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Xiao-Rong Lv

Publications and source records attributed to Xiao-Rong Lv.

4 recordsLinked to original sources

A novel approach to determine photon polarization at collider experiments

The polarization of final-state photons is a critical observable for probing the fundamental mechanisms of particle and nuclear interactions, providing insights into spin and parity structure that are inaccessible through cross-section measurements alone. However, this observable remains largely unexplored in collider experiments, as general-purpose spectrometers traditionally lack the capability to measure it. This paper proposes a novel technique to integrate photon polarimeter function into such a spectrometer without compromising the spectrometer's conventional performance. Key factors to enhance the polarimeter capability are investigated. This successful integration represents the first implementation of a photon polarimeter within a general-purpose spectrometer, establishing a valuable benchmark for the existing and future experiments. The ability to concurrently measure spin polarization and four-momentum data opens a new dimension for analysis, promising a more profound understanding of the underlying physics.

hep-ex

A novel design of general-purpose spectrometer with nucleon polarimeter function

The spin polarization of hadrons is a key observable for probing the details of particle and nuclear interactions, offering information not available from other measurements. Currently, general-purpose spectrometers lack the capability to access final-state polarization. A novel technique to measure nucleon polarization within such a spectrometer has been proposed. Using this technique, a new design based on the proposed hyperon-nucleon spectrometer is developed. Systematic optimization confirms that the nucleon polarimeter functions effectively without impairing the detector's conventional performance. This successful integration, the first attempt of the general-purpose spectrometer, sets a valuable benchmark for future experiments. Ultimately, correlating spin polarization with four-momentum data will lead to a more profound understanding of the underlying physics.

hep-ex

How to determine nucleon polarization at existing collider experiments?

We propose a novel approach to measure spin polarization of nucleons produced in electron--positron collisions. Using existing tracking devices and supporting structure material, general-purpose spectrometers can be utilized as a large-acceptance polarimeter without hardware upgrade. With the proposed approach, the spin polarization of nucleons can be revealed, providing a complementary and accurate description of the final-state particles. This could have far-reaching implications, such as enabling the complete determination of the time-like electromagnetic form factors of nucleons.

hep-ph

X-ray properties of the quasar HE0450-2958

We present an {\it XMM-Newton} EPIC observation of HE0450-2958 which may be a ``naked''quasar as suggested by Magain et al. The \xmm EPIC spectra show a substantial soft X-ray excess, a steep photon index, as well as marginal evidence for a weak Fe K$α$ line. The X-ray absorption is consistent with the galactic level. The 0.3-10 keV EPIC spectra can be fitted by a power law plus a blackbody model, however, the fit by the relativistically blurred photoionized disc reflection is better. We estimate the black hole mass of $2^{+7}_{-1.3} \times 10^{7} M_{\odot}$ from the X-ray variability. This broadly agrees with the value derived from the optical \hb line width. These results support a high-state Seyfert galaxy of the source. HE0450-2958 shares similar properties of transitionary objects from ultra-luminous infrared galaxies to quasars. We suggest that HE0450-2958 is just in the beginning of an optical quasar window.

astro-ph