119907543
Hadron spectroscopy and exotic states
This contribution summarizes some of the main results from the LHC experiments on hadron spectroscopy and exotic states.
126244363
Heavy flavor physics in LHCb
199685274
Observation of overlapping spin-1 and spin-3 $\overline{D}^0 K^-$ resonances at mass $2.86 {\rm GeV}/c^2$
118556144
Jets Plus Same-Sign Dileptons Signatures from Fermionic Leptoquarks at the LHC
Within the 3-3-1 model framework, we consider the production and decay of fermionic leptoquarks into a striking experimental signature at the LHC: a narrow resonance at the b jet plus same-sign dileptons channel. The data already accumulated by the LHC collaborations may hide a large number of events associated to the production and decay of such exotic quarks, allowing one to investigate large portions of the parameters space of the model. The observation or not of such events would shed light on the construction of models presenting heavy exotic quarks. The hypothesis of the existence of new particles carrying two units of lepton number allows us to consider new physical phenomena which can be quite notable, if their masses are within the actual testable TeV energy scale. The decay of such exotic particles would lead to signatures that can not arise from any novel heavy states whose quantum numbers are the same as the ones in the standard model (SM). As a result, the signals would be almost free from SM backgrounds.
197503274
First observations of the rare decays $B^+\!\rightarrow K^+\pi^+\pi^-\mu^+\mu^-$ and $B^+\!\rightarrow\phi K^+\mu^+\mu^-$
First observations of the rare decays $B^+\rightarrow K^+\pi^+\pi^-\mu^+\mu^-$ and $B^+\rightarrow \phi K^+\mu^+\mu^-$ are presented using data corresponding to an integrated luminosity of $3.0\,\mbox{fb}^{-1}$, collected by the LHCb experiment at centre-of-mass energies of $7$ and $8\mathrm{\,TeV}$. The branching fractions of the decays are \begin{eqnarray*} \mathcal{B}(B^+\rightarrow K^+\pi^+\pi^-\mu^+\mu^-) &=& (4.36\,^{+0.29}_{-0.27}\,\mathrm{(stat)}\pm 0.21\,\mathrm{(syst)}\pm0.18\,\mathrm{(norm)})\times10^{-7},\\ \mathcal{B}(B^+\rightarrow\phi K^+\mu^+\mu^-) &=& (0.82 \,^{+0.19}_{-0.17}\,\mathrm{(stat)}\,^{+0.10}_{-0.04}\,\mathrm{(syst)}\pm0.27\,\mathrm{(norm)}) \times10^{-7},\end{eqnarray*} where the uncertainties are statistical, systematic, and due to the uncertainty on the branching fractions of the normalisation modes. A measurement of the differential branching fraction in bins of the invariant mass squared of the dimuon system is also presented for the decay $B^+\rightarrow K^+\pi^+\pi^-\mu^{+}\mu^{-}$.
119180531
New results on the spectroscopy of XYZ states from LHC experiments
The main results from LHC experiments on XYZ charmonium-like candidates are summarized. 1 ar X iv :1 20 9. 01 18 v1 [ he pex ] 1 S ep 2 01 2
15445774
Stop-lepton associated production at hadron colliders
At hadron colliders, the search for R-parity violating supersymmetry can probe scalar masses beyond what is covered by pair production processes. We evaluate the next-to-leading order SUSY-QCD corrections to the associated stop or sbottom production with a lepton through R-parity violating interactions. We show that higher order corrections render the theoretical predictions more stable with respect to variations of the renormalization and factorization scales and that the total cross section is enhanced by a factor up to 70% at the Tevatron and 50% at the LHC. We investigate in detail how the heavy supersymmetric states decouple from the next-to-leading order process, which gives rise to a theory with an additional scalar leptoquark. In this scenario the inclusion of higher order QCD corrections increases the Tevatron reach on leptoquark masses by up to 40 GeV and the LHC reach by up to 200 GeV.
15784150
Multi-photon signatures at the Fermilab Tevatron
Fermiophobic Higgs bosons (hf) exhibiting large branching ratios for decay to two photons can arise in models with two or more scalar doublets and/or triplets. In such models the conventional production mechanisms at hadron colliders, which rely on the hfVV coupling (V=W,Z), may be rendered ineffective due to severe mixing angle suppression. In this scenario, double hf production may proceed via the complementary mechanism qq’→H±hf with subsequent decay H±→hfW*, leading to events with up to four photons. We perform a simulation of the detection prospects of hf in the multi-photon (>3) channel at the Fermilab Tevatron and show that a sizeable region of the (mH±,mhf) parameter space can be probed during Run II.
117282788
Effective field theory approach to the Galactic Center gamma-ray excess
We explore the possibility of explaining a gamma-ray excess in the Galactic center, originally pointed out by Hooper, collaborators, and other groups, in an effective field theory framework. We assume that dark matter annihilation is mediated by particles heavy enough to be integrated out and that such particles couple to all quark families. We calculate the effective coupling required to explain the annihilation signal in the Galactic center and compare with bounds from direct detection, collider searches, and the requirement that the dark matter particles make up the appropriate fraction of the universal energy budget. We find that only a very small set of operators can explain the gamma-ray excess while being consistent with other constraints. Specifically, for scalar dark matter, the viable options are one scalar-type coupling to quarks and one interaction with gluons, while for fermionic (Dirac) dark matter, the viable options are two scalar-type dimension-7 operators or a dimension-6 vector-type operator. In all cases, future searches with the Large Hadron Collider should probe the relevant operators' effective energy scale, while all viable interactions should escape direct detection experiments.
119337438
Spins in Gluino Decays
To unambiguously claim that we see a gluino at the LHC we need to prove its fermionic nature. Looking only at angular correlations we can distinguish a universal extra dimensional interpretation of a gluino cascade decay (assuming a bosonic heavy gluon) from supersymmetry. In addition to the known lepton‐hadron asymmetries we also use of purely hadronic correlations in the gluino‐sbottom decay chain.
119499528
Charged Higgs boson pairs at the CERN LHC
We compute the cross section for pair production of charged Higgs bosons at the LHC and compare the three production mechanisms. The bottom-parton scattering process is computed to next-to-leading order (NLO), and the validity of the bottom-parton approach is established in detail. The light-flavor Drell-Yan cross section is evaluated at NLO as well. The gluon-fusion process through a one-loop amplitude is then compared with these two results. We show how a complete sample of events could look, in terms of total cross sections and distributions of the heavy final states.