P. Z. Skands

Publications (12)0.57 Total impact

• Source

  Available from: ias.ac.in

  Article: Testing the supersymmetric QCD Yukawa coupling in a combined LHC/ILC analysis

  A. Freitas, P. Z. Skands
  [show abstract] [hide abstract]
  ABSTRACT: In order to establish supersymmetry (SUSY) at future colliders, the identity of gauge couplings and the corresponding Yukawa couplings between gauginos, sfermions and fermions needs to be verified. A first phenomenological study for determining the Yukawa coupling of the SUSY-QCD sector is presented here, using a method which combines information from LHC and ILC.
  Pramana 04/2012; 69(5):843-847. · 0.57 Impact Factor
• Source

  Available from: ArXiv

  Article: Higher-Order Corrections to Timelike Jets

  W. T. Giele, D. A. Kosower, P. Z. Skands
  [show abstract] [hide abstract]
  ABSTRACT: We present a simple formalism for the evolution of timelike jets in which tree-level matrix element corrections can be systematically incorporated, up to arbitrary parton multiplicities and over all of phase space, in a way that exponentiates the matching corrections. The scheme is cast as a shower Markov chain which generates one single unweighted event sample, that can be passed to standard hadronization models. Remaining perturbative uncertainties are estimated by providing several alternative weight sets for the same events, at a relatively modest additional overhead. As an explicit example, we consider Z -> q qbar evolution with unpolarized, massless quarks and include several formally subleading improvements as well as matching to tree-level matrix elements through alpha_s^4. The resulting algorithm is implemented in the publicly available VINCIA plugin to the PYTHIA 8 event generator.
  02/2011;
• Source

  Available from: ArXiv

  Article: QCD parton showers and NLO EW corrections to Drell-Yan

  P. Richardson, R. R. Sadykov, A. A. Sapronov, M. H. Seymour, P. Z. Skands
  [show abstract] [hide abstract]
  ABSTRACT: We report on the implementation of an interface between the SANC generator framework for Drell-Yan hard processes, which includes next-to-leading order electroweak (NLO EW) corrections, and the Herwig++ and Pythia8 QCD parton shower Monte Carlos. A special aspect of this implementation is that the initial-state shower evolution in both shower generators has been augmented to handle the case of an incoming photon-in-a-proton, diagrams for which appear at the NLO EW level. The difference between shower algorithms leads to residual differences in the relative corrections of 2-3% in the p_T(mu) distributions at p_T(mu)>~50 GeV (where the NLO EW correction itself is of order 10%).
  11/2010;
• Source

  Available from: ArXiv

  Article: A simple shower and matching algorithm

  W. T. Giele, D. A. Kosower, P. Z. Skands
  [show abstract] [hide abstract]
  ABSTRACT: We present a simple formalism for parton-shower Markov chains. As a first step towards more complete “uncertainty bands,” we incorporate a comprehensive exploration of the ambiguities inherent in such calculations. To reduce this uncertainty, we then introduce a matching formalism which allows a generated event sample to simultaneously reproduce any infrared-safe distribution calculated at leading or next-to-leading order in perturbation theory, up to subleading corrections. To enable a more universal definition of perturbative calculations, we also propose a more general definition of the hadronization cutoff. Finally, we present an implementation of some of these ideas for final-state gluon showers, in a code dubbed Vincia.
  Phys. Rev. D. 07/2008; 78(1).
• Source

  Available from: Lars Sonnenschein

  Article: Standard Model Handles and Candles Working Group: Tools and Jets Summary Report

  C Buttar, J D'Hondt, M Kramer, G. Salam, M Wobisch, N. E. Adam, V Adler, A. Arbuzov, D. Bardin, U. Baur, [......], L Sonnenschein, G. Soyez, R. S. Thorne, M. Tytgat, P Van Mulders, M Vazquez Acosta, A. Vicini, I Villella, D. Wackeroth, C. -P. Yuan
  [show abstract] [hide abstract]
  ABSTRACT: This report summarizes the activity on comparisons of existings tools for the standard model and on issues in jet physics by the SMHC working group during and subsequent to the Workshop "Physics at TeV Colliders", Les Houches, France, 11-29 June, 2007.
  04/2008;
• Source

  Available from: Steffen Schumann

  Article: The NLO multileg working group: summary report

  Z. Bern, S. Dittmaier, L. Dixon, G Heinrich, J Huston, B. Kersevan, Z. Kunszt, D. E. Soper, C. Bernicot, T. Binoth, [......], R. Pittau, T. Reiter, G Sanguinetti, S. Schumann, C. Schwinn, P. Z. Skands, H Stenzel, P. Uwer, S. Weinzierl, G. Zanderighi
  [show abstract] [hide abstract]
  ABSTRACT: This report summarizes the activities of the NLM working group of the Workshop "Physics at TeV Colliders", Les Houches, France, 11-29 June, 2007.
  04/2008;
• Source

  Available from: arxiv.org

  Article: Testing the SUSY-QCD Yukawa coupling in a combined LHC/ILC analysis

  A. Freitas, P.Z. Skands
  [show abstract] [hide abstract]
  ABSTRACT: In order to establish supersymmetry (SUSY) at future colliders, the identity of gauge couplings and the corresponding Yukawa couplings between gauginos, sfermions and fermions needs to be verified. Here a first phenomenological study for determining the Yukawa coupling of the SUSY-QCD sector is presented, using a method which combines information from LHC and ILC. Comment: 5pp, slightly expanded version of contributions to the Proc. of the Linear Collider Workshop (LCWS 06), Bangalore, India, 9-13 March 2006, and the Proc. of the 14th International Conference on Supersymmetry and the Unification of Fundamental Interactions (SUSY 06), Irvine, California, USA, 12-17 June 2006
  09/2006;
• Source

  Available from: ArXiv

  Article: Baryon Number Violation and String Topologies

  T. Sjöstrand, P. Z. Skands
  [show abstract] [hide abstract]
  ABSTRACT: In supersymmetric scenarios with broken R-parity, baryon number violating sparticle decays become possible. In order to search for such decays, a good understanding of expected event properties is essential. We here develop a complete framework that allows detailed studies. Special attention is given to the hadronization phase, wherein the baryon number violating vertex is associated with the appearance of a junction in the colour confinement field. This allows us to tell where to look for the extra (anti)baryon directly associated with the baryon number violating decay. Comment: 1+55 pages, 30 figures
  12/2002;
• Source

  Available from: Michael Spira

  Article: Examining the Identity of Yukawa with Gauge Couplings in Supersymmetric QCD at LHC.

  A. Freitas, DESY Forschung Hochenergiephysik, P.Z. Skands, M. Spira, P. M. Zerwas
  [show abstract] [hide abstract]
  ABSTRACT: Journal article
  JHEP 0707(2007),025.
• Article: SUSY Les Houches Accord: Interfacing SUSY Spectrum Calculators, Decay Packages, and Event Generators

  P. Z. Skands, Benjamin C Allanach, Howard W Baer, C Balázs, G Bélanger, F. Boudjema, A. Djouadi, Rohini M Godbole, J. Guasch, S. Heinemeyer, [......], F Moortgat, S Moretti, M M Mühlleitner, Werner Porod, A E Pukhov, P Richardson, S. Schumann, P. Slavich, Michael Spira, Georg Weiglein
  [show abstract] [hide abstract]
  ABSTRACT: An accord specifying generic file structures for 1) supersymmetric model specifications and input parameters, 2) electroweak scale supersymmetric mass and coupling spectra, and 3) decay tables is defined, to provide a universal interface between spectrum calculation programs, decay packages, and high energy physics event generators.
• Article: Toward High Precision Higgs-Boson Measurements at the International Linear e+e- Collider

  S. Heinemeyer, H Baer, E. L. Berger, A. Birkedal, J C Brient, M S Carena, J. A. R. Cembranos, S Choi, S Godfrei, J. F. Gunion, [......], A V Raspereza, J. Reuter, M. Ronan, P. Z. Skands, A Sopczak, Michael Spira, T. Tait, C Wagner, Georg Weiglein, P. Zerwas
  [show abstract] [hide abstract]
  ABSTRACT: This report reviews the properties of Higgs bosons in the Standard Model (SM) and its various extensions. We give an extensive overview about the potential of the ILC operated at centre-of-mass energies up to 1 TeV (including the gamma gamma option) for the determination of the Higgs boson properties. This comprises the measurement of the Higgs boson mass, its couplings to SM fermions and gauge bosons, and the determination of the spin and the CP quantum numbers of the Higgs. The extensions of the SM that are analyzed in more detail are heavy SM-like Higgs bosons, heavy Higgs bosons in the framework of Supersymmetry (SUSY) and further exotic scenarios. We review recent theoretical developments in the field of Higgs boson physics. The important question what the ILC can contribute to Higgs boson physics after the LHC, the LHC/ILC interplay and synergy is discussed. The impact of Higgs boson physics on cosmology in several SUSY frameworks is analyzed. The impact of the accelerator and detector performance on the precision of measurements are discussed in detail. We propose a strategy to optimize future analyses. Open questions arising for the various topics are listed, further topics of study and corresponding roadmaps are suggested.
• Source

  Available from: arxiv.org

  Article: Baryon number violation and string topologies

  T. Sjöstrand, P.Z. Skands
  [show abstract] [hide abstract]
  ABSTRACT: In supersymmetric scenarios with broken R-parity, baryon number violating sparticle decays become possible. In order to search for such decays, a good understanding of expected event properties is essential. We here develop a complete framework that allows detailed studies. Special attention is given to the hadronization phase, wherein the baryon number violating vertex is associated with the appearance of a junction in the colour confinement field. This allows us to tell where to look for the extra (anti)baryon directly associated with the baryon number violating decay.
  Nuclear Physics B.