P. Shanahan
A5069957010- Particle physics theoretical and experimental studies
- Neutrino Physics Research
- Astrophysics and Cosmic Phenomena
- Quantum Chromodynamics and Particle Interactions
- Dark Matter and Cosmic Phenomena
- High-Energy Particle Collisions Research
- Particle Detector Development and Performance
- Radiation Detection and Scintillator Technologies
- Particle Accelerators and Free-Electron Lasers
- Atomic and Subatomic Physics Research
- Superconducting Materials and Applications
- Particle accelerators and beam dynamics
- Muon and positron interactions and applications
- Advanced NMR Techniques and Applications
- Nuclear Physics and Applications
- Planetary Science and Exploration
- Black Holes and Theoretical Physics
- Pulsars and Gravitational Waves Research
- Electromagnetic Compatibility and Measurements
- Noncommutative and Quantum Gravity Theories
- Nuclear physics research studies
- IoT Networks and Protocols
- Pharmacovigilance and Adverse Drug Reactions
- NMR spectroscopy and applications
- Computational Physics and Python Applications
Fermi National Accelerator Laboratory
2016-2025
Thomas Jefferson National Accelerator Facility
2017
William & Mary
2017
Williams (United States)
2017
National and Kapodistrian University of Athens
2008-2011
Universidade de São Paulo
2011
Université Paris Cité
2008-2009
Délégation Paris 7
2008-2009
California Institute of Technology
2008
University of Arizona
2000-2001
We report the results of a search for ${\ensuremath{\nu}}_{e}$ appearance in ${\ensuremath{\nu}}_{\ensuremath{\mu}}$ beam MINOS long-baseline neutrino experiment. With an improved analysis and increased exposure $8.2\ifmmode\times\else\texttimes\fi{}{10}^{20}$ protons on NuMI target at Fermilab, we find that $2{sin}^{2}({\ensuremath{\theta}}_{23}){sin}^{2}(2{\ensuremath{\theta}}_{13})<0.12(0.20)$ 90% confidence level $\ensuremath{\delta}=0$ normal (inverted) mass hierarchy, with best-fit...
We have compared the decay rates of ${K}_{L}$ and ${K}_{S}$ to ${\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ ${\ensuremath{\pi}}^{0}{\ensuremath{\pi}}^{0}$ final states using a subset data from KTeV experiment (E832) at Fermilab. find that direct-CP-violation parameter $\mathrm{Re}({\ensuremath{\epsilon}}^{\ensuremath{'}}/\ensuremath{\epsilon})$ is equal...
We present precise tests of CP and CPT symmetry based on the full dataset K to pipi decays collected by KTeV experiment at Fermi National Accelerator Laboratory during 1996, 1997, 1999. This contains 16 million 2pi0 69 pi+pi- decays. measure direct violation parameter Re(epsilon'/epsilon) = (19.2 pm 2.1)x10-4. find KL-KS mass difference Deltam (5270 12)x10^6 hbar/s KS lifetime tauS (89.62 0.05)x10-12 s. also several parameters that test invariance. between phase indirect parameter, epsilon,...
We present a series of measurements based on ${K}_{L,S}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ and ${K}_{L,S}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}{\ensuremath{\pi}}^{0}$ decays collected in 1996--1997 by the $\mathrm{KTeV}$ experiment (E832) at Fermilab. compare these four $\stackrel{\ensuremath{\rightarrow}}{K}\ensuremath{\pi}\ensuremath{\pi}$ decay rates to measure direct $\mathrm{CP}$ violation parameter...
The KTeV/E799 experiment at Fermilab has searched for the rare kaon decay KL→π0e+e− . This mode is expected to have a significant CP violating component. measurement of its branching ratio could support standard model or indicate existence new physics. Letter reports results from 1999–2000 data set. One event observed with an background 0.99±0.35 events. We set limit on 3.5×10−10 90% confidence level. Combining previous result based taken in 1997 yields final KTeV result:...
We present new measurements of ${K}_{L}$ semileptonic form factors using data collected in 1997 by the KTeV (E832) experiment at Fermilab. The are based on $1.9\ifmmode\times\else\texttimes\fi{}{10}^{6}$ ${K}_{L}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}{e}^{\ensuremath{\mp}}\ensuremath{\nu}$ and $1.5\ifmmode\times\else\texttimes\fi{}{10}^{6}$...
We report the first observation of a manifestly CP violating effect in K(L)-->pi(+)pi(-)e(+)e(-) decay mode. A large asymmetry was observed distribution these decays CP-odd and T-odd angle straight phi between planes e(+)e(-) pi(+)pi(-) pairs K(L) center mass system. After acceptance corrections, overall is found to be [13.6+/-2. 5(stat)+/-1.2(syst)]%. This largest CP-violating yet when integrating over entire phase space mode such an angular variable.
We present a determination of the Cabibbo-Kobayashi-Maskawa parameter |V(us)| based on new measurements six largest K(L) branching fractions and semileptonic form factors by KTeV (E832) experiment at Fermilab. find |V(us)|=0.2252+/-0.0008(KTeV)+/-0.0021(ext), where errors are from external sources. also use measured to determine CP violation |eta(+-)|=(2.228+/-0.005(KTeV)+/-0.009(ext))x10(-3).
We present new measurements of the six largest branching fractions ${K}_{L}$ using data collected in 1997 by KTeV experiment (E832) at Fermilab. The results are $B({K}_{L}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}{\mathrm{e}}^{\ensuremath{\mp}}\ensuremath{\nu})=0.4067\ifmmode\pm\else\textpm\fi{}0.0011$,...
We present a measurement of the charge asymmetry delta(L) in mode K(L)-->pi(+/-)e(-/+)nu based on 298 x 10(6) analyzed decays. measure value = [3322+/-58(stat)+/-47(syst)]x10(-6), good agreement with previous measurements and 2.4 times more precise than current best published result. The result is used to place stringent limits CPT DeltaS DeltaQ violation neutral kaon system.
We report on a search for the decay KL→π0ν¯ν, carried out as part of E799-II, rare KL experiment at Fermilab. Within standard model, KL→π0ν¯ν is dominated by direct CP violating processes, and thus an observation implies confirmation violation. No events were observed, we set upper limit branching ratio to be <5.9×10−7 90% confidence level.Received 8 July 1999DOI:https://doi.org/10.1103/PhysRevD.61.072006©2000 American Physical Society
We report on a new measurement of the decay ${K}_{L}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}\ensuremath{\gamma}\ensuremath{\gamma}$ by KTeV experiment at Fermilab. determine branching ratio to be $(1.68\ifmmode\pm\else\textpm\fi{}0.07\ifmmode\pm\else\textpm\fi{}0.08)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$. Our data show first evidence for low-mass $\ensuremath{\gamma}\ensuremath{\gamma}$ signal as predicted recent $O({p}^{6})$ chiral perturbation calculations which...
The recent discovery of a large CP violating asymmetry in KL-->pi+pi-e+e- mode has prompted us to seach for the associated KL-->pi 0 pi e+e- decay KTeV-E799 experiment at Fermilab. In 2.7 x 10(11) K(L) decays, one candidate event been observed with an expected background 0.3 event, resulting upper limit branching ratio 6.6 10(-9) 90% C.L.
We present the first measurement of form factor ratios g(1)/f(1) (direct axial vector to vector), g(2)/f(1) (second class current), and f(2)/f(1) (weak magnetism) for decay Xi(0)-->Sigma(+)e(-)nu macro(e) using KTeV (E799) beam line detector at Fermilab. From Sigma(+) polarization measured with Sigma(+)-->p pi(0) e(-)-nu; correlation, we measure be 1.32+/-(0.21)(0.17)(stat)+/-0.05(syst), assuming SU(3)(f) (flavor) values f(2)/f(1). Our results are all consistent exact symmetry.
We searched for the appearance of π+π− pairs with invariant mass ≥648MeV/c2 in a neutral beam. Such an observation could signify decay long-lived light particle. find no evidence this decay. Our null result severely constrains existence R0 hadron, which is lightest bound state gluon and gluino (g˜g), thereby also gluino. Depending on photino mass, we exclude lifetime ranges 1.2–4.6GeV/c2 2×10−10–7×10−4s, respectively.Received 18 July 1997DOI:https://doi.org/10.1103/PhysRevLett.79.4083©1997...
The Near Detector for the MINOS Experiment at Fermilab is composed of alternating planes scintillator strips and steel plates, read out with 64-channel, multi-anode photomultiplier tubes. instrumentation uses a custom integrated circuit designed front end analog processing, called QIE. system can measure single photoelectrons to high precision dynamic range 16 bits. electronics operates in two modes. It records all events that occur during 10 /spl mu/s fast spill beam from Main Injector rate...
We report on a search for the decay KL-->pi(0)e+e- carried out by KTeV/E799 experiment at Fermilab. This is expected to have significant CP violating contribution and measurement of its branching ratio could support Cabibbo-Kobayashi-Maskawa mechanism violation or point new physics. Two events were observed in 1997 data with an background 1.06+/-0.41 events, we set upper limit B(KL-->pi(0)e+e-)<5.1 x 10(-10) 90% confidence level.
The highest-energy measurement of ΔσL(pp) and the first ever ΔσL(p¯p), differences between proton-proton antiproton-proton total cross sections for pure longitudinal spin states, are described. Data were taken using 200-GeV/c polarized beams incident on a polarized-proton target. results measured to be ΔσL(pp)=−42±48(stat)±53(syst) μb ΔσL(p¯p)=−256±124(stat)±109(syst) μb. Many tests systematic effects investigated described, comparison theoretical predictions is also given. Measurements...
We report the first branching fraction measurement of decay ${K}_{L}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{e}^{+}{e}^{\ensuremath{-}}$. With a sample 46 candidates, and an expected background level 9.4 events, is determined to be...
We report on the analysis of rare decay K(L)-->mu(+)mu(-)gamma 1997 data from KTeV experiment at Fermilab. A total 9327 candidate events are observed with 2.4% background, representing a factor 40 increase in statistics over current world sample. find that B(K(L)-->mu(+)mu(-)gamma) = (3.62 +/- 0.04(stat) 0.08(syst)) x 10(-7). The form parameter alpha(K*) is measured to be -0.160(+0.026)(-0.028). In addition, we make first measurement alpha D'Ambrosio-Isidori-Portolés factor, finding -1.54...
The KTeV experiment at Fermilab has isolated a total of 132 events from the rare decay K(L)-->e+ e- mu+ mu-, with an estimated background 0.8 events. branching ratio this mode is determined to be [2.69+/-0.24(stat)+/-0.12(syst)]x10(-9), radiative cutoff M(2)(ee mu mu)/M(2)(K)>0.95. first measurement using parameter alpha D'Ambrosio-Isidori-Portolès (DIP) model K(L)gamma*gamma* vertex yields result -1.59+/-0.37, consistent values obtained other modes. Because limited statistics, no...