10106778
Crystal structure of the ApbE protein (TM1553) from Thermotoga maritima at 1.58 A resolution.
123068508
Near-infrared observations of candidate extrinsic S stars
Photometric observations in the near infrared for 161 S stars, including 18 Tc-rich (intrinsic) stars, 19 Tc-deficient (extrinsic) ones and 124 candidates for Tc-deficient S stars, are presented in this paper. Based on some further investigations into the infrared properties of both Tc-rich and Tc-deficient S stars, 104 candidates are identified as very likely Tc-deficient S stars. The large number of infrared-selected Tc-deficient S stars provides a convenient way to study the physical properties and the evolutionary status of this species of S stars.
120186313
The precise determination of the light yield of the PbWO4 crystal
Abstract A fitting method together with the Monte Carlo simulation is developed to process the pulse-height spectrum of a 137 Cs source in PbWO 4 crystals to get the precise light yields of the crystal in photo-electrons per MeV. This method is also useful for other kinds of crystal measurement.
122096987
ASSOCIATED PRODUCTION OF SINGLE HEAVY T-QUARK IN THE LEFT–RIGHT TWIN HIGGS MODEL AT THE LHC
The heavy T-quark is one of the most crucial ingredients in the left–right twin Higgs model, which is introduced to cancel the largest contribution of the Standard Model top quark to the Higgs boson mass at one-loop level. In this paper, we study the relevant single heavy T-quark production processes, the 2 → 2 partonic processes of qb → q'T and , the 2 → 3 partonic processes of and at the CERN LHC. Our numerical results show that the 2 → 3 process can be quite important, as its cross-section is about 60% of that for the 2 → 2 process at the LHC. We also show the pT distribution and the rapidity distributions for out-going particles. For the 2 → 3 process, the production rate of the final state can be larger than 100 fb with reasonable values of the free parameters. The possible signatures of the heavy T-quark might be detected via the process at the LHC.
118775889
Average transverse momentum in the geometrical branching model with jets
The dependence of the average transverse momentum {l angle}p{sub T}{r angle}{sub n} on multiplicity is investigated in the framework of the geometrical branching model with minijets. A ledge effect in the rise-plateau-rise structure is found. The physical reasons for such an effect are given. 11 refs., 4 figs.
118524929
What hard probes tell us about the quark–gluon plasma: Theory
Abstract In the study of quark–gluon plasma in high-energy heavy-ion collisions, hard and electromagnetic (EM) processes can be used to probe a wide range of properties of the hot and dense medium, from space–time profiles of the bulk matter, bulk transport coefficients to EM responses and the jet transport parameter. These medium properties, how they can be studied through hard and EM probes and the status of recent theoretical and phenomenological investigations are reviewed in this talk.
7527083
Interplay of soft and hard processes and hadron pT spectra in pA and AA collisions
Motivated by a schematic model of multiple parton scattering within the Glauber formalism, the transverse momentum spectra in $\mathrm{pA}$ and $\mathrm{AA}$ collisions are analyzed in terms of a nuclear modification factor with respect to $\mathrm{pp}$ collisions. The existing data at the CERN Super Proton Synchrotron energies are shown to be consistent with the picture of Glauber multiple scattering in which the interplay between soft and hard processes and the effect of absorptive processes lead to nontrivial nuclear modification of the particle spectra. Relative to the additive model of incoherent hard scattering, the spectra are enhanced at large ${p}_{T}$ (hard) by multiple scattering while suppressed at low ${p}_{T}$ (soft) by absorptive correction with the transition occurring at around a scale ${p}_{0}\ensuremath{\sim}1\ensuremath{-}2 \mathrm{GeV}/c$ that separates soft and hard processes. Around the same scale, the ${p}_{T}$ spectra in $\mathrm{pp}$ collisions also change from an exponential form at low ${p}_{T}$ to a power-law behavior at high ${p}_{T}.$ At very large ${p}_{T}\ensuremath{\gg}{p}_{0},$ the nuclear enhancement is shown to decrease as ${1/p}_{T}^{2}.$ Implications of these nuclear effects on the study of jet quenching, parton thermalization, and collective radial flow in high-energy $\mathrm{AA}$ collisions are discussed.