A light scalar in the Minimal Dilaton Model in light of the LHC constraints
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摘要
Whether an additional light scalar exists is an interesting topic in particle physics beyond the Standard Model(SM), as we do not know as yet the nature of physics beyond the SM in the low mass region in view of the inconsistent results of the ATLAS and CMS collaborations in their search for light resonances around 95 GeV in the diphoton channel. We study a light scalar in the Minimal Dilaton Model(MDM). Under the theoretical and the latest experimental constraints, we sort the selected data samples into two scenarios according to the diphoton rate of the light scalar: the large-diphoton scenario(with σ_(γγ)/SM■0.2) and the small-diphoton scenario(with σ_(γγ)/SM■0.2),which are favored by the CMS and ATLAS results, respectively. We compare the two scenarios, test the characteristics of the model parameters, the scalar couplings, production and decay, and consider how they could be further discerned at colliders. We draw the following conclusions for the two scenarios:(i) The large-diphoton scenario has in general a small Higgs-dilaton mixing angle(|sinθ_S|■0.2) and a small dilaton vacuum expectation value(VEV)f(0.5■η≡ v/f■1),and the small-diphoton scenario has large mixing(| sinθ_S|■0.4) or large VEV(η≡v/f ■0.3).(ii) The large-diphoton scenario in general predicts small syy coupling(|C_(sγγ)/SM|■ 0.3) and large sgg coupling(0.6■|C_(sgg)/SM|■1.2), while the small-diphoton scenario predicts small sgg coupling(|C_(sgg)/SM|■0.5).(iii) The large-diphoton scenario can interpret the small diphoton excess seen by CMS at its central value, when m_s■ 95 GeV,η■0.6 and | sinθ_S|■0.(iv) The large-diphoton scenario in general predicts a negative correlation between the Higgs couplings |C_(hγγ)/SMI and |C_(hgg)/SM|, while the small-diphoton scenario predicts that both couplings are smaller than 1,or |C_(hγγ)/SM|■0.9■|C_(hgg)/SM|.
Whether an additional light scalar exists is an interesting topic in particle physics beyond the Standard Model(SM), as we do not know as yet the nature of physics beyond the SM in the low mass region in view of the inconsistent results of the ATLAS and CMS collaborations in their search for light resonances around 95 GeV in the diphoton channel. We study a light scalar in the Minimal Dilaton Model(MDM). Under the theoretical and the latest experimental constraints, we sort the selected data samples into two scenarios according to the diphoton rate of the light scalar: the large-diphoton scenario(with σ_(γγ)/SM ■ 0.2) and the small-diphoton scenario(with σ_(γγ)/SM■0.2),which are favored by the CMS and ATLAS results, respectively. We compare the two scenarios, test the characteristics of the model parameters, the scalar couplings, production and decay, and consider how they could be further discerned at colliders. We draw the following conclusions for the two scenarios:(i) The large-diphoton scenario has in general a small Higgs-dilaton mixing angle(|sinθ_S|■0.2) and a small dilaton vacuum expectation value(VEV)f(0.5■η≡ v/f ■1),and the small-diphoton scenario has large mixing(| sinθ_S|■0.4) or large VEV(η≡v/f■ 0.3).(ii) The large-diphoton scenario in general predicts small syy coupling(|C_(sγγ)/SM|■ 0.3) and large sgg coupling(0.6■|C_(sgg)/SM|■1.2), while the small-diphoton scenario predicts small sgg coupling(|C_(sgg)/SM|■0.5).(iii) The large-diphoton scenario can interpret the small diphoton excess seen by CMS at its central value, when m_s(?) 95 GeV,η■0.6 and | sinθ_S|■0.(iv) The large-diphoton scenario in general predicts a negative correlation between the Higgs couplings |C_(hγγ)/SMI and |C_(hgg)/SM|, while the small-diphoton scenario predicts that both couplings are smaller than 1,or |C_(hγγ)/SM|■0.9■|C_(hgg)/SM|.
Whether an additional light scalar exists is an interesting topic in particle physics beyond the Standard Model(SM), as we do not know as yet the nature of physics beyond the SM in the low mass region in view of the inconsistent results of the ATLAS and CMS collaborations in their search for light resonances around 95 GeV in the diphoton channel. We study a light scalar in the Minimal Dilaton Model(MDM). Under the theoretical and the latest experimental constraints, we sort the selected data samples into two scenarios according to the diphoton rate of the light scalar: the large-diphoton scenario(with σ_(γγ)/SM ■ 0.2) and the small-diphoton scenario(with σ_(γγ)/SM■0.2),which are favored by the CMS and ATLAS results, respectively. We compare the two scenarios, test the characteristics of the model parameters, the scalar couplings, production and decay, and consider how they could be further discerned at colliders. We draw the following conclusions for the two scenarios:(i) The large-diphoton scenario has in general a small Higgs-dilaton mixing angle(|sinθ_S|■0.2) and a small dilaton vacuum expectation value(VEV)f(0.5■η≡ v/f ■1),and the small-diphoton scenario has large mixing(| sinθ_S|■0.4) or large VEV(η≡v/f■ 0.3).(ii) The large-diphoton scenario in general predicts small syy coupling(|C_(sγγ)/SM|■ 0.3) and large sgg coupling(0.6■|C_(sgg)/SM|■1.2), while the small-diphoton scenario predicts small sgg coupling(|C_(sgg)/SM|■0.5).(iii) The large-diphoton scenario can interpret the small diphoton excess seen by CMS at its central value, when m_s(?) 95 GeV,η■0.6 and | sinθ_S|■0.(iv) The large-diphoton scenario in general predicts a negative correlation between the Higgs couplings |C_(hγγ)/SMI and |C_(hgg)/SM|, while the small-diphoton scenario predicts that both couplings are smaller than 1,or |C_(hγγ)/SM|■0.9■|C_(hgg)/SM|.
引文
1(ATLAS Collaboration), Phys. Lett. B, 716:1(2012), arXiv:1207.7214[hep-ex]
2(CMS Collaboration), Phys. Lett. B, 716:30(2012), arXiv:1207.7235[hep-ex]
3 https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/CombinedSu mmaryPlots/HIGGS/
4 https://twiki.cern.ch/twiki/bin/view/CMSPublic/PhysicsResultsHI G
5(ATLAS Collaboration), ATLAS-CONF-2018-031
6(CMS Collaboration), arXiv:1809.10733[hep-ex]
7 K. Cheung, J. S. Lee, and P. Y. Tseng, arXiv:1810.02521[hepph]
8 R. Barate etal, Phys. Lett. B, 565:61(2003)[hep-ex/0306033]
9(CMS Collaboration), arXiv:1811.08459[hep-ex], CMS-PASHIG-17-013
10 R. Vega, R. Vega-Morales, and K. Xie, JHEP, 1806:137(2018),arXiv:1805.01970[hep-ph]
11 D. Liu, J. Liu, C. E. M. Wagner, and X. P. Wang, JHEP, 1806:150(2018)
12 J. H. Kim and I. M. Lewis, JHEP, 1805, 095(2018), arXiv:1803.06351[hep-ph]
13 N. Bizot, G. Cacciapaglia, and T. Flacke, JHEP, 1806:065(2018), arXiv:1803.00021[hep-ph]
14 U. Haisch, J. F. Kamenik, A. Malinauskas, and M. Spira, JHEP,1803:178(2018), arXiv:1802.02156[hep-ph]
15 L. Wang, X. F. Han, and B. Zhu, Phys. Rev. D, 98(3):035024(2018), arXiv:1801.08317[hep-ph]
16 T. Biekotter, S. Heinemeyer, and C. Munoz, Eur. Phys. J. C,78(6):504(2018), arXiv:1712.07475[hep-ph]
17 U. Haisch and A. Malinauskas, JHEP, 1803:135(2018), arXiv:1712.06599[hep-ph]
18 G. F. Giudice, Y. Kats, M. McCullough, R. Torre, and A.Urbano, JHEP. 1806:009(2018), arXiv:1711.08437[hep-ph]
19 R. Vega, R. Vega-Morales, and K. Xie, JHEP, 1803:168(2018),arXiv:1711.05329[hep-ph]
20 G. Cacciapaglia, G. Ferretti, T. Flacke, and H. Serodio, Eur.Phys. J. C, 78(9):724(2018), arXiv:1710.11142[hep-ph]
21 P. J. Fox and N. Weiner, JHEP, 1808:025(2018), arXiv:1710.07649[hep-ph]
22 A. Crivellin, J. Heeck, and D. Muller, Phys. Rev. D, 97(3):035008(2018), arXiv:1710.04663[hep-ph]
23 A. Mariotti, D. Redigolo, F. Sala, and K. Tobioka, Phys. Lett. B,783:13(2018), arXiv:1710.01743[hep-ph]
24 K. Wang, F. Wang, J. Zhu, and Q. Jie, Chinese Physics C, 42(10):103109(2018)
25 J. Liu, C. E. M. Wagner, and X. P. Wang, arXiv:1810.11028[hep-ph]
26 W. G. Hollik, S. Liebler, G. Moortgat-Pick, S. Pabehr, and G.Weiglein, arXiv:1809.07371[hep-ph]
27 Y. G. Kim, C. B. Park, and S. Shin, arXiv:1809.01143[hep-ph]
28 F. Domingo, S. Heinemeyer, S. Pabehr, and G. Weiglein, arXiv:1807.06322[hep-ph]
29 R. Torre, arXiv:1806.04483[hep-ph]
30 J. Tao et al, arXiv:1805.11438[hep-ph]
31 G. Brooijmans et al, arXiv:1803.10379[hep-ph]
32 F. Richard, arXiv:1712.06410[hep-ex]
33 The ATLAS Collaboration(ATLAS Collaboration), ATLASCONF-2018-025
34 A. M. Sirunyan et al(CMS Collaboration), arXiv:1808.01890[hep-ex]
35 A. M. Sirunyan et al(CMS Collaboration), JHEP, 1801:097(2018), arXiv:1710.00159[hep-ex]
36 T. Abe et al, Phys. Rev. D, 86:115016(2012)
37 T. Abe et al, EPJ Web Conf., 49:15018(2013)
38 J. Cao, Y. He, P. Wu, M. Zhang, and J. Zhu, JHEP, 1401:150(2014), arXiv:1311.6661[hep-ph]
39 J. Cao, Z. Heng, D. Li, L. Shang, and P. Wu, JHEP, 1408:138(2014), arXiv:1405.4489[hep-ph]
40 J. Cao, L. Shang, W. Su, Y. Zhang, and J. Zhu, Eur. Phys. J. C,76(5):239(2016), arXiv:1601.02570[hep-ph]
41 B. Agarwal, J. Isaacson, and K. A. Mohan, Phys. Rev. D, 94(3):035027(2016), arXiv:1604.05328[hep-ph]
42 R. Foot, A. Kobakhidze, and R. R. Volkas, Phys. Lett. B, 655:156(2007)
43 W. D. Goldberger, B. Grinstein, and W. Skiba, Phys. Rev. Lett.,100:111802(2008)
44 J. Fan, W. D. Goldberger, A. Ross, and W. Skiba, Phys. Rev. D,79:035017(2009)
45 R. Foot, A. Kobakhidze, and K. L. McDonald, Eur. Phys. J. C,68:421(2010)
46 V. Barger, M. Ishida, and W.-Y. Keung, Phys. Rev. Lett., 108:101802(2012)
47 B. Coleppa, T. Gregoire, and H. E. Logan, Phys. Rev. D, 85:055001(2012)
48 V. Barger, M. Ishida, and W.-Y. Keung, Phys. Rev. D, 85:015024(2012)
49(ATLAS and CMS Collaborations), Phys. Rev. Lett., 114:191803(2015), arXiv:1503.07589[hep-ex]
50 A. Djouadi, Phys. Rept., 457:1(2008)[hep-ph/0503172]; Phys.Rept., 459:1(2008)[hep-ph/0503173]
51 https://twiki.cern.ch/twiki/bin/view/LHCPhysics/LHCHXSWG
52 S. Kanemura, Y. Okada, E. Senaha, and C.-P. Yuan, Phys. Rev.D, 70:115002(2004)[hep-ph/0408364]
53 S. Kanemura, M. Kikuchi, K. Sakurai, and K. Yagyu, Phys. Rev.D, 96(3):035014(2017), arXiv:1705.05399[hep-ph]
54 S. Kanemura, M. Kikuchi, and K. Yagyu, Nucl. Phys. B, 907:286(2016), arXiv:1511.06211[hep-ph]
55 B. A. Kniehl, Nucl. Phys. B, 352:1(1991)
56 S. Kanemura, M. Kikuchi, K. Sakurai, and K. Yagyu, arXiv:1710.04603[hep-ph]
57(ATLAS Collaboration), Phys. Rev. Lett., 113(17):171801(2014), arXiv:1407.6583[hep-ex]
58(CMS Collaboration), CMS-PAS-HIG-14-037
59(ATLAS Collaboration), arXiv:1808.02343[hep-ex]
60(ATLAS Collaboration), arXiv:1808.01771[hep-ex]
61(ATLAS Collaboration), ATLAS-CONF-2018-032
62(CMS Collaboration), CMS-PAS-B2G-17-018
63(CMS Collaboration), arXiv:1805.04758[hep-ex]
64(CMS Collaboration), CMS-PAS-B2G-17-011
65 F. Staub, Comput. Phys. Commun., 185:1773(2014), arXiv:1309.7223[hep-ph]
66 F. Staub, Adv. High Energy Phys., 2015:840780(2015), arXiv:1503.04200[hep-ph]
67 F. Staub et al, arXiv:1602.05581[hep-ph]
68 M. E. Peskin and T. Takeuchi, Phys. Rev. D, 46:381(1992)
69 M. Tanabashi et al, Phys. Rev. D, 98:030001(2018)
70 P. Bechtle, O. Brein, S. Heinemeyer, O. Stal, T. Stefaniak, G.Weiglein, and K. E. Williams, Eur. Phys. J. C, 74(3):2693(2014), arXiv:1311.0055[hep-ph]
71(OPAL Collaboration), Phys. Lett. B, 597:11(2004)[hepex/0312042]
72(OPAL Collaboration), Phys. Lett. B, 544:44(2002)[hepex/0207027]
73(DELPHI Collaboration), Phys. Lett. B, 458:431(1999)
74 J. Cao, F. Ding, C. Han, J. M. Yang, and J. Zhu, JHEP, 1311:018(2013), arXiv:1309.4939[hep-ph]
75(ATLAS Collaboration), ATLAS-CONF-2015-007
76(CMS Collaboration), Eur. Phys. J. C, 75(5):212(2015), arXiv:1412.8662[hep-ex]
77 P. Bechtle, S. Heinemeyer, O. Stal, T. Stefaniak, and G.Weiglein, Eur. Phys. J. C, 74(2):2711(2014), arXiv:1305.1933[hep-ph]
1)For scalar lighter than 65 GeV, we checked that|sinθ_S|are constrained to be very small by the inclusive Higgs search results at the LEP, andηcan be very large because there are no diphoton data at the LHC to constrain it.
1)The data of S and T are from the global fit result to electroweak precision observables(EWPOs), mainly determinated by the EWPOs Z boson mass mZ and widthΓ_Z(correlated with each other experimentally)respectively, so there is a strong correlation(ρ_(ST)=0.92)between the two parameters S and T[69].
2)For the Zjj channel at the LHC[35], background is so large that the excluded limit is hundreds of times larger than the ZH cross section; for the Zjj and Zγγchannels at the LEP[71, 72], Zs production rate at tree level is anti-correlated with the s→gg,γγbranching ratios; for theγS channels at the LEP[73], the loop-induced syy and sZy couplings are both very small. Thus all the existing results in these channels cannot give stronger constraints than the Zbb channel at the LEP[8].
3)By this approach we only consider degrees of freedom in the experimental data, and we judge a model only by how well it can fit to the experimental data, without caring how many parameters in theoretical models. We think it is more objective by this approach since we do not know behind the data what the real theory is.
2(CMS Collaboration), Phys. Lett. B, 716:30(2012), arXiv:1207.7235[hep-ex]
3 https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/CombinedSu mmaryPlots/HIGGS/
4 https://twiki.cern.ch/twiki/bin/view/CMSPublic/PhysicsResultsHI G
5(ATLAS Collaboration), ATLAS-CONF-2018-031
6(CMS Collaboration), arXiv:1809.10733[hep-ex]
7 K. Cheung, J. S. Lee, and P. Y. Tseng, arXiv:1810.02521[hepph]
8 R. Barate etal, Phys. Lett. B, 565:61(2003)[hep-ex/0306033]
9(CMS Collaboration), arXiv:1811.08459[hep-ex], CMS-PASHIG-17-013
10 R. Vega, R. Vega-Morales, and K. Xie, JHEP, 1806:137(2018),arXiv:1805.01970[hep-ph]
11 D. Liu, J. Liu, C. E. M. Wagner, and X. P. Wang, JHEP, 1806:150(2018)
12 J. H. Kim and I. M. Lewis, JHEP, 1805, 095(2018), arXiv:1803.06351[hep-ph]
13 N. Bizot, G. Cacciapaglia, and T. Flacke, JHEP, 1806:065(2018), arXiv:1803.00021[hep-ph]
14 U. Haisch, J. F. Kamenik, A. Malinauskas, and M. Spira, JHEP,1803:178(2018), arXiv:1802.02156[hep-ph]
15 L. Wang, X. F. Han, and B. Zhu, Phys. Rev. D, 98(3):035024(2018), arXiv:1801.08317[hep-ph]
16 T. Biekotter, S. Heinemeyer, and C. Munoz, Eur. Phys. J. C,78(6):504(2018), arXiv:1712.07475[hep-ph]
17 U. Haisch and A. Malinauskas, JHEP, 1803:135(2018), arXiv:1712.06599[hep-ph]
18 G. F. Giudice, Y. Kats, M. McCullough, R. Torre, and A.Urbano, JHEP. 1806:009(2018), arXiv:1711.08437[hep-ph]
19 R. Vega, R. Vega-Morales, and K. Xie, JHEP, 1803:168(2018),arXiv:1711.05329[hep-ph]
20 G. Cacciapaglia, G. Ferretti, T. Flacke, and H. Serodio, Eur.Phys. J. C, 78(9):724(2018), arXiv:1710.11142[hep-ph]
21 P. J. Fox and N. Weiner, JHEP, 1808:025(2018), arXiv:1710.07649[hep-ph]
22 A. Crivellin, J. Heeck, and D. Muller, Phys. Rev. D, 97(3):035008(2018), arXiv:1710.04663[hep-ph]
23 A. Mariotti, D. Redigolo, F. Sala, and K. Tobioka, Phys. Lett. B,783:13(2018), arXiv:1710.01743[hep-ph]
24 K. Wang, F. Wang, J. Zhu, and Q. Jie, Chinese Physics C, 42(10):103109(2018)
25 J. Liu, C. E. M. Wagner, and X. P. Wang, arXiv:1810.11028[hep-ph]
26 W. G. Hollik, S. Liebler, G. Moortgat-Pick, S. Pabehr, and G.Weiglein, arXiv:1809.07371[hep-ph]
27 Y. G. Kim, C. B. Park, and S. Shin, arXiv:1809.01143[hep-ph]
28 F. Domingo, S. Heinemeyer, S. Pabehr, and G. Weiglein, arXiv:1807.06322[hep-ph]
29 R. Torre, arXiv:1806.04483[hep-ph]
30 J. Tao et al, arXiv:1805.11438[hep-ph]
31 G. Brooijmans et al, arXiv:1803.10379[hep-ph]
32 F. Richard, arXiv:1712.06410[hep-ex]
33 The ATLAS Collaboration(ATLAS Collaboration), ATLASCONF-2018-025
34 A. M. Sirunyan et al(CMS Collaboration), arXiv:1808.01890[hep-ex]
35 A. M. Sirunyan et al(CMS Collaboration), JHEP, 1801:097(2018), arXiv:1710.00159[hep-ex]
36 T. Abe et al, Phys. Rev. D, 86:115016(2012)
37 T. Abe et al, EPJ Web Conf., 49:15018(2013)
38 J. Cao, Y. He, P. Wu, M. Zhang, and J. Zhu, JHEP, 1401:150(2014), arXiv:1311.6661[hep-ph]
39 J. Cao, Z. Heng, D. Li, L. Shang, and P. Wu, JHEP, 1408:138(2014), arXiv:1405.4489[hep-ph]
40 J. Cao, L. Shang, W. Su, Y. Zhang, and J. Zhu, Eur. Phys. J. C,76(5):239(2016), arXiv:1601.02570[hep-ph]
41 B. Agarwal, J. Isaacson, and K. A. Mohan, Phys. Rev. D, 94(3):035027(2016), arXiv:1604.05328[hep-ph]
42 R. Foot, A. Kobakhidze, and R. R. Volkas, Phys. Lett. B, 655:156(2007)
43 W. D. Goldberger, B. Grinstein, and W. Skiba, Phys. Rev. Lett.,100:111802(2008)
44 J. Fan, W. D. Goldberger, A. Ross, and W. Skiba, Phys. Rev. D,79:035017(2009)
45 R. Foot, A. Kobakhidze, and K. L. McDonald, Eur. Phys. J. C,68:421(2010)
46 V. Barger, M. Ishida, and W.-Y. Keung, Phys. Rev. Lett., 108:101802(2012)
47 B. Coleppa, T. Gregoire, and H. E. Logan, Phys. Rev. D, 85:055001(2012)
48 V. Barger, M. Ishida, and W.-Y. Keung, Phys. Rev. D, 85:015024(2012)
49(ATLAS and CMS Collaborations), Phys. Rev. Lett., 114:191803(2015), arXiv:1503.07589[hep-ex]
50 A. Djouadi, Phys. Rept., 457:1(2008)[hep-ph/0503172]; Phys.Rept., 459:1(2008)[hep-ph/0503173]
51 https://twiki.cern.ch/twiki/bin/view/LHCPhysics/LHCHXSWG
52 S. Kanemura, Y. Okada, E. Senaha, and C.-P. Yuan, Phys. Rev.D, 70:115002(2004)[hep-ph/0408364]
53 S. Kanemura, M. Kikuchi, K. Sakurai, and K. Yagyu, Phys. Rev.D, 96(3):035014(2017), arXiv:1705.05399[hep-ph]
54 S. Kanemura, M. Kikuchi, and K. Yagyu, Nucl. Phys. B, 907:286(2016), arXiv:1511.06211[hep-ph]
55 B. A. Kniehl, Nucl. Phys. B, 352:1(1991)
56 S. Kanemura, M. Kikuchi, K. Sakurai, and K. Yagyu, arXiv:1710.04603[hep-ph]
57(ATLAS Collaboration), Phys. Rev. Lett., 113(17):171801(2014), arXiv:1407.6583[hep-ex]
58(CMS Collaboration), CMS-PAS-HIG-14-037
59(ATLAS Collaboration), arXiv:1808.02343[hep-ex]
60(ATLAS Collaboration), arXiv:1808.01771[hep-ex]
61(ATLAS Collaboration), ATLAS-CONF-2018-032
62(CMS Collaboration), CMS-PAS-B2G-17-018
63(CMS Collaboration), arXiv:1805.04758[hep-ex]
64(CMS Collaboration), CMS-PAS-B2G-17-011
65 F. Staub, Comput. Phys. Commun., 185:1773(2014), arXiv:1309.7223[hep-ph]
66 F. Staub, Adv. High Energy Phys., 2015:840780(2015), arXiv:1503.04200[hep-ph]
67 F. Staub et al, arXiv:1602.05581[hep-ph]
68 M. E. Peskin and T. Takeuchi, Phys. Rev. D, 46:381(1992)
69 M. Tanabashi et al, Phys. Rev. D, 98:030001(2018)
70 P. Bechtle, O. Brein, S. Heinemeyer, O. Stal, T. Stefaniak, G.Weiglein, and K. E. Williams, Eur. Phys. J. C, 74(3):2693(2014), arXiv:1311.0055[hep-ph]
71(OPAL Collaboration), Phys. Lett. B, 597:11(2004)[hepex/0312042]
72(OPAL Collaboration), Phys. Lett. B, 544:44(2002)[hepex/0207027]
73(DELPHI Collaboration), Phys. Lett. B, 458:431(1999)
74 J. Cao, F. Ding, C. Han, J. M. Yang, and J. Zhu, JHEP, 1311:018(2013), arXiv:1309.4939[hep-ph]
75(ATLAS Collaboration), ATLAS-CONF-2015-007
76(CMS Collaboration), Eur. Phys. J. C, 75(5):212(2015), arXiv:1412.8662[hep-ex]
77 P. Bechtle, S. Heinemeyer, O. Stal, T. Stefaniak, and G.Weiglein, Eur. Phys. J. C, 74(2):2711(2014), arXiv:1305.1933[hep-ph]
1)For scalar lighter than 65 GeV, we checked that|sinθ_S|are constrained to be very small by the inclusive Higgs search results at the LEP, andηcan be very large because there are no diphoton data at the LHC to constrain it.
1)The data of S and T are from the global fit result to electroweak precision observables(EWPOs), mainly determinated by the EWPOs Z boson mass mZ and widthΓ_Z(correlated with each other experimentally)respectively, so there is a strong correlation(ρ_(ST)=0.92)between the two parameters S and T[69].
2)For the Zjj channel at the LHC[35], background is so large that the excluded limit is hundreds of times larger than the ZH cross section; for the Zjj and Zγγchannels at the LEP[71, 72], Zs production rate at tree level is anti-correlated with the s→gg,γγbranching ratios; for theγS channels at the LEP[73], the loop-induced syy and sZy couplings are both very small. Thus all the existing results in these channels cannot give stronger constraints than the Zbb channel at the LEP[8].
3)By this approach we only consider degrees of freedom in the experimental data, and we judge a model only by how well it can fit to the experimental data, without caring how many parameters in theoretical models. We think it is more objective by this approach since we do not know behind the data what the real theory is.