T. Akimoto

Bio: T. Akimoto is an academic researcher from University of Tsukuba. The author has contributed to research in topics: Collider Detector at Fermilab & Production (computer science). The author has an hindex of 57, co-authored 262 publications receiving 10319 citations.

Observation of the narrow state X(3872) → J/ψπ+π- in p̄p collisions at √s = 1.96 TeV

Abstract: The observation of a state consistent with X(3872) decaying into J/ψπ+π- was reported. The X(3872) mass was measured to be 3871.3±0.7(stat)±0.4(syst)MeV/c2 from a sample of 730±90 candidates. The observed width was consistent with the detector resolution. The results were found to be converging well with the measurements by the Belle Collaboration using b± decays.

Measurement of the J/ψ meson and b-hadron production cross sections in pp̄ collisions at √s = 1960 GeV

Abstract: The authors present a new measurement of the inclusive and differential production cross sections of J/{psi} mesons and b-hadrons in proton-antiproton collisions at {radical}s = 1960 GeV The data correspond to an integrated luminosity of 397 pb{sup -1} collected by the CDF Run II detector They find the integrated cross section for inclusive J/{psi} production for all transverse momenta from 0 to 20 GeV/c in the rapidity range |y| 125 GeV/c They find the total cross section for b-hadrons, including both hadrons and anti-hadrons, decaying to J/{psi} with transverse momenta greater than 125 GeV/c in the rapidity range |y(J/{psi})| < 06, is 0330 {+-} 0005(stat){sub -0033}{sup +0036}(syst) {mu}b Using a Monte Carlo simulation of the decay kinematics of b-hadrons to all final states containing a J/{psi}, they extract the first measurement of the total single b-hadron cross section down to zero transverse momentum at {radical}s = 1960 GeV They find the total single b-hadron cross section integrated over all transverse momenta for b-hadrons in themore » rapidity range |y| < 06 to be 176 {+-} 04(stat){sub -23}{sup +25}(syst) {mu}b« less

Measurement of the J/psi meson and b-hadron production cross sections in p(p)over-bar collisions at root s=1960 GeV RID C-1693-2008 RID G-1087-2011 RID E-4473-2011

Abstract: We present a new measurement of the inclusive and differential production cross sections of $J/\ensuremath{\psi}$ mesons and $b$ hadrons in proton-antiproton collisions at $\sqrt{s}=1960\text{ }\text{ }\mathrm{G}\mathrm{e}\mathrm{V}$. The data correspond to an integrated luminosity of $39.7\text{ }\text{ }{\mathrm{p}\mathrm{b}}^{\ensuremath{-}1}$ collected by the CDF run II detector. We find the integrated cross section for inclusive $J/\ensuremath{\psi}$ production for all transverse momenta from 0 to $20\text{ }\text{ }\mathrm{G}\mathrm{e}\mathrm{V}/c$ in the rapidity range $|y|l0.6$ to be $4.08\ifmmode\pm\else\textpm\fi{}0.02(\mathrm{s}\mathrm{t}\mathrm{a}\mathrm{t}{)}_{\ensuremath{-}0.33}^{+0.36}(\mathrm{s}\mathrm{y}\mathrm{s}\mathrm{t})\text{ }\text{ }\ensuremath{\mu}\mathrm{b}$. We separate the fraction of $J/\ensuremath{\psi}$ events from the decay of the long-lived $b$ hadrons using the lifetime distribution in all events with ${p}_{T}(J/\ensuremath{\psi})g1.25\text{ }\text{ }\mathrm{G}\mathrm{e}\mathrm{V}/c$. We find the total cross section for $b$ hadrons, including both hadrons and antihadrons, decaying to $J/\ensuremath{\psi}$ with transverse momenta greater than $1.25\text{ }\text{ }\mathrm{G}\mathrm{e}\mathrm{V}/c$ in the rapidity range $|y(J/\ensuremath{\psi})|l0.6$ is $0.330\ifmmode\pm\else\textpm\fi{}0.005(\mathrm{s}\mathrm{t}\mathrm{a}\mathrm{t}{)}_{\ensuremath{-}0.033}^{+0.036}(\mathrm{s}\mathrm{y}\mathrm{s}\mathrm{t})\text{ }\text{ }\ensuremath{\mu}\mathrm{b}$. Using a Monte Carlo simulation of the decay kinematics of $b$ hadrons to all final states containing a $J/\ensuremath{\psi}$, we extract the first measurement of the total single $b$-hadron cross section down to zero transverse momentum at $\sqrt{s}=1960\text{ }\text{ }\mathrm{G}\mathrm{e}\mathrm{V}$. We find the total single $b$-hadron cross section integrated over all transverse momenta for $b$ hadrons in the rapidity range $|y|l0.6$ to be $17.6\ifmmode\pm\else\textpm\fi{}0.4(\mathrm{s}\mathrm{t}\mathrm{a}\mathrm{t}{)}_{\ensuremath{-}2.3}^{+2.5}(\mathrm{s}\mathrm{y}\mathrm{s}\mathrm{t})\text{ }\text{ }\ensuremath{\mu}\mathrm{b}$.

Search for new particles decaying into dijets in proton-antiproton collisions at s=1.96TeV

Abstract: We present a search for new particles whose decays produce two jets (dijets) using proton-antiproton collision data corresponding to an integrated luminosity of 1.13 fb-1 collected with the CDF II detector. The measured dijet mass spectrum is found to be consistent with next-to-leading-order perturbative QCD predictions, and no significant evidence of new particles is found. We set upper limits at the 95% confidence level on cross sections times the branching fraction for the production of new particles decaying into dijets with both jets having a rapidity magnitude |y| < 1. These limits are used to determine the mass exclusions for the excited quark, axigluon, flavor-universal coloron, E6 diquark, color-octet technirho, W', and Z'.

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

Parton distributions for the LHC

Abstract: We present updated leading-order, next-to-leading order and next-to-next-to-leading order parton distribution functions (“MSTW 2008”) determined from global analysis of hard-scattering data within the standard framework of leading-twist fixed-order collinear factorisation in the $\overline{\mathrm{MS}}$ scheme. These parton distributions supersede the previously available “MRST” sets and should be used for the first LHC data taking and for the associated theoretical calculations. New data sets fitted include CCFR/NuTeV dimuon cross sections, which constrain the strange-quark and -antiquark distributions, and Tevatron Run II data on inclusive jet production, the lepton charge asymmetry from W decays and the Z rapidity distribution. Uncertainties are propagated from the experimental errors on the fitted data points using a new dynamic procedure for each eigenvector of the covariance matrix. We discuss the major changes compared to previous MRST fits, briefly compare to parton distributions obtained by other fitting groups, and give predictions for the W and Z total cross sections at the Tevatron and LHC.

The ATLAS Experiment at the CERN Large Hadron Collider

Abstract: The ATLAS detector as installed in its experimental cavern at point 1 at CERN is described in this paper. A brief overview of the expected performance of the detector when the Large Hadron Collider begins operation is also presented.

The ATLAS Experiment at the CERN Large Hadron Collider

Abstract: This paper describes the ATLAS experiment as installed in i ts experimental cavern at point 1 at CERN. It also presents a brief overview of the expec ted performance of the detector.