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Title: Particle production at large momentum transfer
Creator: Gonçalves, V.p., Sauter, Werner K.
Date: 2013-09-15, 2013-09-15
Publisher: IIT Press
Description: Diffractive particle production in ep collisions and coherent pp interactions is studied assuming that the color singlet t channel exchange...
Show moreDiffractive particle production in ep collisions and coherent pp interactions is studied assuming that the color singlet t channel exchange carries large momentum transfer. The differential and total cross sections for vector meson and photon production are calculated using the non-forward solution of the LO and NLO BFKL equation at high energy and large momentum transfer and the predictions are compared with the DESY HERA data. Moreover, we estimate the rapidity distributions and total cross section for the J/Ψ and ρ production in coherent pp interactions at LHC energies. We predict large rates, which implies that the experimental identification can be feasible at the LHC.
Sponsorship: IIT College of Science, High Energy Physics Division of Argonne National Laboratory
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Collection: Proceedings of the XLIII International Symposium on Multiparticle Dynamics

Title: Color reconnection and its effects on precise measurements at the LHC
Creator: Sjöstrand, Torbjörn
Date: 2013-09-15, 2013-09-15
Publisher: IIT Press
Description: There is experimental evidence for the occurrence of color reconnection, but the mechanisms involved are far from understood. Previous...
Show moreThere is experimental evidence for the occurrence of color reconnection, but the mechanisms involved are far from understood. Previous reconnection studies are briefly summarized, and some potential implications for LHC physics are outlined.
Sponsorship: IIT College of Science, High Energy Physics Division of Argonne National Laboratory
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Collection: Proceedings of the XLIII International Symposium on Multiparticle Dynamics

Title: Parton distributions and event generators
Creator: Carrazza, Stefano, Forte, Stefano, Rojo, Juan
Date: 2013-09-15, 2013-09-15
Publisher: IIT Press
Description: We present the implementation within the Pythia8 event generator of a set of parton distributions based on NNPDF methodology. We construct a...
Show moreWe present the implementation within the Pythia8 event generator of a set of parton distributions based on NNPDF methodology. We construct a set of leading-order parton distributions with QED corrections, NNPDF2.3QED LO set, based on the same data as the previous NNPDF2.3 NLO and NNLO PDF sets. We compare this PDF set to its higher-order counterparts, we discuss its implementation as an internal set in Pythia8, and we use it to study some of the phenomenological implications of photon-initiated contributions for dilepton production at hadron colliders.
Sponsorship: IIT College of Science, High Energy Physics Division of Argonne National Laboratory
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Collection: Proceedings of the XLIII International Symposium on Multiparticle Dynamics

Title: Inclusive measurements at HERA from low to high x
Creator: Behnke, Olaf
Date: 2013-09-15, 2013-09-15
Publisher: IIT Press
Description: New inclusive Deep Inelastic Scattering (DIS) measurements are presented, obtained with the H1 and ZEUS detectors at HERA. The results...
Show moreNew inclusive Deep Inelastic Scattering (DIS) measurements are presented, obtained with the H1 and ZEUS detectors at HERA. The results comprise (flavour) inclusive DIS cross sections as well as inclusive charm production. In the area of inclusive DIS, both H1 and ZEUS completed last year their high Q2 Neutral and Charged current measurements exploiting the large statistics from the HERA II running period. For inclusive charm production, H1 and ZEUS published a combination of numerous existing measurements based on various tagging methods. Among other things a precise determination of the running charm quark mass mc(mc) was obtained from the combined data.
Sponsorship: IIT College of Science, High Energy Physics Division of Argonne National Laboratory
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Collection: Proceedings of the XLIII International Symposium on Multiparticle Dynamics

Title: Polarised Drell-Yan physics at COMPASS
Creator: Franco, Celso
Date: 2013-09-15, 2013-09-15
Publisher: IIT Press
Description: The COMPASS experiment at CERN is one of the leading experiments studying the spin structure of the nucleon. Until now, the Parton...
Show moreThe COMPASS experiment at CERN is one of the leading experiments studying the spin structure of the nucleon. Until now, the Parton Distribution Functions (PDFs) and the Transverse Momentum Dependent Parton Distribution Functions (TMD PDFs) of protons and deuterons have been studied in Semi-Inclusive Deep Inelastic Scattering (SIDIS) measurements. The polarised Drell-Yan (DY) process is a complementary way to access the TMD PDFs, as it allows us to measure convolutions of only PDFs without involving fragmentation functions (FFs). COMPASS aims to perform the first ever polarised DY experiment in the world, which is foreseen to start in late 2014. By detecting dimuons from DY events we will be able to extract azimuthal spin asymmetries, each containing a convolution of two TMD PDFs, one from a negative pion beam with a momentum of 190 GeV/c and the other one from a transversely polarised proton target (NH₃). After their disentangling we can access four of the eight TMD PDFs needed to describe the nucleon structure at leading twist, like the Sivers and the Boer-Mulders functions. The opportunity to study, in the same experiment, the TMD PDFs from both SIDIS and DY processes is unique at COMPASS. Therefore, we are in privileged conditions to confirm or to deny the expected sign change in Sivers and Boer-Mulders functions when accessed via DY or SIDIS processes. An overview of the preparation and future measurements of the polarised DY experiment will be provided.
Sponsorship: IIT College of Science, High Energy Physics Division of Argonne National Laboratory
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Collection: Proceedings of the XLIII International Symposium on Multiparticle Dynamics

Title: Study of pp interactions at high multiplicity at U-70
Creator: Aleev, A., Avdeichikov, V., Balandin, V., Borzunov, Yu., Chencov, Yu., Dunin, V., Furmanec, N., Kekelidze, G., Kireev, V., Kokoulina, E., Ladygin, V., Myalkovsky, V., Nikitin, V., Peshehonov, V., Petukhov, Yu., Rufanov, I., Yukaev, A., Zhidkov, N., Basiladze, S., Bogdanova, G., Erofeeva, I., Grishin, N., Grishkevich, Ya., Karmanov, D., Kramarenko, V., Leflat, A., Merkin, M., Popov, V., Tihonova, L., Vishnevskaya, A., Volkov, V., Voronin, A., Zverev, E., Ardashev, E., Afonin, A., Golovkin, V., Golovnya, S., Gorokhov, S., Kholodenko, A., Kiryakov, A., Kurchaniniv, L., Lobanov, I., Lobanova, E., Mitrofanov, G., Petrov, V., Pleskach, A., Polkovnikov, M., Ronzhin, V., Ryadovikov, V., Senko, V., Soldatov, M., Shalanda, N., Tsyupa, Yu., Vorobiev, A., Yakimchuk, V., Zapolsky, V., Kutov, A.
Date: 2013-09-15, 2013-09-15
Publisher: IIT Press
Description: The E190 Experiment is aimed at the search for collective phenomena in a quark-gluon system and a hadron system. It is carried out at U-70 in...
Show moreThe E190 Experiment is aimed at the search for collective phenomena in a quark-gluon system and a hadron system. It is carried out at U-70 in IHEP, Protvino. The evidence of Bose-Einstein condensation of pions has been confirmed with a twofold increasing of sampling at a level of 7 standard deviations. We study soft photon (smaller than 60 MeV) yield by using of an electromagnetic calorimeter with low energy threshold. In the gluon dominance model we explain multiparticle production by the active gluons. In this model the estimation of the contribution of charge exchange has been obtained.
Sponsorship: IIT College of Science, High Energy Physics Division of Argonne National Laboratory
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Collection: Proceedings of the XLIII International Symposium on Multiparticle Dynamics

Title: The Tevatron energy scan: Findings & surprises
Creator: Field, Rick
Date: 2013-09-15, 2013-09-15
Publisher: IIT Press
Description: At CDF we study charged particle production (pT > 0.5 GeV/c, |η|
Show moreAt CDF we study charged particle production (pT > 0.5 GeV/c, |η| < 0.8) in proton-antiproton collisions at 300 GeV, 900 GeV, and 1.96 TeV. The 300 GeV and 900 GeV data are a result of the “Tevatron Energy Scan” which was performed just before the Tevatron was shut down. We use the direction of the leading charged particle in each event, PTmax, to define three regions of η-φ space; “toward,” “away,” and “transverse.” The “trans- verse” region is further divided into the “transMAX” and “transMIN” con- tributions. The “transMIN” region is very sensitive to the multiple parton interaction component (MPI) of the “underlying event,” while the “trans-DIF” (“transMAX” minus “transMIN”) is very sensitive to the initial and final-state radiation. This CDF analysis together with LHC data provides a detailed study the energy dependence of the various components of the “underlying event” in hadronic collisions.
Sponsorship: IIT College of Science, High Energy Physics Division of Argonne National Laboratory
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Collection: Proceedings of the XLIII International Symposium on Multiparticle Dynamics

Title: Proton structure from multiparticle contribution to elastic pp-scattering at 7 TeV
Creator: Dremin, I. M.
Date: 2013-09-15, 2013-09-15
Publisher: IIT Press
Description: The parton content of protons gets strong peripheral contribution at 1 fm from multiparticle dynamics as revealed by the overlap function in...
Show moreThe parton content of protons gets strong peripheral contribution at 1 fm from multiparticle dynamics as revealed by the overlap function in the unitarity condition for elastic pp-scattering at 7 TeV.
Sponsorship: IIT College of Science, High Energy Physics Division of Argonne National Laboratory
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Collection: Proceedings of the XLIII International Symposium on Multiparticle Dynamics

$Diffraction at the LHC$

Title: Diffraction at the LHC
Creator: Csanád, M.
Date: 2013-09-15, 2013-09-15
Publisher: IIT Press
Description: Proton-proton collisions at the LHC can be classified as elastic, non-diffractive, and diffractive. In this paper we discuss various...
Show moreProton-proton collisions at the LHC can be classified as elastic, non-diffractive, and diffractive. In this paper we discuss various measurements of these above processes at various LHC experiments. We report about the total proton-proton cross-section measurements, about the analysis of diffractive events and also about the pseudorapidity distribution in inelastic events.
Sponsorship: IIT College of Science, High Energy Physics Division of Argonne National Laboratory
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Collection: Proceedings of the XLIII International Symposium on Multiparticle Dynamics

Title: Study of the helix model
Creator: Todorova-nová, Ŝárka
Date: 2013-09-15, 2013-09-15
Publisher: IIT Press
Description: The quantum properties of a helix-like shaped QCD string are studied in the context of the semi-classical Lund fragmentation model. It is...
Show moreThe quantum properties of a helix-like shaped QCD string are studied in the context of the semi-classical Lund fragmentation model. It is shown how simple quantization rules combined with the causality considerations in the string fragmentation process describe the mass hierarchy of light pseudoscalar mesons. The quantized helix string model predicts observable quantum effects related to the threshold behaviour of the intrinsic transverse momentum of hadrons, and of the minimal transverse momentum difference between adjacent hadrons.
Sponsorship: IIT College of Science, High Energy Physics Division of Argonne National Laboratory
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Collection: Proceedings of the XLIII International Symposium on Multiparticle Dynamics

Title: Measurement of the charged kaon correlations at small relative momentum in the SELEX experiment
Creator: Nigmatkulov, Grigory
Date: 2013-09-15, 2013-09-15
Publisher: IIT Press
Description: We report the first measurement of charged kaon Bose–Einstein correlations produced by 600 GeV/c Σ−, π− and 540 GeV/c p beams in the SELEX...
Show moreWe report the first measurement of charged kaon Bose–Einstein correlations produced by 600 GeV/c Σ−, π− and 540 GeV/c p beams in the SELEX experiment. The SELEX (E781) experiment at Fermilab is a fixed target three–stage magnetic spectrometer designed for study hadroproduction at high acceptance for forward interactions (xF ≥ 0.1). One–dimensional charged kaon correlation functions were obtained for all three beams and three pair transverse momentum ranges. The femtoscopic parameters for the radii and correlation strength of the kaon source were extracted. The fit results show the decrease of the emission source radii with the increase of the pair transverse momentum.
Sponsorship: IIT College of Science, High Energy Physics Division of Argonne National Laboratory
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Collection: Proceedings of the XLIII International Symposium on Multiparticle Dynamics

Title: Searching for W' bosons at LHC with single top production
Creator: Duffty, Daniel, Sullivan, Zack
Date: 2013-09-15, 2013-09-15
Publisher: IIT Press
Description: One of the strengths of the LHC is its capacity for the discovery of new physics. As a consequence of many BSM theories, W′ bosons make an...
Show moreOne of the strengths of the LHC is its capacity for the discovery of new physics. As a consequence of many BSM theories, W′ bosons make an ideal particle to search for to constrain many models. One mode in particular has relatively low background: Single top quark production mediated by a W′ boson. For W′ masses less than 1500 GeV, all the decay products of the top quark are visible, and the strongest channel is the top’s decay into an electron or muon, with the associated neutrino and a bottom jet. As the W′ mass increases, the decay products from the highly boosted top and bottom quarks from the W′ appear as fat jets; boosted top tagging algorithms abound, and we propose a boosted bottom tag to set an exclusion limit of 2750 GeV for standard model-like couplings with existing 8 TeV data.
Sponsorship: IIT College of Science, High Energy Physics Division of Argonne National Laboratory
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Collection: Proceedings of the XLIII International Symposium on Multiparticle Dynamics

Title: Large x physics: recent results and future plans
Creator: Holt, Roy J.
Date: 2013-09-15, 2013-09-15
Publisher: IIT Press
Description: The valence region is exceedingly important in hadron physics since this region not only defines a hadron but also is an excellent...
Show moreThe valence region is exceedingly important in hadron physics since this region not only defines a hadron but also is an excellent discriminator of nucleon structure models. Present uncertainties in light quark distribution functions at high x could also impact high energy physics. Here we will describe a new generation of experiments at Jefferson Lab that is aimed at the high x region of the nucleon. It is noted that the proposed Electron Ion Collider could explore the high x regime.
Sponsorship: IIT College of Science, High Energy Physics Division of Argonne National Laboratory
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Collection: Proceedings of the XLIII International Symposium on Multiparticle Dynamics

Title: HERAFitter - an open source QCD fit framework
Creator: Starovitov, Pavel
Date: 2013-09-15, 2013-09-15
Publisher: IIT Press
Description: The patron distribution functions (PDFs) describe the parton content of the proton. They cannot be calculated from the first principle and are...
Show moreThe patron distribution functions (PDFs) describe the parton content of the proton. They cannot be calculated from the first principle and are to be determined empirically by fitting experimental observables to quantum chromodynamics (QCD) predictions. The HERAFitter project aims to provide a framework for QCD analyses of proton structure at leading order (LO), next-to-leading order (NLO) and next-to-next-to-leading (NNLO) orders in perturbative QCD. The framework includes various modules and interfaces enabling a large number of theoretical and methodological options. It also allows to study the impact of the new experimental data on the PDFs from ep, pp and pp̅ scattering processes. The fast development of the project involves active communication with theorists and experimentalist as well as a close collaboration with the main PDF fitting groups. Full information about the project, downloads and documentation can be found in http://herafitter.org.
Sponsorship: IIT College of Science, High Energy Physics Division of Argonne National Laboratory
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Collection: Proceedings of the XLIII International Symposium on Multiparticle Dynamics

Title: Improved isolation of the p-p underlying event based on minimum-bias trigger-associated hadron correlations
Creator: Trainor, Thomas, Prindle, Duncan J.
Date: 2013-09-15, 2013-09-15
Publisher: IIT Press
Description: Some aspects of hadron production in p-p collisions remain unresolved, including the low-hadron-momentum structure of high-parton-energy...
Show moreSome aspects of hadron production in p-p collisions remain unresolved, including the low-hadron-momentum structure of high-parton-energy dijets, separation of triggered dijets from the underlying event (UE), the systematics of multiple parton interactions and possible systematic underestimation of dijet contributions to high-energy nuclear collisions. In this study we apply a minimum-bias trigger-associated (TA) correlation analysis to p-p collisions. We extract a hard component from TA correlations that can be compared with measured jet fragment systematics derived from e+-e− collisions. The kinematic limits on jet fragment production may be determined. The same method may be extended to A-A collisions where the role of minimum-bias jets in spectra and correlations is strongly contested.
Sponsorship: IIT College of Science, High Energy Physics Division of Argonne National Laboratory
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Collection: Proceedings of the XLIII International Symposium on Multiparticle Dynamics

Title: Hadronic final states in high-pT QCD at CDF
Creator: Matera, Keith
Date: 2013-09-15, 2013-09-15
Publisher: IIT Press
Description: The heavy quark content associated with gauge boson production is of great interest to studies of QCD. These events probe the gluon and heavy...
Show moreThe heavy quark content associated with gauge boson production is of great interest to studies of QCD. These events probe the gluon and heavy-quark parton distribution functions of the proton, and also provide a measurement of the rate of final state gluon splitting to heavy favor. In addition, gauge boson plus heavy quark events are representative of backgrounds to Higgs, single top, and supersymmetric particle searches. Recent work with the CDF II detector at the Fermilab Tevatron has measured the cross-section of several gauge boson plus heavy flavor production processes, including the first Tevatron observation of specific charm process p͞p → W + c. Results are found to be in agreement with NLO predictions that include an enhanced rate of g → c͞c =b͞b splitting. Lastly, a new analysis promises to probe a lower pT (c) region than has yet been explored, by fully reconstructing D* → D^0 (Kπ)π decays in the full CDF dataset (9:7 fb^1).
Sponsorship: IIT College of Science, High Energy Physics Division of Argonne National Laboratory
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Collection: Proceedings of the XLIII International Symposium on Multiparticle Dynamics

Title: Overview of Higgs results from CMS
Creator: Merkel, Petra
Date: 2013-09-15, 2013-09-15
Publisher: IIT Press
Description: Sponsorship: IIT College of Science, High Energy Physics Division of Argonne National Laboratory
In this article we present an overview of...
Show moreSponsorship: IIT College of Science, High Energy Physics Division of Argonne National Laboratory
In this article we present an overview of Higgs boson results from the CMS Collaboration as presented at the ISMD13 conference.
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Collection: Proceedings of the XLIII International Symposium on Multiparticle Dynamics

Title: Boosted heavy particles and jet substructure with the CMS detector
Creator: Marchesini, Ivan
Date: 2013-09-15, 2013-09-15
Publisher: IIT Press
Description: In the last years, the understanding of jets and jet substructure has become increasingly important, in particular in the context of new...
Show moreIn the last years, the understanding of jets and jet substructure has become increasingly important, in particular in the context of new physics searches. Many new physics models involve highly boosted hadronically-decaying particles, which result in jet-like objects with large masses and an intrinsic substructure. Discrimination of these heavy jets from ordinary quark and gluon jets is possible through a plethora of new techniques. The understanding of jets can be exploited also for the identification of pileup jets and for the discrimination between quark jets and gluon jets. A sampling of these techniques is discussed together with their validation on collider data recorded in proton-proton collisions at √s = 8TeV with the CMS detector in the year 2012. The commissioning in the boosted regime of algorithms used to identify jets originating from bottom quarks is also discussed. Many studies have highlighted the potential of using jet substructure techniques to improve the sensitivity in physics searches. An overview of recent CMS results employing these techniques is presented.
Sponsorship: IIT College of Science, High Energy Physics Division of Argonne National Laboratory
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Collection: Proceedings of the XLIII International Symposium on Multiparticle Dynamics

$Central exclusive production and the Durham diffractive program$

Title: Central exclusive production and the Durham diffractive program
Creator: Harland-lang, L. A., Khoze, V. A., Ryskin, M. G.
Date: 2013-09-15, 2013-09-15
Publisher: IIT Press
Description: Recent results in central exclusive production within the Durham model are presented. A wide range of processes are considered, and their...
Show moreRecent results in central exclusive production within the Durham model are presented. A wide range of processes are considered, and their theoretical and phenomenological interest is discussed.
Sponsorship: IIT College of Science, High Energy Physics Division of Argonne National Laboratory
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Collection: Proceedings of the XLIII International Symposium on Multiparticle Dynamics

Title: Recent results on vector boson production in association with jets with the CMS detector
Creator: Cornelis, Tom
Date: 2013-09-15, 2013-09-15
Publisher: IIT Press
Description: The production of weak vector bosons in association with jets and their properties are intensively studied using proton-proton collision data...
Show moreThe production of weak vector bosons in association with jets and their properties are intensively studied using proton-proton collision data collected with the CMS detector. In this proceedings, we will show the cross section measurement of the electroweak production of a Z boson in association with 2 jets at √s = 8 TeV, including a new data-driven approach and studies on the hadronic activity in the region between the two tagging jets. The azimuthal correlations and event shapes in Z + jets events at √s= 7 TeV are also presented.
Sponsorship: IIT College of Science, High Energy Physics Division of Argonne National Laboratory
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Collection: Proceedings of the XLIII International Symposium on Multiparticle Dynamics

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