相关论文: Bottomonium dipion transitions
We use 111+/-1 million Upsilon(3S) and 89+/-1 million Upsilon(2S) events recorded by the BaBar detector at the PEP-II B-factory at SLAC to perform a study of radiative transitions between bottomonium states using photons that have been…
We point out some properties of the amplitude of the dipion transition $\Upsilon(3S) \to \Upsilon(1S) \pi \pi$ in relation to the recently reported results of a CLEO analysis of form factors in this amplitude. We find that the reported…
The di-pion spectrum for the $\Upsilon(nS) \to \Upsilon (n'S))$ transition with $n\leq 4$ has the form $\frac{dw}{dq}\sim $ (phase space) $ |\eta-x|^2$, with $x=\frac{q^2-4m^2_\pi}{(\Delta M)^2 -4 m^2_\pi}< q^2 \equiv M^2_{\pi\pi}, $ and…
We study the dipion transitions $\Upsilon(4S) \rightarrow \Upsilon(nS) \pi^+\pi^-$ $(n=1,2)$. In particular, we consider the effects of the two intermediate bottomoniumlike exotic states $Z_b(10610)$ and $Z_b(10650)$ as well as bottom meson…
The bottomonium spectrum is systematically studied within an unquenched quark model. Based on a good description of both the masses and widths for the well-established states, we further give predictions for the higher $S$-, $P$-, and…
Under the Initial Single Pion Emission mechanism, we study the hidden-bottom dipion decays of $\Upsilon(11020)$, i.e., $\Upsilon(11020)\to \Upsilon(nS)\pi^+\pi^-$ $(n=1,2,3)$ and $\Upsilon(11020)\to h_b(mP)\pi^+\pi^-$ $(m=1,2)$. We predict…
The coulomb plus linear (Cornell) potential is used to investigate the mass spectrum of bottomonium. Gaussian wave function is used in position and momentum space to estimate values of potential and kinetic energies, respectively. Based on…
We have searched for the di-pion transition chi_b(2P) -> pi pi chi_b(1P) in the CLEO III sample of Upsilon(3S) decays in the exclusive decay chain: Upsilon(3S) -> gamma chi_b(2P), chi_b(2P) -> pi pi chi_b(1P), chi_b(1P) -> gamma…
New Physics can show up in various well-known processes already studied in the Standard Model, in particular by modifying decay rates to some extent. In this work, I examine leptonic decays of $\Upsilon$ vector resonances of bottomonium…
We present studies in bottomonium spectroscopy carried out with samples of $(98\pm1)$ million $\Upsilon(2S)$ and $(121\pm1)$ million $\Upsilon(3S)$ events recorded with the BaBar detector at the PEP-II asymmetric-energy $e^+ e^-$ collider…
Assuming the QCD multipole expansion is applicable to hadronic transitions of Upsilon(3S) into lower level bottomonia, we consider the possibility that Upsilon(3S) has a D-wave component. This assumption leads to a natural explanation of…
We search for di-muon decays of a low-mass Higgs boson (A^0) produced in radiative \Upsilon(1S) decays. The \Upsilon(1S) sample is selected by tagging the pion pair in the \Upsilon(2S, 3S) \to \pi^+ \pi^- \Upsilon(1S) transitions, using a…
Two-pion transitions in charmonium and bottomonium are considered with the leading relativistic effects taken into account. The contribution of the chromo- magnetic interaction of the charmed quarks to the amplitude of the decay $\psi(2S)…
In order to explain the observed unusually large dipion transition rates of $\Upsilon(10870)$, the scalar resonance contributions in the re-scattering model to the dipion transitions of $\Upsilon(4S)$ and $\Upsilon(5S)$ are studied. Since…
The bottomonium spectrum, consisting of bound states of a $b$ quark and an anti-$b$ quark, provides an excellent laboratory for probing quantum chromodynamics in the non-perturbative regime. While $S$ and $P$-wave bottomonium states are…
We investigate the modification of S and P wave states in the bottomonium spectrum above and below the deconfinement crossover temperature through their spectral functions obtained from the maximum entropy method. Anisotropic ensembles with…
We search for evidence of a light scalar boson in the radiative decays of the Upsilon(2S) and Upsilon(3S) resonances: Upsilon(2S,3S)-> gamma A0, A0 -> mu^+ mu^-. Such a particle appears in extensions of the Standard Model, where a light…
We report about the studies of the decay channels B- -> D0 K-, B0 -> D*- a1+ and B0 -> Ds(*)- pi+ with a sample of 62.10^6 Upsilon(4S) decays into B meson pairs collected with the BaBar detector at the PEP II asymmetric e+ e- collider.
In the framework of the spectral integral equation, we consider the $b\bar b$ states and their radiative transitions. We reconstruct the $b\bar b$ interaction on the basis of data for the levels of the bottomonium states with…
We study some possible experimental consequences of new physics on the spectrum and decays of bottomonium states below $B\bar{B}$ threshold. In addition to lepton universality breaking in Upsilon decays, large widths of pseudoscalar…