46 research outputs found
The Parton Model and its Applications
This is a review of the program we started in 1968 to understand and
generalize Bjorken scaling and Feynman's parton model in a canonical quantum
field theory. It is shown that the parton model proposed for deep inelastic
electron scatterings can be derived if a transverse momentum cutoff is imposed
on all particles in the theory so that the impulse approximation holds. The
deep inelastic electron-positron annihilation into a nucleon plus anything else
is related by the crossing symmetry of quantum field theory to the deep
inelastic electron-nucleon scattering. We have investigated the implication of
crossing symmetry and found that the structure functions satisfy a scaling
behavior analogous to the Bjorken limit for deep inelastic electron scattering.
We then find that massive lepton pair production in collisions of two high
energy hadrons can be treated by the parton model with an interesting scaling
behavior for the differential cross sections. This turns out to be the first
example of a class of hard processes involving two initial hadrons.Comment: Contribution to a book to be published by World Scientific for the
occasion of 50 Years of Quarks. 17 pages, 4 figure
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Public Domain Treaty Compliance Verification in the Digital Age
We explore in this article some of the emerging opportunities, and associated challenges, that the digital age offers for public-domain verification of compliance with international treaties. The increase in data volume, in ever-improving connectivity, and the relentless evolution towards ubiquitous sensors all provide a rapidly changing landscape for technical compliance verification of international treaties. From satellites to cell phones, advances in technology afford new opportunities for verifying compliance with international agreements, on topics ranging from arms control to environmental and public health issues. We will identify some of the engineering challenges that must be overcome in order to realize these new verification opportunities.Physic
Measurement of the W-boson mass in pp collisions at âs=7 TeV with the ATLAS detector
A measurement of the mass of the W boson is presented based on protonâproton collision data recorded in 2011 at a centre-of-mass energy of 7 TeV with the ATLAS detector at the LHC, and corresponding to 4.6 fbâ1 of integrated luminosity. The selected data sample consists of 7.8Ă106 candidates in the WâΌΜ channel and 5.9Ă106 candidates in the WâeÎœ channel. The W-boson mass is obtained from template fits to the reconstructed distributions of the charged lepton transverse momentum and of the W boson transverse mass in the electron and muon decay channels, yielding
mW=80370±7 (stat.)±11(exp. syst.)
±14(mod. syst.) MeV
=80370±19MeV,
where the first uncertainty is statistical, the second corresponds to the experimental systematic uncertainty, and the third to the physics-modelling systematic uncertainty. A measurement of the mass difference between the W+ and Wâbosons yields mW+âmWâ=â29±28 MeV
Nuclear weapons, scientists, and the post-Cold War challenge: selected papers on arms control
This volume includes a representative selection of Sidney Drell's recent writings and speeches (circa 1993 to the present) on public policy issues with substantial scientific components. Most of the writings deal with national security, nuclear weapons, and arms control and reflect the author's personal involvement in such issues dating back to 1960. Fifteen years after the demise of the Soviet Union, the gravest danger presented by nuclear weapons is the spread of advanced technology that may result in the proliferation of nuclear weapons. Of most concern would be their acquisition by hostile governments and terrorists who are unconstrained by accepted norms of civilized behavior. The current challenges are to prevent this from happening and, at the same time, to pursue aggressively the opportunity to escape from an outdated nuclear deterrence trap