# XXIV International Workshop on Deep-Inelastic Scattering and Related Subjects (DIS16)

Apr 11 – 15, 2016
DESY Hamburg
Europe/Berlin timezone

## Interpreting the 750 GeV diphoton signal as technipion

Apr 13, 2016, 4:30 PM
15m
SR4b (DESY Hamburg)

### SR4b

#### DESY Hamburg

Electroweak Physics and Beyond the Standard Model

### Speaker

Prof. Antoni Szczurek (Institute of Nuclear Physics PAN, Krakow and Rzeszow University, Rzeszow)

### Description

We discuss a scenario in which the enhancement in the diphoton final state at $M_{\gamma \gamma}$ = 750 GeV, recently observed by the ATLAS and CMS collaborations, is a technipion. We consider two different detailed minimal scenarios. In a first one (vector-like technicolor model) we assume that the vector-boson fusion is a dominant production mechanism. In a second one (one family walking technicolor model) the technipion is produced dominantly by the gluon-gluon fusion. We adjust parameters of the model (coupling constant) to the size of the signal at $\sqrt{s}$ = 13 TeV and discuss the size of the signal at lower energies (LHC, Tevatron) for $\gamma \gamma$ and jet-jet final states, where it was not observed and check consistency with the existing data. The signal is compared with the background diphoton contributions. As background contributions we include $q \bar q$ annihilation, gluon-gluon fusion via quark boxes, as well as photon-photon fusion via lepton, quark and $W$-bosons boxes. In the latter case (background) as well as for the technipion production (signal) we include elastic-elastic, elastic-inelastic, inelastic-elastic and inelastic-inelastic photon-photon processes, where inelastic'' means associated e.m. dissociation of a proton. In both cases we observe the dominance of inelastic-inelastic processes. We consider also an alternative partonic approach with 2 $\to$ 3 subprocess (with off-shell photons) and compare it to the approach with on shell photons. We predict the signal cross section for purely exclusive $p p \to p p \gamma \gamma$ procesess at $\sqrt{s}$ = 13 TeV to be about 0.5 fb. Such a cross section would be measurable with integrated luminosity about 20 fb$^{-1}$. In all considered cases (other experiments) the signal is below the background or/and below the threshold set by statistics although some tension can be seen. The presentation will be based on our upcoming paper [1]. [1] P. Lebiedowicz, M. {\L}uszczak, R. Pasechnik and A. Szczurek, a paper in preparation.

### Primary author

Prof. Antoni Szczurek (Institute of Nuclear Physics PAN, Krakow and Rzeszow University, Rzeszow)

### Co-authors

Dr Marta Luszczak (Rzeszow University, Rzeszow) Dr Piotr Lebiedowicz (Institute of Nuclear Physics PAN, Krakow) Dr Roman Pasechnik (Lund University, Sweden)

 Slides