Open-charm production as a function of charged particle multiplicity in pp collisions at \sqrt{s}=7 TeV with ALICE

Heavy quarks (charm and beauty) are an effective tool to investigate the properties of the Quark-Gluon Plasma created in heavy-ion collisions as they are produced in initial hard scattering processes and as they experience all the stages of the medium evolution. The measurement of heavy-flavour production cross sections in pp collisions at the LHC, besides providing a reference for heavy-ion studies, allows one to test perturbative QCD calculations. A brief review of ALICE results on the production of heavy-flavoured hadrons measured from fully reconstructed hadronic decay topologies in pp collisions at \sqrt{s} = 7 TeV is presented. Furthermore, heavy-flavour production was also studied as a function of the particle multiplicity in pp collisions. This could provide insight into multi-parton scatterings. A measurement of the inclusive J/{\psi} yield as a function of the charged-particle pseudorapidity density was performed by the ALICE Collaboration at the LHC in pp collisions at \sqrt{s} = 7 TeV. An increase of the J/{\psi} yield with increasing multiplicity was observed. In this context, the study of the yield of D mesons as a function of the charged-particle multiplicity could provide a deeper insight into charm-quark production in pp collisions. We will present the first results obtained for prompt D0, D+, and D*+ mesons using hadronic decay channels at midrapidity in pp collisions \sqrt{s}=7 TeV as a function of the charged-particle multiplicity. The prompt D-meson yields as a function of multiplicity are measured in different pT intervals. These yields will be compared to the results obtained for inclusive and non-prompt J/{\psi}.Comment: Proceeding of SQM 2013, 4 page

Heavy flavour and quarkonia production measurement in pp and Pb-Pb collisions at LHC energies with the ALICE detector

ALICE is the dedicated heavy-ion experiment at the LHC. Its main physics goal is to study the properties of strongly-interacting matter at conditions of high energy density and high temperature expected to be reached in central Pb--Pb collisions. Charm and beauty quarks are well-suited tools to investigate this state of matter since they are produced in initial hard scatterings and are therefore generated early in the system evolution and probe its hottest, densest stage. ALICE recorded pp data at $\rm \sqrt{s}$ = 7 TeV and 2.76 TeV and Pb--Pb data at $\rm \sqrt{s}_{\rm NN}$=2.76 TeV in 2010 and 2011. We present the latest results on heavy flavour and J/$\psi$ production at both central and forward rapidity.Comment: 6 pages, 4 figure

Open Charm Mesons at the LHC with ALICE

The ALICE experiment will be able to detect hadrons containing charm and beauty quarks in proton-proton and heavy ion collisions in the new energy regime of the CERN Large Hadron Collider (LHC). Open charmed mesons are a powerful tool to study the medium produced in heavy ion collisions, since charm quarks are produced on a very short time scale and they experience the whole history of the collision. In addition, the measurements of heavy flavour yield provide a natural normalization for those of charmonia and bottomonia production at LHC. In this talk, after a general overview of ALICE perspectives for heavy flavour physics, we will report some study of D-meson reconstruction through their hadronic decay channels with Monte Carlo simulated data.Comment: 7 pages, 4 figure

Open Charm Analysis at Central Rapidity in ALICE using the first year of pp data at \sqrt{s}=7 TeV

ALICE is the dedicated heavy-ion experiment at the LHC. Its main physics goal is to study the properties of the strongly-interacting matter in the conditions of high energy density (>10 GeV/fm3) and high temperature (> 0.3 GeV) expected to be reached in central Pb\^aPb collisions. Charm and beauty quarks are a powerful tool to investigate this high density and strongly interacting state of matter as they are produced in initial hard scatterings, and due to their long life time, they probe all the stages of the system evolution. The detector design was optimized for heavy ions but is also well suited for pp studies. ALICE recorded pp data at s= 7 TeV since march 2010 and the first run with heavy ion collisions took place in November 2010. The measurement of charm production cross section in pp collisions provides interesting insight into QCD processes and is important as a reference for heavy ion studies. The measurement of the D- meson yield in pp collisions can be used to extract the charm cross section. In this contribution, the ongoing study of reconstruction of D-mesons through hadronic decay channels and the first preliminary results obtained with \sqrt{s}= 7 TeV pp data will be presented.Comment: 4 pages, 2 figures, Conference proceeding to be published in Nucl. Phys.

Study of D-mesons using hadronic decay channels with the ALICE detector

At LHC energy, heavy quarks will be abundantly produced and the design of the ALICE Experiment will allow us to study their production using several channels. We investigate the feasibility of the study of D mesons reconstructed in their exclusive hadronic decay channel. After reviewing the ALICE potential for such studies, we will present some results for the two more promising decay channels i.e D0->KPi and D+ -> K-Pi+Pi+ obtained with 7 TeV pp data and 5.5 A TeV Pb-Pb Monte Carlo data .Comment: 4 Pages, 5 Figures. Conference Proceeding to be published in Nuclear Physics

Effect of Clustering in Map-based Mobility Model on the Performance Issues of Routing Protocols in Delay Tolerant Networks

In This paper analyze the Effect of Clustering in Map-based Mobility Model on the Performance of Routing Protocols in Delay Tolerant Networks propose a new analysis in mobility models for DTN using Epidemic routing, First Contact Routing, and Direct Delivery Routing. This paper presents two scenarios. ONE Simulator is used to perform these scenarios. Map-based mobility model focus on the movement of node on predefines location on the map. It gives the ability to characterize the behavior and performance of routing schemes, which facilitates one to select appropriate routing protocol for the application or the network in hand. The various DTN routing protocols considered for comparison are Direct Delivery, First Contact, Epidemic routing. Among these protocols: the first three routing protocols do not require any knowledge about the network. The results and analysis show that the proposed Clustered map based mobility model increases throughput, increases delivered packets. Hence the Epidemic routing scheme perform best results different to the first contact routing and direct delivery routin

Dynamic Density Response of Trapped Interacting Quantum Gases

An expression for the dynamic density response function has been obtained for an interacting quantum gas in Random Phase Approximation (RPA) including first order self and exchange contribution. It involves the single particle wave functions and eigen values. The expression simplifies when diagonal elements are considered. The diagonal elements of the imaginary part of Fourier transformed response function is relevant in the measurement of Bragg scattering cross-section and in several other applications.Comment: 2 pages, 0 figure, conferenc

Strategy Design Pattern

Design patterns usually describe abstract systems of interaction between classes, objects, and communication flows. So, a description of a set of interacting classes that provide a generalized solution framework to a generalized/specific design problem in a specific context can be said as a design pattern. There are many design patterns that can be used to solve real-life problems, but it remains very difficult to design, implement and reuse software for complex applications. Examples of these include enterprise system, real-time market data monitoring and analysis system. Design patterns provide an efficient way to create more flexible, elegant and ultimately reusable object-oriented software. Each pattern describes a problem which occurs over and over again in our environment, and then describes the core of the solution to that problem, in such a way that you can use this solution a million times over, without ever doing it the same way twice201D;. The solutions of the given problems are expressed in terms of objects and interfaces. Among 23 design patterns, Strategy pattern defines an interface common to all supported algorithms. Context uses this interface to call the algorithm defined by a Concrete Strategy. In accounting framework one thing is mostly needed that is tax calculation. To solve this problem author in the current study has chosen the strategy pattern

Dependence of structure factor and correlation energy on the width of electron wires

The structure factor and correlation energy of a quantum wire of thickness $b\ll a_B$ are studied in random phase approximation and for the less investigated region $r_s<1$. Using the single-loop approximation, analytical expressions of the structure factor have been obtained. The exact expressions for the exchange energy are also derived for a cylindrical and harmonic wire. The correlation energy $\epsilon_c$ is found to be represented by $\epsilon_c (b,r_s)= \frac{\alpha(r_s)}{b} + \beta(r_s)\; ln(b) + \eta(r_s)$, for small $b$ and high densities. For a pragmatic width of the wire, the correlation energy is in agreement with the quantum Monte Carlo simulation data.Comment: Being slightly modifie