Search for gluino-gluino bound states

Pair production of colored particles is in general accompanied by production of QCD bound states (onia) slightly below the pair-production threshold. Bound state annihilation leads to resonant signals, which in some cases are easier to see than the decays of the pair-produced constituents. In a previous paper (arXiv:1204.1119) we estimated the bound state signals, at leading order and in the Coulomb approximation, for particles with various spins, color representations and electric charges, and used 7 TeV ATLAS and CMS resonance searches to set rough limits. Here we update our results to include 8 and 13 TeV data. We find that the recently reported diphoton excesses near 750 GeV could indeed be due to a bound state of this kind. A narrow resonance of the correct size could be obtained for a color-triplet scalar with electric charge −4/3 and mass near 375 GeV, if (as a recent lattice computation suggests) the wave function at the origin is somewhat larger than anticipated. Pair production of this particle could have evaded detection up to now. Other candidates may include a triplet scalar of charge 5/3, a triplet fermion of charge −4/3, and perhaps a sextet scalar of charge −2/3.

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“…For other studies of bound state phenomenology at the LHC, see[6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24].…”

mentioning

confidence: 99%

Resonances from QCD bound states and the 750 GeV diphoton excess

Kats

Strassler

2016

J. High Energ. Phys.

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“…The annihilation decay to light qq pairs is suppressed by the quark masses by chirality considerations. However, decays to tt may have a reasonable rate [5,9]. The branching ratio for the 1 gluinonium is [9] Γ(1 → tt)…”

Section: Annihilation Decaysmentioning

confidence: 99%

“…When a gluino pair is produced close to threshold, it can form a bound state, called gluinonium [1,2,3]. General features of the gluinonium production cross section and annihilation rates, including various perturbative corrections, have been studied in [4,5,6,7,8,9]. Applying these results, we will find that annihilation decays of gluinonium are relevant for realistic SUSY spectra such as some of the SPS benchmark points [10], as well as for more exotic scenarios such as those with a gluino LSP [11,12] or split supersymmetry [13].…”

Section: Introductionmentioning

confidence: 99%

Annihilation decays of bound states at the LHC

Kats

Schwartz

2010

J. High Energ. Phys.

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At the Large Hadron Collider, heavy particles may be produced in pairs close to their kinematic threshold. If these particles have strong enough attractive interactions they may form bound states. Consequently, the bound states may decay through annihilation back into the standard model. Such annihilation decays have the potential to provide much information about the bound particles, such as their mass, spin, or charges, in a manner completely complementary to standard single particle cascade decays. Many of the signatures, such as dijet resonances, will be challenging to find, but may be extremely helpful in unraveling the nature of the new physics. In the standard model, the only novel annihilation decays would be for toponium; these will be hard to see because of the relatively large width of the top quark itself. In models with supersymmetry, marginally visible annihilation decays may occur for example, from bound states of gluinos to dijets or tops. If new particles are bound through forces stronger than QCD, annihilation decays may even be the discovery mode for new physics. This paper presents various theoretical results about bound states and then addresses the practical question of whether any of their annihilation decays can be seen at the LHC.

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“…Thus, the lifetimes of excited gluinonium states may be dominated by gluonic radiative transitions and/or single gluino decays [7].…”

Section: Annihilation Decays Of Gluinoniummentioning

confidence: 99%