http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
ϒ suppression at forward rapidity in Pb–Pb collisions at <sub> s NN </sub> = 5.02 TeV
Acharya, S.,Acosta, F.T.,Adamová,, D.,Adolfsson, J.,Aggarwal, M.M.,Aglieri Rinella, G.,Agnello, M.,Agrawal, N.,Ahammed, Z.,Ahn, S.U.,Aiola, S.,Akindinov, A.,Al-Turany, M.,Alam, S.N.,Albuquerque, Elsevier 2019 Physics letters: B Vol.790 No.-
<P><B>Abstract</B></P> <P>Inclusive ϒ(1S) and ϒ(2S) production have been measured in Pb–Pb collisions at the centre-of-mass energy per nucleon–nucleon pair <SUB> s NN </SUB> = 5.02 TeV, using the ALICE detector at the CERN LHC. The ϒ mesons are reconstructed in the centre-of-mass rapidity interval 2.5 < y < 4 and in the transverse-momentum range <SUB> p T </SUB> < 15 GeV/<I>c</I>, via their decays to muon pairs. In this Letter, we present results on the inclusive ϒ(1S) nuclear modification factor <SUB> R AA </SUB> as a function of collision centrality, transverse momentum and rapidity. The ϒ(1S) and ϒ(2S) <SUB> R AA </SUB> , integrated over the centrality range 0–90%, are 0.37 ± 0.02 ( stat ) ± 0.03 ( syst ) and 0.10 ± 0.04 ( stat ) ± 0.02 ( syst ) , respectively, leading to a ratio R AA ϒ ( 2S ) / R AA ϒ ( 1S ) of 0.28 ± 0.12 (stat) ± 0.06 (syst) . The observed ϒ(1S) suppression increases with the centrality of the collision and no significant variation is observed as a function of transverse momentum and rapidity.</P>
Acharya, S.,Adam, J.,Adamová,, D.,Adolfsson, J.,Aggarwal, M.M.,Aglieri Rinella, G.,Agnello, M.,Agrawal, N.,Ahammed, Z.,Ahmad, N.,Ahn, S.U.,Aiola, S.,Akindinov, A.,Al-Turany, M.,Alam, S.N.,Alba, Elsevier 2018 Physics letters: B Vol.781 No.-
<P><B>Abstract</B></P> <P>First results on the longitudinal asymmetry and its effect on the pseudorapidity distributions in Pb–Pb collisions at <SUB> s NN </SUB> = 2.76 TeV at the Large Hadron Collider are obtained with the ALICE detector. The longitudinal asymmetry arises because of an unequal number of participating nucleons from the two colliding nuclei, and is estimated for each event by measuring the energy in the forward neutron-Zero-Degree-Calorimeters (ZNs). The effect of the longitudinal asymmetry is measured on the pseudorapidity distributions of charged particles in the regions | η | < 0.9 , 2.8 < η < 5.1 and − 3.7 < η < − 1.7 by taking the ratio of the pseudorapidity distributions from events corresponding to different regions of asymmetry. The coefficients of a polynomial fit to the ratio characterise the effect of the asymmetry. A Monte Carlo simulation using a Glauber model for the colliding nuclei is tuned to reproduce the spectrum in the ZNs and provides a relation between the measurable longitudinal asymmetry and the shift in the rapidity ( <SUB> y 0 </SUB> ) of the participant zone formed by the unequal number of participating nucleons. The dependence of the coefficient of the linear term in the polynomial expansion, <SUB> c 1 </SUB> , on the mean value of <SUB> y 0 </SUB> is investigated.</P>
Anisotropic flow in Xe–Xe collisions at <sub> s NN </sub> = 5.44 TeV
Acharya, S.,Acosta, F.T.,Adamová,, D.,Adolfsson, J.,Aggarwal, M.M.,Aglieri Rinella, G.,Agnello, M.,Agrawal, N.,Ahammed, Z.,Ahn, S.U.,Aiola, S.,Akindinov, A.,Al-Turany, M.,Alam, S.N.,Albuquerque, North-Holland Pub. Co 2018 Physics letters. Section B Vol.784 No.-
<P><B>Abstract</B></P> <P>The first measurements of anisotropic flow coefficients <SUB> v n </SUB> for mid-rapidity charged particles in Xe–Xe collisions at <SUB> s NN </SUB> = 5.44 TeV are presented. Comparing these measurements to those from Pb–Pb collisions at <SUB> s NN </SUB> = 5.02 TeV, <SUB> v 2 </SUB> is found to be suppressed for mid-central collisions at the same centrality, and enhanced for central collisions. The values of <SUB> v 3 </SUB> are generally larger in Xe–Xe than in Pb–Pb at a given centrality. These observations are consistent with expectations from hydrodynamic predictions. When both <SUB> v 2 </SUB> and <SUB> v 3 </SUB> are divided by their corresponding eccentricities for a variety of initial state models, they generally scale with transverse density when comparing Xe–Xe and Pb–Pb, with some deviations observed in central Xe–Xe and Pb–Pb collisions. These results assist in placing strong constraints on both the initial state geometry and medium response for relativistic heavy-ion collisions.</P>
Acharya, S.,Adamová,, D.,Adhya, S.P.,Adler, A.,Adolfsson, J.,Aggarwal, M.M.,Aglieri Rinella, G.,Agnello, M.,Agrawal, N.,Ahammed, Z.,Ahmad, S.,Ahn, S.U.,Akindinov, A.,Al-Turany, M.,Alam, S.N.,Alb Elsevier 2019 Physics letters: B Vol.797 No.-
<P><B>Abstract</B></P> <P>An improved value for the lifetime of the (anti-)hypertriton has been obtained using the data sample of Pb–Pb collisions at <SUB> s NN </SUB> = 5.02 TeV collected by the ALICE experiment at the LHC. The (anti-)hypertriton has been reconstructed via its charged two-body mesonic decay channel and the lifetime has been determined from an exponential fit to the d<I>N</I>/d(<I>ct</I>) spectrum. The measured value, τ = 242 − 38 + 34 (stat.) ± 17 (syst.) ps, is compatible with representative theoretical predictions, thus contributing to the solution of the longstanding hypertriton lifetime puzzle.</P>
The hydrogel template method for fabrication of homogeneous nano/microparticles
Acharya, G.,Shin, C.S.,McDermott, M.,Mishra, H.,Park, H.,Kwon, I.C.,Park, K. Elsevier Science Publishers 2010 Journal of controlled release Vol.141 No.3
Nano/microparticles have been used widely in drug delivery applications. The majority of the particles are prepared by the conventional emulsion methods, which tend to result in particles with heterogeneous size distribution with sub-optimal drug loading and release properties. Recently, microfabrication methods have been used to make nano/microparticles with a monodisperse size distribution. The existing methods utilize solid templates for making particles, and the collection of individual particles after preparation has not been easy. The new hydrogel template approach was developed to make the particle preparation process simple and fast. The hydrogel template approach is based on the unique properties of physical gels that can undergo sol-gel phase transition upon changes in environmental conditions. The phase reversible hydrogels, however, are in general mechanically too weak to be treated as a solid material. It was unexpectedly found that gelatin hydrogels could be made to possess various properties necessary for microfabrication of nano/microparticles in large quantities. The size of the particles can be adjusted from 200nm to >50@?m, providing flexibility in controlling the size in drug delivery formulations. The simplicity in processing makes the hydrogel template method useful for scale-up manufacturing of particles. The drug loading capacity is 50% or higher, and yet the initial burst release is minimal. The hydrogel template approach presents a new strategy of preparing nano/microparticles of predefined size and shape with homogeneous size distribution for drug delivery applications.
Acharya, S.,Acosta, F.T.,Adamová,, D.,Adolfsson, J.,Aggarwal, M.M.,Aglieri Rinella, G.,Agnello, M.,Agrawal, N.,Ahammed, Z.,Ahn, S.U.,Aiola, S.,Akindinov, A.,Al-Turany, M.,Alam, S.N.,Albuquerque, Elsevier 2018 Physics letters: B Vol.785 No.-
<P><B>Abstract</B></P> <P>Azimuthally-differential femtoscopic measurements, being sensitive to spatio-temporal characteristics of the source as well as to the collective velocity fields at freeze out, provide very important information on the nature and dynamics of the system evolution. While the HBT radii oscillations relative to the second harmonic event plane measured recently reflect mostly the spatial geometry of the source, model studies have shown that the HBT radii oscillations relative to the third harmonic event plane are predominantly defined by the velocity fields. In this Letter, we present the first results on azimuthally-differential pion femtoscopy relative to the third harmonic event plane as a function of the pion pair transverse momentum <SUB> k T </SUB> for different collision centralities in Pb–Pb collisions at <SUB> s NN </SUB> = 2.76 TeV . We find that the <SUB> R side </SUB> and <SUB> R out </SUB> radii, which characterize the pion source size in the directions perpendicular and parallel to the pion transverse momentum, oscillate in phase relative to the third harmonic event plane, similar to the results from 3+1D hydrodynamical calculations. The observed radii oscillations unambiguously signal a collective expansion and anisotropy in the velocity fields. A comparison of the measured radii oscillations with the Blast-Wave model calculations indicate that the initial state triangularity is washed-out at freeze out.</P>
Neutral pion and η meson production at midrapidity in Pb-Pb collisions at sNN=2.76 TeV
Acharya, S.,Acosta, F. T.-.,Adamová,, D.,Adolfsson, J.,Aggarwal, M. M.,Aglieri Rinella, G.,Agnello, M.,Agrawal, N.,Ahammed, Z.,Ahn, S. U.,Aiola, S.,Akindinov, A.,Al-Turany, M.,Alam, S. N.,Albuqu American Physical Society 2018 Physical review. C Vol.98 No.4
<P>Neutral pion and eta meson production in the transverse momentum range 1 < p(T) < 20 GeV/c have been measured at midrapidity by the ALICE experiment at the Large Hadron Collider (LHC) in central and semicentral Pb-Pb collisions at root S-NN = 2.76 TeV. These results were obtained using the photon conversion method as well as the Photon Spectrometer (PHOS) and Electromagnetic Calorimeter detectors. The results extend the upper p(T) reach of the previous ALICE pi(0) measurements from 12 to 20 GeV/c and present the first measurement of eta meson production in heavy-ion collisions at the LHC. The eta/pi(0) ratio is similar for the two centralities and reaches at high p(T) a plateau value of 0.457 +/- 0.013(stat) +/- 0.018(syst) A suppression of similar magnitude for pi(0) and eta meson production is observed in Pb-Pb collisions with respect to their production in pp collisions scaled by the number of binary nucleon-nucleon collisions. We discuss the results in terms of Next to Leading Order (NLO) pQCD predictions and hydrodynamic models. The measurements show a stronger suppression than observed at lower center-of-mass energies in the p T range 6 < p(T) < 10 GeV/c. For p(T) < 3 GeV/c, hadronization models describe the pi(0) results while for the eta some tension is observed.</P>
Epitaxial Brownmillerite Oxide Thin Films for Reliable Switching Memory
Acharya, Susant K.,Nallagatla, Raveendra Venkata,Togibasa, Octolia,Lee, Bo W.,Liu, Chunli,Jung, Chang U.,Park, Bae Ho,Park, Ji-Yong,Cho, Yunae,Kim, Dong-Wook,Jo, Janghyun,Kwon, Deok-Hwang,Kim, Miyoung American Chemical Society 2016 ACS APPLIED MATERIALS & INTERFACES Vol.8 No.12
<P>Resistive switching memory, which is mostly based on polycrystalline thin films, suffers from wide distributions in switching parameters including set voltage, reset voltage, and resistance in their low- and high-resistance states. One of the most commonly used methods to overcome this limitation is to introduce inhomogeneity. By contrast, in this paper, we obtained uniform resistive switching parameters and sufficiently low forming voltage by maximizing the uniformity of an epitaxial thin film. To achieve this result, we deposited an SrFeOx/SrRuO3 heteroepitaxial structure onto an SrTiO3 (001) substrate by pulsed laser deposition, and then we deposited an Au top electrode by electron-beam evaporation. This device exhibited excellent bipolar resistance switching characteristics, including a high on/off ratio, narrow distribution of key switching parameters, and long data retention time. We interpret these phenomena in terms of a local, reversible phase transformation in the SrFeOx film between brownmillerite and perovskite structures. Using the brownmillerite structure and atomically uniform thickness of the heteroepitaxial SrFeOx thin film, we overcame two major hurdles in the development of resistive random-access memory devices: high forming voltage and broad distributions of switching parameters.</P>