相关论文: pi+ pi+, K+ K+ and B B Interactions

In the framework of an effective chiral theory of mesons, pi K scattering is stydied. The scattering lengths, phase shifts, and cross sections are calculated. Theoretical results agree well with data. There is no new parameter in this…

Analysis of charged and neutral B meson decays into pi+ pi- K, K+ K- K and K0S K0S K0S is performed using a unitary representation of the pi pi and K anti- K final state interactions. Comparison of the theoretical model with the…

K* mesons and in particular the K*(892) were frequently addressed in lattice simulations, but always while ignoring that the K*(892) decays strongly. We present an exploratory extraction of the masses and widths for the K* resonances by…

We study theoretically interaction potentials and low energy collisions between different alkali atoms and alkali ions. Specifically, we consider systems like X + Y$^{+}$, where X(Y$^{+})$ is either Li(Cs$^+$) or Cs(Li$^+$), Na(Cs$^+$) or…

We present an update on the MILC Collaboration's light hadron spectrum calculation with two flavors of dynamical, staggered quarks. We present extrapolations of the nucleon to rho mass ratio to the continuum limit for fixed values of the pi…

The $K^\pi=0^+_1$, $K^\pi=2^-$, and $K^\pi=0^-_1$ bands of $^{20}$Ne are investigated with microscopic structure and reaction calculations via proton and $\alpha$ inelastic scattering off $^{20}$Ne. Structures of $^{20}$Ne are calculated…

Fully constrained bubble chamber data on the pp -> pi+ pn and pp -> pi+ d reactions are used to investigate the ratio of the counting rates for the two processes at low pn excitation energies. Whereas the ratio is in tolerable agreement…

The coupled pi+N, eta+N, gamma+N systems are described by a K-matrix method. The parameters in this model are adjusted to get an optimal fit to pi+N -> pi+N, pi+N -> eta+N, gamma+N -> pi+N and gamma+N -> eta+N data in an energy range of…

We investigate the possibility to measure the nonforward gluon distribution function by means of diffractively produced \pi^+\pi^- and K^+K^- pairs in polarized lepton nucleon scattering. The resulting cross sections are small and are…

The pion structure function is investigated in a simple model, where the pion and its constituent quark fields are coupled through the simplest pseudoscalar coupling. The imaginary part of the forward gamma* pi -> gamma* pi scattering…

State-of-the-art lattice QCD calculations of scattering amplitudes in coupled-channel $D\pi$, $D\eta$ and $D_{s}\bar{K}$ scattering, as well elastic $DK$ scattering are discussed. The methodology employed allows a determination of the…

Usually, B->pi+pi- decays are expressed in terms of weak amplitudes explicitly dependent on the CKM weak phase alpha or gamma. In this letter, we show that the weak amplitudes can be rewritten such that a manifest dependence on beta emerges…

We present preliminary results using NRQCD to describe heavy quarks on the MILC 2+1 flavour dynamical extra coarse ensemble. We calculate the spectra of low lying states in bottomonium to complement earlier results on the finer MILC…

We present an update of the Fermilab-MILC Collaboration's calculation of hadronic matrix elements for B^0-\bar{B^0} mixing. This work is a more extended analysis than our recent publication of the SU(3)-breaking ratio xi [arXiv:1205.7013].…

We study $S$-wave interactions in the $I\left(J^{p}\right)=1/2\left(1/2^{-}\right)$ $\Lambda_{c}K^{+}-pD_{s}$ system on the basis of the coupled-channel HAL QCD method. The potentials which are faithful to QCD S-matrix below the $ pD^{*} $…

We review recent results for B_d and B_s mixing parameters using MILC N_f=2+1 lattices, NRQCD b-quarks and AsqTad light quarks. Latest numbers for decay constants f_B and f_{B_s} are also presented. Combining our lattice results with…

We give an update on our calculation of $B_K$ using HYP-smeared valence staggered quarks. We have results for $B_K$ at tree-level on several coarse MILC lattices ($a\approx 0.12 $fm) and one of the fine lattices ($a\approx 0.09 $fm), using…

We present an update for results on $B$-meson semileptonic decays using the highly improved staggered quark (HISQ) action for both valence and 2+1+1 sea quarks. The use of the highly improved action, combined with the MILC collaboration's…

Semileptonic, B --> pi l,nu, decays are studied on the MILC dynamical configurations using NRQCD heavy and Asqtad light quarks. We work with light valence quark masses ranging between m_s and m_s/8. Preliminary simple linear chiral…

The scaling corrections that affected previous staggered calculations of B_K have been proved to be reduced by using improved actions (HYP, Asqtad) in the quenched approximation. This improved behaviour allows us to perform a reliable…