@misc{10481/62035, year = {2019}, month = {7}, url = {http://hdl.handle.net/10481/62035}, abstract = {Vector boson scatterings are fundamental processes to shed light on the nature of the electroweak symmetry breaking mechanism. Deviations from the Standard Model predictions on the corresponding observables can be interpreted in terms of effective field theories, that however undergo consistency conditions. In this paper, the same-sign W W scattering is considered within the HEFT context and the correct usage of the effective field theory approach is discussed. Regions of the parameters space are identified where a signal of new physics could be measured at HL-LHC with a significance of more than 5σ and the effective field theory description is consistently adopted. These results are then translated into bounds on the ξ parameter in the composite Higgs scenario. The discussion on the agreement with previous literature and the comparison with the equivalent analysis in the SMEFT case are also included.}, organization = {The work of P.K. is supported by the Spanish MINECO project FPA2016-78220-C3-1-P (Fondos FEDER) and by National Science Centre, Poland, the PRELUDIUM project under contract 2018/29/N/ST2/01153. L.M. acknowledges partial nancial support by the Spanish MINECO through the \Ramón y Cajal" programme (RYC-2015-17173), by the Spanish \Agencia Estatal de Investigación" (AEI) and the EU \Fondo Europeo de Desarrollo Regional" (FEDER) through the project FPA2016-78645-P, and through the Centro de excelencia Severo Ochoa Program under grant SEV-2016-0597, and by the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreements No 690575 and No 674896. The work of S.P. is partially supported by the National Science Centre, Poland, under research grants DEC-2015/18/M/ST2/00054 and DEC-2016/23/G/ST2/04301. M.S. is partially supported by the generous COST grant, COST Action No. CA16108 (VBSCan). L.M. thanks the Institute of Theoretical Physics of the University of Warsaw for hospitality during the development of this project. S.P. thanks the Instituto de Física Teórica (IFT UAM-CSIC) in Madrid for its support via the Centro de Excelencia Severo Ochoa Program under Grant SEV-2016-0597.}, publisher = {Springer Nature}, keywords = {Beyond Standard Model}, keywords = {Effective Field Theories}, keywords = {Higgs Physics}, title = {Same-sign WW scattering in the HEFT: discoverability vs. EFT validity}, doi = {10.1007/JHEP07(2019)021}, author = {Kozów, P. and Merlo, L. and Pokorski, S. and Szleper, M.}, }