We investigate the masses of the lowest cc states, the J͞c and h c , in nuclear matter using QCD sum rules. Up to dimension four, the differences between the operator product expansions in vacuum and in medium arise from the density-dependent change in the gluon condensate and from a new contribution proportional to the nucleon expectation value of the twist-2 gluon operator. Both terms together give an attractive shift of about 5 -10 MeV to the J͞c and h c masses in nuclear matter.[S0031-9007(99)09014-6] PACS numbers: 14.40. Gx, 11.55.Hx, 24.85. + p Investigating the behavior of heavy quark systems in a nuclear medium is of great interest, for several reasons. First, the ongoing discussion of J͞c suppression in ultrarelativisitic heavy-ion collisions as a possible quarkgluon plasma signal requires detailed knowledge about the in-medium interactions of the J͞c under "normal," nonplasma conditions. Furthermore, as Brodsky et al. [1] pointed out, multigluon exchange can lead to an attractive potential between a cc meson and a nucleon, such that, for example, the h c could form bound states even with light nuclei. In more recent calculations the estimated charmonium binding energy in nuclear systems was found to be of the order of 10 MeV [2][3][4][5].In the present paper we study the in-medium behavior of the J͞c and h c using QCD sum rules [6]. The QCD sum rule approach connects the spectral density of a given current correlation function via a dispersion relation with the QCD operator product expansion (OPE). Inmedium QCD sum rules have so far been applied only for light quark systems, in order to study possible shifts of the in-medium masses of nucleons [7-9] and vector mesons [10]. Such calculations suffer from uncertainties, e.g., due to assumptions about factorization of fourquark condensates which may not be justified. As we shall see, in-medium QCD sum rules applied to heavy quark systems are expected to be more reliable. Up to dimension four, the order to which the vacuum sum rules for hadrons involving heavy quarks are commonly expanded, all condensate parameters are quite well known and there are no ambiguities in the OPE. We also find that uncertainties caused by possibly large hadronic inmedium decay widths are much smaller than for lightquark systems.Our starting point is the time ordered current-current correlation function of two heavy quark currents in nuclear matter (n.m.), P͑v,q͒ i Z d 4 x e iq?x ͗jT ͓ j͑x͒j͑0͔͒j͘ n.m. . (1) Here q ͑v, q͒, and j͘ n.m. is the ground state of nuclear matter which we take to be at rest. For the J͞c we take the vector current j V m cg m c and for the h c , we use the pseudoscalar current j P icg 5 c. In the region of large and positive Q 2 q 2 2 v 2 we can express the correlation function through an operator product expansion (short distance expansion) [11] and write the left hand side of Eq. (1) asHere the O n are operators of (mass) dimension n, renormalized at a scale m 2 , and C n are the perturbative Wilson coefficients which, in the medium at rest, generally ...

Erratum: Masses of J͞ ͞ ͞c and h c in the Nuclear Medium: QCD Sum Rule Approach [Phys. Rev. Lett. 82, 3396 (1999)] Because of a technical transfer error, Fig. 1 of our Letter is incorrect. The correct Fig. 1, which should replace the one in our original Letter, is shown below. None of the calculations, results, and conclusions in our original Letter are affected by this error. FIG. 1. The h c and J͞c masses calculated according to Eq. (20) for different n at j 1. We show the result in medium at r N 0.17 fm 23 (solid line) in comparison with the vacuum result (dashed line).

QCD sum rules for J/ψ in the nuclear medium: calculation of the Wilson coefficients of gluon operators up to dimension 6 Sungsik Kim and Su Houng LeeDepartment of Physics and Institute of Physics and Applied Physics, Yonsei University, Seoul 120-749, Korea AbstractWe calculate the Wilson coefficients of all dimension 6 gluon operators with non zero spin in the correlation function between two heavy vector currents. For the twist-4 part, we first identify the three independent gluon operators, and then proceed with the calculation of the Wilson coefficients using the fixed point gauge.Together with the previous calculation of the Wilson coefficients for the dimension 6 scalar gluon operators by Nikolaev and Radyushkin, our result completes the list of all the Wilson coefficients of dimension 6 gluon operators in the correlation function between heavy vector currents. We apply our results to investigate the mass of J/ψ in nuclear matter using QCD sum rules. Using an upper bound estimate on the matrix elements of the dimension 6 gluon operators to linear order in density, we find that the density dependent contribution from dimension 6 operators is less than 40% of the dimension 4 operators with opposite sign. The final result gives about −4 MeV mass shift for the charmonium at rest in nuclear matter.

Writing DNA plays a significant role in the fields of synthetic biology, functional genomics and bioengineering. DNA clones on next-generation sequencing (NGS) platforms have the potential to be a rich and cost-effective source of sequence-verified DNAs as a precursor for DNA writing. However, it is still very challenging to retrieve target clonal DNA from high-density NGS platforms. Here we propose an enabling technology called ‘Sniper Cloning’ that enables the precise mapping of target clone features on NGS platforms and non-contact rapid retrieval of targets for the full utilization of DNA clones. By merging the three cutting-edge technologies of NGS, DNA microarray and our pulse laser retrieval system, Sniper Cloning is a week-long process that produces 5,188 error-free synthetic DNAs in a single run of NGS with a single microarray DNA pool. We believe that this technology has potential as a universal tool for DNA writing in biological sciences.

The effects of the inductively coupled plasma (ICP) etching of AlGaN on the interface properties of the Al 2 O 3 /AlGaN/GaN structures prepared by atomic layer deposition were investigated. It was found from the photoassisted capacitance-voltage (C-V ) results that the ICP etching of the AlGaN surface significantly increased the interface state density up to 8 Â 10 12 cm À2 eV À1 at the Al 2 O 3 /AlGaN interface. The transmission electron microscopy and X-ray photoelectron spectroscopy analyses indicated that the monolayer-level roughness, disorder of the chemical bonds at the AlGaN surface caused poor C-V characteristics due to high-density interface states at the Al 2 O 3 /ICP-etched AGaN interface.