Fri·Oct 3, 2014Friday·October 3, 2014

1. 01*

   Centrality Dependence of Particle Production in p--A collisions measured by ALICE

   Alberica Toia (for the ALICE Collaboration)🇩🇪

   We present the centrality dependence of particle production in p-A collisions at sqrt(s_NN) = 5.02 TeV measured by the ALICE experiment, including the pseudo-rapidity and transverse momentum spectra, with a special emphasis on the event classification in centrality classes and its implications for the interpretation of the nuclear effects.

   nucl-exNPA(2014)·15 citations
2. 02*

   QCD sum rule Study of the $d^{\ast }(2380)$

   Hua-Xing Chen🇨🇳 · Er-Liang Cui🇨🇳 · Wei Chen🇨🇦 · T. G. Steele🇨🇦 · Shi-Lin Zhu🇨🇳

   We systematically construct $I(J^P)=0(3^{+})$ six-quark local interpolating currents without derivative operators. We discuss the best choice of operator, and select three $\Delta$-$\Delta$ like operators to perform QCD sum rule analyses to calculate the mass of the $d^{\ast }(2380)$. The mass extracted from this analysis is $M_{d^{\ast }}=2.4\pm 0.2$ GeV, consistent with the $d^{\ast }(2380)$ mass observed by the WASA detector at COSY. We also obtain a sum-rule lower mass bound $M_{d^{\ast }}>2.25$ GeV. We also consider the effect of mixing of singlet dibaryon fields with the same quantum numbers, and perform the QCD sum rule analysis of the mixed interpolating current and extract the mass of the $d^{\ast }(2380)$ and its lower mass bound. With optimized mixing parameters, we find that the mixed current does not change the numerical result significantly.

   ↳ hep-phhep-exnucl-exPRC(2015)·66 citations
3. 03*

   Internal structure of exotic hadrons by high-energy exclusive reactions

   H. Kawamura🇯🇵 · S. Kumano🇯🇵 · T. Sekihara🇯🇵

   We propose to use high-energy exclusive reactions for probing internal structure of exotic hadron candidates. First, the constituent counting rule of perturbative QCD can be used for finding internal configurations of an exotic hadron candidate. It is because the number of constituents ($n$), which participate in the exclusive reaction, is found by the scaling behavior of the cross section $d\sigma /dt\propto 1/s^{n-2}$ at large momentum transfer, where $s$ is the center-of-mass energy squared. As an example, we show that the internal structure of $\Lambda (1405)$ should be found, for example, by the reaction ${\pi }^{-}+p\to K^0+\Lambda (1405)$. Second, the internal structure of exotic hadron candidates should be investigated by hadron tomography with generalized parton distributions (GPDs) and generalized distribution amplitudes (GDAs) in exclusive reactions. Exotic nature should be reflected in the GPDs which contain two factors, longitudinal parton distributions as indicated by the constituent counting rule and transverse form factors as suggested by the hadron size. The GDAs should be investigated by the two-photon process ${\gamma }^{\ast }\gamma \to h\bar{h}$, for example $h=f_0$ or $a_0$, in electron-positron annihilation. Since the GDAs contain information on a time-like form factor, exotic nature should be found by studying the $h\bar{h}$ invariant mass dependence of the cross section. The internal structure of exotic hadron candidates should be clarified by the exclusive reactions at facilities such as J-PARC and KEKB.

   ↳ hep-phhep-exhep-latnucl-ex+1JPS Conf.Proc.(2015)·2 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.