Squarkonium, diquarkonium, and octetonium at the LHC and their diphoton decays

Abstract

Motivated by the recent di-photon excess by both ATLAS and CMS collaborations at the LHC, we systematically investigate the production and di-photon decay of onia formed by pair of all possible color exotic scalars in minimal extension. When such scalar massive meta-stable colored and charged (MMCC) particles are produced in pair near threshold, η onium can be formed and decay into di-photon through annihilation as pp → η → γγ.Squarkonium is formed by meta-stable squarks in supersymmetric models such as stoponium. Diquarkonium is formed by meta-stable color sextet diquarks which may be realized in the Pati-Salam model. Octetonium is formed by color octet scalars bosons as in the Manohar-Wise model. Stoponium prediction is much smaller than the required signal to account for the di-photon excess. Due to the enhancement factor from color and electric charge, predictions of diquarkonium and octetonium are of O(10 fb) which are significantly greater than the stoponium prediction. Since the color enhancement also results in large production at the colliders, such light color exotic states of O(375 GeV) suffer from severe direct search constraints. On the other hand, if their dominant decay mode involve top quark, they may be buried in the tt plus jets samples and can potentially be searched via

Heavy fermion bound states for diphoton excess at 750 GeV — collider and cosmological constraints

“…The colored particles in the bound state can annihilate into gauge bosons, so that they can give a relatively clean diphoton signature. The possibility to observe such a resonance at hadron colliders has been studied extensively for the scalar top case in the past [15][16][17][18][19][20][21] and in the context of the 750 GeV excess [22][23][24][25]. However, such a colored particle of the mass ∼ 375 GeV (750/2 GeV) is severely constrained by the current LHC data.…”

Chiral Gravitons in Fractional Quantum Hall Liquids

“…Physical implications of this geometrical degree of freedom has been discussed extensively [4][5][6][7][8], in particular its experimental observability [9][10][11][12][13][14]. Furthermore, it has also been argued [3,[15][16][17] that this internal metric has its own quantum dynamics, which gives rise to the longwavelength collective excitations in FQH liquids that can be viewed as "gravitons". This provides a new insight into the invisibility of long-wave length intra-Landau level col-lective mode to electromagnetic probes: the graviton carries total angular momentum 2, mismatching that of the photon which carries angular momentum 1.…”

Resonant Higgs pair production as a probe of stop at the LHC

“…The phenomenologies of the stoponium have been studied at colliders [26][27][28][29][30][31][32][33][34]. In particular, the diphoton channel was studied and found to be a promising way to observe stoponium at the LHC in refs.…”