ICHEP 2020

Measurement of rho(770) photoproduction at HERA

30 Jul 2020, 10:55

15m

virtual conference

Talk 06. Strong Interactions and Hadron Physics Strong Interactions and Hadron Physics

Speaker

Arthur Bolz (DESY)

Description

Exclusive photoproduction of $\rho (770)$ mesons is studied using the H1 detector at HERA. The analysis is based on a sample of about 900000 events that were collected in the years 2006-2007. It is used to measure single- and double-differential cross sections for the reaction $\gamma p\to {\pi }^{+}{\pi }^{-}Y$. Reactions where the proton stays intact ($M_Y=M_p$) are statistically separated from those where the proton dissociates to a low-mass hadronic system ($M_p<M_Y<10$ GeV). The double differential cross sections are measured as a function of the invariant mass $m_{\pi \pi }$ of the decay pions and the squared momentum transfer at the proton vertex $t$. These measurements are repeated in bins of the photon-proton collision energy $W_{\gamma p}$. The phase-space restrictions are $0.5<m_{\pi \pi }<2.2$ GeV, $|t|<1.5$ GeV${}^2$ and $20<W_{\gamma p}<80$ GeV. Cross-section measurements are presented for both elastic and dissociative scattering. The observed kinematic dependencies are described by analytic functions. In particular, a Soding model is used to extract the $\rho (770)$ contribution to the ${\pi }^{+}{\pi }^{-}$ cross-sections. From the resulting single-differential $\rho (770)$ cross-section as a function of $t$, measured in bins of $W_{\gamma p}$, the leading effective Regge trajectory is extracted.

Presentation materials

2020_ICHEP_RhoPhotoAtH1.pdf