相关论文: Invisible Quarkonium Decays as a Sensitive Probe o…
We investigate constraints on the interactions of light dark matter with Standard Model quarks in a framework with effective contact operators mediating the decay of heavy flavor bound state quarkonium to dark matter and a photon. When…
We estimate the most important corrections to the branching ratios for the invisible decays of quarkonium states, arising from possible extensions of the standard model. Among the possibilities considered are the presence of extra Z-bosons,…
We search for a light scalar particle produced in single-photon decays of the Upsilon(3S) resonance through the process Upsilon(3S) -> gamma A0, A0 -> invisible. Such an object appears in Next-to-Minimal Supersymmetric extensions of the…
We search for single-photon decays of the Upsilon(1S) resonance, Upsilon->gamma+invisible, where the invisible state is either a particle of definite mass, such as a light Higgs boson A0, or a pair of dark matter particles, chi chi-bar.…
Production mechanisms for quarkonium states in hadronic collisions remain difficult to understand. The decay angular distributions of J/$\psi$ or $\Upsilon(nS)$ states into $\mu^+ \mu^-$ final states are sensitive to the matrix elements in…
Invisible psi and Upsilon decays into light neutralinos, within the MSSM or N(n)MSSM, are smaller than for nu nubar production, even if light spin-0 particles are coupled to quarks and neutralinos. In a more general way, light dark matter…
We point out the physics opportunities of future high-luminosity B-factories at the Upsilon(5S) resonance and above. In this paper we discuss numerous interesting investigations, which can be performed in the e+e- centre-of-mass energy…
psi and Upsilon decays may be used to search for light neutral spin-1 or spin-0 bosons associated with a broken extra-U(1) symmetry, local or global, acting axially on quarks and leptons, as may be present in supersymmetric theories with a…
We examine decays of a spin-1 bottomonium into a pair of light scalar Dark Matter (DM) particles, assuming that Dark Matter is produced due to exchange of heavy degrees of freedom. We perform a model-independent analysis and derive formulae…
We search for the flavor-changing neutral-current decays B->K(*)nu nubar, and the invisible decays J/psi->nu nubar and psi(2S)->nu nubar via B->K(*)J/psi and B->K(*)psi(2S) respectively, using a data sample of 471 x10^6 BB pairs collected…
We search for a new light non-Standard Model CP-odd Higgs boson, $A^0$, decaying to $\tau^+\tau^-$, $\mu^+\mu^-$, and invisible in radiative decays of the $\Upsilon(2S)$ and $\Upsilon(3S)$. We search for the light scalar particle produced…
We present a measurement of the branching fraction of invisible Upsilon(1S) decays, using 1.2 fb^{-1} of data collected at the Upsilon(2S) resonance with the CLEO III detector at CESR. After subtracting expected backgrounds from events that…
Light bosons can be found in large classes of theories beyond the Standard Model. These light bosons may not be ruled out by current experiments and, indeed, may even provide an explanation for some anomalous experimental results. The…
The suppression of heavy quarkonia e.g. $J/\psi$, $\Upsilon$ etc. is considered as a suitable probe to identify the nature of the matter created in heavy ion collisions. Recently we have presented a modified colour screening model for…
We compute the branching fractions of vector quarkonia ($V_Q=J/\psi, \psi', \Upsilon(nS)$) decays into neutrino pairs, considering both Dirac and Majorana types, within the Standard Model (SM) and beyond. The vector nature of quarkonium…
Heavy-quark spin symmetry (HQSS) implies that in the direct decay of a heavy quarkonium with spin $S$, only lower lying heavy quarkonia with the same spin $S$ can be produced. However, this selection rule, expected to work very well in the…
We investigate light dark matter production associated with a heavy quarkonium at B factories in a model-independent way by adopting the effective field theory approach for the interaction of dark matter with standard model particles. We…
Differential production cross sections of J/$\psi$ and $\psi$(2S) charmonium and $\Upsilon$(nS) (n = 1, 2, 3) bottomonium states are measured in proton-proton collisions at $\sqrt{s} =$ 13 TeV, with data collected by the CMS detector at the…
The production yields of Upsilon(1S), Upsilon(2S), and Upsilon(3S) quarkonium states are measured through their decays into muon pairs in the CMS detector, in PbPb and pp collisions at the centre-of-mass energy per nucleon pair of 2.76 TeV.…
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…