Search

We study the di-photon correlations in quark-nucleus and proton-nucleus collisions at RHIC and the LHC.We show that the single fragmentation di-photon produces the away side correlations peak, and the double fragmentation component of prompt diphoton is responsible for the near-side peak, and the long-range in rapidity near-side azimuthal collimation, the so-called “ridge” structure. We show that while di-photon ridge exists at the LHC in quark-nucleus collisions, the effect disappears in proton-nucleus collisions at the LHC. We show that the di-photon correlation measurments in p+A collisions can help to discriminate among models and understand the true origin of the observed dihedron ridge in p+A collisions.

Background Resistance to Fas-mediated apoptosis limits the efficacy of currently available chemotherapy regimens. We identified CD74, which is known to be overexpressed in hematological malignancies, as one of the factors interfering with Fas-mediated apoptosis. Methods CD74 expression was suppressed in human B-lymphoma cell lines, BJAB and Raji, by either transduction with lentivirus particles or transfection with episomal vector, both encoding CD74-specific shRNAs or non-target shRNA. Effect of CD74 expression on Fas signaling was evaluated by comparing survival of mice hydrodynamically transfected with vector encoding full-length CD74 or empty vector. Sensitivity of cells with suppressed CD74 expression to FasL, edelfosine, doxorubicin, and a humanized CD74-specific antibody, milatuzumab, was evaluated by flow cytometry and compared control cells. Fas signaling in response to FasL stimulation and the expression of Fas signaling components were evaluated by Western blot. Surface expression of Fas was detected by flow cytometry. Results We determined that cells with suppressed CD74 are more sensitive to FasL-induced apoptosis and Fas signaling-dependent chemotherapies, edelfosine and doxorubicin, than control CD74-expressing cells. On the other hand, expression of full-length CD74 in livers protected the mice from a lethal challenge with agonistic anti-Fas antibody Jo2. A detailed analysis of Fas signaling in cells lacking CD74 and control cells revealed increased cleavage/activation of pro-caspase-8 and corresponding enhancement of caspase-3 activation in the absence of CD74, suggesting that CD74 affects the immediate early steps in Fas signaling at the plasma membrane. Cells with suppressed CD74 expression showed increased staining of Fas receptor on their surface. Pre-treatment with milatuzumab sensitized BJAB cells to Fas-mediated apoptosis. Conclusion We anticipate that specific targeting of the CD74 on the cell surface will sensitize CD74- expressing cancer cells to Fas-mediated apoptosis, and thus will increase effectiveness of chemotherapy regimens for hematological malignancies. [ABSTRACT FROM AUTHOR]

Abstract: The first moment of the charged-particle transverse momentum spectrum and its correlation with the charged-particle multiplicity provide vital information about the underlying particle production mechanism. The ALICE Collaboration recently reported that versus in Pb+Pb collisions is smaller than in p+p and p+Pb collisions. Other interesting features of data is rather flatness of at high in Pb+Pb and p+Pb collisions in seemingly striking contrast to the case of p+p collisions. With a detailed calculation, we show all these peculiar features in a wide range of energies and system sizes can be well described by the idea of gluon saturation within the Color Glass Condensate framework using the -factorization. This establishes an important fact that the bulk of the produced particles in heavy-ion collisions at the LHC carries signature of the initial stage of collisions. We also show that the recent scaling property seen by the CMS Collaboration between the number of tracks in p+p and p+Pb collisions may provide a strong evidence in favor of geometric-scaling phenomenon and gluon saturation, indicating that the underlying dynamics of high multiplicity events in p+p and p+Pb collisions should be similar. [Copyright &y& Elsevier]

Abstract: We present various predictions for the upcoming collisions at within the color glass condensate (CGC) formalism, including single inclusive charged hadron production, single inclusive prompt photon production, direct photon production, charged hadron multiplicity distribution and photon–hadron azimuthal correlations. Using the running-coupling Balitsky–Kovchegov evolution equation for calculating various observables, we show that the main source of uncertainties is due to less constrained initial nuclear saturation scale. This gives rise to rather large theoretical uncertainties for nuclear modification factor at the LHC. Nevertheless, we propose a simple scheme in which one can still test the main dynamics of the CGC/saturation in collisions at the LHC. [Copyright &y& Elsevier]

This review stresses the theoretical elements that underlie a wide range of phenomenological studies of high-energy QCD, which include both soft and hard processes. After a brief introduction to the basics of QCD, various aspects of QCD-based phenomenology are covered: color transparency, hadronization of color charges, Regge phenomenology, parton model, Bjorken scaling and its violation, DGLAP evolution equation, BFKL formalism, GLR-MQ evolution equation and saturation. In the last part of the review, we employ the light-cone dipole formalism to describe deep inelastic lepton scattering, Drell — Yan processes, direct photon production, diffraction, quark and gluon shadowing in nuclei, the Cronin effect and nuclear broadening. [ABSTRACT FROM AUTHOR]

Recently, it has been reported that antisense RNAs are transcribed from a large number of genes in various species including human and mouse. The Prdx2 gene, which is indicated to be involved in signal transduction related to platelet-derived growth factor as well as to protection from oxidizing agents, has been shown to produce sense and antisense transcripts. To obtain clues for possible roles of Prdx2 antisense transcripts, we have performed Northern blot analysis and in situ hybridization on tissues of 8-week-old C57BL/6J mice. The Northern blot analysis revealed that major parts of sense and antisense transcripts were poly(A–)-RNA. The analysis of the fractionated RNA of fibroblasts indicated that the poly(A–)-RNA would be localized in the cytoplasm of cells. The in situ hybridization demonstrated that the sense and antisense transcripts were localized in almost the same limited areas of brain, testis, and spleen. It also revealed that the sense and antisense transcripts coexisted in Purkinje cells. In thymus and stomach, the antisense transcripts were detected, but sense transcripts were not. When tissues of BALB/c mice were examined by in situ hybridization, the observations were essentially the same as those of C57BL/6J except that it appeared that the amounts of sense and antisense transcripts in testis of BALB/c were greater than those in C57BL/6J, and that the amounts of antisense transcripts in stomach of BALB/c were much smaller than those in C57BL/6J. Copyright © 2008 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Recently we identified and characterized porcine calcitonin receptor-stimulating peptide (CRSP) 1, CRSP2 and CRSP3 as members of the calcitonin/calcitonin gene-related peptide (CT/CGRP) family. In the present study, the genomic sequences and organization of CRSP1, 2, and 3 were determined, and the expression of the genes in the porcine brain was investigated using in situ hybridization. Analysis of 5′-upstream regions of the three CRSPs demonstrated that CRSP1 and CRSP2 have almost identical sequences (>98% similarity) and high sequence similarities including functional transcription binding sites with the corresponding region of human CALCA (CT/αCGRP), whereas CRSP3 retains less similarity with the above genes. RH mapping of CRSPs demonstrated that they resided in a region of swine chromosome 2 (SSC2). The arrangement of the genes in the region was found to be conserved in corresponding human and mouse regions. In situ hybridization demonstrated sense transcripts of the three genes in cerebrum, hippocampus, hypothalamus, pons/midbrain, and thalamus of 3-month-old pigs, and CRSP2 sense transcripts additionally in tractus opticus. The sense transcripts of αCGRP and CALCB (βCGRP) were detected in cerebrum, hippocampus, and pons/midbrain of newborn mice, and to a lesser extent in pons/midbrain of 8-week-old mice. These results taken together with the chromosomal conservation and phylogenetic clustering of CT/CGRP family indicate that CRSP1, 2, and 3 may be functionally different from αCGRP and βCGRP, though they are indicated to have a common progenitor gene. Copyright © 2008 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

To solve the relativistic bound-state problem one needs to systematically and simultaneously decouple the high-energy from the low-energy modes and the many-body from the few-particle states using a consistent renormalization scheme. In a recent Letter we have shown that one such approach can be a combination of the coupled cluster method as used in many-body theory and the Wilsonian exact renormalization group. Even though the method is intrinsically non-perturbative, one can easily implement a loop expansion within it. In this Letter we provide further support for this aspect of our formalism by obtaining results for the two-loop renormalized φ4 theory. We show that the non-unitary representation inherent in our method leads to an economic computation and does not produce any non-Hermiticity in the relevant terms. [Copyright &y& Elsevier]

The Casimir energy for scalar field of two parallel conductors in two-dimensional domain wall background, with Dirichlet boundary conditions, is calculated by making use of general properties of renormalized stress–tensor. We show that vacuum expectation values of stress–tensor contain two terms which come from the boundary conditions and the gravitational background. In two dimensions the minimal coupling reduces to the conformal coupling and stress–tensor can be obtained by the local and nonlocal contributions of the anomalous trace. This work shows that there exists a subtle and deep connection between Casimir effect and trace anomaly in curved space–time. [ABSTRACT FROM AUTHOR]

We study exclusive dijet production in coherent diffractive processes in deep inelastic scattering and real (and virtual) photon-hadron ( γ ( ⁎ ) -h) collisions in the Color Glass Condensate formalism at leading order. We show that the diffractive dijet cross section is sensitive to the color-dipole orientation in the transverse plane, and is a good probe of possible correlations between the q q ¯ -dipole transverse separation vector r and the dipole impact parameter b . We also investigate the diffractive dijet azimuthal angle correlations and t -distributions in γ ( ⁎ ) -h collisions and show that they are sensitive to gluon saturation effects in the small- x region. In particular, we show that the t -distribution of diffractive dijet photo-production off a proton target exhibits a dip-type structure in the saturation region. This effect is similar to diffractive vector meson production. Besides, at variance with the inclusive case, the effect of saturation leads to stronger azimuthal correlations between the jets. [ABSTRACT FROM AUTHOR]