J. Cochran
A5050872391- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Neutrino Physics Research
- Dark Matter and Cosmic Phenomena
- Particle Detector Development and Performance
- Particle Accelerators and Free-Electron Lasers
- Medical Imaging Techniques and Applications
- Computational Physics and Python Applications
- Atomic and Subatomic Physics Research
- Black Holes and Theoretical Physics
- Superconducting Materials and Applications
- Nuclear physics research studies
- Cosmology and Gravitation Theories
- Stochastic processes and statistical mechanics
- Advanced Data Storage Technologies
- Radiation Detection and Scintillator Technologies
- Astrophysics and Cosmic Phenomena
- Particle accelerators and beam dynamics
- Muon and positron interactions and applications
- Stochastic processes and financial applications
- Quantum chaos and dynamical systems
- advanced mathematical theories
- Radioactive Decay and Measurement Techniques
- Radiation Therapy and Dosimetry
University of Iowa
2003-2024
Iowa State University
2013-2022
The University of Adelaide
2022
Adekunle Ajasin University
2022
Ekiti State University
2022
Obafemi Awolowo University
2022
University of California, Irvine
2020
Northern Illinois University
2020
University of Sassari
2020
Istituto Nazionale di Fisica Nucleare, Sezione di Bologna
2020
We search for single-photon events in 53 fb−1 of e+e− collision data collected with the BABAR detector at PEP-II B-Factory. look a single high-energy photon and large missing momentum energy, consistent production spin-1 particle A′ through process e+e−→γA′; A′→invisible. Such particles, referred to as "dark photons," are motivated by theories applying U(1) gauge symmetry dark matter. find no evidence such processes set 90% confidence level upper limits on coupling strength mass range mA′≤8...
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 decay <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:msup><a:mi>B</a:mi><a:mo>+</a:mo></a:msup><a:mo stretchy="false">→</a:mo><a:msup><a:mi>K</a:mi><a:mo>+</a:mo></a:msup><a:mi>ν</a:mi><a:mover accent="true"><a:mi>ν</a:mi><a:mo stretchy="false">¯</a:mo></a:mover></a:math> in a <f:math xmlns:f="http://www.w3.org/1998/Math/MathML" display="inline"><f:mn>362</f:mn><f:mtext> </f:mtext><f:mtext>...
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...
We study the lepton forward-backward asymmetry ${\mathcal{A}}_{FB}$ and longitudinal ${K}^{*}$ polarization ${F}_{L}$, as well an observable ${P}_{2}$ derived from them, in rare decays $B\ensuremath{\rightarrow}{K}^{*}{\ensuremath{\ell}}^{+}{\ensuremath{\ell}}^{\ensuremath{-}}$, where ${\ensuremath{\ell}}^{+}{\ensuremath{\ell}}^{\ensuremath{-}}$ is either ${e}^{+}{e}^{\ensuremath{-}}$ or ${\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$, using full sample of 471 million...
Abstract A series of data samples was collected with the Belle II detector at SuperKEKB collider from March 2019 to June 2022. We determine integrated luminosities these using three distinct methodologies involving Bhabha ( ), digamma and dimuon ) events. The total luminosity obtained Bhabha, digamma, events is (426.88 ± 0.03 2.61) fb −1 , (429.28 2.62) (423.99 0.04 3.83) where first uncertainties are statistical second systematic. resulting combination methods (427.87 2.01) .
We measure the time-integrated <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mi>C</a:mi><a:mi>P</a:mi></a:math> asymmetry in <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:msup><c:mi>D</c:mi><c:mn>0</c:mn></c:msup><c:mo stretchy="false">→</c:mo><c:msubsup><c:mi>K</c:mi><c:mi>S</c:mi><c:mn>0</c:mn></c:msubsup><c:msubsup><c:mi>K</c:mi><c:mi>S</c:mi><c:mn>0</c:mn></c:msubsup></c:math> decays reconstructed <f:math...
We measure the branching fraction of decay <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:msup><a:mrow><a:mi>B</a:mi></a:mrow><a:mrow><a:mn>0</a:mn></a:mrow></a:msup><a:mo stretchy="false">→</a:mo><a:mi>J</a:mi><a:mo>/</a:mo><a:mi>ψ</a:mi><a:mi>ω</a:mi></a:mrow></a:math> using data collected with Belle II detector at SuperKEKB collider. The contain <d:math xmlns:d="http://www.w3.org/1998/Math/MathML" display="inline"><d:mrow><d:mo...
An angular analysis of the decay ${\overline{B} \rightarrow D^\ast \ell^- \overline{\nu}_\ell}$, $\ell\in\{e,\mu\}$, is reported using full $e^+e^-$ collision data set collected by \babar experiment at $\Upsilon(4S)$ resonance. One $B$ meson from ${\Upsilon(4S)\to B\overline{B}}$ fully reconstructed in a hadronic mode, which constrains kinematics and provides determination neutrino momentum vector. The semileptonic described di-lepton mass squared, $q^2$, three angles. first unbinned fit to...
We present the first measurement of ratio branching fractions inclusive semileptonic B-meson decays, R(X_{e/μ})=B(B→Xeν)/B(B→Xμν), a precision test electron-muon universality, using data corresponding to 189 fb^{-1} from electron-positron collisions collected with Belle II detector. In events where partner B meson is fully reconstructed, we use fits lepton momentum spectra above 1.3 GeV/c obtain R(X_{e/μ})=1.007±0.009(stat)±0.019(syst), which most precise lepton-universality its kind and...
We present a measurement of the τ-lepton mass using sample about 175 million e+e−→τ+τ− events collected with Belle II detector at SuperKEKB e+e− collider center-of-mass energy 10.579 GeV. This corresponds to an integrated luminosity 190 fb−1. use kinematic edge τ pseudomass distribution in decay τ−→π−π+π−ντ and measure be 1777.09±0.08±0.11 MeV/c2, where first uncertainty is statistical second systematic. result most precise date.Received 31 May 2023Accepted 13 July...
We determine the Cabibbo-Kobayashi-Maskawa matrix-element magnitude |Vcb| using B¯0→D*+ℓ−ν¯ℓ decays reconstructed in 189 fb−1 of collision data collected by Belle II experiment, located at SuperKEKB e+e− collider. Partial decay rates are reported as functions recoil parameter w and three angles separately for electron muon final states. obtain Boyd-Grinstein-Lebed Caprini-Lellouch-Neubert parametrizations, find |Vcb|BGL=(40.57±0.31±0.95±0.58)×10−3 |Vcb|CLN=(40.13±0.27±0.93±0.58)×10−3 with...
We report measurements of time-dependent <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:mi>C</a:mi><a:mi>P</a:mi></a:mrow></a:math> asymmetries in <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:msup><c:mi>B</c:mi><c:mn>0</c:mn></c:msup><c:mo stretchy="false">→</c:mo><c:msubsup><c:mi>K</c:mi><c:mi>S</c:mi><c:mn>0</c:mn></c:msubsup><c:msup><c:mi>π</c:mi><c:mn>0</c:mn></c:msup><c:mi>γ</c:mi></c:math> decays based on a data sample...
We present a measurement of the branching fraction and time-dependent charge-parity (<a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mi>C</a:mi><a:mi>P</a:mi></a:math>) decay-rate asymmetries in <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:msup><c:mi>B</c:mi><c:mn>0</c:mn></c:msup><c:mo stretchy="false">→</c:mo><c:mrow><c:mi>J</c:mi><c:mo>/</c:mo><c:mi>ψ</c:mi></c:mrow><c:msup><c:mi>π</c:mi><c:mn>0</c:mn></c:msup></c:math> decays. The data...
We study the process $e^+e^- \to \pi^+\pi^-\eta \gamma$, where photon is radiated from initial state. About 8000 fully reconstructed events of this are selected BaBar data sample with an integrated luminosity 469~fb$^{-1}$. Using $\pi^+\pi^-\eta$ invariant mass spectrum we measure \pi^+\pi^-\eta$ cross section in $e^+e^-$ center-of-mass energy range 1.15 to 3.5 GeV. The well described by Vector-Meson Dominance model four $\rho$-like states. observe $49\pm9$ $J/\psi$ decay $\pi^+\pi^-\eta$,...
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 search for the rare decay $B^{+}\rightarrow K^{+}ν\barν$ in a $362\ \rm{fb}^{-1}$ sample of electron-positron collisions at $Υ(4S)$ resonance collected with Belle II detector SuperKEKB collider. use inclusive properties accompanying $B$ meson $Υ(4S) \to B\kern 0.18em\overline{\kern -0.18em B}{}$ events to suppress background from other decays signal candidate and light-quark pair production. validate measurement an auxiliary analysis based on conventional hadronic reconstruction meson....
We present measurements of Collins asymmetries in the inclusive process $e^+e^- \rightarrow h_1 h_2 X$, $h_1h_2=KK,\, K\pi,\, \pi\pi$, at center-of-mass energy 10.6 GeV, using a data sample 468 fb$^{-1}$ collected by BaBar experiment PEP-II $B$ factory SLAC National Accelerator Center. Considering hadrons opposite thrust hemispheres hadronic events, we observe clear azimuthal ratio unlike- to like-sign, and all charged $h_1 h_2$ pairs, which increase with hadron energies. The $K\pi$ are...
The process $e^+e^- \to \pi^+\pi^-2\pi^0\gamma$ is investigated by means of the initial-state radiation technique, where a photon emitted from incoming electron or positron. Using $454.3 \rm{fb}^{-1}$ data collected around center-of-mass energy $\sqrt{s} = 10.58 \rm{GeV}$ BaBar experiment at SLAC, approximately 150000 signal events are obtained. corresponding non-radiative cross section measured with relative uncertainty $3.6\%$ in region $1.5 \rm{GeV}$, surpassing all existing measurements...
The decay ${\ensuremath{\tau}}^{\ensuremath{-}}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{K}_{S}{\ensuremath{\nu}}_{\ensuremath{\tau}}$ has been studied using $430\ifmmode\times\else\texttimes\fi{}{10}^{6}$ ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{\ensuremath{\tau}}^{+}{\ensuremath{\tau}}^{\ensuremath{-}}$ events produced at a center-of-mass energy around 10.6 GeV the PEP-II collider and with BABAR detector. mass spectrum of ${K}^{\ensuremath{-}}{K}_{S}$ system measured...
We report measurements of $\sin{2\beta}$ and $\cos{2\beta}$ from a time-dependent Dalitz plot analysis $B^{0} \to D^{(*)} h^{0}$ with $D K_{S}^{0} \pi^{+} \pi^{-}$ decays, where the light unflavored neutral hadron $h^{0}$ is $\pi^{0}$, $\eta$, or $\omega$ meson. The performed combination final data sets \babar\ Belle experiments containing $471 \times 10^{6}$ $772 $B\bar{B}$ pairs collected at $\Upsilon\left(4S\right)$ resonance asymmetric-energy B factories PEP-II SLAC KEKB KEK,...