The ALICE EMCal L1 trigger first year of operation experience

The ALICE experiment at the LHC is equipped with an electromagnetic calorimeter (EMCal) designed to enhance its capabilities for jet, photon and electron measurement. In addition, the EMCal enables triggering on jets and photons with a centrality dependent energy threshold. After its commissioning in 2010, the EMCal Level 1 (L1) trigger was officially approved for physics data taking in 2011. After describing the L1 hardware and trigger algorithms, the commissioning and the first year of running experience, both in proton and heavy ion beams, are reviewed. Additionally, the upgrades to the original L1 trigger design are detailed.Comment: Proceedings of TWEPP-12, Oxford. 10 pages, 9 figure

Open-beauty production in ppPb collisions at sNN\sqrt{s_{NN}}=5 TeV: effect of the gluon nuclear densities

We present our results on open beauty production in proton-nucleus collisions for the recent LHC $p$Pb run at $\sqrt{s_{NN}}$=5 TeV. We have analysed the effect of the modification of the gluon PDFs in nucleus at the level of the nuclear modification factor. Because of the absence of measurement in $pp$ collisions at the same energy, we also propose the study of the forward-to-backward yield ratio in which the unknown proton-proton yield cancel. Our results are compared with the data obtained by LHCb collaboration and show a good agreement.Comment: 6 pages, 3 figures, Proceedings IS2013 submitted to Nuclear Physics

Production of Neutral Pions and Eta-mesons in pp Collisions Measured with ALICE

Invariant cross sections for neutral pions and eta mesons in pp collisions at sqrt(s) = 0.9, 2.76, and 7 TeV were measured by the ALICE detector at the Large Hadron Collider. Next-to-leading order (NLO) perturbative QCD calculations describe the pi0 and eta spectra at 0.9 TeV, but overestimate the measured cross sections at 2.76 TeV and 7 TeV. The measured eta/pi0 ratio is consistent with mT scaling at 2.76 TeV. At 7 TeV indications for a violation of mT scaling were found.Comment: 4 pages, 2 figures, to appear in the proceedings of the XXII International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions, Quark Matter 2011, Annec

Phenomenological interpolation of the inclusive J/psi cross section to proton-proton collisions at 2.76 TeV and 5.5 TeV

We present a study of the inclusive J/psi cross section at 2.76 TeV and 5.5 TeV. The energy dependence of the cross section, rapidity and transverse momentum distributions are evaluated phenomenologically. Their knowledge is crucial as a reference for the interpretation of A-A and p-A J/psi results at the LHC. Our approach is the following: first, we estimate the energy evolution of the pt-integrated J/psi cross section at mid-rapidity; then, we evaluate the rapidity dependence; finally, we study the transverse momentum distribution trend. Whenever possible, both theory driven (based on pQCD predictions) and functional form (data driven fits) calculations are discussed. Our predictions are compared with the recently obtained results by the ALICE collaboration in pp collisions at 2.76 TeV.Comment: 23 pages, 19 figures, updated text+figures, added comparison to ALICE measurements at 2.76Te

Synthesis, In Silico Studies, Antiprotozoal and Cytotoxic Activities of Quinoline‐Biphenyl Hybrids

This is the pre-peer reviewed version of the following article: Synthesis, In Silico Studies, Antiprotozoal and Cytotoxic Activities of Quinoline‐Biphenyl Hybrids, which has been published in final form at https://doi.org/10.1002/slct.201903835. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived VersionsThe synthesis, in silico studies, antiprotozoal and cytotoxic activities of eleven quinoline‐biphenyl hybrids are described herein. The structure of the synthesized products was elucidated by a combination of spectrometric analyses. The synthesized compounds were evaluated against Plasmodium falciparum, and amastigotes forms both Leishmania (V) panamensis and Trypanosoma cruzi. Cytotoxicity was evaluated against human U‐937 macrophages. 8‐phenylquinoline (4 a) showed similar activity than meglumine antimoniate and 4‐(quinolin‐8‐yl)phenol (4 b) exhibited an activity similar to that of benznidazole. 8‐(3,4‐dimethoxyphenyl) quinoline (4 k) showed the best activity against P. falciparum. Although these compounds were toxic for mammalian U‐937 cells, however they may still have potential to be considered as candidates for drug development because of their antiparasite activity. Molecular docking was used to determine the in silico inhibition of some of the designed compounds against PfLDH and cruzipain, two important pharmacological targets involved in antiparasitic diseases. All hybrids were docked to the three‐dimensional structures of PfLDH and T. cruzi cruzipain as enzymes using AutoDock Vina. Notably, the docking results showed that the most active compounds 4‐(quinolin‐8‐yl)phenol (4 b, CE50: 11.33 μg/mL for T. cruzi) and 8‐(3,4‐dimethoxyphenyl) quinoline (4 k, CE50: 8.84 μg/mL for P. falciparum) exhibited the highest scoring pose (−7.5 and −7.7 kcal/mol, respectively). This result shows a good correlation between the predicted scores with the experimental data profile, suggesting that these ligands could act as competitive inhibitors of PfLDH or T. cruzi cruzipain enzymes, respectively. Finally, in silico ADME studies of the quinoline hybrids showed that these novel compounds have suitable drug‐like properties, making them potentially promising agents for antiprotozoal therapy

Prompt Photon Identification in the ALICE Experiment: The Isolation Cut Method

Submitted for publication in NIMThe ALICE experiment at LHC will detect and identify prompt photons and light neutral mesons with the PHOS and EMCal detectors. Charged particles will be detected and identified by the central tracking system. In this paper, a method to identify prompt photons and to separate them from the background of hadrons and decay photons in PHOS with the help of isolation cuts is presented

Identification of photon-tagged jets in the ALICE experiment

The ALICE experiment at LHC will detect and identify prompt photons and light neutral-mesons with the PHOS detector and the additional EMCal electromagnetic calorimeter. Charged particles will be detected and identified by the central tracking system. In this article, the possibility of studying the interaction of jets with the nuclear medium, using prompt photons as a tool to tag jets, is investigated by simulations. New methods to identify prompt photon-jet events and to distinguish them from the jet-jet background are presented.Comment: NIM A: accepted manuscrip

Effect of heavy-quark energy loss on the muon differential production cross section in Pb-Pb collisions at \sqrtsNN=5.5 TeV

We study the nuclear modification factors RAA and RCP of the high transverse momentum 5<pt<60 GeV/c distribution of muons in Pb--Pb collisions at LHC energies. We consider two pseudo-rapidity ranges covered by the LHC experiments: $|\eta|<2.5$ and $2.5<\eta<4$. Muons from semi-leptonic decays of heavy quarks (c and b) and from leptonic decays of weak gauge bosons (W and Z) are the main contributions to the muon pt distribution above a few GeV/c. We compute the heavy quark contributions using available pQCD-based programs. We include the nuclear shadowing modification of the parton distribution functions and the in-medium radiative energy loss for heavy quarks, using the mass-dependent BDMPS quenching weights. Muons from W and Z leptonic decays, that dominate the yield at high pt, can be used as a medium-blind reference to observe the medium-induced suppression of beauty quarks