M easurements of finalstate particles in welldefined fiducial regions Generally differential cross sections S hould not and mostly do not assume the SM A gree with the SM so far Thus they can potentially exclude extensions ID: 802710
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Slide1
Precision ‘Standard Model’ Measurements
M
easurements of final-state particles in well-defined fiducial regionsGenerally differential cross sectionsShould not (and mostly do not) assume the SMAgree with the SM (so far)Thus they can potentially exclude extensions
June 2019
JMB, DESY
1
Slide2Key tools:
June 2019
JMB, DESY2
Slide3Key tools:
Constraints On New Theories Using Rivet
June 2019JMB, DESY
3
Slide4Key tools:
Constraints On New Theories Using Rivet
C O N T U Rhttps://
contur.hepforge.org/
https://
contur.hepforge.org
/
June 2019
JMB, DESY
4
Slide5Strategy
Use measurements shown to agree with the Standard Model(Currently) assume the data = the background, as in a typical search control region.
Excellent for quick sensitivity/limit scans of new modelsKey for constraining new models if there is a signal (unintended consequences)Key for constraining scale of new physics if there is no signalJune 2019JMB, DESY5
Slide6Dynamic data selection
Measurements of fiducial, particle-level differential cross sections, with existing Rivet routines
Classify according to data set (7, 8, 13 TeV) and into non-overlapping signaturesUse only one plot from each given statistically correlated samplee.g. Jets, lv+jets, ll+jets, g (+jets), gg, 4l, etc …
.“Most sensitive measurement” will vary with model and model parameters
June 2019
JMB, DESY
6
Slide7Some examples
Spontaneously-broken B-L gauge theoryGeneric Light Scalar ModelDark
Matter modelsDark EnergyFlavour anomaliesJune 2019JMB, DESY7
Slide8Some examples
Spontaneously-broken B-L gauge theoryGeneric Light Scalar Model
Dark Matter modelsDark EnergyFlavour anomaliesJune 2019JMB, DESY8
Slide9Spontaneously-broken B-L gauge theory
S. Amrith, JMB,
F.F.Deppisch, W. Liu, A.Varma, D.Yallup 1811.11452, JHEP 1905 (2019) 154UV completeThree pairs of parameters which interplay to give quite a rich phenomenologyNew U(1) gauge symmetry from B-LNew gauge boson Z’, coupling g
1’Spontaneously brokenNew Higgs boson, h
2, can mix with SM Higgs: sin
a
RH neutrinos with
Majorana
masses, natural explanation of light neutrino masses (seesaw mechanism)
Lifetime of neutrino may lead to prompt decays, (far-)displaced-vertex, or effective stability for collider signatures
June 2019
JMB, DESY
9
Slide10Spontaneously-broken B-L gauge theory
June 2019
JMB, DESY
10
Slide11Spontaneously-broken B-L gauge theory
June 2019
JMB, DESY11
Contur
approach is not well-suited for long-lived-particle signatures: most measurements demand prompt particles attached to primary vertex, or else known SM particle (B,
t
…
). See
Deppisch
, Liu,
Mitra
arXiv:1804.04075 for a study of this model
Slide12Case A
June 2019
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Slide13Case B
June 2019
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Slide14Case C
June 2019
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Slide15Case C
June 2019
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Slide16Case D
June 2019
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Slide17Case E
June 2019
JMB, DESY17
Slide18Case D
June 2019
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18
Slide19Some examples
Spontaneously-broken B-L gauge theoryGeneric Light Scalar
ModelDark Matter modelsDark EnergyFlavour anomaliesJune 2019JMB, DESY
19
Slide20Generic Light scalars
Effective couplings to gauge bosons.
Dominant decay to photons sensitivity in inclusive, diphoton and V+photon measurements Model from S. Fichet, G. Moreau. See Les Houches 2017 proceedings arXiv:1803.10379, Contribution 20
June 2019
JMB, DESY
20
Slide21June 2019
JMB, DESY
21
Slide22Some examples
Spontaneously-broken B-L gauge theoryGeneric Light Scalar Model
Dark Matter modelsDark EnergyFlavour anomaliesJune 2019JMB, DESY
22
Slide23Simplified Dark Matter Model
Introduce Z’ mediator, a Majorana fermion DM candidate, and two couplings
Variant considered in Z’ which couples only to first generation quarks JMB, D. Grellscheid, M.Krämer, B.Sarrazin, D.Yallup , arXiv:1606.05296 Have since also looked at coupling to all generations
June 2019
JMB, DESY
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Slide24Comparison to ATLAS search benchmarks
June 2019
JMB, DESY24
arXiv:1903.01400
Slide25Comparison to ATLAS search benchmarks
June 2019
JMB, DESY25
arXiv:1903.01400
Slide26Two Higgs-doublet model, with the pseudoscalar
Higgs acting as mediator to Dark MatterJune 2019
JMB, DESY26
arXiv:1903.01400
ATLAS
arXiv
:1707.03263
CMS arXiv
:1606.01522,
Slide27Some examples
Spontaneously-broken B-L gauge theoryGeneric Light Scalar ModelDark
Matter modelsDark EnergyFlavour anomaliesJune 2019JMB, DESY27
Slide28Scalar Dark Energy Field coupling to SM
Mode introduced by
Brax, Burrage, Englert & Spannowsky in arXiv:1604.04299Neutral scalar dark energy field of mass 𝑀𝜙 couples to Standard Model particles via various Effective Field Theory (EFT) operators which are suppressed by powers of a scale parameter 𝑀𝑆𝐶𝐴𝐿𝐸.Concentrate on couplings 𝐶
1 & 𝐶2 which appear in front on the leading EFT operators, setting
others to zero. This
means that 𝜙 is pair-produced and stable, so
dominant signatures
are expected to involve missing transverse
energy.
June 2019
JMB, DESY
28
Setting 𝐶
1
=𝐶
2
=1 scan in 𝑀
𝜙
and 𝑀
𝑆𝐶𝐴𝐿𝐸
Slide29Scalar Dark Energy Field coupling to SM
Now set 𝑀𝜙=0.1
GeV, and setting 𝐶2=1−𝐶1, scan in 𝐶1 and 𝑀𝑆𝐶𝐴𝐿𝐸.
June 2019
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29
Limits similar to but stronger than reinterpreted
searches in
the original paper (which used 8
TeV
data
)
Most sensitive measure, ATLAS 13
TeV
jets + missing energy.
arXiv:1707.03263
Slide30Some examples
Spontaneously-broken B-L gauge theoryGeneric Light Scalar ModelDark
Matter modelsDark EnergyFlavour anomaliesJune 2019JMB, DESY
30
Slide31Flavour Anomalies
no
June 2019JMB, DESY31
Moriond
2019
Slide32Flavour Anomalies
Introduce a new particle/interaction to explain this: Look at the impact of direct searches and measurements for such a particle
e.g. Allanach, JMB, Corbett arXiv:1904.10954June 2019JMB, DESY32
Slide33Summary…
With the Higgs, the Standard Model could work well above the Electroweak symmetry breaking scale.
Take its predictions seriously!Model independent measurements stored in HepData and Rivet are a powerful and flexible resourceAlready used more MC tuning and validation, comparison to precision SM measurementsCan now be used to constrain BSM physics (several examples shown, more available)June 2019JMB, DESY
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Slide34Summary…
Complementary approachesEFT fits when new states are out of reach
Truly “exotic” signatures (e.g. long lived/(dis)appearing particles etc) require dedicated searchesFutureKeep adding more data. Hopefully the priority of these kind of measurements at LHC will increase Treat correlations better, where availableUse precision SM theory where available: Could then also become a discovery toolJune 2019JMB, DESY
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Slide35Simplified DM model coupling to first generation quarks
June 2019
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Slide36Simplified DM model coupling to all quark
flavours
June 2019JMB, DESY36
Slide37Simplified DM model coupling to all flavours
June 2019
JMB, DESY37ATLAS, arXiv:1502.05923