on a sample corresponding to 4.3 million produced tau-pair events, we have studied hadronic dynamics in the decay tau- --> nu_tau pi- pi0 data recorded by CLEO II detector operating at CESR e+e- collider. The is dominated process tau a_1(1260), with a_1 meson decaying three pions predominantly via lowest dimensional (mainly S-wave) rho pi Born amplitude. From fits Dalitz plot and angular observables, find significant additional contributions from amplitudes for sigma pi, f_0(1370)...
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 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 study the processes $\gamma \gamma \to \eta_c \eta' K^+ K^-$, $\eta' \pi^+ \pi^-$, and $\eta \pi^-$ using a data sample of 519 $fb^{-1}$ recorded with BaBar detector operating at SLAC PEP-II asymmetric-energy $e^+e^-$ collider center-of-mass energies near $\Upsilon(nS)$ ($n = 2,3,4$) resonances. This is first observation decay $\eta_c K^-$ we measure branching fraction $\Gamma(\eta_c K^-)/(\Gamma(\eta_c \pi^-)=0.644\pm 0.039_{\rm stat}\pm 0.032_{\rm sys}$. Significant interference...
A dedicated measurement of additional radiation in e+e−→μ+μ−γ and e+e−→π+π−γ initial-state-radiation events is presented using the full BABAR data sample. For first time results are at next-to- next-to-next-to-leading order, with one two photons, respectively, for from initial final states. Comparison predictions phokhara afkqed Monte Carlo generators performed, revealing discrepancies one-photon rates angular distributions former. This disagreement has a negligible effect on e+e−→π+π−(γ)...
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...
We have studied two-body charmless hadronic decays of B mesons into the final states $\pi\pi$, $K \pi$, and $KK$. Using 3.3 million $B\bar{B}$ pairs collected with CLEO-II detector, we made first observation $B^0\to K^+\pi^-$, $B^+\to K^0\pi^+$, sum $B^+ \to \pi^+\pi^0$ K^+\pi^0$ (an average over charge-conjugate is always implied). place upper limits on branching fractions for remaining decay modes.
We have measured the branching fractions for B -> D_bar X, D and X \ell^+ \nu, where ``B'' is an average over B^0 B^+, ``D'' a sum D^0 D^+, and``D_bar'' D^0_bar D^-. From these results some previously fractions, we obtain Br(b c c_bar s) = (21.9 $\pm$ 3.7)%, s g) < 6.8% @ 90% c.l, Br(D^0 K^- \pi^+) (3.69 0.20)%. Implications ``B semileptonic decay problem'' (measured fraction being below theoretical expectations) are discussed. The increase in value of due to $B X$ eliminates 40% discrepancy.
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
Axionlike particles (ALPs) are predicted in many extensions of the standard model, and their masses can naturally be well below electroweak scale. In presence couplings to bosons, these could emitted flavor-changing B meson decays. We report herein a search for an ALP, a, reaction B^{±}→K^{±}a, a→γγ using data collected by BABAR experiment at SLAC. No significant signal is observed, 90% confidence level upper limits on ALP coupling bosons derived as function mass, improving current...
Using a sample of 3.3 million B-meson decays collected with the CLEO detector at Cornell Electron Storage Ring, we have studied $B^- \to D^0 \ell\nu$ and $\bar{B}^0 D^+ decays, where $\ell$ can be either an electron or muon. We distinguish $B D from other B semileptonic by examining net momentum energy particles recoiling against D-lepton pairs. find decay rate $\Gamma(B D\ell\nu)$ = (14.1 +- 1.0 1.2) ns-1 derive branching fractions for $\bar{B^0} (2.32 0.17 0.20)% 2.20 0.16 0.19)%...
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 $107.8\pm 1.7\pm 2.5$ $107.0\pm 1.4\pm 2.5 MeV/c^2$,...
We present a new determination of ${f}_{{D}_{s}}$ using 5 million ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}c\overline{c}$ events obtained with the CLEO II detector. Our value is derived from our measured ratio $\ensuremath{\Gamma}{(D}_{s}^{+}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}\ensuremath{\nu})/\ensuremath{\Gamma}{(D}_{s}^{+}\ensuremath{\rightarrow}\ensuremath{\varphi}{\ensuremath{\pi}}^{+})=0.173\ifmmode\pm\else\textpm\fi{}0.023\ifmmode\pm\else\textpm\fi{}0.035$. Using...
We study the processes $\gamma \gamma \to K^0_S K^{\pm}\pi^{\mp}$ and K^+ K^- \pi^0$ using a data sample of 519~$fb^{-1}$ recorded with BaBar detector operating at SLAC PEP-II asymmetric-energy $e^+ e^-$ collider center-of-mass energies near $\Upsilon(nS)$ ($n = 2,3,4$) resonances. observe $\eta_c$ decays to both final states perform Dalitz plot analyses model-independent partial wave analysis technique. This allows measurement mass-dependence $I=1/2$ $K \pi$ $\mathcal{S}$-wave amplitude...
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 %
Over the past several years, CMS experiment has made significant changes to its detector simulation application. The geometry been generalized include modifications being for 2015 operations, as well model improvements of current and implementation a number approved possible future configurations. These both completely new tracker calorimetry systems. We have completed transition Geant4 version 10, we progress in reducing CPU resources required run our simulation. achieved through technical...
The process ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{0}\ensuremath{\gamma}$ is studied at a center-of-mass energy near the $\mathrm{\ensuremath{\Upsilon}}(4S)$ resonance using data sample of $469\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ collected with BABAR detector PEP-II collider. We have performed precise measurement...
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...