October 21, 2011
About me About me Started my 4 year PhD in january 2011 at the university of Bergen under the DAMARA project
About me About me Started my 4 year PhD in january 2011 at the university of Bergen under the DAMARA project Subject of thesis partly experimental particle physics and partly theoretical cosmology:
About me About me Started my 4 year PhD in january 2011 at the university of Bergen under the DAMARA project Subject of thesis partly experimental particle physics and partly theoretical cosmology: Experimental: Looking for SUSY with DM as part of the SUSY-τ group in Bergen, where I will take part in the search for SUSY in signals with τ final states. (Supervised by Heidi Sandaker)
About me About me Started my 4 year PhD in january 2011 at the university of Bergen under the DAMARA project Subject of thesis partly experimental particle physics and partly theoretical cosmology: Experimental: Looking for SUSY with DM as part of the SUSY-τ group in Bergen, where I will take part in the search for SUSY in signals with τ final states. (Supervised by Heidi Sandaker) Theoretical: Study scalar field models of Dark Matter from a cosmological perspective. (Supervised by Per Osland and David Mota)
About me About me Started my 4 year PhD in january 2011 at the university of Bergen under the DAMARA project Subject of thesis partly experimental particle physics and partly theoretical cosmology: Experimental: Looking for SUSY with DM as part of the SUSY-τ group in Bergen, where I will take part in the search for SUSY in signals with τ final states. (Supervised by Heidi Sandaker) Theoretical: Study scalar field models of Dark Matter from a cosmological perspective. (Supervised by Per Osland and David Mota) Duties: Teaching, courses, schools and technical task
About me About me Started my 4 year PhD in january 2011 at the university of Bergen under the DAMARA project Subject of thesis partly experimental particle physics and partly theoretical cosmology: Experimental: Looking for SUSY with DM as part of the SUSY-τ group in Bergen, where I will take part in the search for SUSY in signals with τ final states. (Supervised by Heidi Sandaker) Theoretical: Study scalar field models of Dark Matter from a cosmological perspective. (Supervised by Per Osland and David Mota) Duties: Teaching, courses, schools and technical task Current Status: Duties and searching for viable msugra models which can be probed by studying τ-signals using 2011 data.
About me About me Started my 4 year PhD in january 2011 at the university of Bergen under the DAMARA project Subject of thesis partly experimental particle physics and partly theoretical cosmology: Experimental: Looking for SUSY with DM as part of the SUSY-τ group in Bergen, where I will take part in the search for SUSY in signals with τ final states. (Supervised by Heidi Sandaker) Theoretical: Study scalar field models of Dark Matter from a cosmological perspective. (Supervised by Per Osland and David Mota) Duties: Teaching, courses, schools and technical task Current Status: Duties and searching for viable msugra models which can be probed by studying τ-signals using 2011 data. Theory work hopefully started in 2012.
msugra msugra MSSM parameter introduces 105 new parameter Makes probing the parameter space very difficult. To make progress, one assumes that MSSM is a low energy realization of some underlying unified theory which broken at some higher energy. One such assumption is msugra (minimal SUper GRAvity) which in it s simplest form depends on 5 parameters at the GUT scale, m 0,m 1/2,A 0,tanβ,sign[µ] m 0,m 1/2 : Universal sfermino and gaugino masses at GUT A 0: Universal trilinear coupling at GUT tanβ: Ratio between neutral Higgs vev s at GUT sign[µ]: Sign of Higgs mixing parameter. By using Renormalization Group Equations (RGE) we obtain the SUSY masses spectrum at low energies.
SUSY with τ s Coannihilation Region The majority of msugra parameter space yields to much DM compared to cosmological constraints
SUSY with τ s Coannihilation Region The majority of msugra parameter space yields to much DM compared to cosmological constraints Loophole in the τ- χ coannihilation region, where coannihilations reduce DM relic densities
SUSY with τ s Coannihilation Region The majority of msugra parameter space yields to much DM compared to cosmological constraints Loophole in the τ- χ coannihilation region, where coannihilations reduce DM relic densities This mass degeneracy also typically leads to a large branching fractions to τ s
SUSY with τ s Coannihilation Region The majority of msugra parameter space yields to much DM compared to cosmological constraints Loophole in the τ- χ coannihilation region, where coannihilations reduce DM relic densities This mass degeneracy also typically leads to a large branching fractions to τ s We search for SUSY by looking at signatures with τ s +jets + /E T arising from SUSY cascade decays Figure: Signal process
SUSY with τ s Excluded Grid For tanβ < 40, m 0 < 400, m 1/2 < 300 most parameter points are already exluded by accelerator constraints.
SUSY with τ s Excluded Grid For tanβ < 40, m 0 < 400, m 1/2 < 300 most parameter points are already exluded by accelerator constraints. In higher mass region, cross section drops fewer constraints. New data and higher statistics allows us to probe higher.
SUSY with τ s Excluded Grid For tanβ < 40, m 0 < 400, m 1/2 < 300 most parameter points are already exluded by accelerator constraints. In higher mass region, cross section drops fewer constraints. New data and higher statistics allows us to probe higher. We extend search to higher tanβ,m 0 & m 1/2 to look for points with viable DM candidates and detectable τ signatures.
Generated points Search Range Using numerical tools we look at extended model grid with parameter range (GeV units for mass) x [x min,x max] dx # m 0 [400,1200] 5 161 m 1/2 [300,800] 5 101 A 0 [ 1000,1000] 500 5 tan β [30, 60] 5 7 sign[µ] { 1, +1} 2 Total # points 1138270 Table: Parameter Ranges
Generated points Search Range Using numerical tools we look at extended model grid with parameter range (GeV units for mass) x [x min,x max] dx # m 0 [400,1200] 5 161 m 1/2 [300,800] 5 101 A 0 [ 1000,1000] 500 5 tan β [30, 60] 5 7 sign[µ] { 1, +1} 2 Total # points 1138270 Table: Parameter Ranges These points are then run down from GUT to LHC scale using DarkSusy 5.05 s built in IsaJet(ver. 7.79?). # points: 1138270 845736 (74.3%)
Generated points Full Grid Gives us 7 tanβ planes for each of the 10 possible configurations of {A 0,sign[µ]}. Figure: No Cuts: A 0 = 500,sign[µ] = +1
Generated points Full Grid Gives us 7 tanβ planes for each of the 10 possible configurations of {A 0,sign[µ]}. Figure: No Cuts: A 0 = 500,sign[µ] = +1 We focus on A 0 = 500 and sign[µ] = +1 (only configuration passing all cuts).
Results Accelerator Bounds Cut on various checks by IsaSugra (Sparticle masses, B s +γ,ρ and M h0 > 114GeV Figure: Exclusion: A 0 = 500,sign[µ] = +1 # points: 845736 495009 (58.5%)
Results Hierarchy Hierarchy cut M q/ g > M χ 2 0 > M τ1 Figure: Hierarchy: A 0 = 500,sign[µ] = +1 # points: 495009 135248 (27.3%)
Results Coannhilations Coannihilation cut: 5GeV < M τ1 M χ 1 0 < 20GeV Figure: Coannihilation: A 0 = 500,sign[µ] = +1 # points: 135248 3332 (2.5%)
Results Squark/Gluino Cut Upper limit on squark/gluino mass M q/ g < 800GeV Figure: squark/gluino mass: A 0 = 500,sign[µ] = +1 # points: 3332 277(8.3%)
Results Dark Matter After preliminary cuts remaining points are run through DarkSusy s DM Calculation. Cut on Ωh 2 = (1±0.3) 0.1138 (WMAP7) Figure: squark/gluino mass: A 0 = 500,sign[µ] = +1 # points: 277 67(24.2%)
Results NLO Cross Section Final step is NLO cross section calculation of the remaining points. No points over 1pb, 6 over 0.5pb, All of which have A 0 = 500, sign[µ] = +1 and tanβ = 50. Figure: squark/gluino mass: A 0 = 500,sign[µ] = +1 # points: 67 6(9%, 5.3 10 4 % of total)
Results Passed Points Points passing cuts (All point have A 0 = 500,tanβ = 50 and sign[µ] = +1): m 0 m 1/2 Ωh 2 σ NLO err N LO 415.0 425.0 115.79 0.096 0.084 0.002 420.0 430.0 115.8 0.139 0.077 0.002 420.0 435.0 115.81 0.108 0.07 0.002 425.0 445.0 115.95 0.119 0.059 0.002 425.0 450.0 116.04 0.088 0.055 0.002 430.0 455.0 116.06 0.13 0.05 0.002 Table: Sample of points after all cuts, with Ωh 2 reasonably close to WMAP best fit or below
Results Preliminary Conclusions Moving up in parameter space we find models which seem to avoid experimental constraints and gives reasonable values for the Higgs mass and DM relicdensity.
Results Preliminary Conclusions Moving up in parameter space we find models which seem to avoid experimental constraints and gives reasonable values for the Higgs mass and DM relicdensity. Cross sections are rather small but the models might be probable with LHC 2011/2012 data(?).
Results Preliminary Conclusions Moving up in parameter space we find models which seem to avoid experimental constraints and gives reasonable values for the Higgs mass and DM relicdensity. Cross sections are rather small but the models might be probable with LHC 2011/2012 data(?). Note that softening the Higgs mass cut to M h0 > 110 opens up large regions of parameter space and yields points with cross sections up to 3pb.
Results Preliminary Conclusions Moving up in parameter space we find models which seem to avoid experimental constraints and gives reasonable values for the Higgs mass and DM relicdensity. Cross sections are rather small but the models might be probable with LHC 2011/2012 data(?). Note that softening the Higgs mass cut to M h0 > 110 opens up large regions of parameter space and yields points with cross sections up to 3pb. Very preliminary results, need more knowledge on the uncertainties in the derived parameters in order to know wether the results are reliable.