We explore a simple extension of the Standard Model which incorporates a vector field in the fundamental representation of SU(2)L as the only non-standard degree of freedom. This kind of field may appear in models where a new strong sector produce the Higgs doublet as a composite state but does not break the chiral symmetry. We study the model in the presence of a discrete Z2 symmetry. As a...
Long-lived particles naturally appear in models where Dark Matter is produced through the freeze-in mechanism. We discuss how the LHC constraints on long-lived particles can be used to test these scenarios. In particular, using a simplified model, we illustrate how the CMS constraints on heavy stable charged particles can severely constrain the Dark Matter parameter space.
We explore the synchrotron signals generated by flavored Dark Matter candidate with mass region between 10-20 GeV annihilating into the leptonic channels $e^{+}e^{-}$ and $\mu^{+}\mu^{-}$. In these models, the interactions are skewed in flavor space, so that a dark matter particle never couples directly to the Standard Model matter fields of the same flavor, but only to the other two...
The study of a heavy meson decaying to three lighter mesons can be described, in general, as quasi-two-body processes through the production of resonance intermediate states. To understand the dynamics of these processes, a full amplitude analysis of the corresponding Dalitz Plot (the two-dimensional representation of the decay phase space) is necessary. The most naïve way to describe it is...
Searches for CP violation in the decays of B hadrons without charmed particles in the final state offer rich opportunities to test the Standard Model. Charmless b-hadron decays are suppressed in the Standard Model by small CKM matrix elements which brings the tree amplitudes to levels comparable with loop amplitudes, and potentially New Physics amplitudes. CP violation measurements using...
A study of $B^+_c \rightarrow K^+K^−π^+$ decays was performed with data corresponding to 3.0$fb^{−1}$ collected by LHCb at 7 and 8 $TeV$ . Evidence for the decay $B^+_ c \rightarrow χ_{c0}(K^+K^−)π^+$ and indication of $\bar{b}c$ weak annihilation are reported. Prospects of studies of decays in other channels will be discussed.
We discuss how NP signals may show up in 3rd generation observables at the LHC.
The talk includes some of the current working areas of the La Plata group in the ATLAS experiment. The trigger is one of the essential pieces of the ATLAS detector. The e/gamma trigger performance studies to understand, improve and also provide the trigger efficiency to the precision analyses and searches for new physics are presented. Next step in the chain towards data analysis is the...
Several years of LHC data taking has left us empty handed when it comes to SUSY search results. That means one of three things:
1) Nature is not supersymmetric
2) The cross-sections/masses involved are still outside the reach of the LHC.
3) Our search strategies aren't sensitive to the SUSY final states.
While the first two points will take a long time to prove, work is urgently...
This talk includes some of the current working areas of the Buenos Aires group at the three levels of the ATLAS data processing chain: trigger, performance and physics analyses.
Within trigger development, the tuning of the b-jet trigger and improvement of jet trigger efficiency are discussed.
Next, the jet energy calibration and resolution are presented.
Finally, beyond Standard Model...
I will present recent results on searching for two exotics signal at LHC: torsion and bileptons. Torsion models constitute a well known class of extended quantum gravity models. In this work, one investigates the phenomenological consequences of a torsion field interacting with top quarks at the LHC. A torsion field could appear as a new heavy state characterized by its mass and couplings to...
Supersymmetry is a very well motivated framework for physics beyond the standard model. Most of the analyses are carry out in R-parity conserving models, as for instance the Minimal Supersymmetric Standard Model (MSSM). In this context the lightest supersymmetric particle (LSP) is a good dark matter candidate. However, the fact that neutrino are massive, the absent of direct detection signals...
The São Paulo Research and Analysis Center (SPRACE) works on the analyses of the data collected by CMS. One of our main interest is the search for physics beyond standard model. In this talk I will present some of the physics studies that are being pursued at SPRACE, in particular our contribution to the search of dark matter.
In the present talk we will discuss the current status and recent advances in the calculation of the cross section for multiple Higgs production at the LHC, both in the SM as in EFT extensions of it.
We investigate the feasibility of constraining parton distribution functions in the proton through a comparison with data on semi-inclusive deep-inelastic lepton-nucleon scattering. Specifically, we reweight replicas of these distributions according to how well they reproduce recent charged kaon multiplicity measurements and analyze how this procedure optimizes the determination of the sea...
We will discuss issues related to the use of perturbative QCD at relatively low energies. The theoretical problems that arise are often fundamental and touch, for instance, the very nature of the perturbative expansion. We have in mind applications to hadronic tau decays, which remains an important source of information about the strong coupling, $\alpha_s$. We will discuss renormalon...
Inclusive jet and dijet cross-sections were measured in proton-proton collisions at a centre-of-mass energy of 13 TeV. The measurement uses a dataset with an integrated luminosity of 3.2 fb−1 with the ATLAS detector at the Large Hadron Collider. Jets are identified using the anti-kt algorithm with a radius parameter value of R=0.4. The inclusive jet cross-sections are measured...
We study the properties of hadrons and the structure of the QCD phase
diagram in the framework of quark models that include nonlocal interactions.
Effects of external magnetic fields are also analyzed. Model predictions are
compared with experimental data and with the results obtained through
lattice QCD calculations.
New results on the string theory dual description of deep inelastic scattering of charged leptons from hadrons are presented for strongly coupled gauge theories. These include: structure functions of glueballs, scalar and polarized vector mesons and polarized spin 1/2 hadrons. Also universal properties of string theory duals, extended Callan-Gross relations, properties of 1/Nc expansion, as...
We study the behavior of strongly interacting matter under a uniform intense external magnetic field in the context of nonlocal extensions of the Polyakov–Nambu–Jona-Lasinio model. A description of the formalism is presented, considering the cases of zero and finite temperature. In particular, we analyze the effect of the magnetic field on the chiral restoration and deconfinement transitions,...
We study the thermodynamic properties of finite systems at zero chemical potential and finite temperature, in the frame of the Polyakov loop Nambu-Jona-Lasinio model for two light and one heavy quarks. Finite size effects are considered whithin the Multiple Reflection Expansion formalism. We analyze some thermodynamic quantities including the equation of state, the interaction measure, the...
The discovery of high mass Millisecond Pulsars such as J1946+3417 ($1.832
\pm 0.028 M_\odot$), J1614-2230 ($1.928 \pm 0.017 M_\odot$) and J0348+0432 ($2.01 \pm 0.04 M_\odot$) allows the
possible existence of deconfined quarks in the Neutron Stars inner core. In order to represent the matter under extremely high density conditions, we obtain a hadron-quark hybrid equation of state by...
The study of neutron stars establishes a direct connection between astronomy and nuclear and particle physics, allowing a better understanding of the behavior of matter under conditions that are difficult to reach in the laboratory. Massive neutron stars provide very important constraints on high-density nuclear matter and its associated Equation of State (EoS), which is still essentially...
We study the dynamics of inhomogeneous scalar and pseudoscalar chiral order parameters within the framework of the time-dependent Ginzburg-Landau equations. We utilize a nonlocal chiral quark model to obtain the phase diagram of the model as function of temperature and baryon chemical potential and study the formation of metastable spatial domains of matter where the order parameters acquire a...
We suggest a class of hybrid compact star equations of state which support the existence of a third family of compact stars composed of a core of two-flavor
quark matter and a shell of hadronic matter described within a relativistic meanfield model with excluded nucleon volume.
The quark matter equation of state is based on a nonlocal covariant chiral quark model with vector meson and...
