Split (2)

test.2020 · 4.02k rows

talk_id stringclasses 15 values	segment_pos uint16 1 357	title stringclasses 15 values	speaker_id stringclasses 15 values	transcription stringlengths 2 376
856696c114	1	Electroweak Penguin Decays	5034121	Yes. Hi. It's a pleasure to talk to you about the latest results from
856696c114	10	Electroweak Penguin Decays	5034121	the limits on the B to ee branching ratio. On slide four, what would be considered
856696c114	100	Electroweak Penguin Decays	5034121	predictions also changed a bit. The form factor uncertainties actually
856696c114	101	Electroweak Penguin Decays	5034121	decreased. But the sub-leading corrections to the interpolation, it
856696c114	102	Electroweak Penguin Decays	5034121	actually became more conservative. Together with a small shift in central
856696c114	103	Electroweak Penguin Decays	5034121	value of the observation, this results in just a slight decrease in discrepancy with
856696c114	104	Electroweak Penguin Decays	5034121	the Standard Model. But the behaviour of all of our angular observables is now more
856696c114	105	Electroweak Penguin Decays	5034121	consistent with a single change in C9 which is the vector boson coefficient.
856696c114	106	Electroweak Penguin Decays	5034121	Speaking of Wilson coefficients, just one slide on effective theory. This is a
856696c114	107	Electroweak Penguin Decays	5034121	tool that helps us write the process as a sum over effective operators, that
856696c114	108	Electroweak Penguin Decays	5034121	describe the physics happening at this effective four point interaction on the
856696c114	109	Electroweak Penguin Decays	5034121	bottom right block,
856696c114	11	Electroweak Penguin Decays	5034121	as electroweak penguins are the B to sll transitions. So I'm not talking about
856696c114	110	Electroweak Penguin Decays	5034121	and their Wilson coefficients. These parameterise the amount of which kind of
856696c114	111	Electroweak Penguin Decays	5034121	physics happens at this vertex. The idea is that this allows for a model
856696c114	112	Electroweak Penguin Decays	5034121	independent interpretation of which kind of new physics is happening here. But also
856696c114	113	Electroweak Penguin Decays	5034121	it allows to combine different measurements of different processes which
856696c114	114	Electroweak Penguin Decays	5034121	are sensitive to a subset of the same Wilson coefficients. Now, in this Q-
856696c114	115	Electroweak Penguin Decays	5034121	squared region where these bins deviate, the C9 and the C10 - the vector and
856696c114	116	Electroweak Penguin Decays	5034121	axial vector - are actually the most important ones. When we allow a freedom in C9
856696c114	117	Electroweak Penguin Decays	5034121	and C10 in a fit, you can see on the bottom left that we have about 2.8
856696c114	118	Electroweak Penguin Decays	5034121	sigma deviation from the Standard Model. But mostly this appears to be in the C9
856696c114	119	Electroweak Penguin Decays	5034121	direction, so the vector direction. If we only allow to vary C9,
856696c114	12	Electroweak Penguin Decays	5034121	where the gamma is on shell, I'm talking about the diagram shown on the right here.
856696c114	120	Electroweak Penguin Decays	5034121	you see the middle plot, we are actually 3.3 standard deviations away with just
856696c114	121	Electroweak Penguin Decays	5034121	this K*mumu measurement. And then on the right, for comparison, you see
856696c114	122	Electroweak Penguin Decays	5034121	when we change C9 to minus one, which seems to be this preferred value, the
856696c114	123	Electroweak Penguin Decays	5034121	Standard Model and the data - the theory and the data -
856696c114	124	Electroweak Penguin Decays	5034121	match better by eye. So this is going from the solid line or the blue blocks to these
856696c114	125	Electroweak Penguin Decays	5034121	blue dashed lines. Slide 14. I mentioned combinations of different
856696c114	126	Electroweak Penguin Decays	5034121	measurements contributing to the same Wilson coefficients, so it's a natural
856696c114	127	Electroweak Penguin Decays	5034121	moment to move on to the second analysis I wanted to highlight, which is the
856696c114	128	Electroweak Penguin Decays	5034121	measurement of B to ee. This is also a b2sll transition, but it has a different
856696c114	129	Electroweak Penguin Decays	5034121	decay topology, to leptons only. And because of helicity suppression, this is
856696c114	13	Electroweak Penguin Decays	5034121	These are flavour changing and neutral. So these are forbidden at tree level in the
856696c114	130	Electroweak Penguin Decays	5034121	even more suppressed. If you see this equation in the branching ratio here, the
856696c114	131	Electroweak Penguin Decays	5034121	helicity suppression occurs in front of this C10 term, which is the same C10
856696c114	132	Electroweak Penguin Decays	5034121	as we saw for this angular analysis. But there are also scalar and pseudo-scalar
856696c114	133	Electroweak Penguin Decays	5034121	contributions which were not there. They contribute to the
856696c114	134	Electroweak Penguin Decays	5034121	overall picture of the coefficients, of course, but the B to ee analysis is even
856696c114	135	Electroweak Penguin Decays	5034121	more suppressed in C10. So this is a very good probe of scalar new physics. And even
856696c114	136	Electroweak Penguin Decays	5034121	one observation, one event, would actually be a very significant hint for new physics
856696c114	137	Electroweak Penguin Decays	5034121	already. In slide 15, the B to mumu results. Aiden already talked about it. So, I will
856696c114	138	Electroweak Penguin Decays	5034121	not mention that now. But on the bottom left, you can see our results for the
856696c114	139	Electroweak Penguin Decays	5034121	search of B to ee, which resulted in no observation, but a limit that is 30
856696c114	14	Electroweak Penguin Decays	5034121	Standard Model. So they are very suppressed, and called rare decays. And
856696c114	140	Electroweak Penguin Decays	5034121	times better than the previous CDF one. The global picture of those
856696c114	141	Electroweak Penguin Decays	5034121	coefficients will help constrain which kinds of new physics
856696c114	142	Electroweak Penguin Decays	5034121	might explain our other observations.
856696c114	143	Electroweak Penguin Decays	5034121	In slide 16, I'm done with the LHCb measurements. But I just wanted
856696c114	144	Electroweak Penguin Decays	5034121	to mention that there are many independent groups who do these models-independent
856696c114	145	Electroweak Penguin Decays	5034121	fits to a lot of these measurements combined: in the order of 170. And they
856696c114	146	Electroweak Penguin Decays	5034121	find somewhat consistently that C9 only, deviates from zero by four sigma to
856696c114	147	Electroweak Penguin Decays	5034121	five sigma, depending on your assumptions and which group you ask. But
856696c114	148	Electroweak Penguin Decays	5034121	it all seems to be consistent with a single change in a Wilson coefficient, this
856696c114	149	Electroweak Penguin Decays	5034121	factor seems to be minus one, maybe. So this is a very interesting result, how all
856696c114	15	Electroweak Penguin Decays	5034121	because of that, sensitive to new physics in the loops, or even at tree
856696c114	150	Electroweak Penguin Decays	5034121	of these measurements somehow seem to point to a single explanation. I think
856696c114	151	Electroweak Penguin Decays	5034121	that's fascinating. So any kind of vector new physics is very hot at the
856696c114	152	Electroweak Penguin Decays	5034121	moment, of course, because of this. On slide 17, my conclusion. I showed you two
856696c114	153	Electroweak Penguin Decays	5034121	new exciting results on b2sll transitions from LHCb: the angular analysis K*mumu,
856696c114	154	Electroweak Penguin Decays	5034121	and this new rare decay, B to ee, where we have a limit. The discrepancy in this angular
856696c114	155	Electroweak Penguin Decays	5034121	analysis with the Standard Model still stands, although it did not increase
856696c114	156	Electroweak Penguin Decays	5034121	because of various reasons. And all of these results are not done with the full
856696c114	157	Electroweak Penguin Decays	5034121	dataset yet: we’re still analysing the remaining data that we took in Run-2, so we
856696c114	158	Electroweak Penguin Decays	5034121	can expect the what we call ‘Run-1+2 legacy results’ soon. This also
856696c114	159	Electroweak Penguin Decays	5034121	goes for the new B to mumu analysis, which is coming out, hopefully,
856696c114	16	Electroweak Penguin Decays	5034121	level, if that's the form that new physics takes. We can categorise these penguins
856696c114	160	Electroweak Penguin Decays	5034121	very soon. The B to ee analysis, and on top of that, we actually have many other analysis
856696c114	161	Electroweak Penguin Decays	5034121	ongoing. These are R(X) analyses that Miriam will talk about after me, but also we
856696c114	162	Electroweak Penguin Decays	5034121	finally have enough statistics to measure the angular analysis of K*ee
856696c114	163	Electroweak Penguin Decays	5034121	actually. So all kinds of very interesting new results will hopefully come out soon
856696c114	164	Electroweak Penguin Decays	5034121	with that more data.
856696c114	165	Electroweak Penguin Decays	5034121	And that's it. Thank you. Thank you for your attention.
856696c114	166	Electroweak Penguin Decays	5034121	Question to Jacco, please raise your hand
856696c114	167	Electroweak Penguin Decays	5034121	Yeah, my chemical yosity just started. Sure.
856696c114	168	Electroweak Penguin Decays	5034121	So, you mentioned second edition and China is that you can start of course not but
856696c114	169	Electroweak Penguin Decays	5034121	there is one missing I remember the visa are quite old the result from the bar
856696c114	17	Electroweak Penguin Decays	5034121	in three classes: the ratios of different flavours of leptons, which we call R(X),
856696c114	170	Electroweak Penguin Decays	5034121	about B plus C two three plus down that was about two or something time 10 to the
856696c114	171	Electroweak Penguin Decays	5034121	minus three
856696c114	172	Electroweak Penguin Decays	5034121	is quite interesting. I think c said
856696c114	173	Electroweak Penguin Decays	5034121	should be sensitive to the effects massing and the the tweaks doubled more than
856696c114	174	Electroweak Penguin Decays	5034121	So, do you think it is something that can be feasible in Italy should be a thing. So
856696c114	175	Electroweak Penguin Decays	5034121	since you use already final stage without?
856696c114	176	Electroweak Penguin Decays	5034121	Yeah, so
856696c114	177	Electroweak Penguin Decays	5034121	I will I will not say it's not possible? Absolutely not. We've made an attempt at B
856696c114	178	Electroweak Penguin Decays	5034121	to dow which is even more challenging. So it's definitely something we we studied,
856696c114	179	Electroweak Penguin Decays	5034121	we can study I should say. But it is tricky at the LSE. Right? So these these
856696c114	18	Electroweak Penguin Decays	5034121	but that's the subject of the talk by Miriam, which is right after mine. And the
856696c114	180	Electroweak Penguin Decays	5034121	measurements with without, you have to make it takes time. I should say that,
856696c114	181	Electroweak Penguin Decays	5034121	yeah, I would expect the result like that coming from LGB soon, but it doesn't mean
856696c114	182	Electroweak Penguin Decays	5034121	it's not something maybe we can all do. And it adds to the to the full picture. So
856696c114	183	Electroweak Penguin Decays	5034121	it's an interesting channel, I think.
856696c114	184	Electroweak Penguin Decays	5034121	Thank you very much.
856696c114	185	Electroweak Penguin Decays	5034121	Other question
856696c114	186	Electroweak Penguin Decays	5034121	seems not so we can move to the third
856696c114	19	Electroweak Penguin Decays	5034121	measurements of branching fractions and angular observables. We measure these
856696c114	2	Electroweak Penguin Decays	5034121	last March actually, on electroweak penguin decays from LHCb. So on slide 2,
856696c114	20	Electroweak Penguin Decays	5034121	as a function of the Q-squared which is the invariant mass of, in this case, the

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