Searching for the odderon in $pp \to pp K^{+}K^{-}$ and $pp \to pp μ^{+}μ^{-}$ reactions in the $ϕ(1020)$ resonance region at the LHC

Abstract

We explore the possibility of observing odderon exchange in the pp → ppK + K − and pp → ppµ + µ − reactions at the LHC. We consider the central exclusive production (CEP) of the φ(1020) resonance decaying into K + K − and µ + µ − . We compare the purely diffractive contribution (odderon-pomeron fusion) to the photoproduction contribution (photon-pomeron fusion). The theoretical results are calculated within the tensor-pomeron and vector-odderon model for soft reactions. We include absorptive corrections at the amplitude level. In order to fix the coupling constants for the photon-pomeron fusion contribution we discuss the reactions γp → ω p and γp → φp including φ-ω mixing. We compare our results for these reactions with the available data, especially those from HERA. Our coupling constants for the pomeron-odderon-φ vertex are taken from an analysis of the WA102 data for the pp → ppφ reaction. We show that the odderonexchange contribution significantly improves the description of the pp azimuthal correlations and the dP t "glueball-filter variable" dependence of φ CEP measured by WA102. To describe the lowenergy data more accurately we consider also subleading processes with reggeized vector-meson exchanges. However, they do not play a significant role at the LHC. We present predictions for two possible types of measurements: at midrapidity and with forward measurement of protons (relevant for ATLAS-ALFA or CMS-TOTEM), and at forward rapidities and without measurement of protons (relevant for LHCb). We discuss the influence of experimental cuts on the integrated cross sections and on various differential distributions. With the corresponding LHC data one should be able to get a decisive answer concerning the presence of an odderon-pomeron fusion contribution in single φ CEP.

Soft-photon radiation in high-energy proton-proton collisions within the tensor-pomeron approach: bremsstrahlung

“…Clearly, further experimental studies of reactions where odderon effects could be present would be very welcome. Examples of such reactions are photoproduction of f 2 mesons, γp → f 2 p, and central exclusive production of single and double φ mesons, pp → pφp and pp → pφφp; see for instance [77][78][79]. All these reactions can be studied at ALICE3.…”

Central exclusive diffractive production of single photon in high-energy proton-proton collisions within the tensor-pomeron approach

“…And indeed, in the tensor-pomeron model a very satisfactory fit of these data was obtained; see [26]. Applications of the tensor-pomeron concept were given for photoproduction of pion pairs in [27] and for a number of diffractive CEP reactions in pp collisions at high energies [28][29][30][31][32][33][34][35][36][37][38][39].…”

“…Our Ansatz for the Pρ R ρ vertex follows the one for the Pρρ in (3.47) of [23] with the replacements a Pρρ → a Pρ R ρ , b Pρρ → b Pρ R ρ , and similarly for the Pω R ω vertex as well as for f 2R in the place of P. All vertices occurring here were discussed in [23,27,29,34,35] except for POω, f 2R Oω, f 2R Oφ, and a 2R Oρ 0 . In a first approximation, at the high energies discussed here, we shall set these vertices to zero.…”

Extracting the Pomeron-Pomeron- f2(1270) coupling in the pp→ppπ+

“…In the last few years we have undertaken a scientific program to analyse the production of light mesons in the tensor-pomeron and vector-odderon model in several exclusive reactions: pp → ppM [5], pp → ppπ + π − [6,7], pp → pnρ 0 π + (ppρ 0 π 0 ) [8], pp → ppK + K − [9], pp → pp(σσ, ρ 0 ρ 0 → π + π − π + π − ) [10], pp → ppp p [11], pp → pp(φφ → K + K − K + K − ) [12], and pp → pp(φ → K + K − , µ + µ − ) [13]. Some azimuthal angle correlations between the outgoing protons can verify the PPM couplings for scalar f 0 (980), f 0 (1370), f 0 (1500), f 0 (1710) and pseudoscalar η, η ′ (958) mesons [5,9].…”