D. J. Summers
A5023376388- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Particle Detector Development and Performance
- Particle accelerators and beam dynamics
- Particle Accelerators and Free-Electron Lasers
- Superconducting Materials and Applications
- Neutrino Physics Research
- Muon and positron interactions and applications
- Dark Matter and Cosmic Phenomena
- Computational Physics and Python Applications
- Medical Imaging Techniques and Applications
- Distributed and Parallel Computing Systems
- Advanced Data Storage Technologies
- Atomic and Subatomic Physics Research
- Cosmology and Gravitation Theories
- Radiation Detection and Scintillator Technologies
- Astrophysics and Cosmic Phenomena
- Black Holes and Theoretical Physics
- Parallel Computing and Optimization Techniques
- Nuclear physics research studies
- Engineering Applied Research
- Fatigue and fracture mechanics
- Radiation Therapy and Dosimetry
- Pneumonia and Respiratory Infections
University of Mississippi
2013-2022
Institute of High Energy Physics
2010-2017
Fermi National Accelerator Laboratory
1989-2017
IIT Research Institute
2017
Muons (United States)
2016
European Organization for Nuclear Research
2013
Campbell Collaboration
2009-2013
Johannes Gutenberg University Mainz
2009
Laboratoire d’Annecy de Physique des Particules
2002-2006
High Energy Accelerator Research Organization
2003
The status of the research on muon colliders is discussed and plans are outlined for future theoretical experimental studies. Besides continued work parameters a 3-4 0.5 TeV center-of-mass (CoM) energy collider, many studies now concentrating machine near 0.1 that could be factory s-channel production Higgs particles. We discuss various components in such colliders, starting from proton accelerator needed to generate pions heavy-Z target proceeding through phase rotation decay ($\pi \to \mu...
We present the first direct measurements of pion valence-quark momentum distribution which is related to square light-cone wave function. The were carried out using data on diffractive dissociation $500\mathrm{GeV}/c$ ${\ensuremath{\pi}}^{\ensuremath{-}}$ into dijets from a platinum target at Fermilab experiment E791. results show that $|q\overline{q}〉$ asymptotic function describes well for ${Q}^{2}\ensuremath{\sim}10(\mathrm{GeV}/c{)}^{2}$ or more. also measured transverse dijets.
We have studied the diffractive dissociation into dijets of 500 GeV/c pions scattering coherently from carbon and platinum targets. Extrapolating to asymptotically high energies (where t(min)-->0), we find that when per-nucleus cross section for this process is parametrized as sigma = sigma0Aalpha, alpha has values near 1.6, exact result depending on jet transverse momentum. These are in agreement with those predicted by theoretical calculations color-transparency.
We measure forward cross sections for production of ${D}^{+}$, ${D}^{0}$, ${D}_{s}$, ${D}^{*+}$, and ${\ensuremath{\Lambda}}_{c}$ in collisions ${\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}$, ${K}^{\ifmmode\pm\else\textpm\fi{}}$, $p$ on a nuclear target. Production induced by different beam particles is found to be the same within statistics. Strange baryonic final states are seen contribute appreciably total charm section, which our measurements indicate larger than but consistent with...
A leading charm meson is one with longitudinal momentum fraction, xF>0, whose light quark (or antiquark) of the same type as quarks in beam particles. We report on production asymmetry, A=[σ(leading-σ(nonleading)]/[σ(leading)+σ(nonleading)] a function xF. The data consist 1500 fully reconstructed D± and D*± decays Fermilab experiment E 769. find significant asymmetry for not expected perturbative quantum chromodynamics.Received 22 October...
We measure the differential cross sections with respect to Feynman $x$ ( ${x}_{F}$) and transverse momentum ${p}_{T}$) for $\ensuremath{\pi}$, $K$, $p$-induced charm meson production using fully reconstructed ${D}^{+}$, ${D}^{0}$, ${D}_{s}$ decays. The shapes of these are compared theoretical predictions quark next-to-leading order perturbative QCD modern parametrizations pion nucleon parton distributions. observe differences expected in induced by projectiles different gluon distributions,...
We report the result of a search for D0 - D0_bar mixing in data from hadroproduction experiment E791 at Fermilab. use D* tag and semileptonic decay vertices to look wrong-sign decays with time dependence.
We measure the relative cross sections for D mesons produced in interactions of ${\mathrm{\ensuremath{\pi}}}^{\mathrm{\ensuremath{-}}}$ and ${\mathrm{\ensuremath{\pi}}}^{+}$ beams with targets Be, Cu, Al, W. The measurement is based on 1400 fully reconstructed decays types ${\mathit{D}}^{0}$\ensuremath{\rightarrow}${\mathit{K}}^{\mathrm{\ensuremath{-}}}$${\mathrm{\ensuremath{\pi}}}^{+}$,...
We have designed a threshold Cherenkov detector at the Rutherford-Appleton Laboratory to identify muons with momenta between 230 and 350 MeV/c. investigated properties of three aerogels for design. The nominal indices refraction were <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</i> = 1.03, 1.07, 1.12, respectively. Two samples are high density aerogel not commonly used light detection. present results an examination some optical basic test...
We propose the construction of, and describe in detail, a compact Muon Collider s-channel Higgs Factory.
We present results of a search for D0-D0bar mixing and doubly-Cabibbo-suppressed decays the D0 in Fermilab experiment E791, fixed-target charm hadroproduction experiment. look evidence decay chain D* -> pi (K or K pi). If charge pion from is same as kaon D (a ``wrong-sign'' event), may have occurred. Mixing can be distinguished other sources wrong-sign events (such decays) by analyzing distribution times. see no mixing. Allowing possible CP violation, our r_{mix}, ratio mixed to unmixed...
We report results of the first search for pentaquark P_{{c bar}s} which is predicted to be a doublet states: P^0_{{c bar}s}=({c bar} s u d) and P^-_{{c d u). A was made decay --> phi,pi,p in data from Fermilab experiment E791, 500 GeV/c pi^- beam interacted with nuclear targets. present upper limits at 90% confidence level ratio cross section times branching fraction this that D_s phi,pi. The are 0.031 0.063 M(P^0_{{c bar}s}) = 2.75 2.86 GeV/c^2, respectively, assuming lifetime 0.4 ps.
We measure the differential cross section with respect to Feynman-x (xF) and transverse momentum (PT) for charm meson production using targets of Be, Al, Cu, W. In range 0.1<xF<0.7, dσ/dxF is well fit by form (1-xF)n n=3.9±0.3. The difference between n values D− D+ 1.1±0.7. However, we find an asymmetry 0.18±0.06 favoring compared D+. lower PT range, <2 GeV, dσ/dP2T exp(-b×P2T) b=1.03±0.06 GeV−2, while in higher 0.8 3.6 it exp(-b’×PT) b’=2.76±0.08 GeV−1. shape has no significant dependence...
A model-independent partial-wave analysis of the S-wave component Kπ system from decays D + mesons to three-body K -π π final state is described.Data come Fermilab E791 experiment.Amplitude measurements are made independently for ranges invariant mass, and results obtained below 825 MeV/c 2 , where previous exist only in two mass bins.This method parametrizing a decay amplitude represents new approach analysing such decays.Though no model required S-wave, parametrization relatively...
A complete scheme for production and cooling a muon beam three specified colliders is presented. Parameters these are given. The starts with the front end of proposed neutrino factory that yields bunch trains both signs. Emittance exchange in slow helical lattices reduces longitudinal emittance until it becomes possible to merge into single bunches, one each sign. Further all dimensions applied bunches further lattices. Final transverse required parameters achieved 50 T solenoids using high...
A complete scheme for production and cooling a muon beam three specified colliders is presented. Parameters these are given. The starts with the front end of proposed neutrino factory that yields bunch trains both signs. Emittance exchange in slow helical lattices reduces longitudinal emittance until it becomes possible to merge into single bunches, one each sign. Further all dimensions applied bunches further lattices. Final transverse required parameters achieved 50 T solenoids using high...
The ability of high temperature superconducting (HTS) conductor to carry currents at low temperatures makes feasible the development very field magnets for uses in accelerators and beam-lines. A specific application a solenoid is provide small beta region final cooling stages muon collider. Since ionization acts simultaneously on both transverse planes, any improvement maximum has quadratic consequence reduction 6-dimensional (6D) beam emittance. This paper describes conceptual design 45...
Offline software using Transmission Control Protocol/Internet Protocol (TCP/IP) sockets to distribute particle physics events multiple UNIX/RISC workstations is described. A modular, building block approach was taken that allowed tailoring solve specific tasks efficiently and simply as they arose. The modest, initial cost having learn about for interprocess communication. This multiprocessor management has been used control the reconstruction of eight billion raw data from Fermilab Experiment E791.
Muon acceleration from 30 to 750 GeV in 72 orbits using two rings the 1000 m radius Tevatron tunnel is explored. The first ring ramps at 400 Hz and accelerates muons 28 14 GV of 1.3 GHz superconducting RF. duplicates Fermilab main FODO lattice, which had a 61 cell length. survival 80%. second 44 8 T/m quadrupoles are lengthened 87% 3.3 m. four dipoles each half replaced by three ramp 550 -1.8 T +1.8T interleaved with fixed dipoles. ramping oppose other act unison GeV. 92%. Two mm copper...