If you've got this far then you're probably now an expert at identifying different types of Z⁰ and W pair events. Here is a more difficult challenge to keep you on your toes!

In the previous challenge you measured the fractions of Z⁰s that decay to each type of particle-antiparticle pair. Another important measurement is measuring the fractions of W pairs that decay into each possible class. Remember these classes are

the four-jet events: ,

the two lepton, two neutrino events:

or the lepton-neutrino, quark-anti-quark events: , , .

In this challenge you are asked to look through a list of events and keep count of the various types of W pair decays. But beware! There are other types of events, such as Z⁰ decays, mixed in as well. Therefore, for each event you first need to determine whether you're looking at a W pair decay or some other kind of event.

One measurement you can make is to count the total number of W pair events (having "thrown away" all the events you didn't think were W pairs). Count also the number of W pair events in each of the classes listed above. Thus you can determine the fractions of W pair events that end up in the various classes.

We expect the number of , and events each to be 0.29 times the number of events. We also expect to observe that the total number of events to be 0.18 times the number of events. Check your measurements are statistically consistent with these values.

A helpful hint! In challenge part 5 you looked at some more complicated types of events. Here you will meet some Z⁰ decays which involve the production of High Energy Photons in Events Containing a Particle-Antiparticle Pair . Where necessary, both the end-on and side views have been given to help you decide which type of decay has occurred.

The events are listed below. If you're working toghether as a group each of you may like to look at a different set of events and you can then combine your measurements. If you are working on your own, but don't have time to look at all events you can just look at a subset.

Event 1
Event 2
Event 3
Event 4
Event 5
Event 6
Event 7
Event 8
Event 9
Event 10
Event 11
Event 12
Event 13
Event 14
Event 15
Event 16
Event 17
Event 18
Event 19
Event 20
Event 21
Event 22
Event 23
Event 24 end-on side
Event 25
Event 26
Event 27
Event 28
Event 29
Event 30
Event 31 end-on side
Event 32
Event 33
Event 34
Event 35
Event 36
Event 37
Event 38
Event 39
Event 40
Event 41
Event 42
Event 43
Event 44
Event 45
Event 46
Event 47
Event 48
Event 49
Event 50
Event 51
Event 52
Event 53 end-on side
Event 54
Event 55
Event 56
Event 57
Event 58
Event 59
Event 60
Event 61
Event 62
Event 63
Event 64
Event 65
Event 66
Event 67
Event 68
Event 69
Event 70
Event 71
Event 72
Event 73
Event 74
Event 75
Event 76
Event 77
Event 78
Event 79
Event 80
Event 81
Event 82
Event 83
Event 84
Event 85
Event 86
Event 87
Event 88
Event 89
Event 90
Event 91
Event 92
Event 93
Event 94
Event 95
Event 96
Event 97
Event 98
Event 99 end-on side
Event 100
Event 101
Event 102
Event 103
Event 104
Event 105
Event 106
Event 107
Event 108
Event 109
Event 110
Event 111
Event 112
Event 113
Event 114
Event 115
Event 116
Event 117
Event 118
Event 119
Event 120
Event 121
Event 122
Event 123
Event 124
Event 125
Event 126
Event 127
Event 128
Event 129
Event 130
Event 131
Event 132
Event 133
Event 134 end-on side
Event 135
Event 136
Event 137
Event 138
Event 139
Event 140
Event 141
Event 142
Event 143
Event 144
Event 145 end-on side
Event 146
Event 147
Event 148
Event 149
Event 150
Event 151
Event 152
Event 153
Event 154
Event 155
Event 156
Event 157
Event 158
Event 159
Event 160 end-on side
Event 161
Event 162
Event 163
Event 164
Event 165
Event 166
Event 167
Event 168
Event 169
Event 170
Event 171 end-on side
Event 172
Event 173
Event 174
Event 175
Event 176
Event 177
Event 178
Event 179
Event 180
Event 181
Event 182
Event 183
Event 184
Event 185
Event 186
Event 187
Event 188
Event 189
Event 190
Event 191
Event 192
Event 193
Event 194
Event 195
Event 196
Event 197
Event 198
Event 199
Event 200
Event 201
Event 202
Event 203
Event 204
Event 205
Event 206
Event 207
Event 208
Event 209
Event 210
Event 211
Event 212
Event 213
Event 214
Event 215
Event 216
Event 217
Event 218
Event 219
Event 220
Event 221
Event 222
Event 2231
Event 224
Event 225
Event 226
Event 227
Event 228
Event 229
Event 230
Event 231
Event 232
Event 233
Event 234
Event 235
Event 236
Event 237
Event 238
Event 239
Event 240
Event 241
Event 242
Event 243
Event 244
Event 245
Event 246
Event 247
Event 248
Event 249
Event 250
Event 251
Event 252
Event 253
Event 254
Event 255
Event 256
Event 257
Event 258
Event 259
Event 260
Event 261
Event 262
Event 263
Event 264
Event 265
Event 266
Event 267 end-on side
Event 268
Event 269
Event 270
Event 271
Event 272
Event 273
Event 274
Event 275
Event 276
Event 277
Event 278
Event 279
Event 280
Event 281
Event 282
Event 283
Event 284
Event 285
Event 286
Event 287
Event 288
Event 289 end-on side
Event 290
Event 291
Event 292
Event 293
Event 294
Event 295
Event 296
Event 297
Event 298
Event 299
Event 300
Event 301
Event 302
Event 303
Event 304
Event 305 end-on side
Event 306
Event 307
Event 308
Event 309
Event 310
Event 311
Event 312
Event 313
Event 314
Event 315
Event 316
Event 317
Event 318
Event 319
Event 320
Event 321
Event 322
Event 323
Event 324
Event 325
Event 326
Event 327
Event 328
Event 329
Event 330
Event 331
Event 332
Event 333
Event 334
Event 335
Event 336
Event 337
Event 338
Event 339
Event 340
Event 341
Event 342
Event 343
Event 344
Event 345
Event 346
Event 347
Event 348
Event 349
Event 350
Event 351
Event 352
Event 353
Event 354
Event 355
Event 356
Event 357
Event 358
Event 359
Event 360
Event 361
Event 362
Event 363
Event 364
Event 365
Event 366
Event 367
Event 368
Event 369
Event 370
Event 371
Event 372
Event 373
Event 374
Event 375
Event 376
Event 377
Event 378
Event 379
Event 380
Event 381
Event 382
Event 383
Event 384
Event 385
Event 386
Event 387
Event 388
Event 389
Event 390
Event 391
Event 392
Event 393
Event 394
Event 395
Event 396
Event 397
Event 398
Event 399
Event 400
Event 401
Event 402
Event 403
Event 404
Event 405
Event 406
Event 407
Event 408
Event 409
Event 410
Event 411
Event 412
Event 413
Event 414
Event 415
Event 416
Event 417
Event 418
Event 419
Event 420
Event 421
Event 422
Event 423
Event 424
Event 425
Event 426
Event 427
Event 428
Event 429
Event 430
Event 431
Event 432
Event 433
Event 434
Event 435
Event 436
Event 437
Event 438
Event 439
Event 440
Event 441
Event 442
Event 443
Event 444
Event 445
Event 446
Event 447
Event 448
Event 449
Event 450
Event 451
Event 452
Event 453
Event 454
Event 455
Event 456
Event 457
Event 458
Event 459
Event 460
Event 461
Event 462
Event 463
Event 464
Event 465
Event 466
Event 467
Event 468
Event 469
Event 470
Event 471
Event 472
Event 473
Event 474
Event 475
Event 476
Event 477
Event 478
Event 479

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