Violation in Mixing

More documents

Recommendations

Info

98 Strategy and Tools for Charmless Two-body � Decays Analysis ¯ 10.1 million events (�� fb ) ÙÙ, �� and ×× Monte Carlo ¯ 6.2 million events (�� fb ) Monte Carlo ¯ 4.0 million events (�� fb ) � � Monte Carlo ¯ 0.94 million events ( � fb ) generic � charmless Monte Carlo ¯ �k events of each signal Monte Carlo sample The � � � � and � � £ � decays have also been analyzed for control sample studies. All cuts are tuned using Monte Carlo simulation and off-resonance data samples together with the sidebands of the on-resonance data. Cuts were defined before analyzing the signal band of the on-resonance data-set (blind analysis). 4.2 Event selection The preselection is done checking the value of a number of tagbits based on some event variables: each event should pass the so called BGFMultiHadron selection which consists of requiring at least 3 charged tracks and Ê � �� (see Eq. (4.4) for the definition of this variable). Then, a specific selector has been studied to set a tagbit (named TagTwoBody) for a very efficient exclusive selection of charmless twobody B decays. It is designed to look separately for � � , � ¦ Ã Ë, � � ¦ , � � , � Ã Ë and Ã Ë Ã Ë , selected among the charged tracks and the Ã Ë candidates reconstructed with loose criteria (see Sec. 3.1.1). For this selector we consider as a � every cluster in the �Å� (where a cluster is a connected set of �Å� crystals with an energy deposit) with a raw (not calibrated) energy greater than ��Î� . In order to take into account � ’s split in two clusters, we use also a list of pseudoclusters created by every pair of clusters having their centroids closer than ÑÖ��. In order to reduce combinatorics, we loop over charged candidate or neutral cluster lists without considering tracks (clusters) with momentum (energy) less than ��Î� ��Î� . A pair of candidate � � (� ¦ ÃË , ÃËÃË ) is accepted when both tracks (track and ÃË , both ÃË )havea momentum between � and ��Î�1 , when the sum of their momenta (Ô £ � of the � candidate) is in the range – �� Î� , and when the angle � £ between the two tracks (track and Ã Ë, both Ã Ë) is such that Ó× � £ � ��. All quantities (Ô £ and � £ ) are calculated in the center-of-mass (CM) rest-frame. A pair of candidate � ¦ � (� Ã Ë ) is defined when the sum of the energies of a track and a cluster in the CM rest-frame is between �� and ��Îand the angle � £ between track direction and cluster centroid is such that Ó× � £ � ��. A pair of candidate � � is defined when the sum of the energies of the two clusters in the CM rest-frame is between �� and ��Î and the angle � £ between the cluster centroids is such that Ó× � £ � ��. 1 we use � (� ) mass hypothesis for charged track (neutral cluster) MARCELLA BONA
4.2 Event selection 99 channel selection � � � � lists: ChargedTracks, KSLoose (Ã Ë � � � ) � ¦ � � ¦ Ã Ë if Ô� ��Î� � �Ã Ë Ã Ë select two oppositely charged tracks (one track and a Ã Ë ) if each ��Ô £ � ��Î� and if �� Ô Ô £ � �� Î� and if � £ relative angle between tracks Ó× � £ � �� ¦ � � ¦ � lists: ChargedTracks, pseudo-EmcCluster and EmcCluster, KSLoose � � � � if �� Î� � �� ÃË select two EmcClusters (one tracks/Ã Ë and EmcCluster) �� (��) � � � £ � �� (��) � £ relative angle between candidates Ó× � £ � �� Table 4-1. Requirements implemented in TagTwoBody selector for the charmless two-body modes. channel efficiency � � �� ¦ � Ã Ë � ¦ �� ¦ � � � ¦ �� ¦ � � � �� ¦ � � Ã Ë Ã Ë Ã Ë �� ¦ � �� ¦ � Table 4-2. The tagbit TagTwoBody efficiency evaluated with Monte Carlo simulated samples of signal events. Table 4-1 contains the summary of the above described conditions: the tagbit TagTwoBody is the logical OR of these requirements. In Table 4-2 the efficiencies evaluated with fully simulated Monte Carlo signal events are listed. The sample passing these tagbit selections remains primarily background. Further selection criteria are employed to greatly reduce the background while maintaining a high efficiency for signal events. Additional cuts are used to ensure that the PID information for each of the candidates is of sufficient quality to be used in the analysis. STRATEGY AND TOOLS FOR CHARMLESS TWO-BODY � DECAYS ANALYSIS
Page 1 and 2:
ÍÒ�Ú�Ö×�Ø��
Page 3 and 4:
Contents Introduction . ...........
Page 5 and 6:
4 Strategy and Tools for Charmless
Page 7 and 8:
7.2 Branching fraction � � �
Page 9 and 10:
Introduction The main goal of the B
Page 11 and 12:
1 �È Violation in the �� Sys
Page 13 and 14:
1.2 Neutral � Mesons 7 Note, howe
Page 15 and 16:
1.2 Neutral � Mesons 9 Applying t
Page 17 and 18:
1.2 Neutral � Mesons 11 �È �
Page 19 and 20:
1.2 Neutral � Mesons 13 ��
Page 21 and 22:
1.2 Neutral � Mesons 15 � ¡�
Page 23 and 24:
1.2 Neutral � Mesons 17 and � a
Page 25 and 26:
1.2 Neutral � Mesons 19 given tim
Page 27 and 28:
1.3 The Three Types of �È Violat
Page 29 and 30:
Page 31 and 32:
Page 33 and 34:
1.4 �È Violation in the Standard
Page 35 and 36:
Page 37 and 38:
Page 39 and 40:
Page 41 and 42:
Page 43 and 44:
1.5 Determination of « 37 1.5 Dete
Page 45 and 46:
1.5 Determination of « 39 Assuming
Page 47 and 48:
1.5 Determination of « 41 Figure 1
Page 49 and 50:
1.5 Determination of « 43 b q (a)
Page 51 and 52:
1.5 Determination of « 45 � �
Page 53 and 54: 2 The BABAR Experiment 2.1 Physics
Page 55 and 56: 2.1 Physics at � � B Factory op
Page 57 and 58: 2.2 The BABAR detector. 51 Integrat
Page 59 and 60: 2.2 The BABAR detector. 53 The dete
Page 61 and 62: 2.2 The BABAR detector. 55 two oute
Page 63 and 64: 2.2 The BABAR detector. 57 SVT Effi
Page 65 and 66: 2.2 The BABAR detector. 59 324 1015
Page 67 and 68: Efficiency 2.2 The BABAR detector.
Page 69 and 70: 2.2 The BABAR detector. 63 2.2.4 Th
Page 71 and 72: entries per mrad 2.2 The BABAR dete
Page 73 and 74: 2.2 The BABAR detector. 67 entries
Page 75 and 76: 2.2 The BABAR detector. 69 energies
Page 77 and 78: 2.2 The BABAR detector. 71 The main
Page 79 and 80: Efficiency 2.2 The BABAR detector.
Page 81 and 82: 2.2 The BABAR detector. 75 Table 2-
Page 83 and 84: 3 Ã Ë reconstruction and efficien
Page 85 and 86: 3.3 Studies on data 79 19.5° BINS
Page 87 and 88: 3.3 Studies on data 81 ¯ off-reson
Page 89 and 90: 3.3 Studies on data 83 0.504 0.502
Page 91 and 92: 3.3 Studies on data 85 0.03 0.025 0
Page 95 and 96: 3.3 Studies on data 89 N(π + π -
Page 99 and 100: 3.3 Studies on data 93 Figure 3-13.
Page 103: 4 Strategy and Tools for Charmless
Page 107 and 108: 4.2 Event selection 101 ÀÐ �
Page 109 and 110: 4.2 Event selection 103 Figure 4-2.
Page 111 and 112: 4.3 Background fighting 105 Figure
Page 113 and 114: 4.4 PID selection 107 In the case o
Page 115 and 116: 4.4 PID selection 109 θ c Cut Effi
Page 117 and 118: 4.5 Tracking Corrections 111 Ë�
Page 119 and 120: 4.6 Analysis methods 113 Ñ�Ë si
Page 121 and 122: 4.6 Analysis methods 115 Events/2.5
Page 123 and 124: 4.6 Analysis methods 117 Figure 4-1
Page 125 and 126: 4.6 Analysis methods 119 θ c radia
Page 127 and 128: 5 Measurement of Branching Fraction
Page 129 and 130: 5.2 Ã Ë reconstruction 123 1 0.8
Page 131 and 132: 5.3 Analysis Strategy 125 0.35 0.3
Page 133 and 134: 5.4 Background Suppression and PDF
Page 139 and 140: 5.5 Maximum likelihood analysis 133
Page 151 and 152: 5.6 Counting analysis 145 Table 5-1
Page 153 and 154: 5.7 Determination of branching frac
Page 155 and 156:
6 Measurement of Branching Fraction
Page 157 and 158:
6.3 The maximum likelihood analysis
Page 159 and 160:
Page 161 and 162:
Page 163 and 164:
6.4 Counting analysis 157 120 100 8
Page 165 and 166:
6.5 Analysis choice 159 6.5 Analysi
Page 167 and 168:
6.6 Results on the Run1 data-set 16
Page 169 and 170:
6.7 Determination of the branching
Page 171 and 172:
7 Analysis of the time-dependent
Page 173 and 174:
7.3 Analysis strategy 167 Parameter
Page 175 and 176:
7.4 Data samples and event selectio
Page 177 and 178:
7.4 Data samples and event selectio
Page 179 and 180:
7.5 Background characterization 173
Page 181 and 182:
7.5 Background characterization 175
Page 183 and 184:
Page 185 and 186:
Page 187 and 188:
Page 189 and 190:
Page 191 and 192:
7.8 Validation studies 185 Figure 7
Page 193 and 194:
7.8 Validation studies 187 100 75 5
Page 195 and 196:
7.8 Validation studies 189 Figure 7
Page 197 and 198:
7.8 Validation studies 191 Paramete
Page 199 and 200:
7.9 Results 193 Parameter Fit Resul
Page 201 and 202:
7.9 Results 195 Events/2 MeV/c 2 Ev
Page 203 and 204:
7.10 Systematic studies 197 Categor
Page 205 and 206:
7.11 Summary 199 �Ã� Ë��
Page 207 and 208:
7.11 Summary 201 �Ã� Ë��
Page 209 and 210:
7.11 Summary 203 Variation �Ã�
Page 211 and 212:
BIBLIOGRAFIA 205 Bibliografia Chapt
Page 213 and 214:
BIBLIOGRAFIA 207 [38] J. Charles, P
Page 215 and 216:
BIBLIOGRAFIA 209 Chapter 7 [67] D.
show all

Violation in Mixing

Create successful ePaper yourself

Delete template?

Save as template?