 Okay, so we are live so hello everyone and welcome to session 153 of the Latin American webinars on physics. My name is Joel Jones from the PUCP in Peru and I will be your host today. Today we're having Sven Heinemeyer as a speaker. Sven carried out his PhD at Karlsruhe in Germany which was then followed by postdocs at Desi, Brookhaven, LM Mu Munich and then at CERN and he's currently a professor at IFT in Madrid, Spain. So today Sven will talk about recent hints of new physics and colliders specifically at the LHC and LEP which are related to searches for scalars again in Odon styles or digits right and we're very happy to have him as a speaker today. Now before we begin let me remind all viewers that you can ask questions and comments via the YouTube live chat system and these questions will be passed on to Sven at the end of the talk. So perfect we're all yours Sven please share your screen. Okay thanks a lot for having me let's share the screen okay and we go to the full screen mode okay here we go very good yes um thanks a lot for having me I will talk about the possible new Higgs boson at I put it precisely here 95.4 gv you will see how this number comes about I will start with some motivation and oops evidence without the w for a light Higgs boson come to some possible model interpretation and finish with the physics opportunities that future colliders but this particularly e plus e minus colliders good motivation and evidence for a light Higgs boson um let's start for the ones who are not really fully familiar with everything with a more general introduction and I will start with two facts and this is fact number one namely that we have a discovery and these are the original plots that were shown by Atlas and CMS on the 4th of July 2012 where here there's a clear indication at the level of six or five sigma for a new object at around 125 gv and this is already 11 years ago now we know much more we have the discovery of scalar boson that behaves very much like predicted as in the standard model here on the left side there are some recent Atlas results one is always the standard model here so it's normalized to the standard model for the various production modes on the right hand side two CMS plots one for the production modes one for the decay modes and everything lines up nicely to one so this is fact number one but there's also fact number two the standard model cannot be our ultimate theory and there are many reasons that you are probably very familiar with you know that gravity is not included there is a hierarchy problem related to the mass of the expose on that now we know it exists there's no unification of the three forces that matter sort included we don't know anything about the why we have the baron asymmetry of the universe neutrino mass on it included and there's also some experimental data and I always put here the g-2 of the muon we know the caveats but this is not relevant today the other points are more relevant and putting fact number one and fact number two together there's only one possible conclusion the discover ticks cannot be the standard model hicks this is just impossible logically however the real question that we want to ask is does the bsm physics that must exist have any relevant impact on the hick sector and maybe are there already any hints from the lhc that can give us the guideline you we can use as a toy example etc is there something like this and if so which model may maybe doing it good and the the answer how can we answer this question there are several ways of course we can measure the properties of the boson that we've seen like the plots that we've seen just one two minutes ago and we also must check for additional hicks bosons because all these are nearly all changes also change the except often predict the existence of additional hicks boson and here i wrote one should check for the shakes was once above 125 gv this is kind of what everybody thinks but one should also check below 125 gv and when you think this is all excluded we will see about this in a moment yeah because the next point is below 125 maybe is there any evidence yet and we will see about this good this is the motivation now let's come to the evidence and i start with the evidence with a talk that was given by atlas relatively recently this was in june this year i'm correctly i hear six of june and they presented several new results but in particularly they presented new results on the low mass hick search in this mode tp goes to a new hicks decaying to gamma gamma and we've waited for this update of the results for five years the last result they got out which was didn't show anything relevant i come back to this in the moment was presented in 2018 and now finally five years later they used the full run-to data set to come up with a result and the result looks like this and then nearly everybody would say look nothing spectacular seen here yeah so maybe i should explain how this plot what does this plot show this is the mass of the additional exposure this is the cross section times branching ratio in gamma gamma and then this dotted line or the stash line is the expected exclusion and then green is one sigma and yellow is two sigma and then this solid line the solid black line is the observed exclusion limit and everything is within the one sigma range only here it deviates a little bit and this is the highest axis i put it in particular in on purpose and potential marks here at 95.4 gv and this alone wouldn't have cost any attention however the cms result in the same search channel had been presented somewhat before and here the full data set looks like this again we have the mass of the exposure and then this cross section transfer ratio now divided by the standard model expectation so standard model would be here at one again expected and observed and here there's one nice peak that can be observed at atlas it was 1.7 sigma here it is 2.9 sigma and the mass where this occurs is hold and below 95.4 gv exactly the same as for atlas and this of course makes it more interesting now there is something another quantity that i have to introduce which was called the new value and the new value is the cross section times branching ratio experimental result divided by the standard model expectation so you take the standard model you put the hicks artificially to the mass you're interested in this case at 95 and then you divide the observed by the standard model expectation just to give you an idea how strong the signal is and here the signal has the strength of 0.33 with the kind of asymmetric uncertainty but this corresponds to 2.9 sigma on the right hand side by the way it's the same result but without dividing it by the standard model prediction so it's more closely related or better comparable to the atlas result which we saw here on the previous slide but the new value is 0.33 plus 0.19 minus 0.12 at 2.9 sigma and the corresponding atlas value that was not provided but we read it off from the plot and the presentations is 0.18 plus minus 0.10 1.7 sigma good may i have one more plot here which is this one this is only the cms result because it looks so nice this is again the mass and then this is the number of gamma gamma events weighted in a certain way and red is the standard model plus background fit or effectively it's the background that one would expect sorry it's the background I would expect and one can't see anything yeah the data points appear to lie exactly exactly on this line however if one subtracts the background component as shown in the lower plot here then the stash is background only and then red is background plus signal one can see this nice peak here at around 95 gd and I like this plot particularly because it looks exactly as the first plots in the gamma gamma mode for the h135 have looked like so I think it's a particularly beautiful plot and again I said this is the new value for the cms channel now one can ask the question are atlas and cms compatible with each other and our x-ray interference did not try to answer this question so it's up to theorists to answer this question and this is the plot that we came up with again the mass then this new value that I talked about before and the black gash is again cms expected one and two sigma black solid is cms observed with this bump here and then this line here the central value plus the uncertainty is the new value observed by cms overlaid in red again expected and dash and solid observed is the atlas result again with its new value here at one sigma and one can see at the level of one sigma there's nice agreement between atlas and cms and since there is nice agreement not only in the location but also more or less in the value that we find from you here one can ask the question what is the combined value again our experimental friends didn't dare to go that far so we had to do it ourselves this is the one we come up with the new value is 0.24 with this only very slightly asymmetric uncertainty and then we reached the 3.1 sigma level in this channel alone and slightly provocative we know apart from starting from three sigma something like this can be called evidence and yeah this is where we are with the gamma gamma channel in atlas and in cms good now this is a very old plot this is the result from the Higgs searches at lab lab for the younger ones among you was an E plus and minus collider located in the LHC tunnel and it was looking for Higgs boson in the channel the plus and minus goes to Z goes to Z Higgs and the Higgs decays to BB bar again we have the expected limit we have the one and two sigma line boundaries here and then black is observed and one can see there's only one point where it goes outside the two sigma range and this is the highest axis on it 98 GB but it's the BB bar final state which is very broad so it's also fully compatible with 95 GB and here this new value is 0.12 plus minus 0.62 sigma not much on its own but it's nice that there's the only axis that came out of the lab searches was located exactly at the same mass in a completely different channel so one more channel to add here which is the tau tau channel so cms and atlas are also looking for new Higgs bosons decaying to tau plus tau minus and this is the latest result from cms the low mass region at the high mass region and then when you show this to people you can ask them can you spot the axis they say yes of course there's an axis here but can you also spot the axis at 95 100 GB which is not very well visible here but there's one plot that shows it better which is this one this is for a fixed mass of 100 GB the observed cross-section times branching ratio glue glue going to light Higgs with a decay to tau plus tau minus and on this axis here is a different production mode bb going to bb Higgs and then the same decay mode this is the standard model because there is no additional exposure and it should be at zero zero but we see that in the glue glue production mode we are something like three sigma away yeah from the expectation that there's no additional exposure there's also three sigma axis now this was for 100 GB it's slightly weaker at 95 GB if one goes there and finds a new value of 1.2 plus minus 0.5 which is 2.4 sigma and yeah this is what we also use as supporting interesting evidence in the tau tau channel there's one important caveat that will become important in a moment this new value here implies a certain coupling strength of the new object to tau and there are also other limits also from CMS mainly for example in the TT bar Higgs channel with a light Higgs for example at 95 GB and the Z Higgs channel again with Higgs decaying to tau plus tau minus so it's the same decay mode and indeed these two searches make this new value impossible yeah so something at the lower 1.5 sigma range of this new value might be compatible with the limits obtained in these two search channels this one has to keep in mind for later interpretation but this is the number one gets straightforward from the tau tau channel now we have three axes at 95 GB I repeat here the three signal strength BB channel gamma gamma channel and the tau tau channel corresponding to these sigmas 2 3.1 and 2.4 if you look at searches for new particles it's important to keep in mind that somewhere you expect axes looks completely normal however these axes all appear now at the same mass and therefore this famous look elsewhere effect that kind of diminishes the local significance to global significance as a theorist against a provocative say that I don't have to take this into account and assuming that these three channels are effectively independent one would end up at the level of 4.6 sigma however as I said this takes this at face value it does not take to account the other search channels that would diminish the possible signal strength in the tau tau channel but somewhere in the four sigma ballpark we would end up and in order to test this one can construct a new chi-square measure this what we call chi-square 95 which is simply the prediction of a model in the BB bar channel minus central value square divided by uncertainty squared same for gamma gamma same for tau plus tau minus yeah and in this way you can analyze different models see how well they can accommodate such a light exposure of course take account all relevant other constraints I'll come back to this in a moment and the question is is it possible to fit all these axes together in the let's say non-contrived model and this is what I will talk about in the next moments now possible model interpretations and we can see already here this is an extended x-sector obviously we look particularly in one type of models which is twig-stabbit model extended with a singlet and there are several models like this on the market and I describe here this like the so-called n-to-hdm which extends the twig-stablets phi-1 and phi-2 with one real singlet there's also the s-to-hdm that we will use later it has a complex singlet meaning it has an additional degree of freedom in the singlet here but this is not really relevant for the investigation that we are doing as I said in this model we have here one the standard model like doublet an additional doublet and the singlet then we have the potential with all the possible combinations which have these coefficients lambda in the twig-stabbit model it's very well known that in order to avoid flavor transition currents one elegant way to do is to impose a z-2 symmetry acting like this which reduces the number of terms that are allowed in the potential and in the case of the n-to-hdm there's another z-2 symmetry that was originally introduced showing here only gives a minus sign to the singlet to produce dark matter however this was only the original motivation this is broken by the veth so then this model there's no dark matter candidate which is different in the s-to-hdm that the symmetry structure is also different but in the s-to-hdm the additional degree of freedom in the singlet can actually act as a dark matter candidate this particle can be stable and indeed can give the correct value density but I'll not talk about this much more in this talk what is important for us we have in this model three cp-even-higgs bosons one cp-odd in the case of the s-to-hdm would be two cp-odd and a pair of charged exposons now this is our physics content our particle content in this model now as I was saying the z-2 symmetry is needed in order to avoid flavor transition currents and extending the z-2 symmetry to the fermions up type down type and charged leptons it gives us the famous four types of the two example model which is exactly the same what we also have here in the n-to-hdm or the s-to-hdm and yeah I mean they are defined by the doublet to which the various fermions coupling type one type three four exactly as in the two hdm furthermore we start out with three cp-even-states and I go back one slide the row one the row two and the row s our original states but because of the potential they're all mixed with each other and in order to arrive at the mass eigen states we have to diagonalize this matrix these these three states with the matrix r three by three orthogonal matrix governed by three mixing angles alpha one two three completely standard so we rotate it and then we arrive at these three mass eigen states h one two three very good now um using this information one can look at the couplings of the Higgs bosons in this model and how they change with respect to the standard model one can look at the couplings to the gauge bosons it's a combination of the alphas the r's and there's also beta I didn't say it so far the one parameter is tangent beta which is the ratio of the two wefts of the two Higgs doublet so it's v2 divided by v1 this is 10 beta as in the two hdm like in the mssm or nmssm whatsoever yeah this famous 10 beta so beta also enters here these are the couplings of the cp-even Higgs bosons to gauge bosons and here one can also see the couplings of the Higgs bosons to top quarks bottom quarks or tau electrons these three categories that I was mentioned before you can see it's always a combination of this arm matrix that enters and the sine or cosine beta good this will become important in the next slide the physical input parameters that we use in the model are the mixing angles alpha one two three 10 beta this v which is a combination of v1 and v2 so v squared like in this is exactly the v squared in the standard model it's given by v1 squared plus v2 squared that have the singlet the mass of our physical particles the physical Higgs bosons and one parameter as in the two hdm that softly breaks the z2 symmetry in the Higgs potential but this is also not very irrelevant here for us fine now why do I tell you all this let's have a look at the gamma gamma and pbx's first and see what do we need in order to fit them in order to describe them in the model well first of all of course we have to set one Higgs boson mass to 95 gb and the second one to 125 gb yeah we have to be in agreement with the experimental data at the LHC now in order to get the bb bar channel from left right we need that the coupling of the Higgs to gauge bosons is strongly reduced which is in agreement with the fact that the Higgs at 125 coupled strongly to the gauge bosons yeah because of the some somewhere that exists there there's not much space left and this can be arranged on the other hand we also need a large branching ratio of the light Higgs at 95 gb to gamma gamma for the cms and atlas axis and you can think about for example putting additional stuff in the loop I mean Higgs to tend to photons is mediated by a loop and for example the charge fixed boson can play a role here however we found that this effect was always very small and the only way to substantially enhance this branching ratio is to diminish the branching ratio in the leading channel and the leading channel the dominant channel for this decay is H1 to bb bar so if we want to make H1 to bb bar smaller we have to make this coupling H1 bb bar small on the other hand we shouldn't make the coupling of the H1 to tt bar small as well otherwise we would reduce also the gamma gamma load which is blue blue going via top triangle to the light Higgs so we must not make this one small and if one then looks at the coupling structures one sees that in type 1 and type 3 the couplings of the H1 to b quarks and the top quarks is identical so we can't fulfill these two conditions at the same time only type 2 and type 4 can do it yeah there these are couplings these modifiers are different in a principle they can be used to fit these two excesses now how do they differ they differ exactly by the coupling to tau leptons when type 2 the coupling to tau goes like with bb bar it's then suppressed whereas in type 4 it goes like the coupling to tops and it can be enhanced so the tau channel may decide between these two types these two yukawa types of our models good so this is all this is setting the stage for our investigation this is why we only look at type 2 and type 4 and then we did the parameter scan and we did it in the end to hdm and in the s to hdm and in order to do this properly we need a lot of tools and in order to do a little bit justice to these tools because they are provided by putting many many years of work by many many physicists yeah I just mentioned them here the parameter scan is either performed originally with scanner s or that this is a code that tomas beaker provided the s to hdm tools this is also also can do the parameter scan in this model for you free level productivity is checked so this is also done with scanner s or s to hdm tools the minimum of the potential should be the global minimum checked by these tools or should be sufficiently long lift which is done with a code evade of course all points that we have should respect all the search limits coming from lab teratron and the lhc and here we use our own code hicks bounce which does all these checks for you in a model independent way we have to ensure that the hicks at 125 behaves like according to the measurements at the lhc yeah so all the measures of the lhc they are encoded are again in one of our own codes hicks signals which needs the input for the decays like from n to hdk or s to hdm tools and for the production cross section as provided by sushi and this again this code gives you another chi-square the chi-square 125 which well we can evaluate for the standard model and for the 125 actually exposed in your model and you can compare these two values there can be limits or restrictions from flavor physics and here mainly this branching ratio the b sub s to s gamma can be important or the delta mbs this oscillation can be important and here the charge kicks was a mass place a row where we use super iso for the predictions finally also electric precision data that can be important here we focus on the t and s parameters the peskin takoshi parameters which is sufficient for our purposes when we look at pure hick sector extension of the standard model and again these two codes have been used now equipped with all this we perform the parameter scan and what is the result of the parameter scan now shown for the s to hdm left side type 2 right side type 4 we show the mu gamma gamma x here x is here and here this is the mu bb bar x you can see the current ellipse it's nearly ellipse because the uncertainties are slightly asymmetric from atlas and cms in the gamma gamma channel it's slightly asymmetric but this is the current ellipse before the atlas is i came out we had this dash gray dash ellipse from cms only also moved to higher values but now we have this black one the um points that we find in the parameter scan are these and the color coding tells you how well the hicks at 125 gv uh is an agreement with the measurements at the lhc zero means it behaves as good as the standard model prediction where this year is the kites worth the standard model dark values means it's even better than the standard model and up to 6.18 to sigma we allow that the still very well compatible with the lhc measurements and one can see that they're all kinds of colors in this one sigma ellipse yeah so this ellipse is highly populated meaning the model while being the green with all the constraints that i've shown you before theoretical and experimental and the measurements of the 125 and the measure of 95 this model does the job for these two channels bb bar and gamma gamma similarly in type 4 also here we find all these points with the same meaning of all the color codes and the contours you see less points here but this is just a scan artifact we could have scanned longer and found the same number of points so you can't deduce from the point density that type 2 fits better than type 4 yeah point density doesn't have a physical meaning but it's important to conclude that type 2 and type 4 can flip the gamma gamma and the b bar axis simultaneously good now we look also at the tau tau channel gamma gamma versus tau tau type 2 on the left type 4 on the right and as expected in type 2 nothing can be done about tau tau we don't even reach point 2 as a new value here where this is the one sigma ellipse in type 4 looks somewhat better than the old one sigma ellipse some points were inside now with a new one marginally it can get there not very well but it comes close or so yeah and the fact that we do not find points that are above this point five lines here just this is the effect of the additional searches in the tt hicks or zhicks channel with the same final state tau bar uh total final state so only type 4 can fit marginally both excesses at the same time this is our result here and i come back to the implications in a moment but first i like super symmetry what does susie can susie say about it and um as we know the type 2 is needed for susie and as i was also telling you for the tau type excess is most strongly in contradiction with other measurements and therefore we leave the tau tau excess out for a moment and are there any models with additional singlets that may be able to do the job yeah models with additional singlets and we look particularly at two of them one is the very well known n mssm the mssm extended by one thick singlet and the other one is so-called new new ssm i'll explain in a moment what this is it's also the msm effectively extended by several singlets and the question is can the models fit the excesses despite the strong really strong additional susie constraints on the hic sector and we will see what the answer and one prediction that was made by these models before the last round of accidental results first of all the n mssm this already is the old paper but still the result that i like to show um we fixed the parameters in a certain way details are not important we just fixed them and then uh varied some parameters here and uh this is again the mass of the light exposure and then this xi b corresponds to our lab channel and one can see that yes for a mass of 95 gb we are exactly in the range that we need here at this point one two maybe point one five uh we are for 95 gb exposure for the xi gamma which is the gamma gamma channel one can see that uh we end up here at 95 at the range of nine of point four or so yeah so both of these excesses can be fitted simultaneously using this what i call now new new new gamma gamma value i didn't tell you the full history this would go to long but originally cms had seen a new value of point six and we couldn't get to point six we could only get to point four at most in our model now this was the result of in the n mssm and it looks very similar as i can tell you in the new ssm as i said uh i have here two lines of introduction it's effectively the nmsm really with three singlets more plus some well-motivated operative violation and uh with uh via an electric seesaw one can reproduce the neutrino data this is why how the model was uh why the model was constructed about um now how many 17 years ago by these two professors here and yeah this is the new new ssm and again can this model fit the excesses again we fix the parameters in a certain way details are not important i have here the results in the plane of one of two of the parameters new and a kappa from the x potential this is the new gamma gamma value which those days we call new cms because atlas didn't have a result and one can see that here in this part of the parameter space yeah we are more or less in the same ballpark in the right ballpark if one looks at the new new gamma gamma value between the our point uh well the new new gamma gamma value is the very new one is point two four but round point three or so is easily reachable here and this is the lap result the bb bar channel again one ends up more or less in the right ballpark here a little bit on the high side yeah so we find effectively what we found in the nmsm this bb bar channel comes out a bit high and the gamma gamma channel comes out a bit low and the reason is that all these restrictions in the hiccector of supersymmetry they force the strong relation between new gamma gamma and new bb bar which we plotted here some years ago in this new ssm i can see this is a nearly it's a very strong correlation and enforced by supersymmetry and then one can say that lap enforces that this new gamma gamma value should be smaller than point three five so i was telling you originally it was at point six but those days uh the susie model interpretation told us that if susie is realized the new value must be smaller otherwise it's incompatible and what happened then in later years i don't have the plot here but what happened is that it came down from point six to point three and now even if in the combination point two four you know and point two four here would even be well this is the right ballpark yeah this is where we have to end up and here both axes this can be described nearly perfectly uh by our supersymmetric model very good i come to my last part what can we learn from future measurements yeah if there's something what can we see in what is the prediction for future experiments from these axes how can we investigate it well we can continue and we will continue with a measurement of the couplings of the h1h25 at the lhc and the halloumi lhc but also at a future plus or minus collider i always write here ilc because these are the numbers that we actually used that i will show to you in a moment but effectively in this context ilc means international linear collider or nea plus or minus collider that operates uh at 250 gb cent of mass energy okay so we can measure these couplings however of course we can also directly produce this new exposure at the lhc halloumi lhc or at future plus or minus colliders and if we can produce it there this will also allow us some detailed this hopefully this will allow us to do some detailed coupling measurements of this new Higgs boson at the future plus minus colliders one could also look at the production of other bsm Higgs bosons but this is too speculative yeah so i will focus on these two possibilities and just for the people who are not familiar with this i have one slide about a possibly plus or minus machine this is one of the linear ones at the ilc international linear collider which if it's constructed then most likely in japan but they take a bit long with their decisions there it would start operation at 250 g and could be extended to 1000 gb to detect us um it has polarized the plus and minus beams which was very interesting for many physics analysis and it has tunnel energy so it makes it very versatile uh collider now and so we collide them and here we hope to produce the new Higgs boson i come back to this in a moment but let's first um have a look at uh what can be seen whether this kind of new Higgs boson could be seen uh at any plus or minus machine and here i have a plot where again these the mass of the initial Higgs boson is shown relative to the coupling of the Higgs boson to z bosons divided by this the normalize standard model value squared so one is the standard model here and now this blue line in this blue area is the one excluded by left this corresponds exactly to the left line that i've shown you before where here this small axis of two sigma is located you'll see it with later and now there's been they have been done in analysis for the ilc using either what's called recall method or the traditional method with the b bar final state i will not go into details here but one can see that substantially smaller couplings can be investigated particularly here yeah so really a much larger parameter much smaller couplings can be investigated and this is important for the production of such a new object at the at any plus or minus line good how could one see it and this is a very nice plot i think um one could see it via this type of process the plus minus goes to z and the z radiates the Higgs and the Higgs decays however it wants yeah it can decay invisibly we just do not care we just look at the recoil of the z this is how the initial measurements at any plus minus slider for the 125 gb are supposed to take place and then one has several standard model backgrounds shown in green here depending on the mass of the reconstructed object and here for example we have the z background this is the 125 gb higgs background and these colored spikes are the expected signals depending on the mass of the additional object here and for example this one here is 95 it's located here it's very close to the z of course this was to be expected but i think looking at this plot it's considerable it can be distinguished from the z and of course this kind of analysis has been taken into account to produce this kind of limit here but this is the channel how i could initially see it even without looking at the decay of the Higgs boson the new exposon but then one can probably also do some analysis of the Higgs one decays i come back to this but first i'll show you one plot going back to the h125 i said this is the first thing one can do one can measure one can continue the measure the couplings of the h125 here coupling to tau plus tau minus versus the coupling to engage bosons this is the cloud that we predict in the s2 hdm type 2 this is the cloud that we predict in the s2 hdm type 4 and this here is the standard model point 1 1 green dotted is the precision one can expect at the high lumie lhc so if standard models realize these models would be excluded at the two sigma level or vice versa if one of these points realizes standard model would be excluded at two sigma or more depending on what is realized if one includes also a plus and minus measurements which are of course much more precise and on top of that completely model independent one gets down to this pinkish ellipse and here something like a five sigma so can easily be established now so high lumie lhc can get you to the two sigma level whereas the a plus minus precision the lc precision can get you to a five sigma deviation so that imagine one of these points is realized would have a large standard model would be ruled out with a very high significance on the other hand it may not be possible to distinguish the two types from each other depending which point is realized if this point is realized yes if this point here is realized probably not because they're too close to each other these two clouds however i told you that also this new expose on can be produced as in the pacemines slider this again this effectively this plot i've shown you before this is the mass this is this coupling strength modifier this is the lap observed exclusion the blue line the yellow dotted line is lap expected this was this two sigma axis and our axis of points sits exactly here this is the limit up to which the ilc 250 could explore or could find this new particle and we can see all the model points are far above this green line meaning indeed with a coupling that we have to to gauge bosons this expose on would be produced about or can be produced abundantly and then one can ask the question can we measure the couplings and i have two more plots before i conclude in this plot we show the relative precision that we can expect for a certain decay mode of the coupling of the h1 or the h95 particle x and x can be b bar tau plus tau minus blue blue ww or zz these four are determined from the decay where zz is directly measured from the production of this new exposure and there we have a lot of events and therefore this is the precise most precise measurement or the others they range between something like two and eight percent the only difference we can observe is in the tau tau mode the reason is that in type four we produce many more towels and therefore the measurement is more precise whereas in type two we produce less towels and the measurement is less precise this to be expected what about model discrimination this is the final plot i want to show you now coupling of the h95 to tau plus tau minus versus h95 coupling to gauge bosons the blue ones are the cloud is the cloud from type two the orange one are the cloud from type four and these little shaded ellipses are the anticipated precisions on each point that is realized here and one can see that the two modernizations are clearly distinguishable yeah there's no overlap between one of these points with the other group whatsoever so this shows that the high precision measurements that can be performed at the future plus minus collider for such light exposure will enable us to say a lot about the underlying structure about the hick sector about the coupling of this new object and this may allow us to really pin down the hick sector that is realized in nature with this i conclude i told you there's evidence for a Higgs boson 95.4 gv in the gamma gamma channel alone from cms and atlas combined 3.1 this one adds in the left channel and the tau tau channel one ends up at above about above four sigma possible model interpretations i first looked at two hdms extended by a real or complex singlet and the post vaccinations the gamma gamma the b bar channel can be described equally well in type 2 and type 4 the tau tau marginally in type 4 looking at susie models i showed you the nms assignment the mu rsm susie's with additional singlets and here gamma gamma and bb bar can nicely be described provided the mu value of gamma gamma is at the level where it is now and not where it was a few years back at 0.6 this cannot be explained in supersymmetry in the future we can measure the properties of the h925 at the plus minus colliders and their precision measurements of the cuppings they can distinguish these singlet extensions from the standard model this will be possible at the several sigma level no problem the distinction between these two types may not be possible depending on where we are in the parameter space however we can also look at the production of this new particle and this can be done at the isc 250 or a plus minus client operating 250 gv center of mass energy can be produced abundantly the positions of the couplings are at the level of eight one to eight percent where the coupling to z both on this best from the production mode and the coupling measurements in the combination of these two can clearly distinguish these two types why are the high precision possible in future the plus minus colliders and with this i conclude thanks a lot thank you very much for the very very nice talk so i was wondering if anybody in the audience has got any any questions i have a couple but let's oh nicole that's okay there you go well i had a question but after this last live maybe uh no after this one you don't have any questions yes okay thank you thank you very very nice very clear uh so i was wondering why i mean if you throw this excess whatever you're calling me kicks what i have in mind is if the experiment giving us some uh ideas about the spin for instance it has to be spin zero it has to be uh cp even these are very good questions and indeed i think spin zero it could also be a spin two particle in principle yeah from the decay to gamma gamma we know all the discussion that we had for the h 125 um hicks is for me the most natural thing because we expect extended hick sectors for many reasons not only for this one also for example iron or symmetry in the universe or so or as i was saying you could also give give us a dark matter candidate etc extended hick sectors come kind of naturally in particularly if you are a fan of supersymmetry like i am then also extended hick sector comes naturally and it's you are not okay but i would say hicks extensions come naturally they are really in the focus of of today's vsm analysis there are models which do not really extend the hick sector like a radion models with the radion mixes with the hicks or so i think there was an analysis very early also looking at radion models but this has not been followed up yeah so um i think nearly all explanations that are on the market and tomas has this nice over here i could have put it in of all the models that have investigated this yeah and they are they are i don't know something like 20 25 papers by now looking at these excesses and most of them are hicks sector extensions nearly all of them yeah uh tomas do you remember any non-hicks extension that has been analyzed recently i don't know whether he's still here uh yes i am okay yeah um well i think most of it is six extension the only difference is maybe that in some cases it's a pseudo-scaler instead of a scaler so yes and this is one thing we also have to discuss in our collaboration in a moment yeah but yeah exactly but uh if tomas um if you have uh if you have another no tomas um so what was the name ben i'll um nicolas nicolas sorry sorry if you have a different model uh in mine that you think would fit i would be happy to to see this how this works out yeah here as i said it comes out of naturally yeah you don't have to twist the model you don't have to go to well of course you have to get the right couplings but you don't have to go to parameter regions that appear unnatural or so i would say yeah that comes out naturally when you remember the 750 gb axis i i think there was no model on the market that was neither contrived or either the model was contrived or it had to go to a very specific part of the parameter space a very fine tune one to explain these excesses this is not the case here here we're really in a normal parameter space which makes it attractive i think okay thank you very much yeah i have another question but maybe you can look through other people okay anybody else has got any questions there are a couple questions from the audience also but let me ask first a question myself so so can you go back to slide the 13 please were you were showing this um really yeah this one this one right so so here here we we do see that a production of this scalar with the two the budgets is is favored right so so wouldn't wouldn't this kind of like suggest that combining the data with the tiles and that from lip is destined to fail not necessarily because um also for the gamma gamma mode we need a reduction of the coupling to b quarks and um if one looks at the i don't have the detailed values here if one looks at the cut links indeed bb bar is reduced and it's reduced to a level that it's fully compatible with this uh with these measurements yeah yeah it's not zero of course so you don't get zero you get somewhere i don't know where you're not probably somewhere in this range here but it's fully allowed but the fact that you need the cutting reduction to b quarks also for the gamma gamma mode doesn't make this more or less compatible or incompatible with the rest what makes it less compatible are the other searches in the total mode that i was mentioning here right because i was thinking rather than in your susie models you you you ditched the tau data right yes so that's correct but but maybe maybe it should be the lip data the one that could be ditched right so yeah it's always difficult for theorists to pick results yeah if you do this you can favor one or the other model and of course i'm also um i can also fall for this so i i might be tempted to do this and this is well i ditched the total data for susie because it's as good as uh as this one here that i was showing to you this one yeah you can't do it point period yeah it's uh yeah if this is how tau is true um well you can't do it in this kind of models of course you can you can construct models with more than susie models with more than two doublets or so there are four doublet models this was metric on the market that may be able to do it i know that uh some people may be looking into this but um let's say the normal susie types they would all be ruled out i think i think so i was as i was saying before um originally the gamma gamma value was here at the point six level yeah this was the original value that came out from cms in 2017 at what and stood there for for many many years and susie said we can't get there yeah we can't do a point six we can only get to uh i don't know if this one should be correct we could get at the point three range or something like this yeah but not more so susie kind of predicted that this value would go down and this is exactly what happened and therefore susie predicts but can be falsified this is a good thing can be falsified by the prediction that the tau tau is not right if tau tau is confirmed for example with a new atlas measure there's no atlas measurement in the low hicks mass search in the tau tau final state if they would confirm this axis then i would drop mms m or nms m explanations immediately they can't do the job it's impossible then one has to look at type four models or models with more than two doublets making them in my opinion less attractive you are having the minimal models while it's doing the job is already quite some achievement super super thank you thank you very much so let's go to the to the questions from the from the audience so we have a question from from amaro suarez um so so so his question goes like it's so is is there any reason for this new boson to have masses relatively close to z and w and could this suggest that there could be other vector bosons with masses close to a the hicks mass interesting question but i do not have a very good answer to it for me this is a coincidence yeah there's no deeper reason behind if somebody could explain it well only that i mean 125 is already it's the electric scale yeah it's or everything is proportional to the veth in the standard model yeah it's squared of how is it squared of lambda times the veth or something like this and naturally we get something in the scale and the masses of the w and the z are given by the veth of the standard model times the weak cut lengths yeah so that we end up somewhere in the same range is normal and that with this fix we end up also in the same range looks normal to me but it of course depends on how you choose the other input parameters you can you can take the the the n2 htm or the s2 htm and make everything heavy it's easy you can just do it yeah so in this sense there's no reason it's it's kind of natural but i don't know any deeper reason for this and therefore i also wouldn't predict any new gauge bosons in that mass range yeah i would in fact be surprised because new gauge bosons usually couple relatively strongly also to fermions and one one would have seen some hints or so yeah yeah yeah i was i was thinking that this could can like be connected to nico last question right yeah but yeah yeah it's it's it would be difficult yeah if they couple the fermings so so super let's go to the next question which comes from marvin flores so he says thanks ven for the nice talk here are my questions so here's the two questions first does this excess appear in the zz start to four leptin channels right since also very good question and we've been asked this question before and then we've looked into the numbers and those days the number of events that we found based on our model predictions was around one event and so if it's there yes it should be there but we need much more luminosity to see it and i do not know we never investigated this whether the high lumi lhc might get us to a level where the zz channel may be observable this might be something interesting to look at nobody did it so far but yeah with the current luminosity and also with now run three i don't think that we can hope for the zz section it's just too long the number of and the second question is if uh it's possible to have any decays from the 125 hicks to the 95 plus gamma in principle this may be possible i think although let me of course it would be loop induced uh no well it's been one particle connected to two spin zero particles i think is it's not possible okay don't nail me on this yeah but so for example the okay in the standard model this was never investigated of course because there's only one expose on but i'm not aware of any kind of this uh no i'm not aware of anything like this and it's probably forbidden because of the spin and ct interesting and i thought about that okay so very good so we have Omar saying thanks um project marion will in like 15 seconds when he gets this yeah so and then if there's any other question from the audience yes i have a very very nice to talk as them i enjoyed it a lot uh so i have kind of two questions like um if it is necessary to have two doublets for the to have this and i access i mean this is the first i mean let me tell you too because as i've connected yes could be related in some sense could be produce the same signature for instance by introducing uh hicks a doublet plus a triplet hicks model and could be connected with the w mass anomaly this problem with the mass i mean i can answer i mean it's very easily i can answer the second question easily um let's first get rid of the chat here uh okay because it disturbs the view and um the first question so i don't know about a triplet um there are explanations going with the georgia mhc model but not necessarily only for this excess but more with other excesses so in this kind of model it well in the georgia mhc model um as far as i know it's possible we also looked at it a bit yeah so in this sense with triplets you can do it so you don't need necessarily a singlet but this is also kind of natural because you have much more freedom with the triplet yeah and of course you have additional constraints you have additional predictions for w child fixes etc but in principle this can be done yes about the uh well talk about the w boson mass right and let me i have something in the backup because we looked at it and um we investigated this i think let me see um yeah this one right this is our model um this is the uh plane w boson mass versus effective weak mixing angle coupling of the z to fermions measured at the z boson pole and we did a dedicated scan to get the contribution by the t-parameter to get to this infamous cdf value we know that this by now kind of world average or so which would be somewhere closer but if you get to cdf you get to everything in between as well and one can see here what this is the standard set these are the two measurements um w boson mass weak mixing angle from led and the same from sld this is the world average of the two and uh one can see that this is what our model predicts so it's effectively aligned with a t-parameter going here and uh yes one can get higher values and the reason is that we mainly work here for the 95 with a singlet which may mainly singlet like and the standard model like hicks the 125 the heavier hicks are kind of independent and so you can arrange them in a way to get larger contributions to the t-parameter which then gives you i can show this i have the formula here um this is the formula to the row parameter which is t-parameter times uh alpha you can get these corrections with the heavy hicks boson masses you see only the heavy hicks boson masses enter here and then you can get the correct value easily if you want to end up here you can also end up in between wherever you want it's possible no problem at all so it doesn't give you any additional restrictions or predictions i would say it's just possible okay thank you okay we have another question from nicolez and before that marvin says thank you also yeah thanks okay thank you uh so it was wondering to the two-heels of lead model plus a singlet it's not possible to feed this excess with a for instance just with that two-heels of lead model or just with a singlet and okay double it yes um the simplest thing would be uh let's go back would be uh standard model plus a singlet right but if one looks at this here the two hicks bosons that you have they have only one mixing angle that um yeah well mixes them which means that the couplings to tops and bottom quarks always goes in the same direction there's no way out that all the couplings are reduced with the same sine or cosine theta depending how you set up the model so this model is too simple it can't do it two doublets is something that we looked at in the beginning and we found that we really need a large singlet component of the light expose on to do a proper job there are a few papers looking at it there was an original paper that used six model type one but with a different production mode which looked very contrived to me this was by willy hyish and company and then recently my collaborator tomas with some other with a Portuguese group they looked at the complex to example model where they could do it to some extent but if i remember correctly not as well as we could do it here in our singlet extensions you know i don't know whether tomas wants to add something here if he's still here i cannot hear him sorry it took me a minute to turn on the camera when the the two hdmi you kind of the excesses you can do but you have tensions with indirect constraints from from flavor observables and from from edm's because you need the cp violation so there is kind of attention with these indirect constraints as i said but this is why these two hdmi and plus singlet extensions are kind of easier because you can avoid these issues and even within this model or two historic model plus singlet is important for the single to to acquire that could you just make a no vet for this guy i never looked at this i have to admit um as i said i think in the end to hdm if you don't have the vet for the singlet then the additional scalar because of this additional z2 symmetry is a dark meta candidate so this wouldn't work but you can of course neglect them this z2 prime symmetry which is a different incarnation of the twig starlet model plus singlet then it may be possible again but i i don't look at i didn't look at it there are many variations that are quite subtle yeah the symmetries that you have um as i said the vet that you have whether you have real or complex singlet yeah there there's a plethora of models you can investigate but i would be happy to see this yeah i'm not aware that anybody did it so so in this sense um of course i've ever break the z2 symmetry but you're also adding a soft explicit breaking term well there are two there are two symmetries maybe i'll go back to this slide one set two symmetry is included to avoid the flare change in neutral currents um sorry yeah so this is the first set two symmetry that is always there except that increase double model of course this here doesn't play a role here you only have this one and this one is softly broken by the m1 true parameter which is shown here via this term but um this at the tree level doesn't induce flavor changing neutral currents yeah it's only it breaks the set two symmetry but it's said softly because it doesn't introduce this kind of flavor changing recurrence at the tree level and then this is the second set two symmetry that in the end to hdm is usually assumed for historical purposes i would say or the model that has this set two prime symmetry is then called end to hdm if it doesn't have to set two prime symmetry i don't know how it's called but as i said there are many many models like this on the market there's also the two hdms which has a z3 symmetry instead of the z2 prime symmetry or so there are many models on the market okay thank you very much super thank you uh let's see we don't have any other question from from the audience um from from the youtube channel i don't know if there's anything else from the audience we're a bit past the time but if there's any urgent questions it seems not okay so so we're good to go um well i have more questions but we can do that offline thank you very much for the for the very very nice for the very nice talk um and yep let me remind all viewers that we will be back on the 8th of november with basabendu barman giving a talking dark matter i think um so thank you once more and uh we'll see you around okay see you all right