LHC signatures of neutrino mass generation throughR-parity violation (original) (raw)
Related papers
Probing R-parity violating models of neutrino mass at the LHC
2012
It is shown that the R-parity violating decays of the lighter top squarks (t 1) triggered by the lepton number violating couplings λ ′ i33 , where the lepton family index i = 1-3, can be observed at the LHC via the dilepton di-jet channel even if the coupling is as small as 10 −4 or 10 −5 , which is the case in several models of neutrino mass, provided it is the next lightest supersymmetric particle(NLSP) the lightest neutralino being the lightest supersymmetric particle(LSP). We have first obtained a fairly model independent estimate of the minimum observable value of the parameter (P ij ≡ BR(t → l + i b)×BR(t * → l − jb)) at the LHC for an integrated luminosity of 10fb −1 as a function of m t 1 by a standard Pythia based analysis. We have then computed the parameter P ij in several representative models of neutrino mass constrained by the neutrino oscillation data and have found that the theoretical predictions are above the estimated minimum observable levels for a wide region of the parameter space.
ProbingR-parity violating models of neutrino mass at the LHC via top squark decays
Physical Review D, 2009
It is shown that the R-parity violating decays of the lighter top squarks (t 1) triggered by the lepton number violating couplings λ ′ i33 , where the lepton family index i = 1-3, can be observed at the LHC via the dilepton di-jet channel even if the coupling is as small as 10 −4 or 10 −5 , which is the case in several models of neutrino mass, provided it is the next lightest supersymmetric particle(NLSP) the lightest neutralino being the lightest supersymmetric particle(LSP). We have first obtained a fairly model independent estimate of the minimum observable value of the parameter (P ij ≡ BR(t → l + i b)×BR(t * → l − jb)) at the LHC for an integrated luminosity of 10fb −1 as a function of m t 1 by a standard Pythia based analysis. We have then computed the parameter P ij in several representative models of neutrino mass constrained by the neutrino oscillation data and have found that the theoretical predictions are above the estimated minimum observable levels for a wide region of the parameter space.
JU-PHYSICS/11/06 New signals of a R-parity violating model of neutrino
2007
In a variety of models of neutrino masses and mixings the lighter top squark decays into competing R- parity violating and R- parity conserving channels. Using Pythia we have estimated in a model independent way the minimum value of P ≡ BR ( ˜t1 → c˜χ 0 1) × BR(˜t1 → l + i b), where li = e + and µ +, corresponding to an observable signal involving the final state 1l + jets +E/T (carried by the neutrinos from the ˜χ 0 1 Run II. For the kinematical cuts designed in this paper P depends on m ˜t1 decay) at Tevatron only. We then compute P for representative choices of the model parameters constrained by the oscillation data and find that over a significant region of the allowed parameter space P is indeed larger than Pmin. This signal is complementary to the dilepton + dijet signal studied in several earlier experimental and phenomenological analyses and may be observed even if BR ( ˜t1 → l + i b) is an order of magnitude smaller than BR(˜t1 → c˜χ 0 1). The invariant mass distribution o...
Collider signatures of neutrino masses and mixing from R-parity violation
Physical Review D - PHYS REV D, 2002
R-parity violation in the supersymmetric standard model can be the source of neutrino masses and mixing. We analyze the neutrino mass matrix coming from either bilinear or trilinear R-parity violation and its collider signatures, assuming that the atmospheric and solar neutrino data are explained by three active neutrino oscillations. Taking the gauge mediated supersymmetry breaking mechanism, we show that the lightest neutralino decays well inside the detector and the model could be tested by observing its branching ratios in the future colliders. In the bilinear model where only the small solar neutrino mixing angle can be accommodated, the relation, 10310^3103 BR($\nu e^\pm \tau^\mp$) sim\simsim BR($\nu \mu^\pm \tau^\mp$) approx\approxapprox BR($\nu \tau^\pm \tau^\mp$), serves as a robust test of the model. The large mixing angle solution can be realized in the trilinear model which predicts BR($\nu e^\pm \tau^\mp$) sim\simsim BR($\nu \mu^\pm \tau^\mp$) sim\simsim BR($\nu \tau^\pm \tau^\mp$). In either ca...
Physical Review D, 2005
Within the framework of R-parity violating minimal supergravity model, at least three relatively large lepton-number violating λ ′ type trilinear couplings at the GUT scale, not directly related to neutrino physics, can naturally generate via renormalization group (RG) evolution and/or CKM rotation the highly suppressed bilinear and trilinear parameters at the weak scale required to explain the neutrino oscillation data. The structure of the RG equations and the CKM matrix restrict the choices of the three input couplings to only eight possible combinations, each with its own distinctive experimental signature. The relatively large input couplings may lead to spectacular low energy signatures like rare weak decays of the τ lepton and K mesons, direct lepton number violating decays of several sparticles, and unconventional decay modes (and reduced lifetime) of the lightest neutralino, assumed to be the lightest supersymmetric particle (LSP), all with sizable branching ratios. Several low background signals at the Tevatron and LHC have been suggested and their sizes are estimated to be at the observable level. From the particle content of the signal and the relative rate of different final states the input couplings at the GUT scale, i.e., the origin of neutrino masses and mixing angles, can be identified.
JU-PHYSICS/11/06 New signals of a R-parity violating model of neutrino mass at the Tevatron
2006
In some models of neutrino masses and mixings the lighter top squark decays into competing R- parity violating and R- parity conserving channels. Using Pythia we have estimated in a model independent way the minimum value of P ≡ BR ( ˜t1 → c˜χ 0 1) × BR(˜t1 → l + i b), where li = e + and µ +, corresponding to an observable signal involving the final state 1l + jets +E/T (carried by the neutrinos from the ˜χ 0 1 decay) at Tevatron Run II. For the kinematical cuts designed in this paper P depends on m only. We then ˜t1 compute P for representative choices of the parameters constrained by the oscillation data and find that over a significant region of the allowed parameter space P is indeed larger than Pmin. This signal is complementary to the dilepton + dijet signal studied in several earlier experimental and phenomenological analyses and may be observed even if BR ( ˜t1 → l + i b) is an order of magnitude smaller than BR(˜t1 → c˜χ 0 1). The invariant mass distribution of the hardest ...
New signals of a R-parity violating model of neutrino mass at the Tevatron
2007
In a variety models of neutrino masses and mixings the lighter top squark decays into competing R - parity violating and R - parity conserving channels. Using Pythia we have estimated in a model independent way the minimum value of P ≡ BR( t_1 → c χ_1^0 ) × BR( t_1 → l^+_i b), where l_i = e^+ and μ^+, corresponding to an observable signal involving the final state 1l + jets + (carried by the neutrinos from the χ̃_1^0 decay) at Tevatron Run II. For the kinematical cuts designed in this paper P depends on m_ t_1 only. We then compute P for representative choices of the model parameters constrained by the oscillation data and find that over a significant region of the allowed parameter space P is indeed larger than P_min. This signal is complementary to the dilepton + dijet signal studied in several earlier experimental and phenomenological analyses and may be observed even if BR( t_1 → l^+_i b) is an order of magnitude smaller than BR( t_1 → c χ_1^0). The invariant mass distribution o...
New signals of anR-parity violating model of neutrino mass at the Fermilab Tevatron
Physical Review D, 2007
In a variety of models of neutrino masses and mixings the lighter top squark decays into competing R-parity violating and R-parity conserving channels. Using Pythia we have estimated in a model independent way the minimum value of P ≡ BR(t 1 → c χ 0 1) × BR(t 1 → l + i b), where l i = e + and µ + , corresponding to an observable signal involving the final state 1l + jets +E / T (carried by the neutrinos from the χ 0 1 decay) at Tevatron Run II. For the kinematical cuts designed in this paper P depends on m t 1 only. We then compute P for representative choices of the model parameters constrained by the oscillation data and find that over a significant region of the allowed parameter space P is indeed larger than P min. This signal is complementary to the dilepton + dijet signal studied in several earlier experimental and phenomenological analyses and may be observed even if BR(t 1 → l + i b) is an order of magnitude smaller than BR(t 1 → c χ 0 1). The invariant mass distribution of the hardest lepton and the hardest jet may determine m t 1 and reveal the lepton number violating nature of the underlying interaction. The invariant mass distribution of the two lowest energy jets may determine m χ 0 1 .
Neutrino masses from R-parity violation with a Z_{3} symmetry
Physical Review D, 2012
We consider a supersymmetric model where the neutrino mass matrix arises from bilinear and trilinear R-parity violation, both restricted by a Z 3 flavor symmetry. Assuming flavor blind soft supersymmetry (SUSY) breaking conditions, corrected at low energies due to running effects, we obtain a neutrino mass matrix in agreement with oscillation data. In particular, a large θ 13 angle can be easily accommodated. We also find a correlation between the reactor and atmospheric mixing angles. This leads in some scenarios to a clear deviation from θ 23 = π/4. The Lightest Supersymmetric Particle (LSP) decay, dominated by the trilinear couplings, provides a direct way to test the model at colliders.