12619305
Scattering of noncommutative solitons in 2+1 dimensions
Abstract Interactions of noncommutative solitons in a modified U ( n ) sigma model in 2+1 dimensions can be analyzed exactly. Using an extension of the dressing method, we construct explicit time-dependent solutions of its noncommutative field equation by iteratively solving linear equations. The approach is illustrated by presenting bound states and right-angle scattering configurations for two noncommutative solitons.
120112297
Fundamental chiral strings
The problem of the non-uniqueness of the string theory in the space Rd-1,1 with d ≤ 10 and the procedure of the compactification and the deompactification are discussed. We consider a compact bosonic string defined as a closed string moving in the Lorentizian torus T25,1 and introduce fundamental chiral bosonic string (FCBS) as a universal cover of a compact string. It is shown that the Fock spaces of any standard strings are embedded into the Fock space of FCBS.
8413784
Noncommutative instantons in higher dimensions, vortices and topological K-cycles
We construct explicit BPS and non-BPS solutions of the U(2k) Yang-Mills equations on the noncommutative space 2nθ × S2 with finite energy and topological charge. By twisting with a Dirac multi-monopole bundle over S2, we reduce the Donaldson-Uhlenbeck-Yau equations on 2nθ × S2 to vortex-type equations for a pair of U(k) gauge fields and a bi-fundamental scalar field on 2nθ. In the SO(3)-invariant case the vortices on 2nθ determine multi-instantons on 2nθ × S2. We show that these solutions give natural physical realizations of Bott periodicity and vector bundle modification in topological K-homology, and can be interpreted as a blowing-up of D0-branes on 2nθ into spherical D2-branes on 2nθ × S2. In the generic case with broken rotational symmetry, we argue that the D0-brane charges on 2nθ × S2 provide a physical interpretation of the Adams operations in K-theory.
14915418
On nonperturbative solutions of superstring field theory
Abstract Nonperturbative solutions to the nonlinear field equations in the NS sector of cubic as well as nonpolynomial superstring field theory can be obtained from a linear equation which includes a “spectral” parameter λ and a coboundary operator Q ( λ ). We borrow a simple ansatz from the dressing method (for generating solitons in integrable field theories) and show that classical superstring fields can be constructed from any string field  T subject merely to Q ( λ ) T =0. Following the decay of the non-BPS D9 brane in IIA theory and shifting the background to the tachyon vacuum, we repeat the arguments in vacuum superstring field theory and outline how to compute classical solutions explicitly.
121874825
Solutions of Yang-Mills and Yang-Mills-Higgs equations
15075469
Solving string field equations: new uses for old tools
It is argued that the (NS-sector) superstring field equations are integrable, i.e. their solutions are obtainable from linear equations. We adapt the 25-year-old solution-generating “dressing” method and reduce the construction of nonperturbative superstring configurations to a specific cohomology problem. The application to vacuum superstring field theory is outlined.
203032325
Search for a Higgs boson in diphoton final states with the D0 detector in 9.6 fb-1 of $p\bar{p}$ collisions at $\sqrt{s}=1.96$ TeV
We present a search for a Higgs boson decaying into a pair of photons based on 9.6 fb-1 of p-pbar collisions at sqrt(s)=1.96 TeV collected with the D0 detector at the Fermilab Tevatron Collider. The search employs multivariate techniques to discriminate signal from the non-resonant background and is separately optimized for a standard model and a fermiophobic Higgs boson. No significant excess of data above the background prediction is observed and upper limits on the product of the cross section and branching fraction are derived at the 95% confidence level as a function of Higgs boson mass. For a standard model Higgs boson with mass of 125 GeV, the observed (expected) upper limits are a factor of 12.8 (8.7) above the standard model prediction. The existence of a fermiophobic Higgs boson with mass in the 100-113 GeV range is excluded at the 95% confidence level.
29211053
Combination of CDF and D0 W-Boson Mass Measurements
We summarize and combine direct measurements of the mass of the W boson in s√=1.96TeV proton-antiproton collision data collected by CDF and D0 experiments at the Fermilab Tevatron Collider. Earlier measurements from CDF and D0 are combined with the two latest, more precise measurements: a CDF measurement in the electron and muon channels using data corresponding to 2.2fb−1 of integrated luminosity, and a D0 measurement in the electron channel using data corresponding to 4.3fb−1 of integrated luminosity. The resulting Tevatron average for the mass of the W boson is $MW = 80,387 pm 16 ext{MeV}$. Including measurements obtained in electron-positron collisions at LEP yields the most precise value of $MW = 80,385 pm 15 ext{MeV}$.
3911219
Direct measurement of the mass difference between top and antitop quarks.
We present a measurement of the mass difference between t and t[over] quarks in lepton + jets final states of tt[over] events in 1 fb;{-1} of data collected with the D0 detector from Fermilab Tevatron Collider pp[over] collisions at sqrt[s] = 1.96 TeV. The measured mass difference of 3.8 +/- 3.7 GeV is consistent with the equality of t and t[over ] masses. This is the first direct measurement of a mass difference between a quark and its antiquark partner.
12120470
Search for the standard model Higgs boson in tau final states.
We present a search for the standard model Higgs boson using hadronically decaying tau leptons, in 1 fb(-1) of data collected with the D0 detector at the Fermilab Tevatron pp collider. We select two final states: tau+/- plus missing transverse energy and b jets, and tau+ tau- plus jets. These final states are sensitive to a combination of associated W/Z boson plus Higgs boson, vector boson fusion, and gluon-gluon fusion production processes. The observed ratio of the combined limit on the Higgs production cross section at the 95% C.L. to the standard model expectation is 29 for a Higgs boson mass of 115 GeV.
1879572
Search for large extra dimensions via single photon plus missing energy final states at sqrt s = 1.96 TeV.
We report on a search for large extra dimensions in a data sample of approximately 1 fb(-1) of pp[over] collisions at sqrt s=1.96 TeV. We investigate Kaluza-Klein graviton production with a photon and missing transverse energy in the final state. At the 95% C.L. we set limits on the fundamental mass scale M(D) from 884 to 778 GeV for two to eight extra dimensions.