scholarly journals Model-independent global constraints on new physics

1994 ◽  
Vol 49 (11) ◽  
pp. 6115-6147 ◽  
Author(s):  
C. P. Burgess ◽  
Stephen Godfrey ◽  
Heinz König ◽  
David London ◽  
Ivan Maksymyk
2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Aoife Bharucha ◽  
Diogo Boito ◽  
Cédric Méaux

Abstract In this paper we consider the decay D+ → π+ℓ+ℓ−, addressing in particular the resonance contributions as well as the relatively large contributions from the weak annihilation diagrams. For the weak annihilation diagrams we include known results from QCD factorisation at low q2 and at high q2, adapting the existing calculation for B decays in the Operator Product Expansion. The hadronic resonance contributions are obtained through a dispersion relation, modelling the spectral functions as towers of Regge-like resonances in each channel, as suggested by Shifman, imposing the partonic behaviour in the deep Euclidean. The parameters of the model are extracted using e+e− → (hadrons) and τ → (hadrons) + ντ data as well as the branching ratios for the resonant decays D+ → π+R(R → ℓ+ℓ−), with R = ρ, ω, and ϕ. We perform a thorough error analysis, and present our results for the Standard Model differential branching ratio as a function of q2. Focusing then on the observables FH and AFB, we consider the sensitivity of this channel to effects of physics beyond the Standard Model, both in a model independent way and for the case of leptoquarks.


2001 ◽  
Vol 16 (supp01b) ◽  
pp. 888-890
Author(s):  
◽  
BRUCE KNUTESON

We present a quasi-model-independent search for physics beyond the standard model. We define final states to be studied, and construct a rule that identifies a set of variables appropriate for any particular final state. A new algorithm ("Sleuth") searches for regions of excess in the space of those variables and quantifies the significance of any detected excess. After demonstrating the sensititvity of the method, we apply it to the semi-inclusive channel eμX collected in ≈108 pb -1 of [Formula: see text] collisions at [Formula: see text] at the DØ experiment at the Fermilab Tevatron. We find no evidence of new high pT physics in this sample.


2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Yong Du ◽  
Hao-Lin Li ◽  
Jian Tang ◽  
Sampsa Vihonen ◽  
Jiang-Hao Yu

Abstract The Standard Model Effective Field Theory (SMEFT) provides a systematic and model-independent framework to study neutrino non-standard interactions (NSIs). We study the constraining power of the on-going neutrino oscillation experiments T2K, NOνA, Daya Bay, Double Chooz and RENO in the SMEFT framework. A full consideration of matching is provided between different effective field theories and the renormalization group running at different scales, filling the gap between the low-energy neutrino oscillation experiments and SMEFT at the UV scale. We first illustrate our method with a top- down approach in a simplified scalar leptoquark model, showing more stringent constraints from the neutrino oscillation experiments compared to collider studies. We then provide a bottom-up study on individual dimension-6 SMEFT operators and find NSIs in neutrino experiments already sensitive to new physics at ∼20 TeV when the Wilson coefficients are fixed at unity. We also investigate the correlation among multiple operators at the UV scale and find it could change the constraints on SMEFT operators by several orders of magnitude compared with when only one operator is considered. Furthermore, we find that accelerator and reactor neutrino experiments are sensitive to different SMEFT operators, which highlights the complementarity of the two experiment types.


2012 ◽  
Vol 2012 (4) ◽  
Author(s):  
Wolfgang Altmannshofer ◽  
Paride Paradisi ◽  
David M. Straub

2009 ◽  
Vol 808 (1-2) ◽  
pp. 326-346 ◽  
Author(s):  
Tobias Hurth ◽  
Gino Isidori ◽  
Jernej F. Kamenik ◽  
Federico Mescia

2008 ◽  
Vol 2008 (03) ◽  
pp. 049-049 ◽  
Author(s):  
M Bona ◽  
M Ciuchini ◽  
E Franco ◽  
V Lubicz ◽  
G Martinelli ◽  
...  

2010 ◽  
Vol 25 (17) ◽  
pp. 1383-1401 ◽  
Author(s):  
PIERRE-HUGUES BEAUCHEMIN ◽  
PIERRE SAVARD

Events featuring high energy jets and a large amount of missing transverse energy constitute a key signature for a wide spectrum of new physics models. In this review, the results of two searches with such signatures are presented. The benefits of performing these searches in a model-independent way are discussed and data-driven techniques used to estimate Standard Model backgrounds are described in detail. These data-driven techniques will be an important part of searches for new physics at the LHC, especially in the early data-taking period.


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