1,315 research outputs found

    Search for a Ridge Structure Origin with Shower Broadening and Jet Quenching

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    We investigate the role of jet and shower parton broadening by the strong colour field in the Δη\Delta\eta-Δϕ\Delta\phi correlation of high pTp_T particles. When anisotropic momentum broadening (Δpz>ΔpT\Delta p_z > \Delta p_T) is given to jet and shower partons in the initial stage, a ridge-like structure is found to appear in the two hadron correlation. The ratio of the peak to the pedestal yield is overestimated.Comment: Talk given at 20th Int. Conf. on Ultra-Relativistic Nucleus-Nucleus Collisions, Jaipur, India, Feb.4-10, 200

    QGP collective effects and jet transport

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    We present numerical simulations of the SU(2) Boltzmann-Vlasov equation including both hard elastic particle collisions and soft interactions mediated by classical Yang-Mills fields. We provide an estimate of the coupling of jets to a hot isotropic plasma, which is independent of infrared cutoffs. In addition, we investigate jet propagation in anisotropic plasmas, as created in heavy-ion collisions. The broadening of jets is found to be stronger along the beam line than in azimuth due to the creation of field configurations with B_t>E_t and E_z>B_z via plasma instabilities.Comment: 4 pages, 5 figures. Presented at the 20th International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions: Quark Matter 2008 (QM2008), Jaipur, India, 4-10 Feb 200

    Back-to-back correlations of high p_T hadrons in relativistic heavy ion collisions

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    We investigate the suppression factor and the azimuthal correlation function for high pTp_T hadrons in central Au+Au collisions at sNN=200\sqrt{s_{NN}}=200 GeV by using a dynamical model in which hydrodynamics is combined with explicitly traveling jets. We study the effects of parton energy loss in a hot medium, intrinsic kTk_T of partons in a nucleus, and p⊄p_{\perp} broadening of jets on the back-to-back correlations of high pTp_T hadrons. Parton energy loss is found to be a dominant effect on the reduction of the away-side peaks in the correlation function.Comment: 4 pages, 4 figures; version to appear in Phys. Rev. Let

    Pseudorapidity dependence of parton energy loss in relativistic heavy ion collisions

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    We analyze the recent data from the BRAHMS Collaboration on the pseudorapidity dependence of nuclear modification factors in Au+Au collisions at sNN\sqrt{s_{NN}} = 200 GeV by using the full three dimensional hydrodynamic simulations for the density effects on parton energy loss. We first compute the transverse spectra at η=0\eta=0 and 2.2, and next take a ratio Rη=RAA(η=2.2)/RAA(η=0)R_{\eta}=R_{AA}(\eta=2.2)/R_{AA}(\eta=0), where RAAR_{AA} is a nuclear modification factor. It is shown that hydrodynamic components account for Rη≃1R_{\eta}\simeq 1 at low pTp_\mathrm{T} and that quenched pQCD components lead Rη<1R_{\eta} < 1 at high pTp_\mathrm{T} which are consistent with the data. Strong suppression at η=2.2\eta=2.2 is compatible with the parton energy loss in the final state.Comment: 5 pages, 4 figures; one figure adde

    Re-Hardening of Hadron Transverse Mass Spectra in Relativistic Heavy-Ion Collisions

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    We analyze the spectra of pions and protons in heavy-ion collisions at relativistic energies from 2 A GeV to 65+65 A GeV by using a jet-implemented hadron-string cascade model. In this energy region, hadron transverse mass spectra first show softening until SPS energies, and re-hardening may emerge at RHIC energies. Since hadronic matter is expected to show only softening at higher energy densities, this re-hardening of spectra can be interpreted as a good signature of the quark-gluon plasma formation.Comment: 10 pages, 3 figures, 1 table, Poster presentation at QM2001, Revised to correct latex error in citation on April 6, 200

    MANAJEMEN INFEKSI RABIES BERISIKO TINGGI: STUDI KASUS TANPA SERUM ANTI-RABIES

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    AbstrakRabies merupakan masalah kesehatan masyarakat yang cukup serius terutama di daerah dan telah masuk dalam program daerah namun terabaikan selama masa pandemi. Seorang anak laki laki berusia empat tahun dibawa ke RSUD TC Hillers Maumere datang dengan keluhan demam dan mual muntah lebih dari lima kali. Dari anamnesis melalui keluarganya diketahui bahwa pasien memiliki riwayat digigit anjing di area wajah dan pergelangan tangan kanan pada 14 hari sebelum muncul keluhan. Pada kasus ini pasien sudah mendapatkan perawatan luka dan Vaksin Anti Rabies (VAR) dosis kedua tetapi tidak mendapatkan Serum Anti Rabies (SAR). Pada kasus dengan area gigitan resiko tinggi, pemberian VAR harus disertai pemberian SAR untuk mengurangi moralitas. Kata kunci: rabies, serum anti-rabies, anakAbstract Rabies is a serious public health problem, especially in the regions and has been included in regional programs but neglected during the pandemic. A four-year-old boy taken to TC Hillers Maumere Hospital came in complaining of fever and nausea, vomiting more than five times. From the history through his family, it is known that the patient had a history of being bitten by a dog in the face and right wrist area in the 14 days before complaints appeared. In this case, the patient has received wound care and the second dose of Anti-Rabies Vaccine (VAR) but did not get Anti-Rabies Serum (SAR). In cases with high-risk bite areas, VAR should be accompanied by SAR to reduce mortality.  Keywords: rabies, anti-rabies serum, chil

    Thermalization and the chromo-Weibel instability

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    Despite the apparent success of ideal hydrodynamics in describing the elliptic flow data which have been produced at Brookhaven National Lab's Relativistic Heavy Ion Collider, one lingering question remains: is the use of ideal hydrodynamics at times t < 1 fm/c justified? In order to justify its use a method for rapidly producing isotropic thermal matter at RHIC energies is required. One of the chief obstacles to early isotropization/thermalization is the rapid longitudinal expansion of the matter during the earliest times after the initial nuclear impact. As a result of this expansion the parton distribution functions become locally anisotropic in momentum space. In contrast to locally isotropic plasmas anisotropic plasmas have a spectrum of soft unstable modes which are characterized by exponential growth of transverse chromo-magnetic/-electric fields at short times. This instability is the QCD analogue of the Weibel instability of QED. Parametrically the chromo-Weibel instability provides the fastest method for generation of soft background fields and dominates the short-time dynamics of the system.Comment: 8 pages, 4 figures, Invited plenary talk given at the 19th International Conference on Ultrarelativistic Nucleus-Nucleus Collisions: Quark Matter 2006 (QM 2006), Shanghai, China, 14-20 Nov 200

    Study of relativistic nuclear collisions at AGS energies from p+Be to Au+Au with hadronic cascade model

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    A hadronic cascade model based on resonances and strings is used to study mass dependence of relativistic nuclear collisions from p+Be to Au+Au at AGS energies (\sim 10\AGeV) systematically. Hadron transverse momentum and rapidity distributions obtained with both cascade calculations and Glauber type calculations are compared with experimental data to perform detailed discussion about the importance of rescattering among hadrons. We find good agreement with the experimental data without any change of model parameters with the cascade model. It is found that rescattering is of importance both for the explanation of high transverse momentum tail and for the multiplicity of produced particles.Comment: 27 pages, 30 figure

    Volatile organic compounds and risk of asthma and allergy: A systematic review

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    Volatile organic compounds (VOCs) are ubiquitous domestic pollutants. Their role in asthma/allergy development and exacerbations is uncertain. This systematic review investigated whether domestic VOC exposure increases the risk of developing and/or exacerbating asthma and allergic disorders.&nbsp; We systematically searched 11 databases and three trial repositories, and contacted an international panel of experts to identify published and unpublished experimental and epidemiological studies.&nbsp; 8455 potentially relevant studies were identified; 852 papers were removed after de-duplication, leaving 7603 unique papers that were screened. Of these, 278 were reviewed in detail and 53 satisfied the inclusion criteria. Critical appraisal of the included studies indicated an overall lack of high-quality evidence and substantial risk of bias in this body of knowledge. Aromatics (i.e. benzenes, toluenes and xylenes) and formaldehyde were the main VOC classes studied, both in relation to the development and exacerbations of asthma and allergy. Approximately equal numbers of studies reported that exposure increased risks and that exposure was not associated with any detrimental effects.&nbsp; The available evidence implicating domestic VOC exposure in the risk of developing and/or exacerbating asthma and allergy is of poor quality and inconsistent. Prospective, preferably experimental studies, investigating the impact of reducing/eliminating exposure to VOC, are now needed in order to generate a more definitive evidence base to inform policy and clinical deliberations in relation to the management of the now substantial sections of the population who are either at risk of developing asthma/ allergy or living with established disease. &copy;ERS 2015
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