arXiv subjects

Claudia Patrignani

Publications and source records attributed to Claudia Patrignani.

3 recordsLinked to original sources

arXiv2012

Recent Results in Bottomonium

Great strides have been made in the understanding of bound states of a bottom quark $b$ and its antiquark $\bar b$ since the discovery of the first $Υ$ resonances in 1977. These {\it bottomonium} bound states have a rich spectrum whose masses and transition amplitudes shed valuable light on the strong interactions. The present article reviews some recent developments in bottomonium physics. These include the discovery of the spin-singlet states $η_b$ and $h_b$, the first D-wave states, one or more candidates for spin-triplet $χ_b(3P)$ excitations, and above-threshold states with strong transitions to states below threshold. Information on transitions, production, and signatures of new physics is also presented.

hep-ex↗

arXiv2004

E835 at FNAL: Charmonium Spectroscopy in $\bar p p$ Annihilations

I present preliminary results on the search for $h_c$ in its $η_cγ$ and $J/ψπ^0$ decay modes. We observe an excess of η_cγ$ events near 3526 MeV that has a probability ${\cal P} \sim 0.001$ to arise from background fluctations. The resonance parameters are $M=3525.8 \pm 0.2 \pm 0.2 $MeV, $Γ\leq$ 1 MeV, and $10.6\pm 3.7\pm3.4(br) < Γ_{\bar{p}p}B_{η_cγ} < 12.8\pm 4.8\pm4.5(br) $eV. We find no event excess within the search region in the $J/ψπ^0$ mode.

hep-ex↗

arXiv2001

On the Particle Data Group evaluation of Psi' and chi_c Branching Ratios

I propose a new evaluation of $ψ'(2S)$ and $χ_c(1P)$ branching ratios which avoids the correlations affecting the current Particle Data Group evaluation. These correlations explain the apparent technique-dependent discrepancies between the available determinations of the ${\cal B}(χ_c(1P)\to p\bar p)$ and $Γ(χ_c(1P)\to γγ)$ under the hypotesis that the current values of the $ψ'(2S)\toχ_c(1P)γ$ branching ratios are overestimated. In the process I also noticed that Particle Data Group has not restated many of the older measurements, when necessary, for the new value of ${\cal B}(J/ψ\to l^+l^-)$, which significantly affects the evaluation of some relevant $ψ'(2S)$ and $χ_c(1P)$ exclusive branching ratios.

hep-ex↗