Forward Physics at the HL-LHC
Total Page:16
File Type:pdf, Size:1020Kb
Forward Physics at the HL-LHC Lucian Harland-Lang, University of Oxford Oxford blue Visual identity guidelines LHC Working Group on Forward Physics and Diffraction CERN, 19 December 2018 1 Outline/Context • QCD and SM Working Group for HL-LHC and HE-LHC Yellow Report released recently: CERN-LPCC-2018-03 1 CERN-LPCC-2018-03 December 12, 2018 2 Standard Model Physics 3 at the HL-LHC and HE-LHC 4 Report from Working Group 1 on the Physics of the HL-LHC, and Perspectives at the HE-LHC 6 5 200 6.6.17 Editors: Top quark charge asymmetries at LHCb . 143 1 2 3 4 5 8 P. Azzi , S. Farry , P. Nason , A. Tricoli , D. Zeppenfeld 201 6.6.2 A method to determine V at the weak scale in top quark decays at the LHC . 144 | cb| 202 6.79 Contributors: Flavour changing neutral current . 146 6 7 8 9 9 10 203 10 R. Abdul Khalek , J. Alimena , N. Andari , L. Aperio Bella , A.J. Armbruster , J. Baglio , S. 7 Effective11 coupling12 interpretations13 for top14 quark cross8 sections and13 properties15 . 149 11 Bailey , E. Bakos , A. Bakshi , C. Baldenegro , F. Balli , A. Barker , W. Barter , J. de 204 7.116 , The1 top quark17 couplings18 to the W boson19 . .8 . .20 . .21 . 149 • As part of this-12 Blas chapter, F. Blekman ,on D. Bloch forward, A. Bodek , M. Boonekamp physics., E. Boos , J.D. Bossio Sola , L. 22 9 23 24 25 4 205 137.2Cadamuro t¯tγ .............................................., S. Camarda , F. Campanario , M. Campanelli , Q.-H. Cao , V. Cavaliere , A. 151 26 27 28 29 30 3 31 14 Cerri ¯, B. Chargeishvili , C. Charlot , S.-L. Chen , T. Chen , L. Cieri , M. Ciuchini , G. 206 7.3 ttZ..............................................32 33 34 1 35 36 151 15 Corcella , J.M. Cruz-Martinez , M. Czakon , A. Dainese , N.P. Dang , L. Darmé , S. 207 8 Forward4 physics .37 . .9 . .8 . .38 . .39 . .40 . 153 16 Dawson , H. De la Torre , M. Deile , F. Deliot , S. Demers , A. Denner , F. Derue , L. Di 41 42 43 20 27 208 178.1Ciaccio Photon-induced, W.K. Di Clemente collisions, D. Dominguez at the HL–LHC Damiani . ., . L. Dudko . ., . A. Durglishvili . ., . M. 153 9 44 45 3 99 30 18 Dünser , J. Ebadi , R. B. Ferreira De Faria , G. Ferrera , A. Ferroglia , T. M. Figy , K.D. 209 8.1.146 Anomalous quartic45 gauge couplings47 with48 proton tagging49 ,50 at the HL-LHC45 . .51 . 153 19 Finelli , M.C.N. Fiolhais , E. Franco , R. Frederix , B. Fuks , B. Galhardo , J. Gao ,J. 210 9 52 53 54 55 56 208.2R. Gaunt Central, T. Gehrmann exclusive production:, A. Gehrmann-De QCD Ridder prospects, J. Giljanovic . ., . F. Giuli . ., E.W.N. Glover . ., . 155 49 45 41 52 9 211 218.3M. D. Goodsell Tagged proton, E. Gouveia at the HL–LHC:, C. Goy experimental, M. Grazzini prospects, J.F. Grosse-Oetringhaus . .,P. 157 57 11 11 58 59 9 Mario’s talk 22 Gunnellini , C. Gwenlan , L. A. Harland-Lang , P.F. Harrison , G. Heinrich , C. Helsens , C. 212 8.4 Low-mass9 central60 exclusive production61 .62 . .34 . .63 ., .64 . .9 . 162 23 Helsens , M. Herndon , O. Hindrichs , A. Hoang , K. Hoepfner , J.M. Hogan , A. Huss , 52 65 66 9 13 43 67 68 24 G. Isidori , S. Jahn , Sa. Jain , S. P. Jones , A.W. Jung , H. Jung , S. Kallweit , D. Kar , 52 52 8 69 70 25 A. Karlberg , M. Kerner , M.K. Khandoga , Hamzeh Khanpour , S. Khatibi , A. 71 9 56 2 42 72 43 26 Khukhunaushvili , J. Kieseler , F. Krauss , J. Kretzschmar , J. Kroll , E. Kryshen , V.S. Lang 73 4 74 47 75 14 37 43 • Here - summarise27 , L. Lechner physics, C.A. Lee , M. Leigh prospects, D. Lelas , R. Les discussed, I. M. Lewis , B. Li , Y.here Li ,J. + beyond. 43 76 56 77 78 60 17 28 Lidrych , Z. Ligeti , J.M. Lindert , Y. Liu , K. Lohwasser , K. Long , D. Lontkovskyi , G. 66 17 79 9 17 80 29 Majumder , M. Mancini , P. Mandrik , M.L. Mangano , I. Marchesini , C. Mayer , K. 66 9 45 43 30 Mazumdar , J.A. McFayden , P. M. Mendes Amaral2 Torres Lagarelhos , A.B. Meyer , S. 81 82 83 44 9 31 Mikhalcov , S. Mishima , A. Mitov , M. Mohammadi Najafabadi , M. Moreno Llácer , M. 9 63 47 84 85 76 48 32 Mulders , M. Narain , A. Nisati , T. Nitta , A. Onofre , S. Pagan Griso , D. Pagani , A. 83 86 83 20 9 9 87 33 Papanastasiou , K. Pedro , M. Pellen , M. Perfilov , B.A. Petersen , M. Pierini , J. Pires , 4 62 43 52 56 5 9 ,88 34 M.-A. Pleier , S. Plätzer , K. Potamianos , S. Pozzorini , A. C. Price , M. Rauch , E. Re , 89 43 90 14 60 66 86 35 L. Reina , J. Reuter , J. Rojo , C. Royon , A. Savin , S. Sawant , B. Schneider , R. 73 9 5 9 2 47 ,9 36 Schoefbeck , M. Schoenherr , H. Schäfer-Siebert , M. Seidel , T. Shears , L. Silvestrini , M. 91 17 73 92 93 86 19 37 Sjodahl , K. Skovpen , D. Spitzbart , P. Starovoitov , C. J. E. Suster , P. Tan , R. Taus , D. 60 94 95 66 45 52 58 38 Teague , K. Terashi , J. Terron , S. Uplap , F. Veloso , M. Verzetti , M. A. Vesterinen , V.E. 58 20 20 12 12 9 39 Vladimirov , P. Volkov , G. Vorotnikov , M. Vranjes Milosavljevic , N. Vranjes , E. Vryonidou 56 9 96 8 74 40 11 40 , D. Walker , M. Wiesemann ,Y.Wu , T. Xu , S. Yacoob , J. Zahreddine , G. Zanderighi , M. 90 43 97 98 63 96 96 41 Zaro , O. Zenaiev , G. Zevi Della Porta , C. Zhang , W. Zhang , H. Zhu , H.L. Zhu , R. 43 9 42 Zlebcik , F. N. Zubair 6 1Introduction The use of diffractive processes to study the Standard Model (SM) and New Physics at the LHC has only been fully appreciated within the last few years; see, for example [1, 2, 3, 4], or the recent reviews [5, 6, 7], and references therein. By detecting protons that have lost only about 1-3% of their longitudinal momentum [8, 9], a rich QCD, electroweak, Higgs and BSM programme becomes accessible experimentally, with the potential to study phenomena which are unique to the LHC, and difficult even at a future linear collider. Particularly interesting are the so-called central exclusive production (CEP) processes which provide an extremely favourable environment to search for, and identify the nature of, new particles at the LHC. The first that comes to mind are the Higgs bosons, but there is also a potentially rich, more exotic, physics menu including (light) gluino and squark production, searches for extra dimensions, gluinonia, radions, and indeed any new object which has 0++ (or 2++)quantumnumbersand couples strongly to gluons, see for instance [2, 10, 11]. By “central exclusive” we mean a process of the type pp → p + X + p, where the + signs denote the absence of hadronic activity (that is, the presence of rapidity gaps) between the outgoing protons and the decay products of the centrally produced system X. The basic mechanism driving the process is shown in Fig. 1. There are several reasons why CEP is especially attractive for searches for new heavy objects. Central exclusive reactionsFirst, if processes the outgoing protons remain intact and scatter through small angles then, to a very good approximation, the primary active di-gluon system obeys a Jz =0,C-even,P-even, selection rule [12]. Here Jz is the projection of the total angular momentum along the proton beam axis. This selection rule readily permits a clean determination of the quantum numbers of the observed new (for example, Higgs-like) resonance, when the dominant production is a scalar state. Secondly, because the process is exclusive, the energy loss of the outgoing protons Central Exclusiveis directly related Production to the mass of the central at system,HL-LHC allowing a potentially excellent mass resolution, irrespective of the decay mode of the centrally produced system. Thirdly, in many Central exclusive reactionstopical cases,pp in particular,p + X for+ Higgsp bosoncan production, be studied a signal-t byo-background measuring ratio ofX orderin a central 1 (or even better)! is achievable [3, 11], [13]-[18]. In particular, due to Jz = 0 selection, leading- 2 detector and the intactorder protons QCD b¯b productionpp with is suppressed forward by a factor proton (mb/E detectors.T ) ,whereET is the transverse energy ¯ < • Two productionof the b, mechanismsb jets. Therefore, of forinterest a low mass*: Higgs, MH ∼ 150 GeV, there is a possibility to observe p p + − Fig. 5.31: Di-photon exclusive Standard Model productionPhoton-inducedFigure via QCD 1: (left) The and basic photon mechanism induced (right) forQCD-induced the exclusive process pp → p + X + p.ThesystemX is processes at the lowest order of pertubation theory. produced by the fusion of two active gluons, with a screening gluon exchanged to neutralize Higher mass the colour. ‘Lower’ mass p whereas the photon induced ones (QED processes) dominate at higher diphoton masses [176]. It is p very important to notice that the W loop• contributionSensitive dominates to atrather high diphoton different masses [174, physics/areas 175, 177] of phase space. Play whereas this contribution is omitted in most studies. This is the first time that we put all terms inside a MC generator, FPMC [179]. different roles @ HL-LHC. 2 6.1.2 StandardMeasure Model WW and theZZ prduction proton fractional momentum3 loss *In⇠ addition-= ∆p photoproduction/p with forward proton In the Standard Model (SM) of particle physics, the couplings of fermions and gauge bosons are con- i strained by thespectrometers.