相关论文: On semi-exclusive measurement of $\gamma\gamma\to\…
We discuss several possible extensions of present studies of $\gamma \gamma \to \gamma \gamma$ scattering in ultraperipheral heavy ion collisions. One of the possible extensions are studies for lower diphoton invariant masses (smaller…
We present a theoretical estimation for the cross-section of exclusive two $\rho$-meson production in two photon collision when one of the initial photons is highly virtual. The compatibility of our analysis with recent experimental data…
A semi-classical picture is given for the production of exclusive meson pairs in \gamma\gamma^* scattering using elements of the Lund string fragmentation model, spin and C-parity conservation. The model can be generalized to the production…
An experimental study of $\omega$ photoproduction on the proton was conducted by using the Crystal Ball and TAPS multiphoton spectrometers together with the photon tagging facility at the Mainz Microtron MAMI. The $\gamma p\to\omega p$…
The exclusive production of baryon antibaryon pairs in the collisions of two quasi-real photons have been studied in different experiments at e+e- colliders. Results are presented for the processes gamma gamma to proton antiproton and gamma…
Exclusive $\gamma\gamma \to$ hadron pairs are among the most fundamental processes in QCD, providing a detailed examination of Compton scattering in the crossed channel. In the high momentum transfer domain $(s,t, {large},\theta_{cm}$ for…
We study the feasibility of measuring semi-exclusive photon production \gamma + p \to \gamma + Y at HERA. The cross section of photons produced at large transverse momenta, recoiling off an inclusive system Y of limited mass, can without…
Tagging two-photon production offers a significant extension of the LHC physics programme. Effective luminosity of high-energy gamma-gamma collisions reaches 1% of the proton-proton luminosity and the standard detector techniques used for…
We report the first observation of Z/gamma* production in Compton scattering of quasi-real photons. This is a subprocess of the reaction e+e- to e+e-Z/gamma*, where one of the final state electrons is undetected. Approximately 55 pb-1 of…
We discuss diphoton semi(exclusive) production in ultraperipheral lead-lead collisions at energy of $\sqrt{s_{NN}}$ = 5.5 TeV (LHC) and in proton-proton collisions at $\sqrt{s_{pp}}$ = 7 TeV (LHC) and $\sqrt{s_{pp}}$ = 100 TeV (FCC). The…
The process e+e- -> gamma gamma (gamma) is studied using data collected by the OPAL detector at LEP between the years 1997 and 2000. The data set corresponds to an integrated luminosity of 672.3pb-1 at centre-of-mass energies lying between…
We analyze the LHC prospects for measurements of the $t\bar{t}$ pair produced exclusively in photon-photon or semi-exclusively in photon-Pomeron and Pomeron-Pomeron processes using protons tagged in forward proton detectors on both sides of…
The nuclear two-photon or double-gamma ($2\gamma$) decay is a second-order electromagnetic process whereby a nucleus in an excited state emits two gamma rays simultaneously. To be able to directly measure the $2\gamma$ decay rate in the…
Exclusive hadron production processes in photon-photon collisions provide important tests of QCD at the amplitude level, particularly as measures of hadron distribution amplitudes and skewed parton distributions. The determination of the…
At the Mott transition of a quark/meson plasma, mesons become unbound. This leads to the effect of critical scattering, which is studied by investigating photon pair production due to the process $q\bar q\to\gamma\gamma$. This process can…
Possibilities of observing a signal of an $\eta ^{\prime} n$ bound state are investigated by considering photoproductions of the $\eta$ and $\eta ^{\prime}$ mesons on a deuteron target with forward proton emission. For this purpose, we take…
We consider Semi-Exclusive Deeply Virtual Compton Scattering, gamma* p \to gamma Y (SECS), where Y is an inclusive state of intermediate mass, \Lambda_QCD << m_Y << Q. When the photon is produced with a large transverse momentum k_T \sim…
This is a short review of some hard two-photon processes: $\\ a) \,\,\gamma\gamma\to {\overline P}_1 P_2,\,\, {\overline P}_1 P_2= \{\pi^+\pi^-, K^+ K^-, K_S K_S, \pi^o\pi^o, \pi^o\eta\}\,, \\ b) \,\,\gamma\gamma\to V_1 V_2,\,\, V_1…
The exclusive production of proton-antiproton pairs in the collisions of two quasi-real photons has been studied using data taken at sqrt(s_ee) = 183 GeV and 189 GeV with the OPAL detector at LEP. Results are presented for proton-antiproton…
The two-photon exclusive production of charged supersymmetric pairs at the LHC has a clean and unique signature - two very forward scattered protons and two opposite charged leptons produced centraly. For low-mass SUSY scenarios,…