1 00:00:05,730 --> 00:00:07,530 Okay, so good morning everyone. I will talk about CP violation in B decays. 2 00:00:17,039 --> 00:00:23,609 Okay. So first a brief introduction. We know CP violating observed in k, B and D 3 00:00:23,609 --> 00:00:28,919 meson decays, and they are well consistent with CP standard model prediction, 4 00:00:29,549 --> 00:00:36,179 but they are still too small to explain the absence of anti-matter in the in the 5 00:00:36,179 --> 00:00:44,129 universe. So more searches are needed. This slide will will show the 6 00:00:44,279 --> 00:00:49,499 two analysis one is about Lambda b to p 3 pion , the other is B to three pion decays. 7 00:00:49,499 --> 00:00:54,779 For the Unitary triangles measurements, please see the talk from Mark 8 00:00:54,779 --> 00:01:03,989 tomorrow. About Lambda b to p three pion decays. The previous measurements 9 00:01:03,989 --> 00:01:12,779 shows a 3.3 sigma for CPV using the triple product asymmetries. This 10 00:01:12,779 --> 00:01:19,289 measurement performed in the regions of phase space. So we will update it with more 11 00:01:19,349 --> 00:01:29,039 data set to see if this is true or due to statistical fluctuation. For the new 12 00:01:29,039 --> 00:01:37,199 analysis of this decay is updated using 6.6 inverse feta, inverse feta bar data. and 13 00:01:37,199 --> 00:01:45,479 about 27 thousand yields observed which is about four times than the 14 00:01:45,479 --> 00:01:53,699 previous and two approaches are exploited. One is triple product asymmetry use with improved 15 00:01:53,699 --> 00:01:59,099 binning schemes. The other is unbinned energy test method. You can see the 16 00:01:59,159 --> 00:02:09,239 clear signal on the right plot. The trip products are constructed in the 17 00:02:09,239 --> 00:02:21,149 mother particle rest frame and using momenta of final three particles in the lambda b rest frame, 18 00:02:21,149 --> 00:02:24,959 or the lambda b bar rest frame using the corresponding anti 19 00:02:24,959 --> 00:02:33,329 particles. And then we can construct the p-odd asymmetries by comparing the 20 00:02:33,449 --> 00:02:40,649 different sign of the CT for the lambda b decay, and correspondingly compare 21 00:02:40,679 --> 00:02:45,599 comparing the the the signals with different sign of the CT bar for the 22 00:02:45,599 --> 00:02:52,319 lambda b bar decays. After that we can construct the CP violating or the P 23 00:02:52,319 --> 00:02:59,129 violating observable observables as the difference or the sum of the AT and AT 24 00:02:59,129 --> 00:03:10,469 bar. That's shown on the red or the blue boxes, so, how to to get the improved 25 00:03:11,459 --> 00:03:18,629 binning schemes. First we developed an amplitude modes based on these two theoretical 26 00:03:18,629 --> 00:03:27,779 papers and, and then we can introduce. So, first we have model which which is 27 00:03:27,809 --> 00:03:34,079 can reproduce a similar phase space distributions as data observed from the 28 00:03:34,109 --> 00:03:40,559 previous measurements, then we'll introduce the p-odd CP violation, that might 29 00:03:40,559 --> 00:03:46,109 from could from the S and P wave interference as shown in the following 30 00:03:46,109 --> 00:03:52,379 decay chains. The lambda b to N star plus one half and N star plus three half 31 00:03:54,029 --> 00:04:02,489 the phase space region of this decay allows for many N star plus and Delta plus. So, this this 32 00:04:02,489 --> 00:04:10,799 model actually is an approximation of the nature. So, we can do sensitivity studies 33 00:04:10,949 --> 00:04:20,549 based on using this model. With this model, we have a new improved the scheme A 34 00:04:21,149 --> 00:04:28,859 which which is for the phase space division in the polar and the azimuthal angles of the 35 00:04:28,859 --> 00:04:34,679 proton in the Delta plus plus rest frame, or the Delta plus plus in the N star plus 36 00:04:34,679 --> 00:04:43,619 rest frame. We also have a scheme B which is which is based on the absolute 37 00:04:43,619 --> 00:04:51,449 value of the Phi angle defined by the two decay plans. We keep it we use it 38 00:04:51,449 --> 00:04:57,269 because this is a this is this is the same as the previous measurements we want to 39 00:04:57,269 --> 00:05:01,559 check if the symmetries are still there. So, 40 00:05:03,179 --> 00:05:10,049 for the phase space integrated measurements, the acp is consistent with CP symmetry you 41 00:05:10,049 --> 00:05:18,419 can see from the top, then the the ap variables, there is about 5.5 sigma deviation 42 00:05:18,449 --> 00:05:24,869 from the p symmetry. There's Parity violation here. For the measurements in 43 00:05:24,869 --> 00:05:29,279 the different regions of phase space, the sample first split into two samples. 44 00:05:29,609 --> 00:05:35,489 Sample A is for the a1 resonance dominated events, sample two is for the 45 00:05:35,489 --> 00:05:39,899 multiple N star dominated events. As you can see from plots, the first two plots 46 00:05:39,899 --> 00:05:47,249 are for the a1 top two plots, then the bottom two plots are for the N star plots, dominated 47 00:05:47,249 --> 00:05:56,909 events. The red point is for the acp oberservations and the blue points for the 48 00:05:57,269 --> 00:06:04,619 ap measurements. There's no evidence for the CP validation, the highest 49 00:06:04,619 --> 00:06:12,329 significance is about 2.9 sigma, as you can see in the scheme B on the right, 50 00:06:12,719 --> 00:06:21,689 bottom right plot. So for the energy test, energy test is a model-independent 51 00:06:21,689 --> 00:06:26,099 unbinned test, which is sensitive to the local difference between two samples, 52 00:06:26,489 --> 00:06:36,689 which might which might from the CP violation. The statistical test is about 53 00:06:37,259 --> 00:06:42,959 three terms the first two terms are calculation in two samples separately 54 00:06:43,169 --> 00:06:49,589 and the third is for calculation between two samples. The weighted function has two 55 00:06:49,589 --> 00:06:55,499 parameters. The d parameter is the distance between two candidates in 56 00:06:55,499 --> 00:06:59,789 the samples, which is determined by in the space determined by the decay topology 57 00:06:59,999 --> 00:07:05,729 and delta is distance scale can be optimized from the Monte Carlo. The total 58 00:07:05,729 --> 00:07:10,679 sample are divided into four sub sub samples according to the transformation 59 00:07:10,679 --> 00:07:17,429 under the charge and parity transformation. So, we can do the P-odd CP 60 00:07:17,429 --> 00:07:23,429 test by comparing sample I IV versus sample II III. And also P-even CP 61 00:07:23,429 --> 00:07:28,169 test by comparing sample I II versus sample III IV. And also we can do 62 00:07:28,529 --> 00:07:33,809 parity test. By comparing sample I III and the sample II IV 63 00:07:37,709 --> 00:07:39,509 So from the Monte Carlo we have. 64 00:07:40,860 --> 00:07:49,230 We can have three kinds of delta values, then do the test shown in the first in the 65 00:07:49,230 --> 00:07:56,040 previous slide. For the P-even CP conservation test as shown in the blue box. 66 00:07:57,810 --> 00:08:03,210 The highest significance is about 3.0 sigma corresponding to a 67 00:08:03,240 --> 00:08:10,350 delta value equal to 2.7. After combining these three measurements, 68 00:08:10,380 --> 00:08:16,320 the significance is less than 3 sigma. So unfortunately, here there is no evidence 69 00:08:16,320 --> 00:08:26,100 confirmed. For the P Conservation conservation test. The first two test has more 70 00:08:26,100 --> 00:08:33,330 than five sigma. And when combine all three measurements and the parity test 71 00:08:33,330 --> 00:08:39,300 is about 3. 5.3 deviation from the parity conservation. So, here's 72 00:08:39,300 --> 00:08:46,890 the parity violation here. About B to 3 pi decays, the previous analysis 73 00:08:46,890 --> 00:08:51,570 show, shows the raw symmetry localized in regions of Dalitz Plots as you 74 00:08:51,570 --> 00:08:57,690 can see from plot, the colors for different values of the asymmetry. 75 00:08:57,690 --> 00:09:05,130 which may come from the low mass S-wave contribution and rho interference, or 76 00:09:05,130 --> 00:09:10,380 the rho omega mixing, all pipi-kk rescattering. So, an amplitude analysis is 77 00:09:10,380 --> 00:09:17,460 needed to find the correct source of the CPV. For the amplitude analysis, the 78 00:09:17,850 --> 00:09:24,210 models models are built separately for B plus and B minus. And they are two kinds 79 00:09:24,210 --> 00:09:31,410 of parameters the C is complex coefficients for the CP violating and an F is strong 80 00:09:31,410 --> 00:09:36,780 dynamics part, contains the lineshape and the angular distributions 81 00:09:37,140 --> 00:09:43,080 and is CP conserving part. There are three different methods 82 00:09:43,110 --> 00:09:49,080 to describe the S wave contributions, the isobar model, K-matrix and the quasi model 83 00:09:49,080 --> 00:09:54,510 independent approach. And then we construct two observables, the ACP for the 84 00:09:54,510 --> 00:09:58,470 CP violating measurements by comparing the squared 85 00:09:58,500 --> 00:10:05,310 the coefficients And the fit fraction as the integral of each contributions, 86 00:10:06,839 --> 00:10:09,929 so about 20 87 00:10:11,820 --> 00:10:17,610 thousands signals constructed using three inverse feta bar data. And you can see 88 00:10:17,610 --> 00:10:23,700 that there's different structures in the Dalitz Plot. Obviuously the red box 89 00:10:24,000 --> 00:10:31,200 corresponding to to the low resonance, or might rho omega mixing here. And also there's 90 00:10:31,680 --> 00:10:42,270 f2 probably in the plots and also might pipi-KK rescattering. So, from the 91 00:10:42,570 --> 00:10:47,910 numerical results, we can see that the dominant contributions are from the rho 92 00:10:47,970 --> 00:10:56,670 770, which is about to a 55%. And s-wave about 25%. There are larger 93 00:10:56,700 --> 00:11:07,530 CP violation from f2(1270), about 45% and from the s-wave about 14%. But 94 00:11:07,860 --> 00:11:12,090 there's no asymmetry from rho(770) which's large contribution in the 95 00:11:12,090 --> 00:11:24,450 decays, both three methods give the consistent results. 96 00:11:24,720 --> 00:11:31,830 For the rho(770), if you look at the symmetries projections in the cosine theta, 97 00:11:31,830 --> 00:11:37,710 helicity dangles and also the mass. There are small very small asymmetries 98 00:11:37,710 --> 00:11:47,100 almost consistent with zero. But if we look at the asymmetry projections, below, and 99 00:11:47,100 --> 00:11:52,050 above the rho mass, you can see the clear asymmetries and asymmetry change the 100 00:11:52,050 --> 00:11:58,530 signs crossing mass, cross rho mass. If you put them together the 101 00:11:58,560 --> 00:12:08,040 asymmetries cancer perfectly. this characteristic pattern is due to the SP 102 00:12:08,040 --> 00:12:14,340 wave interference, which proportional to the cosine the helicity. So when 103 00:12:15,090 --> 00:12:20,220 integral over this angle, asymmetry vanishes. That's why we cannot see the 104 00:12:20,280 --> 00:12:27,600 asymmetries for the integrated measurements. And also we'll find 105 00:12:27,690 --> 00:12:33,750 first observation for a CPV in the process involving intense f2(1270) you 106 00:12:33,750 --> 00:12:40,440 can see the larger asymmetries from the from the plot. A large plot CP 107 00:12:40,440 --> 00:12:48,720 asymmetry can go to 40% and there's a small discrepancy between 108 00:12:48,720 --> 00:12:55,590 the mode and the data in the mass of the f2. afters some systematic studies the 109 00:12:56,010 --> 00:12:58,530 this CP violation here is robust. 110 00:13:01,140 --> 00:13:03,510 For the s-wave results, 111 00:13:05,400 --> 00:13:12,990 these three approaches are well in good agreement. And if you look at the left 112 00:13:13,020 --> 00:13:16,860 top left plots for the squared amplitude and 113 00:13:18,119 --> 00:13:18,869 114 00:13:21,630 --> 00:13:22,410 if you look at the 115 00:13:23,880 --> 00:13:26,850 top right plot, this is the phase of amplitude model. 116 00:13:29,010 --> 00:13:34,200 The phase is hard to describe because due to different assumptions here and also 117 00:13:34,530 --> 00:13:42,960 here is clear that you can see there's no f0(1500) are in the isobar model. And 118 00:13:42,960 --> 00:13:51,390 also this comparison can be made by by split B plus and B minus. So as 119 00:13:51,390 --> 00:13:57,840 shown in the bottom three plots, is clear that there are similar CPV 120 00:13:57,870 --> 00:14:03,750 pattern for these three approaches. Like, for example, the, the there's larger 121 00:14:03,840 --> 00:14:11,310 asymmetries in the low mass region. And the asymmetries change sign when the pipi 122 00:14:11,310 --> 00:14:19,260 mass goes to one GeV which is corresponding to f0(980) and also the and started to 123 00:14:19,260 --> 00:14:27,690 change a sign from if mass larger than one GeV. So, so there is last page, the summary. 124 00:14:28,230 --> 00:14:32,550 So, these multiple decays are an interesting place to search for CP 125 00:14:32,550 --> 00:14:39,540 violation, because the rich phase space structures allow, allow to, to to improve 126 00:14:39,540 --> 00:14:47,070 the sensitivity for CPV and parity violation observed in Lambda b to p 3 pion 127 00:14:47,070 --> 00:14:54,660 decays, but we didn't confirm the evidence of CP violation. So the more data are needed 128 00:14:54,990 --> 00:15:03,240 to do further studies and we found the several sources of CPV in B to 3 pion decays. 129 00:15:03,570 --> 00:15:10,320 The new CPV the pattern of the rho(770) and the CPV found in process was 130 00:15:10,320 --> 00:15:18,240 a tensor tensor f2(1270) and CPV in ths s-wave contributions in the low 131 00:15:18,240 --> 00:15:21,060 mass regions. That's all. Thank you. 132 00:15:23,280 --> 00:15:25,530 Thank you very much Jinlin, was very clear. 133 00:15:26,910 --> 00:15:34,350 For questions, so please ask people to use the hand raising feature from 134 00:15:36,660 --> 00:15:42,690 raise your hand on the application, if possible, if you can't put a comment in 135 00:15:42,690 --> 00:15:47,700 the chat. And we'll try to get you to speak at the right moment. So is there any 136 00:15:47,700 --> 00:15:49,800 question for the speaker at this time? 137 00:15:51,419 --> 00:15:52,379 Maybe to start 138 00:15:53,730 --> 00:16:04,170 since I don't see any hand. I have a comment on the first analysis on Lambda b. Sorry, in your first paper 139 00:16:04,170 --> 00:16:10,830 using the same channel you publishes in nature, yes, you publish the 140 00:16:10,830 --> 00:16:17,400 evidence for CP violation and know nothing, let's say for P violation. Now 141 00:16:17,400 --> 00:16:24,540 you use a same qualities partially correlated with the first one, and you 142 00:16:24,540 --> 00:16:28,590 have a bit less than three sigma for CP violation, I don't think is the issue 143 00:16:28,590 --> 00:16:35,220 since you moved from three point what was 3.3 to something, let's face it, it can be 144 00:16:35,250 --> 00:16:41,700 of course, due to the statistics, but you have now five on five sigma for the 145 00:16:41,820 --> 00:16:47,460 P violation. So I have a couple of questions. So did you check the 146 00:16:47,460 --> 00:16:54,960 compatibility for these two analyses that that that use the same final state? For 147 00:16:54,960 --> 00:17:00,600 example, you may be you did? Okay, you could try to perform the old analysis 148 00:17:00,630 --> 00:17:05,160 on the new data set the total sample that you use now or vice versa in order to in 149 00:17:05,160 --> 00:17:12,510 order to see if you have agreement or not since moving from no evidence to 5.5 sigma 150 00:17:12,510 --> 00:17:16,470 for violation, I think that is a bit strange. 151 00:17:19,230 --> 00:17:26,100 Actually, we did some comparisons separately for for the first example, and 152 00:17:26,130 --> 00:17:37,320 the second samples also applied the same same selections. Found actually there's 153 00:17:38,010 --> 00:17:51,390 there's about 2.6 sigma consistent between two to two samples. So we think that this 154 00:17:51,390 --> 00:17:56,850 is due to the sense of statistical fluctuation for the CP violation, but 155 00:17:56,850 --> 00:18:01,050 for the parity violation, and we think that this is Due to the we have the 156 00:18:01,050 --> 00:18:10,290 larger statistics, so we can find that it's is about 5.5 sigma 157 00:18:10,290 --> 00:18:10,890 deviation. 158 00:18:14,940 --> 00:18:15,690 Okay, thank you. 159 00:18:21,690 --> 00:18:23,370 I would have a question if I can. 160 00:18:26,640 --> 00:18:30,810 Yes Luccia go ahead. So this is more referred to the second measurement, you show 161 00:18:30,810 --> 00:18:42,600 B to the 3 pions . So it's great to observe new sources of CP violation. 162 00:18:42,600 --> 00:18:51,570 My question about these is, can you get any CKM information from this decays? 163 00:18:53,550 --> 00:18:59,490 I don't think so. Because here is the phase that actually is associated with the 164 00:18:59,490 --> 00:19:09,360 resonance or rescattering? So, in this kind of level, I don't think it's direct to the 165 00:19:09,360 --> 00:19:10,860 CKM angles. 166 00:19:16,139 --> 00:19:18,839 Because when when you construct the amplitudes 167 00:19:21,330 --> 00:19:29,310 when construct the amplitudes actually this is on the hadron level. So, the phase 168 00:19:29,880 --> 00:19:31,830 is not direct to the CKM angle. 169 00:19:36,540 --> 00:19:37,530 Okay, thanks. 170 00:19:39,450 --> 00:19:41,340 Okay. There are no other 171 00:19:42,450 --> 00:19:45,990 burning questions so we'll move to the next talk. So we're still on time. 172 00:19:48,000 --> 00:19:48,990 All right, thanks.