122908470
A note on the discovery of a 2Modot pulsar
119279262
PSR B1257+12: a quark star with planets?
A recent observation has shown that PSR B1257+12 could have quite small X‐ray emitting area, only about 2000 m2, which is more than three orders smaller than the canonical polar cap size. We suggest here that PSR B1257+12 could be a low‐mass quark star with radius of R≃0.6 km and mass of M≃3×10−4 M⊙. Such a low‐mass quark star system may form in an accretion induced collapse process or a collision process of two quark stars.
117033142
Are AXPs/SGRs magnetars?
Anomalous X-ray Pulsars and Soft Gamma-Ray Repeaters have been generally recognized as neutron stars with super strong magnetic fields, namely "magnetars". The "magnetars" manifest that the luminosity in X-ray band are larger than the rotational energy loss rate, i.e. $L_{X}>\dot {E}_{\rm rot}$, and then the radiation energy is coming from the energy of magnetic field. Here it is argued that magnetars may not really exist. Some X-ray and radio observational results are contradicted with the magnetar model. 
(1) The X-ray luminosity of PSR J1852+0040 is much larger than the rotational energy loss rate ($L_{X}/\dot {E}_{\rm rot}\simeq 18)$, but the magnetic field is just $3.1\times 10^{11}$ G. Does this X-ray radiation energy come from the magnetic field? 
(2) In contrast to the above, the magnetic fields of radio pulsars J1847-0130 and PSR J1718-3718 are higher than that of AXP 1E 2259+586, why is the radiation energy of those two radio pulsars still coming from rotational energy? Furthermore, the magnetic field of the newly discovered SGR 0418+5729 with the lowest magnetic field is 3.0 e13 G, lower than the critical magnetic field $B_{\rm C}=4.414$ e13 G) (Esposito et al. 2010). 
(3) Some "magnetars" also emit normal transient radio pulses, what is the essential difference between radio pulsars and the "magnetars"? 
The observational fact arguments will be presented at first, then we discuss in what situation the conventional method to obtain magnetic field could not be correct.
118508611
The state of cold quark matter: a model-independent view
From a model-independent point of view, we address the possibility that quark clustering could occur in cold quark matter at realistic baryon densities because of the likely strong coupling between quarks in compact stars.
118541626
H-cluster stars
The study of dense matter at ultra-high density has a very long history, which is meaningful for us to understand not only cosmic events in extreme circumstances but also fundamental laws of physics. It is well known that the state of cold matter at supra-nuclear density depends on the non-perturbative nature of quantum chromo-dynamics (QCD) and is essential for modeling pulsars. A so-called H-cluster matter is proposed in this paper as the nature of dense matter in reality. 
In compact stars at only a few nuclear densities but low temperature, quarks could be interacting strongly with each other there. That might render quarks grouped in clusters, although the hypothetical quark-clusters in cold dense matter has not been confirmed due to the lack of both theoretical and experimental evidence. Motivated by recent lattice QCD simulations of the H-dibaryons (with structure uuddss), we are therefore considering here a possible kind of quark-clusters, H-clusters, that could emerge inside compact stars during their initial cooling, as the dominant components inside (the degree of freedom could then be H-clusters there).Taking into account the in-medium stiffening effect, we find that at baryon densities of compact stars $H$-cluster matter could be more stable than nuclear matter. We also find that for the H-cluster matter with lattice structure, the equation of state could be so stiff that it would seem to be "superluminal" in most dense region. However, the real sound speed for H-cluster matter is in fact hard to calculate, so at this stage we do not put constraints on our model from the usual requirment of causality.
118501168
The Extremely Long-period X-Ray Source in a Young Supernova Remnant: A Thorne-Żytkow Object Descendant?
The origin of the 6.67 hr period X-ray source, 1E161348-5055, in the young supernova remnant RCW 103 is puzzling. We propose that it may be the descendant of a Thorne-Żytkow Object (TŻO). A TŻO may at its formation have a rapidly spinning neutron star as a core and a slowly rotating envelope. We found that the core could be braked quickly to an extremely long spin period by the coupling between its magnetic field and the envelope, and that the envelope could be disrupted by some powerful bursts or exhausted via stellar wind. If the envelope is disrupted after the core has spun down, the core will become an extremely long-period compact object, with a slow proper motion speed, surrounded by a supernova-remnant-like shell. These features all agree with the observations of 1E161348-5055. TŻOs are expected to have produced extraordinarily high abundances of lithium and rapid proton process elements that would remain in the remnants and could be used to test this scenario.
121743620
Improved measurements of electroweak parameters fromZ decays into fermion pairs
AbstractThe properties of theZ resonance are measured on the basis of 190 000Z decays into fermion pairs collected with the ALEPH detector at LEP. Assuming lepton universality,Mz=(91.182±0.009exp±0.020L∶P) GeV,ГZ=(2484±17) MeV, σhad0=(41.44±0.36) nb, andГjad/Гℓℓ=21.00±0.20. The corresponding number of light neutrino species is 2.97±0.07. The forward-back-ward asymmetry in leptonic decays is used to determine the ratio of vector to axial-vector coupling constants of leptons:gv2(MZ2)/gA2(MZ2)=0.0072±0.0027. Combining these results with ALEPH results on quark charge and
$$b\bar b$$
 asymmetries, and τ polarization, sin2θW(MZ2). In the contex of the Minimal Standard Model, limits are placed on the top-quark mass.
209832961
Transverse momentum correlations in hadronic Z decays
Using data obtained with the ALEPH detector at the Z resonance, a measure based on transverse momentum is shown to exhibit a correlation between the two halves of a hadronic event which cannot be explained by energy-momentum conservation, flavour conservation, the imposition of an event axis or imperfect event reconstruction. Two possible explanations based on Monte Carlo models are examined: a) ARIADNE, with the correlation forming early in the parton shower and with the transition from partons to hadrons playing only a minor part; b) JETSET, with the correlation forming at the fragmentation stage. A correlation technique based on a jet cluster analysis is used to make a comparison of the models with the data. It is concluded that both non-perturbative and perturbative effects make important contributions to the observed correlation.
201261767
Search for gamma gamma ---> eta(b) in e+ e- collisions at LEP-2
A search for the pseudoscalar meson ηb is performed in two-photon interactions at LEP 2 with an integrated luminosity of 699 pb−1 collected at e+e− centre-of-mass energies from 181 GeV to 209 GeV. One candidate event is found in the six-charged-particle final state and none in the four-charged-particle final state, in agreement with the total expected background of about one event. Upper limits of eV, eV are obtained at 95% confidence level, which correspond to upper limits of 9.0% and 25% on these branching ratios.
122306809
Measurements of the b baryon Lifetime
Using about 1.5 million hadronic Z decays recorded with the aleph detector, the lifetime of the b baryons has been measured using two independent data samples. From a maximum likelihood fit to the impact parameter distribution of leptons in 519 Λl− combinations containing a b baryon sample of 290 decays, the measured b baryon lifetime is τb—baryon = 1.05−0.11+0.12(stat)±0.09(syst) ps. The lifetime of the Λb0 baryon from a maximum likelihood fit to the proper time distribution of 58 Λc+l− candidates containing a Λb0 sample of 44 decays, is τΛb0 = 1.02−0.18+0.23(stat) ± 0.06(syst) ps.
107065256
Networking with China
This paper presents the history and current status Of computer networking between IHEP in Beijing, China and the rest of the world, starting with no links at the beginning of 1987 thru X.25 public networks and dial up links, to the installing, in March 1993, of one of the first dedicated 64 kbps satellite computer links between China and the outside world. In May 1994, IHEP became the first Chinese institution to have a fully operational world-wide Internet connection. Experience with this dedicated link between SLAC and IHEP will be presented together with future plans to add a land line between KEK and IHEP and to extend the links within China.