Study Of Heavy Flavor Production Research Articles

Summary of charm results from ALICE

An overview of the most recent charm measurements from the ALICE Collaboration is presented in this document. The study of heavy-flavour production is important to understand the properties of the hot and dense medium formed in ultra-relativistic heavyion collisions. In this document the journey of charm in the medium, from the production to the hadronisation into hadrons, is described. Both open charm and quarkonium measurements are presented, starting from D-meson and J/ψ production cross sections in pp collisions and their comparison with theoretical calculations. Recent measurements of relative abundances of different particle species are discussed, in particular the Ds/D0 and ratios, that are sensitive to the hadronisation mechanisms and to the strangeness and to the baryon-to-meson enhancement. The energy loss mechanisms and the collective motion in the medium are investigated through the D-meson and J/ψ nuclear modification factor and the elliptic flow measurements. Further investigations on possible medium-like effects observed in high-multiplicity pp and p-Pb collisions are also addressed.

PHENIX Measurements of Heavy Flavor in Small Systems

The study of heavy flavor production in proton-nucleus and nucleus-nucleus collisions is a sensitive probe of the hot and dense matter created in such collisions. Installation of silicon vertex detectors in the PHENIX experiment, and increased performance of the BNL RHIC collider allowed collection of large amount of data on heavy flavor production in small colliding systems. In this talk we will present recent PHENIX results on open heavy flavor and quarkonia production in p+p, p+A, d+A, and He3+A colliding systems in a broad rapidity range, and discuss how these measurements help us to better understand all stages of nuclear collisions at high energy.

Production and spectroscopy in heavy flavour

A wide programme of studies of heavy flavour production at the LHC is performed with the ATLAS detector. This paper covers recent results in measurements of pair b-quark production, di- J/ψ production cross-section and effective cross-section from double parton scattering. Studies on the production of ψ (2S) and X (3872) are presented as well. Paper also covers the measurement of J/ψ -meson non-prompt production fraction and B ± -meson mass reconstruction.

Measurement of electrons from Heavy Quarks in PHENIX

Abstract Heavy quarks are one of the most valuable probes for the matter produced in relativistic heavy ion collisions. PHENIX experiment @ RHIC is designed specifically to study leptons, so electrons from the decay of heavy quarks are one of the most important tools in PHENIX for the study of heavy flavour production. Measurements of electron spectra at mid rapidity region has been done by PHENIX in broad p T regions for various collision species starting from p+p to Au+Au. The techniques used by PHENIX for measuring electrons from heavy quarks and the latest results in collision species p+p, d+Au, Cu+Cu and Au+Au will be discussed in this article.

Upgrade of the ALICE inner tracking system

The Inner Tracking System (ITS) is the key ALICE detector for the study of heavy flavor production at LHC. Heavy flavor can be studied via the identification of short-lived hadrons containing heavy quarks which have a mean proper decay length in the order of 100–300μm. To accomplish this task, the ITS is composed of six cylindrical layers of silicon detectors (two pixel, two drift and two strip) with a radial coverage from 3.9 to 43cm and an average material budget of 1.1% X0 per layer.In order to enhance the ALICE physics capabilities, and, in particular, the tracking performance for heavy-flavor detection, the possibility of an ITS upgrade has been studied in great detail. It will make use of the spectacular progress made in the field of imaging sensors over the last 10years as well as the possibility to install a smaller radius beampipe. The upgraded detector will have greatly improved features in terms of the impact parameter resolution, standalone tracking efficiency at low pt, momentum resolution and readout capabilities.The usage of the most recent monolithic and/or hybrid pixel detector technologies allows the improvement of the detector material budget and the intrinsic spatial resolution both by a factor of three with respect to the present ITS. The installation of a smaller beam-pipe reduces the distance between the first detector layer and the interaction vertex. Under these assumptions, simulations show that an overall improvement of the impact parameter resolution by a factor of three is possible.The Conceptual Design Report for the Upgrade of the ALICE ITS, which covers the design and performance requirements, the upgrade options, as well as the necessary R&D efforts, was made public in September 2012. An intensive R&D program has been launched to review the different technological options under consideration. The new detector should be ready to be installed during the long LHC shutdown period scheduled in 2017–2018.

ALICE potential for heavy-flavour physics

Heavy quarks will be abundantly produced in Heavy Ion Collisions at LHC energies. Both the production of open heavy flavoured mesons and quarkonia will probe the strongly interacting medium created in these reactions. In particular, the ALICE detector will be able to measure heavy flavour production down to low transverse momentum, combining leptonic and hadronic channels, covering a large rapidity range |η| < 0.9 and −4 < η < −2.5. In this talk we will present the main physics motivations for the study of heavy flavour production at LHC energies and some examples of physics analyses developed by the heavy flavour working group of ALICE.

Heavy-quark and electromagnetic probes

The study of heavy-flavour production and electromagnetic probes in nuclear collisions provides unique access to the properties of strongly interacting matter at extreme energy densities. Highlights of experimental results presented at the Quark Matter 2006 conference are reviewed and open issues are discussed.

Open heavy-flavour production at RHIC

The study of heavy-flavour production in relativistic heavy-ion collisions is an extreme experimental challenge but provides important information on the properties of the quark–gluon plasma (QGP) created in Au+Au collisions at RHIC. Heavy quarks are believed to be produced in the initial stages of the collision, and are essential for the understanding of parton energy loss in the dense medium created in such environment. Moreover, heavy quarks can help to investigate the fundamental properties of QCD in elementary p+p collisions. In this work, we review recent results on heavy-flavour production and their interaction with the hot and dense medium at RHIC.

Heavy flavor measurements at RHIC

The study of heavy flavor production in relativistic heavy ion collisions is an extreme experimental challenge but provides important information on the properties of the Quark-Gluon Plasma (QGP) created in Au+Au collisions at RHIC. Heavy quarks are believed to be produced in the initial stages of the collision, and are essential on the understanding of parton energy loss in the dense medium created in such environment. Moreover, heavy-flavor quarkonia production is an important tool to understand deconfinement. In this work we review recent results on open heavy flavor and quarkonia production and their interaction with the hot and dense medium at RHIC.

Heavy Quark Production in Large Rapidity in d+Au Collisions at RHIC

At RHIC energy, heavy flavor production in hadronic collisions is dominated by gluonic processes and so is a sensitive probe of the gluon structure function in the nucleon and its modification in nuclei. A study of heavy flavor production in p+p and d+Au collisions in various kinematic regions presents an opportunity to probe various cold nuclear medium effects: parton shadowing, color glass condensate, initial state energy loss, and coherent multiple scattering in final state interactions. We study cold nuclear medium effects on open charm and J / ψ production in d+Au collisions with the PHENIX muon spectrometers at forward and backward rapidity 1.2 < | η | < 2.4 . The latest results are presented.

Measurement of open heavy flavour production with single muons in p + p and d + Au collisions at RHIC

Heavy flavour production in hadronic collisions is dominated by gluonic processes and so is a sensitive probe of the gluon structure function in the nucleon and its modification in nuclei. A study of heavy flavour production in p + p and d + Au collisions in various kinematic regions presents an opportunity to probe cold nuclear medium effects: parton shadowing, colour glass condensate, initial-state energy loss and coherent multiple scattering in final-state interactions. The PHENIX muon arms cover both forward and backward directions in the rapidity range 1.2 < |η| < 2.4. We investigate single muon production from open heavy flavour and light meson decays in p + p and d + Au collisions at forward and backward rapidities.

Study of heavy flavour production in events with a muon accompanied by jet(s) at the CERN proton-antiproton collider

We present a study of heavy flavour (charm and beauty) production using data collected with the UA1 detector at the CERN Proton-Antiproton collider at a centre-of-mass energy of 630 GeV for an integrated luminosity of 556 nb−1. This follows our earlier study ofb $$\bar b$$ andc $$\bar c$$ production in dimuon events and the evidence for mixing betweenB 0 and $$\bar B^0 $$ states. Properties of an inclusive sample of events containing a muon withp T >6 GeV/c are compared with QCD predictions for heavy flavour production, using the ISAJET Monte Carlo program. The predicted largep T muon yield from heavy flavour production and decay agrees with the data to within 30%. For events with a muon ofp T >10 GeV/c and at least one jet withE T >10 GeV, we measure the ratio charm/(charm+beauty) to be (24±8±9)%. We also show that the correlations observed between the two heavy quark jets expected by flavour conservation are consistent with the mixture of lowest and higher order QCD processes. We study in detail the topological and kinematic properties of a subsample of events containing a highp T muon and one or more jets. The good agreement of the theoretical predictions with our data in a region dominated by the production of charm and beauty shows that one of the main background sources to a new heavy quark signature is well understood.