1 00:00:01,949 --> 00:00:08,609 okay, so I will start now. so I'm going to present today about what we have learned 2 00:00:09,029 --> 00:00:12,629 on the Higgs sector in terms of production, decay properties and differential 3 00:00:12,629 --> 00:00:17,879 distribution at LHC. so first of all a small reminder that the Higgs sector 4 00:00:17,879 --> 00:00:21,719 was introduced in the Standard Model, thanks to several seminal papers, which 5 00:00:21,719 --> 00:00:25,799 here you have a small selections, and that the Higgs boson was discovered 6 00:00:25,799 --> 00:00:31,529 in 2012 by the ATLAS and CMS collaborations at LHC. so if now we 7 00:00:31,529 --> 00:00:36,209 look into the Standard Model Lagrangian, the first thing that strikes out is that 8 00:00:36,209 --> 00:00:39,299 the Higgs boson is the only fundamental particle of spin zero the standard model 9 00:00:39,539 --> 00:00:43,949 that it appears in several of its terms. so for example, we have here the terms 10 00:00:43,949 --> 00:00:48,809 that describe the interaction of the Higgs boson to the fermions, which in 11 00:00:48,809 --> 00:00:52,889 particular, the term which is proportional to the fermion mass, and also we have the 12 00:00:52,889 --> 00:00:57,539 kinematic term that also include the so called, let's say, standard interaction 13 00:00:57,539 --> 00:01:04,559 with the gauge bosons of the Higgs, and as well as the finally the Higgs potential, which is 14 00:01:04,559 --> 00:01:09,539 responsible for the electroweak symmetry breaking, and makes the Higgs field 15 00:01:09,809 --> 00:01:16,169 special. so then, what I'm going to talk today about is mainly about the 16 00:01:16,169 --> 00:01:19,979 precision measurements that you see here, the couplings, differential cross section, 17 00:01:19,979 --> 00:01:24,659 the interpretation, the mass, and the spin CP, as well as the Yukawa interaction with the 18 00:01:24,659 --> 00:01:30,749 third generation fermions. and the other topics in orange will be covered by 19 00:01:30,749 --> 00:01:36,929 Giovanni talk later in the session. I also like to point out the specific talks are 20 00:01:36,929 --> 00:01:42,809 in the parallel session that where you can see these topics expanded in more details 21 00:01:42,839 --> 00:01:49,859 if you're interested. so let's start now with the what are the predictions in 22 00:01:49,859 --> 00:01:54,479 terms of production and decay for the Higgs bosons so when we look at 13 TeV, 23 00:01:54,479 --> 00:01:59,549 which is the energy in the center of mass of the LHC during Run two. we see that 24 00:01:59,579 --> 00:02:03,659 the gluon-gluon fusion production is by far the dominant production mode of the 25 00:02:03,659 --> 00:02:08,429 Higgs boson followed by the vector fusions and the associated production with 26 00:02:08,429 --> 00:02:16,319 the vector bosons. and finally, the ttH associated production. we also 27 00:02:16,319 --> 00:02:21,119 have other production modes not least here like bbH and single-top Higgs productions 28 00:02:21,479 --> 00:02:26,729 that are also in in this plot. also I would like to point out that the first two 29 00:02:26,729 --> 00:02:31,439 that gluon-gluon fusion and the VBF production were observed already during Run one of the LHC 30 00:02:31,829 --> 00:02:36,299 while the the associated production with vector boson and ttH were observed 31 00:02:36,629 --> 00:02:44,549 on the during Run 2. so, the in terms of the decay modes, the b b-bar is the 32 00:02:44,579 --> 00:02:50,819 dominant decay of the Higgs bosons but not the easiest one at the LHC. and, in 33 00:02:50,819 --> 00:02:58,019 fact of the case of in two photons and two Z and even in particular the case 34 00:02:58,019 --> 00:03:02,189 where the Z the decays to four leptons were in fact among the first to be discovered, 35 00:03:02,189 --> 00:03:07,229 despite their low branching ratio, thanks to the good signal to background ratio 36 00:03:07,229 --> 00:03:11,609 together with the WW, which is also the other bosonic channels that contributed to 37 00:03:11,609 --> 00:03:17,519 the first observation of the Higgs boson. at the end of Run two, Run one, the Higgs to tau tau was 38 00:03:17,519 --> 00:03:23,999 also observed, and Higgs to b b-bar was later observed during the Run two of the LHC. 39 00:03:24,899 --> 00:03:32,849 now the the just a small slide on the ATLAS and CMS detector that in particular 40 00:03:32,849 --> 00:03:38,759 during the run one and run two had very good performance and the LHC as well in 41 00:03:38,759 --> 00:03:44,879 fact, already past their design performance in terms of peak luminosity, 42 00:03:44,879 --> 00:03:51,989 as you can see, that LHC already doubled the nominal peak luminosity of 10 to 43 00:03:51,989 --> 00:03:55,919 the 34. and also in terms of number of interaction per bunch crossing. the average 44 00:03:55,919 --> 00:04:01,079 in Run two was 34 compared to the design value of about 23. and that they 45 00:04:01,079 --> 00:04:08,189 delivered luminosity by the accelerator was around 30 inverse femtobarns during Run one 46 00:04:08,339 --> 00:04:13,469 then 160 during Run two. so, quite good performance, I would say. 47 00:04:14,790 --> 00:04:20,070 now discussing the the measurement of the Higgs bosons, I would like to start with 48 00:04:20,070 --> 00:04:25,770 the cross sections one if we believe the Standard Model, there should be about 49 00:04:26,160 --> 00:04:30,270 56,000 Higgs bosons produced per inverse femptobarn for each of the 50 00:04:30,270 --> 00:04:34,770 experiments in each of the interaction point of the LHC and the ATLAS and CMS 51 00:04:34,770 --> 00:04:40,320 experiments can reconstruct about 200 per inverse femtobarn. so the this 52 00:04:40,320 --> 00:04:44,640 allows to make, especially during Run two, precise measurement of the Higgs boson's cross 53 00:04:44,640 --> 00:04:49,860 section. and you have here an example of this measurement by ATLAS, where this is 54 00:04:50,040 --> 00:04:56,280 done by production mode and by in decay channel and you see that several of 55 00:04:56,310 --> 00:05:00,990 these measurements are still limited by statistic which is highlighted by this yellow 56 00:05:00,990 --> 00:05:09,060 band and the table is a is also quote complete. and a way also to make the cross 57 00:05:09,060 --> 00:05:13,590 section to to present the cross sectional measurement was already established 58 00:05:13,890 --> 00:05:19,260 by the during Run one by the first measurements. these are the so called 59 00:05:19,260 --> 00:05:22,380 signal strength which is basically the cross section divide the Standard Model 60 00:05:22,380 --> 00:05:29,640 prediction and you have in this CMS summary a good example of how the 61 00:05:29,670 --> 00:05:37,050 experiment is able to cover very well the the all the production modes and the decay 62 00:05:37,050 --> 00:05:41,850 modes also here the mu mu is a for which we only have upper limits is also 63 00:05:41,850 --> 00:05:47,940 included here. and finally, you have here in in this part, the common signal 64 00:05:47,940 --> 00:05:53,520 strength measurement by the two experiments, the most recent ones. okay, 65 00:05:53,520 --> 00:06:01,140 so, then new somehow measurements are not in any way satisfactory from 66 00:06:01,140 --> 00:06:05,820 several point of view. so, already doing Run one, a new framework was developed 67 00:06:05,820 --> 00:06:10,680 especially for the combination of the measurements by the two experiments and 68 00:06:10,680 --> 00:06:16,170 from different channels. so, this first attempt was the so called Kappa framework, 69 00:06:16,380 --> 00:06:20,400 which is basically modification of the Higgs coupling's vertex at the leading 70 00:06:20,400 --> 00:06:25,020 order, where one can express the production and the decay of the Higgs bosons 71 00:06:25,200 --> 00:06:31,770 in terms of Kappa modificators and then feed these parameters. so, you have here 72 00:06:32,340 --> 00:06:40,290 one of these results by CMS for run two data which were in fact, no undetectable 73 00:06:40,290 --> 00:06:46,020 invisible decays of the Higgs bosons are allowed. so, basically only standard 74 00:06:46,020 --> 00:06:50,520 model, decays to standard model particle, coupling to standard model particles are allowed 75 00:06:50,520 --> 00:06:55,420 here. and you see that the agreement with the Standard Model expressed by the p value 76 00:06:55,680 --> 00:07:01,530 is very high. and also you have in a similar example, by ATLAS of the 77 00:07:01,740 --> 00:07:06,360 measurement of the couplings where here you have three different interpretation in 78 00:07:06,360 --> 00:07:12,060 case of only a coupling to Standard Model and also when you allow Higgs decays 79 00:07:12,060 --> 00:07:17,190 to invisible final states, from Higgs to invisible searches, and also when you allow 80 00:07:17,190 --> 00:07:26,340 modification of the total width of the Higgs, of the Higgs width from off-shell width 81 00:07:26,340 --> 00:07:32,700 measurement searches, and you see, in particular that the Kappa modifiers have a 82 00:07:32,700 --> 00:07:39,030 typical accuracy which is of the order of 10 to 20% for most of these parameters. 83 00:07:40,710 --> 00:07:49,020 now, more recently, a way also to measure the Higgs cross sections and make possible 84 00:07:49,410 --> 00:07:54,870 investigations on the B, beyond Standard Model contributions has been to measure 85 00:07:54,870 --> 00:08:00,210 the Higgs cross section in exclusive fiducial regions of phase space so called bins. so, 86 00:08:00,510 --> 00:08:04,980 under the simplify template cross section. later STXS. so, in these 87 00:08:04,980 --> 00:08:09,240 cases, what happens is that the measurements are done in reconstruction 88 00:08:09,240 --> 00:08:13,980 event categories as you can see on this part of the slide, and then these are 89 00:08:13,980 --> 00:08:20,730 unfolded at particle level in order to couple to the phase space bins that we 90 00:08:20,730 --> 00:08:26,580 want to measure. so, why this is important is because, these definitions are common 91 00:08:26,880 --> 00:08:30,570 between the experiments and the theory. so, this helps, especially in the 92 00:08:30,570 --> 00:08:36,660 combinations and minimize the theoretical uncertainties and improve the experimental 93 00:08:36,660 --> 00:08:41,940 sensitivity to this final state. now, I'd like to present you an example of these 94 00:08:41,940 --> 00:08:47,640 kinds of STXS measurements by ATLAS of a from a measurement that was being released 95 00:08:48,540 --> 00:08:55,800 in April. and you can see for example, in in this plot here, as a function of the 96 00:08:55,830 --> 00:09:00,270 reconstructed event categories here, the purity of the different production mode 97 00:09:00,270 --> 00:09:06,210 bins that we have seen in the previous slides. and in this in this analysis 98 00:09:06,240 --> 00:09:07,380 actually the number of 99 00:09:08,730 --> 00:09:13,920 categories is not particularly high because a neural network is used to to 100 00:09:13,920 --> 00:09:18,300 discriminate the different production modes. and in this particular search as 101 00:09:18,300 --> 00:09:23,430 you can see from the bottom summary, the uncertainties are still dominated by 102 00:09:23,430 --> 00:09:28,140 statistical uncertainties. the the STXS measurements can be done on different 103 00:09:28,140 --> 00:09:33,240 stages from stage 0 to up to stage two. and this particular depending on the number of 104 00:09:33,240 --> 00:09:38,430 bins and the granularity used for the fiducial bins, and you can see that this 105 00:09:38,430 --> 00:09:43,890 result is done in terms of the so called reduced stage one point one. in general, the 106 00:09:43,890 --> 00:09:47,940 agreement with the standard model is good as again shown by the p value of a 107 00:09:47,940 --> 00:09:56,340 standard model agreement. so, finally, a way also to extract information about new 108 00:09:56,340 --> 00:10:02,970 physics, from the Higgs measurements is the possibility to, to use effective field 109 00:10:02,970 --> 00:10:07,440 theories EFT and these allows to interpret the measurements extending the 110 00:10:07,440 --> 00:10:12,960 Standard Model Lagrangian with higher order operators of order six or above. and 111 00:10:13,170 --> 00:10:18,570 this is done for example in the in with the Higgs effective Lagrangian that uses 112 00:10:18,570 --> 00:10:24,840 the strong interaction light Higgs basis. and you have here an example of how the 113 00:10:24,870 --> 00:10:29,520 Wilson's coefficient related to these operators, higher order operators, can modify 114 00:10:29,580 --> 00:10:34,500 simplify template cross sections quite significantly, and that there is also an 115 00:10:34,500 --> 00:10:42,660 alternative let's say EFT model that can be used which is a standard model EFT 116 00:10:43,050 --> 00:10:50,760 based on the Warsaw basis. and this, for example, is in yeah in a show this plot 117 00:10:50,760 --> 00:10:57,600 show an example of how the electroweak Higgs production with two quarks can be 118 00:10:57,600 --> 00:11:06,510 modified in terms of PT of the leading jet by this by the by these higher order operators 119 00:11:06,570 --> 00:11:13,740 action. so, these in fact the STSX and the differential measurements are particularly 120 00:11:13,740 --> 00:11:18,090 interesting for these kind of operations and we are going to see now, some example 121 00:11:18,090 --> 00:11:25,950 of these. the first example is about the measurements coming from the in terms of 122 00:11:26,160 --> 00:11:31,830 Standard Model EFT coming from the Higgs to four leptons measurement that we have 123 00:11:31,830 --> 00:11:39,600 seen before and these he is in these cases the the measurement is not necessarily 124 00:11:39,600 --> 00:11:45,690 sensitive to all the possible operators. therefore, only the Wilson's coefficient 125 00:11:45,690 --> 00:11:51,120 to which the analysis more sensitive are fitted and the others are just set to 126 00:11:51,150 --> 00:11:56,130 nominal zero value. therefore, here you have a an example of the fit where only 127 00:11:56,130 --> 00:12:01,110 the relevant relevant Wilson coefficients are fitted. and then you can see in the 128 00:12:01,110 --> 00:12:06,600 bottom plot the what will be the effect of these operators if they're different from 129 00:12:06,600 --> 00:12:10,920 zero by these quantities. and this depends of course, depending on the category you 130 00:12:10,920 --> 00:12:15,360 can have one operator which is more important than others, and in particular, 131 00:12:15,360 --> 00:12:21,240 the ones that are related to the gluon-gluon fusion are more sensitive to hg coefficient and and 132 00:12:21,270 --> 00:12:27,120 then the ones that for example are in the ttH bin are of course a you are more 133 00:12:27,120 --> 00:12:32,310 sensitive to the couplings to the up type quark. a similar measurement can also be 134 00:12:32,310 --> 00:12:37,380 done from the combination of different from all he combination of the measurement This is 135 00:12:37,380 --> 00:12:42,870 done by this ATLAS result. in this case in terms of the Higgs effective Lagrangian 136 00:12:43,200 --> 00:12:48,450 and therefore a different basis but equivalent and here you can see the 137 00:12:48,450 --> 00:12:53,700 results that are obtained for for these operators again, only the important 138 00:12:53,700 --> 00:13:01,590 the operator which to which analyses are sensitive is are shown. okay, so Now, I 139 00:13:01,590 --> 00:13:07,170 also would like to show you a result from a differential cross sections. and again 140 00:13:07,200 --> 00:13:14,190 we have a new results, which was released in in April by ATLAS. and both 141 00:13:14,190 --> 00:13:18,870 experiment have done measurement in fiducial cross sections defined in terms 142 00:13:18,870 --> 00:13:25,500 of Higgs boson kinematics, jet, multiplicity etc. and the here from from 143 00:13:25,500 --> 00:13:29,070 this ATLAS measurement, you have an example of differential cross sections, 144 00:13:29,100 --> 00:13:34,410 double differential cross section, in terms of the PT Higgs candidate and the number of 145 00:13:34,500 --> 00:13:39,810 jets. so you see here that it's possible not only to make a differential cross sections 146 00:13:39,930 --> 00:13:45,300 in terms of one viable but even more than one. and also in in this case also from an 147 00:13:45,300 --> 00:13:50,730 Higgs to four lepton analysis, you can see instead, the differential cross 148 00:13:50,730 --> 00:13:56,040 sections done in terms of the rapidity distribution of the of the Higgs, which as 149 00:13:56,040 --> 00:14:00,000 you've seen from Sally talk before, is sensitive to the perturbative QCD 150 00:14:00,000 --> 00:14:00,600 prediction. 151 00:14:01,979 --> 00:14:07,829 so, then, another way to exploit the differential measurement is also to try to 152 00:14:07,829 --> 00:14:12,989 set limits on some of the Kappa parameters which are not easy to access directly. one 153 00:14:12,989 --> 00:14:17,129 of these example is the Kappa C so the couplings to the C quark. so this for 154 00:14:17,129 --> 00:14:23,369 example, is an example of how to use the PT Higgs distribution differential 155 00:14:23,369 --> 00:14:30,149 distributions in order to set limits on Kappa C and Kappa B. because these 156 00:14:30,149 --> 00:14:35,489 are two Kappa parameters can modify quite strongly the PT Higgs distribution as 157 00:14:35,489 --> 00:14:42,929 shown in this in this block here. so, therefore, these measurements can can be 158 00:14:42,929 --> 00:14:47,189 constrain can be set under different number of assumptions. here you have one 159 00:14:47,219 --> 00:14:53,159 of these limits, which actually is the most restrictive one that use the largest 160 00:14:53,159 --> 00:14:57,119 number of assumptions, where the modification not only to the shape of the 161 00:14:57,119 --> 00:15:02,819 PT of the Higgs, but also to the branching ratios. coming from these two Kappa parameters 162 00:15:03,029 --> 00:15:07,739 are are exploited and therefore, you have a better limit, but even if we only assume 163 00:15:08,039 --> 00:15:15,119 the modification only to the shape of the PT of the Higgs, still, in this 164 00:15:15,119 --> 00:15:20,549 indirect way we can still put limits on kappa C which is comparable from what 165 00:15:20,549 --> 00:15:27,029 we get from direct searches. okay, so, then there is still one more differential 166 00:15:27,209 --> 00:15:33,179 measurement I would like to talk about which is t CMS measurements from Higgs to WW 167 00:15:33,179 --> 00:15:37,559 in the leptonic final statse where the categories are defined according to this 168 00:15:37,559 --> 00:15:43,019 sub-leading lepton flavor electron or muon and the PT. and in this case the 169 00:15:43,049 --> 00:15:45,899 measurements, the differential measurement, is done in terms of 170 00:15:45,899 --> 00:15:53,429 the PT of the Higgs up to last bin goes above 200 GeV and also number of jets above four 171 00:15:53,489 --> 00:15:59,039 four jets and then you see that the uncertainty on the fiducial cross section 172 00:15:59,039 --> 00:16:04,019 is of the order of 20 percent and on the last the bin the the limitation is still 173 00:16:04,139 --> 00:16:08,609 mostly statistics, but still we are getting we are getting there 174 00:16:10,169 --> 00:16:10,949 okay now, 175 00:16:12,029 --> 00:16:16,889 I will discuss a bit more the Yukawa couplings. that as I said before is a 176 00:16:16,889 --> 00:16:22,859 new kind of introduction that can can reveal a novel feature which are not seen 177 00:16:22,949 --> 00:16:28,349 in gauge boson interaction and therefore, is something that is been 178 00:16:28,979 --> 00:16:33,299 receiving a lot of attention in the Higgs measurements. the first one will be the 179 00:16:33,329 --> 00:16:39,659 discusses the Higgs tau tau where we have the latest Higgs ATLAS analysis in the Higgs tau tau 180 00:16:39,659 --> 00:16:46,049 final state where six channels are analyzed and the cross section is obtained 181 00:16:46,049 --> 00:16:51,719 from the fit of the di-tau invariant mass. and you see that this result has been 182 00:16:51,719 --> 00:16:57,149 interpreted also in terms of simplified template cross sections for gluon-gluon fusion and 183 00:16:57,149 --> 00:17:00,839 VBF. and in particular for the VBF production model. this channel is 184 00:17:00,839 --> 00:17:05,819 particularly important thanks to its sensitivity. CMS has also shown the 185 00:17:05,819 --> 00:17:11,249 results which also include more data than the ATLAS up to 2017. and in this 186 00:17:11,249 --> 00:17:16,619 case four channels has been analyzed and the Z tau tau is modeled in a data driven 187 00:17:16,619 --> 00:17:22,499 way. and instead of the m tau tau fit the the cross section is extracted from the neural 188 00:17:22,499 --> 00:17:27,329 network distribution from a neural network distributions. in this case CMS provided a 189 00:17:27,329 --> 00:17:30,959 stage one simplified template cross sections for these channels. and you can 190 00:17:30,959 --> 00:17:36,809 see here the bins in terms, for gluon-gluon fusion , in term of PT Higgs and for VBF 191 00:17:36,809 --> 00:17:47,189 terms of VBF topology and etc. alright, so, the other fermionic final state is the 192 00:17:47,609 --> 00:17:53,309 the Higgs decaying to b quarks and the here they in order to reduce the 193 00:17:53,309 --> 00:17:56,519 background, usually they associated production with a vector boson is 194 00:17:56,519 --> 00:18:03,449 exploited. and you see a recent results by ATLAS from this year where in fact the 195 00:18:03,779 --> 00:18:08,639 exploits a large number of signal regions and the control regions with a different 196 00:18:09,029 --> 00:18:14,069 charged leptons multiplicity in order to be sensitive to several final states and 197 00:18:14,069 --> 00:18:19,139 also a dedicated b-jet algorithm is used in order to improve the b b-bar mass 198 00:18:19,289 --> 00:18:24,839 resolutions. in particular the these dedicated energy recalibration 199 00:18:24,839 --> 00:18:29,939 algorithm improves by more than 40% the b b-bar mass resolution with respect to the 200 00:18:29,939 --> 00:18:36,509 standard jet calibration case. and the in this case of a simplified template cross 201 00:18:36,509 --> 00:18:41,609 section is provided in terms of the vector boson PT from in two bins from 202 00:18:41,639 --> 00:18:48,089 150 to 250 and above 250. and this analysis is also quite sensitive to 203 00:18:48,089 --> 00:18:52,199 the these two production modes as you can see that in fact can achieve the 204 00:18:52,199 --> 00:18:57,839 observation of the ZH production with more five sigma significance and also in the 205 00:18:57,839 --> 00:19:06,479 case of WH it gets it achieves a very strong evidence of a four sigma. so, now we'd 206 00:19:06,479 --> 00:19:11,699 like to discuss also a different way to also target the Higgs to b b-bar decay, 207 00:19:11,699 --> 00:19:17,369 which is to look for, instead of resolving the, the, the jet from the b quark 208 00:19:17,369 --> 00:19:22,859 from the Higgs decay, reconstructing a large R parameter Jets and 209 00:19:22,859 --> 00:19:27,899 then look inside of it for the signature of it two b jets. so this is done by ATLAS 210 00:19:27,899 --> 00:19:32,819 and CMS with a slightly different target in the case of ATLAS the target 211 00:19:32,819 --> 00:19:38,519 production mode is VH. like in the previous case, and the PT of the Jets has 212 00:19:38,519 --> 00:19:42,479 to be above 250 GeV. and you see [Chair: Luca 213 00:19:42,600 --> 00:19:44,430 you have just under five minutes.] 214 00:19:45,869 --> 00:19:52,559 Yes, thanks. and you can see here that allows to give to achieve to extend their 215 00:19:52,559 --> 00:19:59,249 sensitivity in PT up to 400 up to 400 GeV. in the case of CMS, this is an inclusive 216 00:19:59,249 --> 00:20:03,509 search so mainly for targeting gluon-gluon fusions, and here the PT 217 00:20:03,509 --> 00:20:10,289 requirement of the jet is 450 GeV . but in and in this case CMS also try 218 00:20:10,289 --> 00:20:14,249 first attempt of differential cross section for the PT Higgs in this in this final 219 00:20:14,249 --> 00:20:19,049 state. and as again as you have seen from Sally talk before, this can be quite 220 00:20:19,049 --> 00:20:23,729 interesting in the future because while at low PT we are sensitive to the gluon-gluon fusion 221 00:20:23,729 --> 00:20:29,369 when we go after these bin of large PT we start to be sensitive also not only to 222 00:20:29,369 --> 00:20:32,819 gluon-gluon fusion but also to other production modes and therefore is this 223 00:20:32,819 --> 00:20:33,959 become quite interesting. 224 00:20:35,460 --> 00:20:40,320 okay, I just have one slide here about ttH for completeness, but I'm going to discuss 225 00:20:40,320 --> 00:20:44,850 more about these production more later, I just want to say that for this for the for 226 00:20:44,850 --> 00:20:50,490 this production model, that is from which we can extract the Higgs to top 227 00:20:50,520 --> 00:20:54,780 couplings directly, we are exploiting several decay modes of the 228 00:20:54,810 --> 00:20:59,940 of the top anti top as well as Higgs decay modes. as you can see from this 229 00:21:00,480 --> 00:21:08,370 table from ATLAS and and CMS. so, now I will talk about the properties. so the 230 00:21:08,370 --> 00:21:13,770 first property I talk about is the Higgs mass measurements. and the Higgs mass is 231 00:21:13,770 --> 00:21:17,370 you know, is a question of the naturalness of the Standard Model, since these 232 00:21:17,370 --> 00:21:21,120 are the the basis of the so called hierarchy problem but it's also an important 233 00:21:21,120 --> 00:21:25,770 parameter for the what concern of the importing agreement for the electroweak 234 00:21:25,770 --> 00:21:30,210 fits. and also for the understanding of the stability of the vacuum as well as to 235 00:21:30,210 --> 00:21:34,200 understand if the Higgs has a role as inflaton candidates. at LHC the 236 00:21:34,200 --> 00:21:38,130 measurement is performed in the two photons and four leptons final states because they 237 00:21:38,130 --> 00:21:43,020 have by far the best resolution and remind you that at the end of Run one, the 238 00:21:43,020 --> 00:21:48,150 combination measurements of the two experiments had a precision of 240 239 00:21:48,210 --> 00:21:53,730 MeV. so I want to now to show you a new measurement by ATLAS that improves the 240 00:21:53,730 --> 00:21:59,430 techniques used previously by relying on event by event resolution method instead of 241 00:21:59,430 --> 00:22:05,370 average resolution. and also use a kinematic fit by constraining the invariant mass of the 242 00:22:05,370 --> 00:22:11,100 leading lepton pairs to the Z mass in order to improve the precisions and use a 243 00:22:11,100 --> 00:22:15,540 double sided crystal ball to fit the signal, as you can see here. so, this is 244 00:22:15,540 --> 00:22:22,230 result is summarized in this table, and is a still limited by far by Statistics 245 00:22:22,230 --> 00:22:27,540 uncertainty in all the channels. and but I would like to point out that the systematic 246 00:22:27,540 --> 00:22:33,900 uncertainty on this measurement is quite low is only 90 MeV and 60 minus 60 MeV, 247 00:22:34,260 --> 00:22:41,310 which is mainly coming from the muon momentum scale. and also CMS has recently 248 00:22:41,310 --> 00:22:46,230 provided a Higgs mass measurement, this time on the di-photon using the di-photon 249 00:22:46,230 --> 00:22:51,810 channel with 36 inverse femtobarn of data and it's both in several categories. and 250 00:22:52,140 --> 00:22:56,520 in these cases, the signal is modeled with a sum of up to four Gaussian 251 00:22:56,520 --> 00:23:04,680 function depending on the actual category and by itself this measurement has an 252 00:23:04,680 --> 00:23:11,820 accuracy of 260 MeV, but when it is combined with the Run one CMS result, it 253 00:23:11,820 --> 00:23:16,620 achieve a total uncertainty of 140 MeV, Which is a very low is only about one point one 254 00:23:16,620 --> 00:23:17,580 per mill uncertainty. okay the last topic I'm going to talk about is the spin achieve a total uncertainty of 140 MeV, Which is a very low is only about one point one 255 00:23:17,580 --> 00:23:21,990 per mill uncertainty. okay the last topic I'm going to talk about is the spin 256 00:23:22,020 --> 00:23:26,550 CP of the Higgs boson which, as you know, the prediction on the standard model is 257 00:23:26,610 --> 00:23:30,720 that the Higgs boson is a 0 plus plus state and that already during Run one 258 00:23:30,720 --> 00:23:36,000 the coupling to the vector boson has been studied at length, where the zero plus 259 00:23:36,000 --> 00:23:42,180 state was favored with respect to different alternatives, but anyway is 260 00:23:42,180 --> 00:23:47,640 true that the Higgs to fermions couplings can also give us some more hints 261 00:23:47,640 --> 00:23:52,320 because in this case, the CP odd contribution can be on the same level of 262 00:23:52,650 --> 00:23:57,060 the CP even ones while in the case of the vector boson couplings are suppressed by 263 00:23:57,270 --> 00:24:02,520 the scale of new physics to the second power to the Second power. so, now, just 264 00:24:02,520 --> 00:24:08,820 to finish the results from the two experiments, which are done in the ttH 265 00:24:09,120 --> 00:24:12,780 where the Higgs decay to the photons final state. both results are very new coming 266 00:24:12,780 --> 00:24:18,750 out came out in in March for CMS and April for ATLAS. and this result is a 267 00:24:19,320 --> 00:24:23,910 basically the parameter of interest is a is there a difference between different 268 00:24:23,910 --> 00:24:27,450 definition by to explain, but they are equivalent in the case of ATLAS is the 269 00:24:27,450 --> 00:24:34,080 alpha angle here which 90 degrees is a full is a complete the CP odd state and 270 00:24:34,080 --> 00:24:40,020 in the case of a CMS instead the Kappa T tilda parameters is used and in 271 00:24:40,020 --> 00:24:47,970 particular, this is used to define the fractional CP even contribution FCP. that is 272 00:24:48,000 --> 00:24:55,350 fitted here. so, Kappa T tilda 00 will be the Standard Model. okay, so here they 273 00:24:55,350 --> 00:24:59,670 in both cases the m gamma gamma is fitted in all categories and this is a 274 00:24:59,670 --> 00:25:04,050 summary of the results where both experiments can have excluded the pure CP odd 275 00:25:04,050 --> 00:25:10,500 couplings with more than three sigma 3.9 for ATLAS and 3.2 for CMS. and also, 276 00:25:11,040 --> 00:25:15,870 in the the case of ATLAS a fit of tH to ttH fraction has been performed or 277 00:25:15,870 --> 00:25:19,740 giving a limit of 12 times standard model on the single [Chair: Luca your 278 00:25:19,770 --> 00:25:20,610 time is up.] 279 00:25:21,180 --> 00:25:28,920 yeah. and last slide. so just to conclude the, also ATLAS has a sensitivity to the 280 00:25:28,950 --> 00:25:35,760 Kappa T cosine of alpha sign and the combining with the with the combination of 281 00:25:35,760 --> 00:25:42,810 the Higgs measurements. and and then I would like just to give you the summary, 282 00:25:43,440 --> 00:25:47,040 saying that thanks to the outstanding performance of the LHC and experiments we 283 00:25:47,040 --> 00:25:52,410 run two, was possible to improve significantly our understanding of the 284 00:25:52,410 --> 00:25:59,970 Higgs bosons both in terms of production mode and as well as a CP structure and the 285 00:26:00,000 --> 00:26:06,570 Mass measurements and that run three and run in the future run four etc. 286 00:26:06,990 --> 00:26:11,400 looks bright, as you can see from these projections by the two experiments. thank 287 00:26:11,400 --> 00:26:11,550 you. 288 00:26:12,809 --> 00:26:14,429 Chair: great, thanks a lot Luca 289 00:26:15,900 --> 00:26:17,460 any questions? 290 00:26:22,770 --> 00:26:25,410 please, if you have any questions, feel free to raise your hand. 291 00:26:29,099 --> 00:26:33,419 all right. if not, then I had one. back when you were talking about the EFT 292 00:26:33,419 --> 00:26:40,439 interpretations. I was trying to sort of understand the differences between the 293 00:26:40,439 --> 00:26:47,429 ATLAS and the CMS results that you showed. in particular, like trying to compare I was 294 00:26:47,429 --> 00:26:51,389 looking at hw and noticing that it seems that there was quite different precision. 295 00:26:51,659 --> 00:26:55,589 but you mentioned that these were coming from two quite different analyses. could 296 00:26:55,589 --> 00:26:57,929 you say a little bit more about the differences. 297 00:26:59,250 --> 00:27:02,220 the slide was Let me just get the number it was slide 15. 298 00:27:02,970 --> 00:27:06,900 Luca: yeah, unfortunately, okay with the full screen mode. I think I'm a bit lost with a 299 00:27:06,900 --> 00:27:11,070 slide. but , I think the point is that one has to realize that this 300 00:27:11,070 --> 00:27:16,680 were done under the different bases. so in one case, it was a SM EFT. and the 301 00:27:16,680 --> 00:27:20,610 other case was the Higgs effective Lagrangian, therefore, the parameters don't have the 302 00:27:20,610 --> 00:27:24,120 same meaning. so they are not directly comparable, let's say 303 00:27:26,040 --> 00:27:28,290 in [chair: Okay], so, 304 00:27:28,409 --> 00:27:33,089 yeah. Chair: so that's the main reason now, I was just noticing that you had the comment 305 00:27:33,089 --> 00:27:37,049 that there was some strong anti correlation from the inputs in the CMS 306 00:27:37,049 --> 00:27:40,859 case. but I guess it's really the differed basis that are making the main 307 00:27:40,859 --> 00:27:41,549 differences. 308 00:27:42,900 --> 00:27:44,610 Person: then you're also 309 00:27:44,640 --> 00:27:49,020 comparing I mean, the one on the right is from a combination of all the channels 310 00:27:49,020 --> 00:27:50,970 where the one on the left is essentially 311 00:27:50,970 --> 00:27:52,680 only ZZ four leptons. so 312 00:27:52,680 --> 00:27:56,940 Luca: yes, they in the case of the let's say, on the left, you are mainly sensitive to the 313 00:27:56,940 --> 00:28:03,360 Higgs to ZZ. therefore, here you have a strong Let's say sensitivity to the b, which 314 00:28:03,360 --> 00:28:11,250 is basically the the gauge field rate to the close more closely related, let's say 315 00:28:11,250 --> 00:28:16,230 to the Z. while instead yeah, the CMS case you have the combination This is coming 316 00:28:16,230 --> 00:28:19,350 from the combination of the channels, therefore, you have a more complete view a 317 00:28:19,920 --> 00:28:22,920 complete pictures of the couplings. yeah. 318 00:28:24,450 --> 00:28:27,060 Chair: Okay, thanks. other questions? 319 00:28:31,710 --> 00:28:38,730 I see two hands are up. but somehow, okay, I'm Michael spirit. you want to go ahead. 320 00:28:41,070 --> 00:28:46,170 Michael: okay, because it was, I'm not really sure if I got it right. for the determination 321 00:28:46,170 --> 00:28:50,640 of Kappa C for the charm Yukawa coupling , do you extract it from the 322 00:28:50,640 --> 00:28:54,180 gluon fusion cross section or from c c-bar to Higgs. 323 00:28:55,470 --> 00:28:59,760 Luca: in, well, this limit is extracted from the differential measurements from 324 00:28:59,760 --> 00:29:05,910 the PT Higgs. but, this also includes somehow the effect of the modification not 325 00:29:05,910 --> 00:29:09,390 only to the spectrum, but also to the branching ratios. therefore, has a bit more 326 00:29:09,390 --> 00:29:14,670 of assumption in the big Kappa, have somehow the limits when instead you 327 00:29:14,670 --> 00:29:23,670 only consider the, the, the limit from the, from the, from the shape. now, I'm 328 00:29:24,300 --> 00:29:30,660 sorry, I'm a bit slow moving through slides, but they maybe can jump quickly to 329 00:29:31,380 --> 00:29:33,510 to these results, just to show you. 330 00:29:34,800 --> 00:29:38,010 oops, I think I went too much. 331 00:29:43,230 --> 00:29:44,790 okay, looks like I'm a bit 332 00:29:46,410 --> 00:29:48,990 a bit slow with moving through the slide. so, but 333 00:29:54,840 --> 00:30:01,540 Michael: because the real reason why I'm asking is that I don't understand why the fit is 334 00:30:01,600 --> 00:30:04,260 symmetric for positive negative Kappa C 335 00:30:07,680 --> 00:30:14,250 Luca: well yeah the fit is indeed quite symmetric Now the about the sign I 336 00:30:15,090 --> 00:30:18,960 Well, I mean it's symmetric in the sense that there is no sensitive to the to the 337 00:30:18,960 --> 00:30:27,240 sign Yeah. yes I think only because enter quadratically it only enters 338 00:30:27,240 --> 00:30:29,610 quadratically in the fit. 339 00:30:30,450 --> 00:30:35,820 Michael: yeah, but then of course, this cannot be the gluon fusion. this because this must 340 00:30:35,820 --> 00:30:37,290 be done with c c-bar to HIggs. 341 00:30:37,680 --> 00:30:41,280 Luca: well, these are these also there is also Yeah, okay. there are also box of course 342 00:30:41,280 --> 00:30:45,810 there is a box contribution as well. you have to consider this also is very 343 00:30:45,810 --> 00:30:51,810 sensitive to the Higgs plus jet diagram. Yeah, which is, let's say, box related. so yeah, 344 00:30:51,810 --> 00:30:52,740 it's not only 345 00:30:53,040 --> 00:30:54,750 Michael: but again in the gluon fusion. 346 00:30:56,369 --> 00:30:57,800 Luca: yeah, mainly I would say gluon fusion. 347 00:30:57,800 --> 00:30:58,049 Michael: I'll bet you are fitting an interference term basically, which is sensitive to the sign. Luca: yeah, mainly I would say gluon fusion. 348 00:30:58,049 --> 00:31:03,120 Michael: I'll bet you are fitting an interference term basically, which is sensitive to the sign. 349 00:31:04,650 --> 00:31:10,890 Luca: okay, on this, maybe somebody can answer better than me. I'm, I'm really not expert 350 00:31:10,890 --> 00:31:14,790 only tell you about the if the interference is a [] or not 351 00:31:15,000 --> 00:31:18,510 Michael: because that's one of the deeper reasons of my question that I don't understand. 352 00:31:20,100 --> 00:31:24,150 Then I don't understand this fit is symmetric with respect to the sign if this 353 00:31:24,150 --> 00:31:28,590 is coming from the gluon field. so this must be coming from cc bar to Higgs 354 00:31:28,590 --> 00:31:29,130 plus jets. 355 00:31:30,990 --> 00:31:31,980 then it's quadratic. 356 00:31:33,750 --> 00:31:38,340 Luca: well, I'm sure that all the contributions are considering here. I am pretty sure 357 00:31:38,340 --> 00:31:40,950 that the gluon gluon fusion is one of the main ones to be honest. 358 00:31:41,340 --> 00:31:45,000 Michael: but then it must be asymmetric because then it's sensitive to the sign. 359 00:31:46,440 --> 00:31:48,450 Chair: I think Karsten might want to answer 360 00:31:51,960 --> 00:31:52,680 perhaps 361 00:31:58,380 --> 00:31:59,550 maybe he can't unmute 362 00:32:00,000 --> 00:32:02,910 Luca: mean I know that the the limit Karsten: now I can 363 00:32:02,940 --> 00:32:04,290 [several people at once] 364 00:32:04,770 --> 00:32:06,150 Chair: yeah perfect Go ahead. 365 00:32:06,930 --> 00:32:15,300 Karsten: so, the charm charm to Higgs is is included here. so this is really the using the 366 00:32:15,300 --> 00:32:22,500 fully unfolded kinematic PT Higgs distribution or PT four lepton I should say, but the 367 00:32:22,500 --> 00:32:23,220 thing is 368 00:32:25,290 --> 00:32:26,130 due to low 369 00:32:27,210 --> 00:32:33,270 resolution we had a have a rather large bin from zero to 10 GeV. if you go back to 370 00:32:33,270 --> 00:32:39,120 your original slides you see from like the theory plot that a large fraction of the 371 00:32:39,120 --> 00:32:43,920 sensitivity comes even if you would split it even further from zero to 372 00:32:43,920 --> 00:32:47,670 five and five to 10 however, we didn't have the experimental statistics and 373 00:32:47,670 --> 00:32:51,450 resolution to do that. so so this is something maybe for the future or for 374 00:32:51,450 --> 00:32:57,270 gamma gamma channels and these kind of things. so in that sense it's it's all 375 00:32:57,270 --> 00:33:02,430 included here, but yeah, we use We only have a certain sensitivity with the 376 00:33:02,430 --> 00:33:03,240 current statistics. 377 00:33:04,890 --> 00:33:09,300 Michael: because it is also interesting because in the plots on the upper right, you'll see 378 00:33:09,300 --> 00:33:13,260 if you are comparing the green with the red curve that you are indeed sensitive 379 00:33:13,260 --> 00:33:13,920 to the sign. 380 00:33:16,680 --> 00:33:23,190 Karsten: yes, but that's exactly the issue here and if you look at the upper right, the the 381 00:33:23,190 --> 00:33:27,810 main sensitivity from the sign is from if you compare zero to five and five and 382 00:33:27,810 --> 00:33:33,270 above GeV in PT Higgs. and exactly what we are watching out by because we integrate from 383 00:33:33,270 --> 00:33:40,470 zero to 10. because the limit limited statistics and resolution in this and here 384 00:33:40,470 --> 00:33:43,830 the gamma gamma channel and if you try with a combination and also with a 385 00:33:43,830 --> 00:33:48,810 combination with CMS can help if we, if we make this experimental binning finer 386 00:33:48,810 --> 00:33:53,760 here, we will have still quite experimental anti correlations between 387 00:33:53,760 --> 00:33:57,030 those but hopefully it's good enough to make a better statement. 388 00:33:58,230 --> 00:34:01,710 Chair: okay, I think let's leave the rest of this. discussion for the coffee break. I 389 00:34:01,710 --> 00:34:05,610 think there was another question from Makkah. scalia. you want to go ahead? 390 00:34:11,849 --> 00:34:19,979 Makkah: hello, if you could go on page 26 391 00:34:23,490 --> 00:34:29,430 Okay, so so so I guess that the mass age pole and the mass top pole is different to the 392 00:34:29,430 --> 00:34:33,150 experimental measurement it means that probably you are doing some additional 393 00:34:33,150 --> 00:34:40,200 treatment and so the question is, when will theorist update this kind of plot with 394 00:34:40,200 --> 00:34:41,220 the most recent one 395 00:34:42,720 --> 00:34:46,680 Luca: Okay, I think this is not a question for me, but maybe it's an open question for 396 00:34:46,680 --> 00:34:50,850 the theory at least in the in the room. what we know well the difference between 397 00:34:50,850 --> 00:34:57,840 the top pole and the so called Monte Carlo, experimental top mass. okay, a I leave it 398 00:34:57,840 --> 00:35:01,290 any experimenters want to take this question. I will leave it to you 399 00:35:01,290 --> 00:35:01,560 them. 400 00:35:03,750 --> 00:35:04,710 any theoretists 401 00:35:07,080 --> 00:35:09,120 Chair: I don't see any hands. 402 00:35:10,920 --> 00:35:12,900 Chair: spira you'd like to take the question? 403 00:35:13,530 --> 00:35:18,810 Michael: I think that impossible this issue is related to the because this related 404 00:35:18,810 --> 00:35:24,240 to the final fit of consistent top quark mass and this is an enterprise that's now 405 00:35:24,240 --> 00:35:28,470 starting from the experimental side, because I think what you really have to do 406 00:35:29,010 --> 00:35:35,070 it this is one of the possible ways to fit the msbar top mass, or it was some consistent 407 00:35:35,070 --> 00:35:39,480 definition of the top quark mass and this is now starting. the Higgs mass itself doesn't 408 00:35:39,480 --> 00:35:44,340 play such a big role. but of course, I agree that the fit of the value of the 409 00:35:44,340 --> 00:35:52,290 top quark mass really is crucial here. and the first fits of as far as I remember is [] 410 00:35:52,290 --> 00:35:58,140 consistent top quark mass are pointing towards the point that this ellipse moves 411 00:35:58,200 --> 00:36:02,700 a little bit more towards the absolute stability region but it's really in the 412 00:36:02,700 --> 00:36:06,180 vicinity of the border between absolute stability and meta stability. 413 00:36:09,450 --> 00:36:12,000 Chair: thank you Okay.