arXiv subjects

Pavel Fileviez Perez

Publications and source records attributed to Pavel Fileviez Perez.

At least 91 records · Page 5Linked to original sources

arXiv2011

Gauge Origin of M-Parity and the mu-Term in Supersymmetry

In this article we present a simple theoretical framework where the origin of the mu-term and the matter-parity violating interactions of the minimal supersymmetric standard model can be understood from the spontaneous breaking of new Abelian gauge symmetries. In this context the masses of the Z' gauge bosons, the M-parity violating scale and the mu-term are determined by the supersymmetry breaking scale. The full spectrum of the theory is discussed in detail. We investigate the predictions for the Higgs masses in detail showing that it is possible to satisfy the LEP2 bounds even with sub-TeV squark masses. The model predicts the existence of light colored fields, lepton and baryon number violation, and new neutral gauge bosons at the Large Hadron Collider.

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arXiv2011

The LSP Stability and New Higgs Signals at the LHC

The fate of R-parity in the context of the minimal supersymmetric standard model is a central issue which has profound implications for particle physics and cosmology. In this article we discuss the possibility of testing the mechanism responsible for the stability of the lightest supersymmetric particle at the Large Hadron Collider (LHC). The simplest theoretical framework where R-parity conservation can be explained dynamically allows for two types of B-L models. In the first scenario the new Higgses decay mainly into two right-handed neutrinos giving rise to exotic lepton number violating signals together with displaced vertices. In the second model one could have peculiar channels with multileptons and/or multiphotons in the final state. In both cases, the local B-L gauge symmetry is broken at the TeV scale and the discovery of the new Higgs bosons may be possible at the LHC. We investigate in detail the production mechanisms for the Higgs bosons relevant for the LHC and the key decays which would shed light on how R-parity is conserved. These results may help to understand the link between the cold dark matter of the universe and the missing energy that could be observed at the LHC if supersymmetry is realized in nature.

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arXiv2011

R-parity Conservation via the Stueckelberg Mechanism: LHC and Dark Matter Signals

We investigate the connection between the conservation of R-parity in supersymmetry and the Stueckelberg mechanism for the mass generation of the B-L vector gauge boson. It is shown that with universal boundary conditions for soft terms of sfermions in each family at the high scale and with the Stueckelberg mechanism for generating mass for the B-L gauge boson present in the theory, electric charge conservation guarantees the conservation of R-parity in the minimal B-L extended supersymmetric standard model. We also discuss non-minimal extensions. This includes extensions where the gauge symmetries arise with an additional U(1)_{B-L} x U(1)_X, where U(1)_X is a hidden sector gauge group. In this case the presence of the additional U(1)_X allows for a Z' gauge boson mass with B-L interactions to lie in the sub-TeV region overcoming the multi-TeV LEP constraints. The possible tests of the models at colliders and in dark matter experiments are analyzed including signals of a low mass Z' resonance and the production of spin zero bosons and their decays into two photons. In this model two types of dark matter candidates emerge which are Majorana and Dirac particles. Predictions are made for a possible simultaneous observation of new physics events in dark matter experiments and at the LHC.

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arXiv2011

Breaking Local Baryon and Lepton Number at the TeV Scale

Simple models are proposed where the baryon and lepton number are gauged and spontaneously broken near the weak scale. The models use a fourth generation that is vector-like with respect to the strong, weak and electromagnetic interactions to cancel anomalies. One does not need large Yukawa couplings to be consistent with the experimental limits on fourth generation quark masses and hence the models are free of Landau poles near the weak scale. We discuss the main features of simple non-supersymmetric and supersymmetric models. In these models the light neutrino masses are generated through the seesaw mechanism and proton decay is forbidden even though B and L are broken near the weak scale. For some values of the parameters in these models baryon and/or lepton number violation can be observed at the Large Hadron Collider.

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arXiv2011

Low Energy Supersymmetry with Baryon and Lepton Number Gauged

We investigate the spontaneous breaking of the Baryon (B) and Lepton (L) number at the TeV scale in supersymmetric models. A simple extension of the minimal supersymmetric standard model where B and L are spontaneously broken local gauge symmetries is proposed. The B and L symmetry breaking scales are defined by the supersymmetry breaking scale. By gauging B and L we understand the absence of the baryon and lepton number violating interactions of dimension four and five in the MSSM. Furthermore we show that even though these symmetries are spontaneously broken there are no dangerous operators mediating proton decay. We discuss the main properties of the spectrum, the possible baryon number violating decays and the implications for the dark matter candidates. In this model one can have lepton number violating signals from the decays of the right-handed neutrinos and baryon number violating signals from the decays of squarks and gauginos without conflict with the bounds coming from proton decay, n-nbar oscillations and dinucleon decays.

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arXiv2011

Testing the Mechanism for the LSP Stability at the LHC

The lightest supersymmetric particle (LSP) is a natural candidate for the cold dark matter of the universe. In this Letter we discuss how to test the mechanism responsible for the LSP stability at the LHC. We note that if R-parity is conserved dynamically one should expect a Higgs boson which decays mainly into two right-handed neutrinos (a "leptonic" Higgs) or into two sfermions. The first case could exhibit spectacular lepton number violating signals with four secondary vertices due to the long-lived nature of right-handed neutrinos. These signals, together with the standard channels for the discovery of SUSY, could help to establish the underlying theory at the TeV scale.

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arXiv2011

Dark Forces At The Tevatron

A simple explanation of the W+dijet excess recently reported by the CDF collaboration involves the introduction of a new gauge boson with sizable couplings to quarks, but with no or highly suppressed couplings to leptons. Anomaly-free theories which include such a leptophobic gauge boson must also include additional particle content, which may include a stable and otherwise viable candidate for dark matter. Based on the couplings and mass of the Z' required to generate the CDF excess, we predict such a dark matter candidate to possess an elastic scattering cross section with nucleons on the order of sigma ~ 10^-40 cm^2, providing a natural explanation for the signals reported by the CoGeNT and DAMA/LIBRA collaborations. In this light, CDF may be observing the gauge boson responsible for the force which mediates the interactions between the dark and visible matter of our universe.

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arXiv2010

Lepton Number Violation from Colored States at the LHC

The possibility to search for lepton number violating signals at the Large Hadron Collider (LHC) in the colored seesaw scenario is investigated. In this context the fields that generate neutrino masses at the one-loop level are scalar and Majorana fermionic color-octets of SU(3). Due to the QCD strong interaction these states may be produced at the LHC with a favorable rate. We study the production mechanisms and decays relevant to search for lepton number violation signals in the channels with same-sign dileptons. In the simplest case when the two fermionic color-octets are degenerate in mass, one could use their decays to distinguish between the neutrino spectra. We find that for fermionic octets with mass up to about 1 TeV the number of same-sign dilepton events is larger than the standard model background indicating a promising signal for new physics.

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arXiv2010

Three Layers of Neutrinos

In this letter we point out that in a class of models for spontaneous R-parity breaking based on gauged B-L, the spectrum for neutrinos is quite peculiar. We find that those models generally predict three layers of neutrinos: one heavy sterile neutrino, two massive active neutrinos, and three near massless (one active and two sterile) neutrinos.

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arXiv2010

Dark Matter, Baryon Asymmetry, and Spontaneous B and L Breaking

We investigate the dark matter and the cosmological baryon asymmetry in a simple theory where baryon (B) and lepton (L) number are local gauge symmetries that are spontaneously broken. In this model, the cold dark matter candidate is the lightest new field with baryon number and its stability is an automatic consequence of the gauge symmetry. Dark matter annihilation is either through a leptophobic gauge boson whose mass must be below a TeV or through the Higgs boson. Since the mass of the leptophobic gauge boson has to be below the TeV scale one finds that in the first scenario there is a lower bound on the elastic cross section of about 5x10^{-46} cm^2. Even though baryon number is gauged and not spontaneously broken until the weak scale, a cosmologically acceptable baryon excess is possible. There is tension between achieving both the measured baryon excess and the dark matter density.

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arXiv2010

Baryon and Lepton Number as Local Gauge Symmetries

We investigate a simple theory where Baryon number (B) and Lepton number (L) are local gauge symmetries. In this theory B and L are on the same footing and the anomalies are cancelled by adding a single new fermionic generation. There is an interesting realization of the seesaw mechanism for neutrino masses. Furthermore, there is a natural suppression of flavour violation in the quark and leptonic sectors since the gauge symmetries and particle content forbid tree level flavor changing neutral currents involving the quarks or charged leptons. Also one finds that the stability of a dark matter candidate is an automatic consequence of the gauge symmetry. Some constraints and signals at the Large Hadron Collider are briefly discussed.

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arXiv2010

The Fate of R-Parity

The possible origin of the R-parity violating interactions in the minimal supersymmetric standard model and its connection to the radiative symmetry breaking mechanism (RSBM) is investigated. In the context of the simplest model where the implementation of the RSBM is possible, we find that in the majority of the parameter space R-parity is spontaneously broken at the low-scale. These results hint at the possibility that R-parity violating processes will be observed at the Large Hadron Collider, if Supersymmetry is realized in nature.

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arXiv2010

Gauge Mediated SUSY Breaking via Seesaw

We present a simple scenario for gauge mediated supersymmetry breaking where the messengers are also the fields that generate neutrino masses. We show that the simplest such scenario corresponds to the case where neutrino masses are generated through the Type I and Type III seesaw mechanisms. The entire supersymmetric spectrum and Higgs masses are calculable from only four input parameters. Since the electroweak symmetry is broken through a doubly radiative mechanism, meaning a nearly zero B-term at the messenger scale which runs down to acceptable values, one obtains quite a constrained spectrum for the supersymmetric particles whose properties we describe. We refer to this mechanism as "nu-GMSB".

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arXiv2009

The Origin of Neutrino Masses and Physics Beyond the Standard Model

We discuss the simplest models for the generation of neutrinos masses at tree level and one-loop level. The realization of the different seesaw mechanisms in the context of renormalizable SU(5) and SO(10) theories is reviewed. A new mechanism for the generation of neutrino masses at one-loop level is presented. We discuss the first realization of the Type III seesaw mechanism in the context of a renormalizable SU(5) theory, called "Adjoint SU(5)".

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arXiv2009

Testability of Type I Seesaw at the CERN LHC: Revealing the Existence of the B-L Symmetry

We study the possibility to test the Type I seesaw mechanism for neutrino masses at the CERN Large Hadron Collider. The inclusion of three generations of right-handed neutrinos (N_i) provides an attractive option of gauging the B-L accidental symmetry in the Standard Model (as well as an extended symmetry X=Y-5(B-L)/4). The production mechanisms for the right-handed neutrinos through the Z' gauge boson in the U(1)_{B-L} and U(1)_X extensions of the Standard Model are studied. We discuss the flavor combinations of the charged leptons from the decays of N_i in the Delta L=2 channels. We find that the clean channels with dilepton plus jets and possible secondary vertices of the N decay could provide conclusive signals at the LHC in connection with the hierarchical pattern of the light neutrino masses and mixing properties within the Type I seesaw mechanism.

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arXiv2009

TeV Scale Spontaneous R-Parity Violation

Understanding the origin or absence of the R-parity violating interactions in the minimal supersymmetric Standard Model is a vital and open issue. Here we show that in the minimal B-L models, R-parity and B-L are spontaneously broken at the TeV scale. We also briefly discuss the phenomenological and cosmological aspects of these scenarios.

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arXiv2009

The Right Side of Tev Scale Spontaneous R-Parity Violation

We study a simple extension of the minimal supersymmetric Standard Model in which the Abelian sector of the theory consists of B-L and right-handed isospin. In the minimal model this Abelian gauge structure is broken to the standard model hypercharge gauge group by non-vanishing vacuum expectation values of the right-handed sneutrinos, resulting in spontaneous R-parity violation. This theory can emerge as a low energy effective theory of a left-right symmetric theory realized at a high scale. We determine the mass spectrum of the theory, and discuss the generation of neutrino masses and R-parity violating interactions. The possibility of distinguishing between R-parity violating models with a gauged B-L broken at the TeV scale at the Large Hadron Collider is discussed.

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arXiv2009

On the Origin of Neutrino Masses

We discuss the simplest mechanisms for generating neutrino masses at tree level and one loop level. We find a significant number of new possibilities where one can generate neutrino masses at the one-loop level by adding only two new types of representations. These models have renormalizable interactions that automatically conserve baryon number. Adding to the minimal standard model a scalar color octet with SU(3) X SU(2) X U(1) quantum numbers, (8,2,1/2), and a fermionic color octet in the fundamental or adjoint representation of SU(2) one can generate neutrino masses in agreement with the experiment. Signals at the LHC, and constraints from flavour violation are briefly discussed.

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