Showing 1–5 of 5 results for author: Bell, M

Les Houches 2015: Physics at TeV Colliders Standard Model Working Group Report

Authors: S. Badger, J. Bendavid, V. Ciulli, A. Denner, R. Frederix, M. Grazzini, J. Huston, M. Schönherr, K. Tackmann, J. Thaler, C. Williams, J. R. Andersen, K. Becker, M. Bell, J. Bellm, E. Bothmann, R. Boughezal, J. Butterworth, S. Carrazza, M. Chiesa, L. Cieri, M. Duehrssen-Debling, G. Falmagne, S. Forte, P. Francavilla , et al. (70 additional authors not shown)

Abstract: This Report summarizes the proceedings of the 2015 Les Houches workshop on Physics at TeV Colliders. Session 1 dealt with (I) new developments relevant for high precision Standard Model calculations, (II) the new PDF4LHC parton distributions, (III) issues in the theoretical description of the production of Standard Model Higgs bosons and how to relate experimental measurements, (IV) a host of phen… ▽ More This Report summarizes the proceedings of the 2015 Les Houches workshop on Physics at TeV Colliders. Session 1 dealt with (I) new developments relevant for high precision Standard Model calculations, (II) the new PDF4LHC parton distributions, (III) issues in the theoretical description of the production of Standard Model Higgs bosons and how to relate experimental measurements, (IV) a host of phenomenological studies essential for comparing LHC data from Run I with theoretical predictions and projections for future measurements in Run II, and (V) new developments in Monte Carlo event generators. △ Less

Submitted 16 May, 2016; originally announced May 2016.

Comments: Proceedings of the Standard Model Working Group of the 2015 Les Houches Workshop, Physics at TeV Colliders, Les Houches 1-19 June 2015. 227 pages

Bilinear quark operator renormalization at generalized symmetric point

Authors: J. M. Bell, J. A. Gracey

Abstract: We compute Green's functions with a bilinear quark operator inserted at non-zero momentum for a generalized momentum configuration to two loops. These are required to assist lattice gauge theory measurements of the same quantity in matching to the high energy behaviour. The flavour non-singlet operators considered are the scalar, vector and tensor currents as well as the second moment of the twist… ▽ More We compute Green's functions with a bilinear quark operator inserted at non-zero momentum for a generalized momentum configuration to two loops. These are required to assist lattice gauge theory measurements of the same quantity in matching to the high energy behaviour. The flavour non-singlet operators considered are the scalar, vector and tensor currents as well as the second moment of the twist-2 Wilson operator used in deep inelastic scattering for the measurement of nucleon structure functions. △ Less

Submitted 17 February, 2016; originally announced February 2016.

Comments: 19 latex pages, 4 figures, anc directory contains electronic version of amplitudes

Report number: LTH 1077

Journal ref: Phys. Rev. D 93, 065031 (2016)

Maximal abelian and Curci-Ferrari gauges in momentum subtraction at three loops

Authors: J. M. Bell, J. A. Gracey

Abstract: The vertex structure of QCD fixed in the maximal abelian gauge (MAG) and Curci-Ferrari gauge is analysed at two loops at the fully symmetric point for the 3-point functions corresponding to the three momentum subtraction (MOM) renormalization schemes. Consequently the three loop renormalization group functions are determined for each of these three schemes in each gauge using properties of the ren… ▽ More The vertex structure of QCD fixed in the maximal abelian gauge (MAG) and Curci-Ferrari gauge is analysed at two loops at the fully symmetric point for the 3-point functions corresponding to the three momentum subtraction (MOM) renormalization schemes. Consequently the three loop renormalization group functions are determined for each of these three schemes in each gauge using properties of the renormalization group equation. △ Less

Submitted 3 November, 2015; originally announced November 2015.

Comments: 23 latex pages, 4 figures, anc directory contains txt files with electronic version of renormalization group functions, coupling constant mappings, conversion functions and amplitudes in analytic form for each gauge

Report number: LTH 1062

MOM renormalization group functions in the maximal abelian gauge

Authors: J. M. Bell, J. A. Gracey

Abstract: The one loop 3-point vertex functions of QCD in the maximal abelian gauge (MAG) are evaluated at the fully symmetric point at one loop. As a consequence the theory is renormalized in the various momentum (MOM) schemes which are defined by the trivalent vertices, as well as in the MSbar scheme. From these the two loop renormalization group functions in the MOM schemes are derived using the one loop… ▽ More The one loop 3-point vertex functions of QCD in the maximal abelian gauge (MAG) are evaluated at the fully symmetric point at one loop. As a consequence the theory is renormalized in the various momentum (MOM) schemes which are defined by the trivalent vertices, as well as in the MSbar scheme. From these the two loop renormalization group functions in the MOM schemes are derived using the one loop conversion functions. In parallel we repeat the analysis for the Curci-Ferrari gauge which corresponds to the MAG in a specific limit. The relation between the Lambda parameters in different schemes is also provided. △ Less

Submitted 1 October, 2013; originally announced October 2013.

Comments: 32 latex pages, anc directory contains txt file with beta-functions, anomalous dimensions, coupling constant mappings, conversion functions and amplitudes in analytic form

Report number: LTH 985

Use of event-level neutrino telescope data in global fits for theories of new physics

Authors: P. Scott, C. Savage, J. Edsjö, the IceCube Collaboration, :, R. Abbasi, Y. Abdou, M. Ackermann, J. Adams, J. A. Aguilar, M. Ahlers, D. Altmann, K. Andeen, J. Auffenberg, X. Bai, M. Baker, S. W. Barwick, V. Baum, R. Bay, K. Beattie, J. J. Beatty, S. Bechet, J. Becker Tjus, K. -H. Becker, M. Bell , et al. (253 additional authors not shown)

Abstract: We present a fast likelihood method for including event-level neutrino telescope data in parameter explorations of theories for new physics, and announce its public release as part of DarkSUSY 5.0.6. Our construction includes both angular and spectral information about neutrino events, as well as their total number. We also present a corresponding measure for simple model exclusion, which can be u… ▽ More We present a fast likelihood method for including event-level neutrino telescope data in parameter explorations of theories for new physics, and announce its public release as part of DarkSUSY 5.0.6. Our construction includes both angular and spectral information about neutrino events, as well as their total number. We also present a corresponding measure for simple model exclusion, which can be used for single models without reference to the rest of a parameter space. We perform a number of supersymmetric parameter scans with IceCube data to illustrate the utility of the method: example global fits and a signal recovery in the constrained minimal supersymmetric standard model (CMSSM), and a model exclusion exercise in a 7-parameter phenomenological version of the MSSM. The final IceCube detector configuration will probe almost the entire focus-point region of the CMSSM, as well as a number of MSSM-7 models that will not otherwise be accessible to e.g. direct detection. Our method accurately recovers the mock signal, and provides tight constraints on model parameters and derived quantities. We show that the inclusion of spectral information significantly improves the accuracy of the recovery, providing motivation for its use in future IceCube analyses. △ Less

Submitted 1 October, 2012; v1 submitted 3 July, 2012; originally announced July 2012.

Comments: 29 pages, 6 figures. v2 adds additional explanation in p-value derivation, matches version accepted for publication in JCAP

Journal ref: JCAP 11(2012)057