26-30 July 2021
Europe/Berlin timezone

Searching for the odderon in exclusive $pp \to pp \phi$ and $pp \to pp \phi \phi$ reactions at the LHC

26 Jul 2021, 11:30


Parallel session talk QCD and Hadronic Physics T06: QCD and Hadronic Physics


Piotr Lebiedowicz (IFJ PAN, Cracow)


We discuss the possibility to use the exclusive $pp \to pp \phi$ and $pp \to pp \phi \phi$ reactions in identifying the odderon exchange, the charge conjugation C = -1 counterpart of the C = +1 pomeron. The odderon was introduced on theoretical grounds in [1]. Results of the TOTEM collaboration suggest that the odderon exchange can be responsible for a disagreement of theoretical calculations and the TOTEM data [2,3]. It is premature to draw definite conclusion. Here we present some recent studies for two related processes where the odderon exchange may show up. We apply recently proposed the tensor-pomeron and vector-odderon model [4]. The first reaction is central exclusive production (CEP) of pairs of $\phi$ mesons [5]. Here odderon exchange is not excluded by the WA102 experimental data [7] for high $\phi \phi$ invariant masses. The process is advantageous as here odderon does not couple to protons. Comparison with data from the WA102 experiment and predictions for the LHC experiments will be presented. The observation of large $M_{\phi \phi}$ and $Y_{\phi \phi}$ (rapidity distance between the $\phi$) seems well suited to identify odderon exchange. We discuss also the $p p \to p p \phi$ reaction [6]. At high energies probably the photon-pomeron fusion is the dominant process. The odderon-pomeron fusion is an interesting alternative. Adding odderon exchange with parameters adjusted for the $\phi \phi$ production improves considerably description of the proton-proton angular correlations measured by the WA102 collaboration [8]. At the low energy we consider also some other subleading processes that turned out to be rather small. A combined analysis of both the $K^+ K^-$ and $\mu^+ \mu^-$ channels should be the ultimate goal in searches for odderon in single $\phi$ CEP at the LHC. Predictions for the LHC experiments will be presented.

[1] L. Łukaszuk, B. Nicolescu, Lett. Nuovo Cim. 8 (1973) 405;
[2] E. Martynov, B. Nicolescu, Phys. Lett. B786 (2018) 207;
[3] TOTEM Collaboration, Eur. Phys. J. C79 (2019) 785, Eur. Phys. J. C80 (2020) 91;
[4] C. Ewerz, M. Maniatis, O. Nachtmann, Annals Phys. 342 (2014) 31;
[5] P. Lebiedowicz, O. Nachtmann, A. Szczurek, Phys. Rev. D99 (2019) 094034;
[6] P. Lebiedowicz, O. Nachtmann, A. Szczurek, Phys. Rev. D101 (2020) 094012;
[7] WA102 Collaboration, Phys. Lett. B432 (1998) 436;
[8] A. Kirk, Phys. Lett. B489 (2000) 29.

Collaboration / Activity IFJ PAN, Cracow

Primary authors

Piotr Lebiedowicz (IFJ PAN, Cracow) Prof. Otto Nachtmann (Heidelberg U.) Antoni Szczurek (Institute of Nuclear Physics PAN, Krakow and Rzeszow University, Rzeszow)

Presentation Materials