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.
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.
119632193
Unravelling the sbottom spin at the CERN LHC
Establishing that a signal of new physics is undoubtedly supersymmetric requires not only the discovery of the supersymmetric partners but also probing their spins and couplings. We show that the sbottom spin can be probed at the CERN Large Hadron Collider using only angular correlations in the reaction pp{yields}b-tildeb-tilde*{yields}bbpe{sub T}, which allow us to distinguish a universal extra dimensional interpretation with a fermionic heavy bottom quark from supersymmetry with a bosonic bottom squark. We demonstrate that this channel provides a clear indication of the sbottom spin provided the sbottom production rate and branching ratio into b{chi}-tilde{sub 1}{sup 0} are sufficiently large to have a clear signal above standard model backgrounds.
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.
118401678
Searching for Elko dark matter spinors at the CERN LHC
The aim of this paper is to explore the possibility of discovering a fermionic field with mass dimension one, the Elko field, in the Large Hadron Collider. Due to its mass dimension, an Elko can only interact either with Standard Model spinors and gauge fields at one-loop order or at tree level through a quartic interaction with the Higgs field. In this Higgs portal scenario, the Elko is a viable candidate to a dark matter constituent which has been shown to be compatible with relic abundance measurements from WMAP and direct dark matter searches. We propose a search strategy for this dark matter candidate in the channel at the LHC. We show the LHC potential to discover the Elko considering a triple Higgs–Elkos coupling as small as ~0.5 after 1 ab-1 of integrated luminosity. Some phenomenological consequences of this new particle and its collider signatures are also discussed.
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.
119907543
Hadron spectroscopy and exotic states
This contribution summarizes some of the main results from the LHC experiments on hadron spectroscopy and exotic states.
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