M. Breidenbach
A5107296695- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Particle Detector Development and Performance
- Dark Matter and Cosmic Phenomena
- Neutrino Physics Research
- Particle Accelerators and Free-Electron Lasers
- Atomic and Subatomic Physics Research
- Radiation Detection and Scintillator Technologies
- Nuclear physics research studies
- Particle accelerators and beam dynamics
- Computational Physics and Python Applications
- CCD and CMOS Imaging Sensors
- Superconducting Materials and Applications
- Distributed and Parallel Computing Systems
- Astrophysics and Cosmic Phenomena
- Nuclear Physics and Applications
- Quantum, superfluid, helium dynamics
- Medical Imaging Techniques and Applications
- Electron and X-Ray Spectroscopy Techniques
- Advanced Data Storage Technologies
- Black Holes and Theoretical Physics
- Photocathodes and Microchannel Plates
- Magnetic confinement fusion research
- Muon and positron interactions and applications
SLAC National Accelerator Laboratory
2015-2024
Menlo School
1998-2024
Stanford University
2004-2023
Fraunhofer Institute for Applied Information Technology
2022
Lawrence Berkeley National Laboratory
1978-2019
Stanford Synchrotron Radiation Lightsource
1997-2018
University of California, Berkeley
1978-2018
Aomori University
2002
Massachusetts Institute of Technology
1968-2000
Adelphi University
1997-2000
We have observed a very sharp peak in the cross section for ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}\mathrm{hadrons}, {e}^{+}{e}^{\ensuremath{-}}$, and possibly ${\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$ at center-of-mass energy of 3.105\ifmmode\pm\else\textpm\fi{}0.003 GeV. The upper limit to full width half-maximum is 1.3 MeV.
We have found events of the form e++e−→e±+μ∓+missingenergy, in which no other charged particles or photons are detected. Most these detected at above a center-of-mass energy 4 GeV. The missing-energy and missing-momentum spectra require that least two additional be produced each event. conventional explanation for events.Received 18 August 1975DOI:https://doi.org/10.1103/PhysRevLett.35.1489©1975 American Physical Society
Results of electron-proton inelastic scattering at 6\ifmmode^\circ\else\textdegree\fi{} and 10\ifmmode^\circ\else\textdegree\fi{} are discussed, values the structure function ${W}_{2}$ estimated. If interaction is dominated by transverse virtual photons, $\ensuremath{\nu}{W}_{2}$ can be expressed as a $\ensuremath{\omega}=\frac{2M\ensuremath{\nu}}{{q}^{2}}$ within experimental errors for ${q}^{2}>1$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^{2}$ $\ensuremath{\omega}>4$, where...
Cross sections for inelastic scattering of electrons from hydrogen were measured incident energies 7 to 17 GeV at angles 6\ifmmode^\circ\else\textdegree\fi{} 10\ifmmode^\circ\else\textdegree\fi{} covering a range squared four-momentum transfers up 7.4 ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^{2}$. For low center-of-mass the final hadronic system cross section shows prominent resonances momentum transfer and diminishes markedly higher transfer. high excitations only weak...
We present evidence, from a study of multihadronic final states produced in ${e}^{+}{e}^{\ensuremath{-}}$ annihilation at center-of-mass energies between 3.90 and 4.60 GeV, for the production new neutral state with mass 1865\ifmmode\pm\else\textpm\fi{}15 MeV/${\mathit{c}}^{2}$ decay width less than 40 that decays to ${K}^{\ifmmode\pm\else\textpm\fi{}}{\ensuremath{\pi}}^{\ensuremath{\mp}}$...
We have observed a second sharp peak in the cross section for ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}\mathrm{hadrons}$ at center-of-mass energy of 3.695\ifmmode\pm\else\textpm\fi{}0.004 GeV. The upper limit full width half-maximum is 2.7 MeV.
We report on a search for neutrinoless double-beta decay of $^{136}$Xe with EXO-200. No signal is observed an exposure 32.5 kg-yr, background ~1.5 x 10^{-3} /(kg yr keV) in the $\pm 1\sigma$ region interest. This sets lower limit half-life $T_{1/2}^{0\nu\beta\beta}$($^{136}$Xe) > 1.6 10$^{25}$ (90% CL), corresponding to effective Majorana masses less than 140-380 meV, depending matrix element calculation.
We have found evidence for jet structure in ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}\mathrm{hadrons}$ at center-of-mass energies of 6.2 and 7.4 GeV. At GeV the jet-axis angular distribution integrated over azimuthal angle was determined to be proportional $1+(0.78\ifmmode\pm\else\textpm\fi{}0.12){cos}^{2}\ensuremath{\theta}$.
We report evidence for the production of a new narrow charged state in e+e− annihilation at center-of-mass energy 4.03 GeV. This state, which has mass 1876± 15 MeV/c2, is observed exotic channel K∓π±π±, but not nonexotic K∓π+π−. It produced primarily association with system 2.01±0.02 GeV/c2. These characteristics are just those expected charmed meson.Received 21 July 1976DOI:https://doi.org/10.1103/PhysRevLett.37.569©1976 American Physical Society
A search for neutrinoless double-beta decay ($0\nu\beta\beta$) in $^{136}$Xe is performed with the full EXO-200 dataset using a deep neural network to discriminate between $0\nu\beta\beta$ and background events. Relative previous analyses, signal detection efficiency has been raised from 80.8% 96.4$\pm$3.0% energy resolution of detector at Q-value improved $\sigma/E=1.23\%$ $1.15\pm0.02\%$ upgraded detector. Accounting new data, median 90% confidence level half-life sensitivity this analysis...
Results from a search for neutrinoless double-beta decay (0νββ) of ^{136}Xe are presented using the first year data taken with upgraded EXO-200 detector. Relative to previous searches by EXO-200, energy resolution detector has been improved σ/E=1.23%, electric field in drift region raised 50%, and system suppress radon volume between cryostat lead shielding implemented. In addition, analysis techniques that improve topological discrimination 0νββ background events have developed....
We have carried out an experimental study of the neutron and proton deep-inelastic electromagnetic structure functions. The functions were extracted from electron-proton electron-deuteron differential cross sections measured in three experiments spanning angles 6\ifmmode^\circ\else\textdegree\fi{}, 10\ifmmode^\circ\else\textdegree\fi{}, 15\ifmmode^\circ\else\textdegree\fi{}, 18\ifmmode^\circ\else\textdegree\fi{}, 19\ifmmode^\circ\else\textdegree\fi{}, 26\ifmmode^\circ\else\textdegree\fi{},...
The deep-inelastic electromagnetic structure functions of deuterium and aluminum nuclei have been measured. kinematic dependence the ratio is similar to steel functions, provides further evidence for distortion quark momentum distributions nucleons bound in a nucleus.
The total cross section for hadron production by ${e}^{+}{e}^{\ensuremath{-}}$ annihilation has been measured at center-of-mass energies between 2.4 and 5.0 GeV. Aside from the very narrow resonances $\ensuremath{\psi}(3105)$ $\ensuremath{\psi}(3695)$, varies 32 17 nb over this region with structure in vicinity of 4.1
We report the observation of two-neutrino double-beta decay in Xe-136 with T_1/2 = 2.11 +- 0.04 (stat.) 0.21 (sys.) x 10^21 yr. This second order process, predicted by Standard Model, has been observed for several nuclei but not Xe-136. The rate provides new input to matrix element calculations and search more interesting neutrino-less decay, most sensitive probe existence Majorana particles measurement neutrino mass scale.
Received 20 December 1967DOI:https://doi.org/10.1103/PhysRevLett.20.292©1968 American Physical Society
We present a study of the decay properties charmed D mesons produced near peak ψ''(3770) resonance in e+e− annihilation. Branching fractions for nine Cabibbo-favored and three Cabibbo-suppressed modes are presented along with upper limits on one additional four modes. A Kππ-decay-mode Dalitz plots reveals large quasi-two-body pseudoscalar-vector component D0 decays an apparent nonuniform population plot D+ into K−π+π+. Using tagged events, we measure charged-particle multiplicity...
The Proceedings of the 2011 workshop on Fundamental Physics at Intensity Frontier. Science opportunities intensity frontier are identified and described in areas heavy quarks, charged leptons, neutrinos, proton decay, new light weakly-coupled particles, nucleons, nuclei, atoms.
The average lifetime of bottom hadrons was measured with the Mark II vertex detector at storage ring PEP. determined by measuring impact parameters leptons produced in decays. ${\ensuremath{\tau}}_{b}=({12.0}_{\ensuremath{-}3.6}^{+4.5}\ifmmode\pm\else\textpm\fi{}3.0)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}13}$ sec found.
We report on an improved measurement of the $2\ensuremath{\nu}\ensuremath{\beta}\ensuremath{\beta}$ half-life ${}^{136}$Xe performed by EXO-200. The use a large and homogeneous time-projection chamber allows for precise estimate fiducial mass used measurement, resulting in small systematic uncertainty. also discuss detail data-analysis methods double-$\ensuremath{\beta}$ decay searches with EXO-200, while emphasizing those directly related to present measurement. is found be...
Cross sections for inelastic scattering of electrons from hydrogen and deuterium were measured incident energies 4.5 to 18 GeV, at angles 18\ifmmode^\circ\else\textdegree\fi{}, 26\ifmmode^\circ\else\textdegree\fi{}, 34\ifmmode^\circ\else\textdegree\fi{}, covering a range squared four-momentum transfers up $20 {(\frac{\mathrm{GeV}}{c})}^{2}$. Neutron cross extracted the data using an impulse approximation. Comparisons with proton measurements show significant differences between neutron sections.