DOCSLIB.ORG

Soft Gluons and Non-Global Observables Mike Seymour – University of Manchester / CERN TH on Behalf of Rene Angeles Martinez, Matthew De Angelis, Jeffrey R

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Soft Gluons and Non-Global Observables Mike Seymour – University of Manchester / CERN TH on Behalf of Rene Angeles Martinez, Matthew De Angelis, Jeffrey R Soft Gluons and Non-global Observables Mike Seymour – University of Manchester / CERN TH on behalf of Rene Angeles Martinez, Matthew De Angelis, Jeffrey R. Forshaw, Simon Plätzer, Michael H. Seymour based on JHEP 05 (2018) 044 (arxiv:1802.08531) Soft gluon evolution • In particular, how does soft gluon emission affect subsequent soft gluon evolution? Soft Gluons and Non-global Observables • Soft gluon emission evolution algorithm • An IR-finite reformulation • The ordering variable • Colour flow basis • (Towards) an exact numerical implementation • (“amplitude-level parton shower”) et al [14], as well as Weigert and Caron-Huot [7, 11, 30]. In Appendix B we make the can- cellation of infrared divergences explicit for observables that are inclusive below a resolution scale, and in Appendix C we explicitly calculate contributions in a fixed-order expansion. Finally, Appendix D sets up the machinery to deal with the fact that most colour bases are not orthogonal (see [31] for a notable exception). 2Thegeneralalgorithm Our starting point is the cross section for emitting n soft gluons. At this stage we will assume that it is ok to order successive emissions in energy. This assumption is ok for processes that are insensitive to Coulomb gluon exchanges but appears not to be valid otherwise [29, 32]. We have that σ =Tr(V H(Q)V† ) Tr A (µ) 0 µ,Q µ,Q ⌘ 0 µ σ =Tr(V D V H(Q)V† D† V† ) ⇧ d 1 µ,E1 1 E1,Q E1,Q 1µ µ,E1 d 1 Tr A (µ) d⇧ ⌘ 1 1 ⌫ µ σ =Tr(V D V D V H(Q)V† D† V† D† V† ) ⇧ ⇧ d 2 µ,E2 2 E2,E1 1 E1,Q E1,Q 1µ E2,E1 2⌫ µ,E2 d 1d 2 Tr A (µ) d⇧ d⇧ ⌘ 2 1 2 etc. (2.1) et al [14], as well as Weigert and Caron-Huot [7, 11, 30]. In Appendix B we make the can- wherecellationH( ofQ) infraredis the hard divergences scattering explicit matrix, forH observables= thatand, are in inclusive the eikonal below approximation, a resolution |MihM| scale, and in Appendixµ C we explicitly calculate contributions in a fixed-order expansion. µ pj Finally,Di = AppendixTj Ei Detsets al [,14 up], as the well machinery as Weigert and to deal Caron-Huot with the [7, 11 fact, 30]. that In Appendix most colourB we make bases the are can- pj qi not orthogonalXj (see [cellation·31] for of a infrared notable divergences exception). explicit for observables that are inclusive below a resolution 2✏ 3 2✏ ↵s µ dEi scale,d⌦i and− in Appendix C we explicitly calculate contributions in a fixed-order expansion. Softd⇧i = gluon, emission evolution(2.2) – general algorithm 1+2✏ 2✏ 2Thegeneralalgorithm− ⇡ Ei Finally,4⇡(2⇡) Appendix− D sets up the machinery to deal with the fact that most colour bases are not2 orthogonal✏ b (see [31] for a notable exception). 3 2✏ 2 2✏ Our starting point↵ issµ the crossd sectionEk for emitting n softd⌦k gluons.− At this⌦ stage− we will Va,b = P exp ( Ti Tj) !ij(kˆ) i⇡ δij , assume that it2− is⇡ ok(2⇡ to) 2 order✏ E successive1+2✏ − emissions· in energy.4⇡ This assumption− 2⇡ is ok3 for where2Thegeneralalgorithm− ⇥(Ea Ekn) isi<j the Heaviside function.( A general observable, ⌃, can be computed) Z X Z processes that4 are insensitiveusing to Coulomb gluon exchanges but appears not to bee valid5 • Explicit1 calculation of amplitude otherwiseand [29, 32]. WeOur have starting that point is the cross section for emitting n soft gluons. At this stage we will assume that it is⌃ ok(µ to)= order successived(pσn unp(k emissions)1,k2, ,k inn) energy., This assumption is ok(2.5) for (-squared) ˆ 2 i j ··· |ℳ⟩ = = processes that! areij(k insensitive)=Ek n to Coulomb· gluon. exchanges but appears not to be(2.3) valid Z X(pi k)(pj k) σ0 =Tr(Vµ,QH(Q)V† ) Tr A0(µ)n· · otherwise [29µ,Q, 32].⌘ We have that If partons i and j are bothµ in the initial= state ord⇧ theyi Tr A aren(µ) bothun(k1 in,k2, thekn final) , state then dσ1 =Tr(Vµ,E D VE ,QH(Q)V† D† V† ) d⇧1 ··· 1 1 1 E1n,Q i=11µZ µ,E!1 µ δij =1otherwise δij =0. Note that the sumX overY partons j in the definition Di is context- Tr A1(µ) d⇧σ 1 =Tr(V H(Q)V† ) Tr A (µ) specific, i.e.⌘ it runs overwhere any the0 priorun are soft theµ,Q observable gluon emissionsµ,Q dependent in0 measurement addition functionsto the partons and the k ini are the soft hard gluon µ ⌘ ⌫ µ e dσ2 =Tr(Ve µ,E2 D2VE2,E1 D1 VE1,QH(Q)V† D1†µV† D2†⌫V† ) d⇧1d⇧2 | ⟩⟨ | scattering. Likewise,momenta. the colourσ =Tr( We charge suppressV D operators, dependenceV H(Q onT)EVj1 the†,,Q and hardD† theV partons†E Sudakov2,E) 1 ⇧ and integration operators,µ,E2 overV theira,b,are phase ℳ ℳ = & = & d 1 µ,E1 1 E1,Q E1,Q 1µ µ,E1 d 1 in a context-specificTr A2space.(µ representation) d⇧1d⇧2 of SU(3) . The operators A satisfy the recurrence ⌘ Tr A1(µ) d⇧1 c n ⌘ µ 0 equation etc. In the above, we should⌫ take theµ limit , though we will consider non-zero(2.1) values dσ2 =Tr(Vµ,E2 D2VE2,E1 D1 VE1,QH(!Q)VE† ,QD1†µVE† ,E D2†⌫Vµ,E† ) d⇧1d⇧2 in what follows. The carat on kˆ reminds us that !ij(kˆ1) is dependent2 1 only upon2 the direction Tr Aµ(µ) d⇧ d⇧ where H(Q) is theA hardnof(E the)= scattering vectorVE,Ek ninD matrix, then2 Aijnrest11H(E frame.2=n) D Thenµ† V path-ordering,E,E† and,⇥( inE the P,E ineikonaln) the, definition approximation, of V (2.4)is not ⌘ − |MihM| n a,b 1 d d/2 actuallyµ neededetc. here, because the expression in curly brackets in Eq. (2.2) is independent(2.1) µNote: ⌦ =2⇡ /pΓj(d/2). Di = Tj Ei of the, ordering variable, Ek. The cross sections in Eq. (2.1) are the general building blocks pj whereqi H(Q) is the hard scattering matrix, H = and, in the eikonal approximation, • emissionXj for· any and observable and exchange they can be used as the|M basisihM| forclosely a Monte Carlo computer code to 2✏ 3 2✏ µ ↵ µ dE generatedµ⌦ − partonic events.pj s i D =i T E , d⇧i = 1+2✏ i 2✏ j, i 2 (2.2) related− ⇡ E 4⇡(2We⇡) can− also writepj qi an evolution equation : i Xj · –3– 2✏ @bA2✏(E) 3 2✏ 3 2✏ 2 2✏ ↵ µ ↵s µdn EdEi d⌦i − d⌦ µ− ⌦ sd⇧i = E k = ΓAn(E, ) An(E)Γ† + Dkn An 1(E)ˆDnµ† E δ(E −En) , (2.6)(2.2) Va,b = P exp 2✏ − ⇡ @E1+21+2✏ ✏4⇡(2−⇡() 2T✏ i −Tj) −!ij(k) i⇡ − δij , 2−⇡(2⇡) Ei −− · 4⇡ − 2⇡ 3 − Za k i<j (Z ) where X2✏ b 3 2✏ 2 2✏ * ↵ µ E ⌦ − ⌦ 4 s ↵s d k d⌦k d k ˆ e− 5 d0 1 Va,b = P exp Γ = ( T T () Ti Tj) ! (kˆ) i⇡ δ!ij(k.) i⇡ δij , and 2−⇡(2⇡) 2✏ E1+2i✏ j − · ij 4⇡ ij − 2⇡ (2.7)3 − ⇡ Za −k ·i<j 4⇡ (Z − ) '(,* = exp . Γ i<j (p Xp )⇢Z 4 ˆ X2 i j e 5 0 1 !ij(k)=Ek · . e (2.3) ( Whenand the measurement function(p factorizes,k)(p i.e.k) un(k1,k2, kn)=u(E1, kˆ1) u(En, kˆn), i · j · ··· ··· we can define (p p ) If partons i and j are both in the initial state! (kˆ)= orE they2 arei j both. in the final state then ij nk · (2.3) (pi k)(pj k) µ δij =1otherwise δij =0. Note that the sum over partonsd·jEiin the· definition Di is context- Gn(E)= An(E) (2.8) specific, i.e. it runs over any priori softj gluon emissions in additionEi to the partons in the hard If partons and are both in the initiali=1 Z state or they are both in the final state then e e Y µ scattering. Likewise,δij the=1 colourotherwise chargeδij =0 operators,. Note that theTj sum, and over the partons Sudakovj in the operators, definition DVi isa,b context-,are and Eq. (2.6) becomes in a context-specificspecific, representation i.e. it runs over of any SU(3) priorc. soft The gluon operators emissions inA additionn satisfy to the the partons recurrence in the hard e e equation scattering. Likewise,@Gn(E) the colour charge operators, Tj,µ and the Sudakov operators,ˆ Va,b,are E = ΓGn(E) Gn(E)Γ† + Dn Gn 1(E) Dnµ† u(E,kn). (2.9) in a context-specific@E representation− − of SU(3) . The operators− A satisfy the recurrence µ c n An(E)=VE,En Dn An 1(En) Dnµ† V† ⇥(E En) , (2.4) Thisequation can be re-written as− E,En 1Note: ⌦d =2⇡d/2/Γ(d/2). µ A (E)=V D A (E ) D V† ⇥(E E ) , @Gn(E) ↵ns E,Ed⌦nk n n 1 n nµ† E,En n (2.4) E = !ij(kˆ) −Ti Tj Gn + Gn Ti Tj (2.10) 1 @Ed d/2⇡ " 4⇡ · · Note: ⌦ =2⇡ /Γ(Xi<jd/2). Z ⇣ ⌘ ˆ ˆ !ij(kn)(Ti Gn 1Tj† + Tj Gn 1Ti†) u(E,kn) + Coulomb terms.
Load more

Recommended publications
  • CONTENTS Group Membership, January 2002 2
    CONTENTS Group Membership, January 2002 2 APPENDIX 1: Report on Activities 2000-2002 & Proposed Programme 2002-2006 4 1OPAL 4 2H1 7 3 ATLAS 11 4 BABAR 19 5DØ 24 6 e-Science 29 7 Geant4 32 8 Blue Sky and applied R&D 33 9 Computing 36 10 Activities in Support of Public Understanding of Science 38 11 Collaborations and contacts with Industry 41 12 Other Research Related Activities by Group Members 41 13 Staff Management and Implementation of Concordat 41 APPENDIX 2: Request for Funds 1. Support staff 43 2. Travel 55 3. Consumables 56 4. Equipment 58 APPENDIX 3: Publications 61 1 Group Membership, May 2002 Academic Staff Dr John Allison Senior Lecturer Professor Roger Barlow Professor Dr Ian Duerdoth Senior Lecturer Dr Mike Ibbotson Reader Dr George Lafferty Reader Dr Fred Loebinger Senior Lecturer Professor Robin Marshall Professor, Group Leader Dr Terry Wyatt Reader Dr A N Other (from Sept 2002) Lecturer Fellows Dr Brian Cox PPARC Advanced Fellow Dr Graham Wilson (leave of absence for 2 yrs) PPARC Advanced Fellow James Weatherall PPARC Fellow PPARC funded Research Associates∗ Dr Nick Malden Dr Joleen Pater Dr Michiel Sanders Dr Ben Waugh Dr Jenny Williams PPARC funded Responsive Research Associate Dr Liang Han PPARC funded e-Science Research Associates Steve Dallison core e-Science Sergey Dolgobrodov core e-Science Gareth Fairey EU/PPARC DataGrid Alessandra Forti GridPP Andrew McNab EU/PPARC DataGrid PPARC funded Support Staff∗ Phil Dunn (replacement) Technician Andrew Elvin Technician Dr Joe Foster Physicist Programmer Julian Freestone
    [Show full text]
  • Coulomb Gluons and Colour Evolution
    Coulomb gluons and colour evolution René Ángeles-Martínez in collaboration with Jeff Forshaw Mike Seymour JHEP 1512 (2015) 091 DPyC, BUAP & arXiv:1602.00623 (accepted for publication) 2016 In this talk: Progress towards including the colour interference of soft gluons in partons showers. PDF Hard process (Q) Parton Shower: Approx: Collinear + Soft radiation Q qµ ⇤ QCD Underlying event Hadronization Hadron-Hadron collision, Soper (CTEQ School) … 2 Motivation • Why? Increase precision of theoretical predictions for the LHC • Is this necessary? Yes, for particular non-inclusive observables. • Are those relevant to search for new physics? Yes, these can tell us about the (absence of) colour of the production mechanism (couplings). 3 Outline • Coulomb gluons, collinear factorisation & colour interference. • Concrete effect: super-leading-logs. • Including colour interference in partons showers. (Also see JHEP 07, 119 (2015), arXiv:1312.2448 & 1412.3967) 4 One-loop in the soft approximation kµ Q ⌧ ij Hard subprocess is a vector Colour matrices acting on 2 colour + spin d d k ↵ pi pj ig2T T − · 2 s i · j (2⇡)d [p k i0][ p k i0][k2+i0] Z j · ± − i · ± ↵ i : i0 i :+i0 i : i0 − − j : i0 j :+i0 j :+i0 − 2 ↵ Introduction: one-loop soft gluon correction After contour integration: d4k (2⇡)δ(k2)✓(k0) (2⇡)2δ(p k)δ( p k) g2µ2✏T T p p + iδ˜ i · − j · 2 s i · j i · j (2⇡)4 [p k][p k] ij 2[k2] Z j · i · ↵ (On-shell gluon: Purely real) (Coulomb gluon: Purely imaginary) 1ifi, j in , ˜ δij = 81ifi, j out , <>0 otherwise.
    [Show full text]
  • Arxiv:Hep-Ph/0403045V2 5 Mar 2004 .Maltoni F
    Les Houches Guidebook to Monte Carlo Generators for Hadron Collider Physics Editors: M.A. Dobbs1, S. Frixione2, E. Laenen3, K. Tollefson4 Contributing Authors: H. Baer5, E. Boos6, B. Cox7, M.A. Dobbs1, R. Engel8, S. Frixione2, W. Giele9, J. Huston4, S. Ilyin6, B. Kersevan10, F. Krauss11, Y. Kurihara12, E. Laenen3,L.Lonnblad¨ 13, F. Maltoni14, M. Mangano15, S. Odaka12, P. Richardson16, A. Ryd17, T. Sjostrand¨ 13, P. Skands13, Z. Was18, B.R. Webber19, D. Zeppenfeld20 1Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA 2INFN, Sezione di Genova, Via Dodecaneso 33, 16146 Genova, Italy 3NIKHEF Theory Group, Kruislaan 409, 1098 SJ Amsterdam, The Netherlands 4Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824-1116, USA 5Department of Physics, Florida State University, 511 Keen Building, Tallahassee, FL 32306-4350, USA 6Moscow State University, Moscow, Russia 7Dept of Physics and Astronomy, University of Manchester, Oxford Road, Manchester, M13 9PL, U.K. 8 Institut f¨ur Kernphysik, Forschungszentrum Karlsruhe, Postfach 3640, D - 76021 Karlsruhe, Germany 9Fermi National Accelerator Laboratory, Batavia, IL 60510-500, USA 10Jozef Stefan Institute, Jamova 39, SI-1000 Ljubljana,Slovenia; Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19,SI-1000 Ljubljana, Slovenia 11Institut f¨ur Theoretische Physik, TU Dresden, 01062 Dresden, Germany 12KEK, Oho 1-1, Tsukuba, Ibaraki 305-0801, Japan 13Department of Theoretical Physics, Lund University, S-223 62 Lund, Sweden 14Centro Studi e Ricerche “Enrico Fermi”, via Panisperna, 89/A - 00184 Rome, Italy 15CERN, CH–1211 Geneva 23, Switzerland 16Institute for Particle Physics Phenomenology, University of Durham, DH1 3LE, U.K. 17Caltech, 1200 E.
    [Show full text]
  • Double Diffractive Higgs and Di-Photon Production at The
    MAN/HEP/2001/03 MC-TH-01/09 October 2001 Double Diffractive Higgs and Di-photon Production at the Tevatron and LHC Brian Cox and Jeff Forshaw Dept. of Physics and Astronomy, University of Manchester Manchester M13 9PL, England [email protected] Beate Heinemann Oliver Lodge Laboratory, University of Liverpool Liverpool, L69 7ZE, England [email protected] Abstract We use the POMWIG Monte Carlo generator to predict the cross-sections for double diffractive higgs and di-photon production at the Tevatron and LHC. We find that the higgs production cross-section is too small to be observable at Tevatron energies, and even at arXiv:hep-ph/0110173v2 13 Oct 2001 the LHC observation would be difficult. Double diffractive di-photon production, however, should be observable within one year of Tevatron Run II. 1 Introduction With the start of Run II at the Tevatron the possibility of detecting a light higgs boson has of course been the focus of much attention. One suggested experimentally clean search strategy is to look in double diffractive collisions in which the final state contains only intact protons, which escape the central detectors, and the decay products of the higgs, in this case two b quark jets. The protons would be tagged in roman pot detectors a long way down stream of the interaction point, allowing a very precise determination of the higgs mass, using the so-called missing mass method [1]. With such proton tagging, the available center of mass energy of up to 200 GeV means that the preferred higgs mass of around 115 GeV is kinematically accessible, at least in principle.
    [Show full text]
  • Report from Science Committee
    Report From Science Committee JennyReport Thomas, IoP Town Meeting From Science Committee One year since last Town Meeting SC scientific business Reapproval of LHC-GPDs High Performance Computing Funding of new projects Statements of Interest Accelerator Centres SC administrative business New Members/Retiring members Meetings with Peer-Review and AP chairs Visits to PP institutes SLA Review Review of Peer Review Structure Jenny Thomas, IoP Town Meeting SCSC StrategyStrategy SC has defined a strategy over the last few years New projects are essential to the life blood of our field Longer term and shorter term projects must be planned for High impact science will be funded where: UK can play a major and intellectually leading role Science is internationally excellent, timely and fundamental Sun-setting is a natural part of a vibrant programme Blue skies R&D is an important investment in the future The financial outlook Jenny Thomas, IoP TownThe Meeting financial outlook We have a balanced budget over 10 year period SC has wrestled with the spreadsheets and understands the numbers In the short term, there are shortfalls We don’t have much wiggle room until 05/06 We do have lots of stuff we want to do Ian just has to get the money from OST. If we get 4% we may be able to do everything we want Start thinking of great new science to do. Who is SC? Jenny Thomas, IoP Town Meeting Who is SC? Martin Ward, Leicester (Chair) Jenny Thomas, UCL (Deputy Chair) Jordan Nash, IC Richard Hills, Cambridge Jeff Forshaw, Manchester John Peacock, Edinburgh
    [Show full text]
  • {PDF} Why Does E=Mc2?: (And Why Should We Care?)
    WHY DOES E=MC2?: (AND WHY SHOULD WE CARE?) PDF, EPUB, EBOOK Brian Cox,Jeff Forshaw | 272 pages | 09 Mar 2010 | The Perseus Books Group | 9780306819117 | English | Cambridge, MA, United States Why Does E=mc2?: (And Why Should We Care?) by Brian Cox, Jeff Forshaw, Paperback | Barnes & Noble® NOOK Book. Home 1 Books 2. Add to Wishlist. Sign in to Purchase Instantly. Members save with free shipping everyday! See details. Brian Cox and Professor Jeff Forshaw go on a journey to the frontier of twenty-first century science to unpack Einstein's famous equation. Explaining and simplifying notions of energy, mass, and light-while exploding commonly held misconceptions-they demonstrate how the structure of nature itself is contained within this equation. Along the way, we visit the site of one of the largest scientific experiments ever conducted: the now-famous Large Hadron Collider, a gigantic particle accelerator capable of re-creating conditions that existed fractions of a second after the Big Bang. Jeff Forshaw is a Professor of Theoretical Physics at the University of Manchester, specializing in the physics of elementary particles. He was awarded the Institute of Physics Maxwell Medal in for outstanding contributions to theoretical physics. Related Searches. A nutritionist offers recipes and a diet program to aid in determining which foods cause View Product. Between You and Me. At the age of 87, Mike Wallace is a legendary figure in broadcast journalism. Now, after 60 years of reporting on important events around the world, he shares his personal
    [Show full text]
  • Forward Physics at 420M at LHC
    Brian Cox DIS 2005, Madison, April 2005 Forward Physics at 420m at LHC • Selection rules mean that central system is (to a good approx) 0++ • If you see a new particle produced exclusively with proton tags you know its quantum numbers • CP violation in the Higgs sector shows up directly as azimuthal asymmetries • Proton tagging may be the discovery channel in certain regions of the MSSM • Tagging the protons means excellent mass resolution (~ GeV) irrespective of the decay products of the central system • Unique access to a host of interesting QCD Very schematically it’s a glue – glue collider where you know the beam energy of the gluons - source of pure gluon jets - and central production of any 0++ state which couples strongly to glue is a possibility … Central Production at LHC xIP~ 0.007 xIP~ 0.03 Plots from Henri Kowalski and TOTEM (Helsinki group) Central Production at LHC xIP~ 0.007 xIP~ 0.03 The KMR Calculation of the Exclusive Process q -> Proton Dominant uncertainty: KMR estimate factor of 2-3. Independent estimate by Lund group “definitely less than 10”. Divergent: controlled by Sudakov Jeff Forshaw, HERA LHC Workshop The KMR Calculation of the Exclusive Process q -> Proton Dominant uncertainty: KMR estimate factor of 2-3. Independent estimate by Lund group “definitely less than 10”. Divergent: controlled by Sudakov Jeff Forshaw, HERA LHC Workshop Latest Acceptance curves from Helsinki Group R. Orava, FP420 FNAL meeting , 26 April The Benchmark process : SM Higgs production The Benchmark process : SM Higgs production b jets : MH = 120 GeV = 2 fb MH = 140 GeV = 0.7 fb -1 MH = 120 GeV : 11 signal, S/B ~ 1 in 30 fb 0++ Selection rule Also, since resolution of taggers > Higgs width: QCD Background ~ •The b jet channel is possible, with a good understanding of detectors and clever level 1 trigger •The WW* (ZZ*) channel is extremely promising : no trigger problems, better mass resolution at higher masses (even in leptonic / semi-leptonic channel) •If we see Higgs + tags - the quantum numbers are 0++ Resolution from R.
    [Show full text]
  • Gaps Between Jets at the LHC
    Gaps between jets at the LHC Simone Marzani University of Manchester Collider Physics 2009: Joint Argonne & IIT Theory Institute May 18th -22nd , 2009 In collaboration with Jeff Forshaw and James Keates arXiv:0905.1350 [hep-ph] Outline • Jet vetoing: Gaps between jets – Global and non-global logarithms – Discovery of super-leading logarithms • Some LHC phenomenology – Global logarithms – Super-leading logarithms • Conclusions and Outlook Jet vetoing:" Gaps between jets! The observable Production of two jets with! • transverse momentum Q ! • rapidity separation Y! jet radius R! Y! • Emission with !kT >Q0 forbidden in the inter-jet region! Plenty of QCD effects! “wider” gaps! Y! Forward BFKL Non- forward BFKL (Mueller-Navelet jets) (Mueller-Tang jets) Super-leading logs Wide-angle soft radiation Fixed order Q L = ln “emptier” gaps! Q0 Higgs +2 jets! Weak boson fusion! Gluon fusion! • Different QCD radiation in the inter-jet region! • To enhance the WBF channel, one can make a veto Q0 on additional radiation between the tagged jets! • QCD radiation as in dijet production! Forshaw and Sjödahl arXiv:0705.1504 [hep-ph] • Important in order to extract the VVH coupling! Soft gluons in QCD! • What happens if we dress a hard scattering with soft gluons?! • Sufficiently inclusive observables are not affected: real and virtual cancel via Bloch-Nordsieck theorem! • Soft gluon corrections are important if the real radiation is constrained into a small region of phase-space! • In such cases BN fails and miscancellation between real and virtual induces
    [Show full text]
  • A Guide to the Cosmos Brian Cox
    A Guide To The Cosmos Brian Cox homologous!Maurits syllabicates Hari antagonising her anklebone heroically ne'er, Origenisticwhile vapourish and Madagascan. Nealy osculating Reverse sparkishly Bert empowers or jobes ruddy. some arteriole and mitring his Klein so Failed to sender name cannot be to buy official wonders of reshipping the cosmos brian cox as normal Author Brian Cox J R ForshawPublisher Allen Lane 2016ISBN-10 146144361ISBN-13 97146144363Condition Very GoodBinding Hardcover with dust. This accessible illustrated guide plug the cosmos is for switch the new. Brian Cox and Adele's producer Paul Epworth discuss music. Deep Astronomy Bookshelf Universal A look to the Cosmos by Brian Cox u0026 Jeff Foreshaw by Deep Astronomy 3 years ago 13 minutes 30 seconds. Wonders app also something to rigorously derived theory of consciousness, cox to a the cosmos brian cox. Podcaster Tony Darnell Title Universal A Guide tap the Cosmos by Brian Cox Jeff Foreshaw Organization Deep Astronomy. An awe-inspiring unforgettable journey of scientific exploration from Brian Cox and Jeff Forshaw the time ten bestselling authors of The Quantum UniverseWe dare to fact a time before the whole Bang when we entire tower was compressed into our space smaller than an atom. Professor Brian Cox 3Arena. And has recently co-written Universal A Guide all the Cosmos with Professor Brian Cox. Universal A high to the Cosmos de Cox Brian en Gandhi. ProfBrianCox my doctor is wants a good beginner's guide to stars their feature in the universe Do only have one probe's it called please X. New developments like a popular and the whole new posts can confirm the magic show and a guide to radio and buy and dig into this.
    [Show full text]
  • Phenomenology of a Triplet Higgs and Searching for a MSSM Higgs in Diffraction
    Phenomenology of a Triplet Higgs and Searching for a MSSM Higgs in Diffraction Jeff Forshaw University of Manchester XXXVIIIth Rencontres de Moriond QCD & High Energy Hadron Interactions Triplet Higgs Model: How to avoid a light higgs boson. MSSM Higgs with CP violation: How to have a very light higgs boson. Triplet Model: with B. White, D. Ross, A. Sabio-Vera JHEP 0110:007,2001; hep-ph/0302256. MSSM Higgs: with B. Cox, J-S. Lee, J. Monk, A. Pilaftsis. hep-ph/0303206 Precise data (0.1%) from LEP/SLC/Tevatron imply a light Higgs boson when interpreted within the Standard Model: 53 mh 87 34 GeV Similar conclusions in SUSY extensions (< 130 GeV). See lepewwg.web.cern.ch [Blank & Hollik] I ntroduce a real triplet (Y= 0): v 246 GeV Mass spectrum 2 MW 1 2 2 2 M Z cos W cos 2 2 mh 1v 2 2 2 mk m 4v / 0 3 2 4 / 4 2 m mk m v [Custodial symmetry] One-loop RG analysis reveals model is well defined up to 1 TeV. Mass splitting need not be much smaller than v if appreciable mixing in neutral sector. Oblique Corrections i.e. not vertex or box (q) g (q2 ) (m) (m2 ) (0) [Lynn, Stuart; Peskin, Takeuchi] S, T and U are gauge invariant and finite: SM (mh ) ASM S({mi }) BSM T ({mi }) CSM U ({mi }) General observable New physics enters only via S, T and U In the triplet model we work to lowest order in Hence quantum corrections are negligible: S 0 No hypercharge T 0 Custodial symmetry But tree level corrections are interesting: • Direct correction to W mass since 2 2 2 2 MW M Z cos W (1 ) 2 • Indirect correction to all observables since tree level SM 2 GF GF (1 ) SM (mh ) ASM STM (mk ,m ) BSM ( TTM (mk ,m ) tree ) CSM UTM (mk ,m ) Tree Level Effects 95% CL contour Standard Model ref mh 100 GeV Tree level violation of custodial symmetry can permit the lightest higgs to be as heavy as 500 GeV.
    [Show full text]
  • CERN Courier – Digital Edition Welcome to the Digital Edition of the December 2013 Issue of CERN Courier
    I NTERNATIONAL J OURNAL OF H IGH -E NERGY P HYSICS CERNCOURIER WELCOME V OLUME 5 3 N UMBER 1 0 D ECEMBER 2 0 1 3 CERN Courier – digital edition Welcome to the digital edition of the December 2013 issue of CERN Courier. This edition celebrates a number of anniversaries. Starting with the “oldest”, 2013 saw the centenary of the birth of Bruno Pontecorvo, whose life and Towards the contributions to neutrino physics were celebrated with a symposium in Rome in September. Moving forwards, it is the 50th anniversary of the Institute for intensity frontier High Energy Physics in Protvino, Russia, and also of CESAR – CERN’s first storage ring, which saw the first beam in December 1963 and paved the way for the LHC. More recently, a new network for mathematical and theoretical physics started up 10 years ago, re-establishing connections between scientists in the Balkans. At the same time, the longer-standing CERN School of Computing began a phase of reinvigoration. There is also a selection of books for more relaxed reading during the festive season. To sign up to the new-issue alert, please visit: http://cerncourier.com/cws/sign-up. To subscribe to the magazine, the e-mail new-issue alert, please visit: http://cerncourier.com/cws/how-to-subscribe. JUBILEE ALICE SCIENCE IN IHEP, Protvino, Forward muons celebrates its join the upgrade THE BALKANS EDITOR: CHRISTINE SUTTON, CERN 50th anniversary programme The story behind a DIGITAL EDITION CREATED BY JESSE KARJALAINEN/IOP PUBLISHING, UK p28 p6 physics network p21 CERNCOURIER www. V OLUME 5 3 N UMBER 1 0 D ECEMBER 2 0 1 3 CERN Courier December 2013 Contents Covering current developments in high-energy physics and related fi elds worldwide CERN Courier is distributed to member-state governments, institutes and laboratories affi liated with CERN, and to their personnel.
    [Show full text]
  • Outreach-Book-List-Physics.Pdf
    Outreach Book List - Physics Physics Title of book Suggested by Blurb Review 1 The Quantum Universe: Everything Suggested by Joe Sykes, Research From the bestselling authors of Why does This was the book that opened my eyes to the strange quantum aspect of that can happen does happen” by Postgraduate Mathematics E=mc2? comes The Quantum Universe, in which Brian Cox, physics (something that is hardly ever touched on in A level physics but Jeff Forshaw and Brian Cox presenter of the BBC's Wonders of the Solar underpins all of physics) and ultimately made up my mind that I needed to go System and Wonders of the Universe, and Jeff Forshaw go to university and do physics because I needed to understand how this weird on a brilliantly ambitious mission to show that everyone can (and in my nerdy opinion very cool) quantum stuff worked. The book is very understand the deepest questions of science. accessible as it is written for the general public and isn’t too mathematical But just what is quantum physics? How does it help us and is very good at intriguing the reader to want to find out more. understand our amazing world? Where does it leave Newton and Einstein? And why, above all, can we be sure that the theory is good? Here, Brian Cox and Jeff Forshaw give us the real science behind the bizarre behaviour of the atoms and energy that make up the universe, and reveal exactly how everything that can happen, does happen. 2 The Perfect Theory: A Century of Suggested by Renee Boling, STEM Albert Einstein’s General Theory of Relativity is possibly the As an aerospace engineer I have always been fascinated by space and the Geniuses and the Battle Over Programmes Coordinator Pre-16 most perfect intellectual achievement in modern physics.
    [Show full text]