118422811
Measuring asymmetries in flavor asymmetric machines
The LHC offers a unique opportunity to investigate an ample spectra of phenomenous ranging from the Electro-Weak (EW) to the QCD sector of the Standard Model (SM). Among the quantities which can be measured in the LHC experiments are the CP and production asymmetries for several particles in a wide variety of decay modes. In this work we discuss about the interplay between production and CP asymmetries for particles produced in proton-proton interactions and the effects of one on the measurement of the other. This kind of effects are not present in flavor symmetric machines like the Tevatron or $e^+-e^-$ colliders.
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
126244363
Heavy flavor physics in LHCb
119907543
Hadron spectroscopy and exotic states
This contribution summarizes some of the main results from the LHC experiments on hadron spectroscopy and exotic states.
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 $B^+\rightarrow K^+\pi^+\pi^-\mu^{+}\mu^{-}$.
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.
56111830
Is There a Hidden Principle in the Higgs Boson Decay to Photons
It is remarkable that the measured Higgs boson mass is so close to the value which maximizes the Higgs decay rate to photons as predicted by the Standard Model. In this letter we explore the consequences to assume that an ∼ 126 GeV Higgs boson mass is not accidental, but fixed by some fundamental principle that enforces it to maximize its decay rate into photons. We provide evidence that only a very narrow slice of the parameters space of the Standard Model, which contains their measured values, could lead to a maximal Higgs boson with that mass. If the principle actually holds, several Standard Model features get fixed, as the number of fermion families, quark colors, and the CP nature of the new boson, for example. We also ilustrate how such principle can place strong bounds on new physics scenarios as a Higgs dark portal model, for example.
119279733
Production of Charged Higgs Bosons in a 3-3-1 Model at the CERN LHC
We perform a study of the charged Higgs production from an $SU(3{)}_{C}\ensuremath{\bigotimes}SU(3{)}_{L}\ensuremath{\bigotimes}U(1{)}_{X}$ model with right-handed neutrinos, postulating a custodial symmetry which reduces the number of free parameters in the scalar potential. We compute the cross sections for charged scalars for typical and new production modes. One of the new $SU(3{)}_{L}$ neutral gauge bosons, ${Z}^{\ensuremath{'}}$, affects some production cross sections distinguishing the model from other standard model extensions like, for example, the minimal supersymmetric standard model and general two-Higgs doublets models. The interplay between the Higgs sector of the model and that ${Z}^{\ensuremath{'}}$ gauge boson enhances substantially all the production rates of the lightest charged Higgs boson, ${H}_{1}^{\ifmmode\pm\else\textpm\fi{}}$, at hadron colliders compared to the MSSM. We found that a large portion of the parameters space can be probed at the LHC running at 14 TeV center-of-mass energy in the associated $pp\ensuremath{\rightarrow}{W}^{\ifmmode\pm\else\textpm\fi{}}{H}_{1}^{\ensuremath{\mp}}+X$ production channel in the low luminosity run stage of the experiment.
118412313
A model with chiral quarks of electric charges −4/3 and 5/3
A bstractWe present a new model based on the SU(3)⨂SU(2)⨂U(1) symmetry, in which there is a new consistent set of chiral fermion fields that renders the model free from anomalies. The new fermions do not share the usual family structure of the Standard Model and some of them have exotic electric charges, as the quarks X and Y with electric charge 5/3 and −4/3, respectively. Interestingly, the model contains a new heavy neutral lepton which may be a dark matter candidate. Two Higgs doublets are present in our construction, so that two CP even scalars are present in the model particle spectrum. One of them is similar to the Standard Model Higgs boson, while the other one couples mainly with the new exotic fermions. We performed a discovery analysis showing that the 8 TeV LHC can find the Y quark from single and pair production with masses from 300 GeV up to ~ 750 GeV. We also show that the new spectrum does not contribute significantly to the oblique EW parameters, and that dangerous flavor changing neutral currents are suppressed. Characteristic signatures from the other new fermions in the model are also commented.
118654190
Maximum Entropy Principle and the Higgs boson mass
A successful connection between Higgs boson decays and the Maximum Entropy Principle is presented. Based on the information theory inference approach we determine the Higgs boson mass as MH=125.04±0.25GeV, a value fully compatible to the LHC measurement. This is straightforwardly obtained by taking the Higgs boson branching ratios as the target probability distributions of the inference, without any extra assumptions beyond the Standard Model. Yet, the principle can be a powerful tool in the construction of any model affecting the Higgs sector. We give, as an example, the case where the Higgs boson has an extra invisible decay channel within a Higgs portal model.
119240724
Observing Higgs dark matter at the CERN LHC
Triggering the electroweak symmetry breaking may not be the only key role played by the Higgs boson in particle physics. In a recently proposed warped five-dimensional SO(5) ⊗ U(1) gauge-Higgs unification model, the Higgs boson can also constitute the dark matter that permeates the universe. The stability of the Higgs boson in this model is guaranteed in all orders of perturbation theory by the conservation of an H-parity quantum number that forbids triple couplings to all standard model (SM) particles. Such a unique feature of the model shows up as a delay in the restoration of the tree-level unitarity, which in turn enhances the production cross section as compared to the standard model analogue. Recent astrophysical data constrain the mass of such a Higgs dark matter particle to a narrow window of 70-90 GeV range. We show that the Large Hadron Collider can observe these Higgs bosons in the weak boson fusion channel with about 260 fb -1 of integrated luminosity in that mass range.