# ICHEP 2020

28 July 2020 to 6 August 2020
virtual conference
Europe/Prague timezone

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

29 Jul 2020, 15:55
15m
virtual conference

#### virtual conference

Talk 06. Strong Interactions and Hadron Physics

### Speaker

Piotr Lebiedowicz (Institute of Nuclear Physics PAN)

### Description

We discuss the possibility to use the $pp \to pp \phi$ and $pp \to pp \phi \phi$ reactions in identifying the odderon exchange. So far there is no unambiguous experimental evidence for the odderon, the charge conjugation C = -1 counterpart of the C = +1 pomeron, introduced on theoretical grounds in [1]. Last year results of the TOTEM collaboration [2] suggest that the odderon exchange can be responsible for a disagreement of theoretical calculations and the TOTEM data [4] for elastic proton-proton scattering. Similar conclusion can be drawn when comparing recent result for $\sqrt{s}$ = 2.76 TeV with the Tevatron data [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 tensor-pomeron and vector-odderon model for soft high-energy reactions [5].

The first reaction is central exclusive production of pairs of $\phi$ mesons. Here odderon exchange is not excluded by the WA102 experimental data [8] for high $\phi \phi$ invariant masses. The process is advantageous [6] as here odderon does not couple to protons (the corresponding coupling constant is probably small). Predictions for the LHC will be presented. The observation of $M_{\phi \phi}$ and the rapidity difference $Y_{\phi \phi}$ seems well suited to identify odderon exchange.

Finally we discuss the $p p \to p p \phi$ reaction [7]. 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 [9]. At the low energy we consider also some other subleading processes that turned out to be rather small. Predictions for the LHC will be presented.

[1] L. Łukaszuk, B. Nicolescu, Lett. Nuovo Cim. 8 (1973) 405.
[2] TOTEM Collaboration, Eur. Phys. J. C79 (2019) 785.
[3] TOTEM Collaboration, TOTEM-2018-002, arXiv:1812.08610 [hep-ex].
[4] E. Martynov, B. Nicolescu, Phys. Lett. B786 (2018) 207.
[5] C. Ewerz, M. Maniatis, O. Nachtmann, Annals Phys. 342 (2014) 31.
[6] P. Lebiedowicz, O. Nachtmann, A. Szczurek, Phys. Rev. D99 (2019) 094034.
[7] P. Lebiedowicz, O. Nachtmann, A. Szczurek, arXiv:1911.01909 [hep-ph].
[8] WA102 Collaboration, Phys. Lett. B432 (1998) 436.
[9] A. Kirk, Phys. Lett. B489 (2000) 29.

### Primary authors

Piotr Lebiedowicz (Institute of Nuclear Physics PAN) Antoni Szczurek (Institute of Nuclear Physics)