Measurements of the b baryon lifetime

Buskulic, D.; Casper, D.; Bonis, I. De; Décamp, D.; Ghez, Ph.; Goy, C.; Lees, J. P.; Minard, M.-N.; Odier, P.; Pietrzyk, B.; Ariztizabal, F.; Chmeissani, M.; Crespo, J.M.; Efthymiopoulos, I.; Fernández, E.; Fernández-Bosman, M.; Gaitan, V.; Garrido, Ll.; Martı́nez, M.; Orteu, S.; Pacheco, A.; Aranda, C. Padilla; Palla, F.; Pascual, Á.; Perlas, J. A.; Sanchez, F. J. Munoz; Teubert, F.; Colaleo, A.; Creanza, D.; Palma, M. De; Farilla, A.; Gelao, G.; Girone, M.; Iaselli, G.; Mäggi, G.; Marinelli, N.; Natali, S.; Nuzzo, S.; Ranieri, A.; Raso, G.; Romanò, F.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Zito, G.; Huang, X. T.; Lin, J.; Ouyang, Q.; Wang, T.; Xie, Y.; Xu, R.; Xue, S.; Zhang, J.; Zhang, L.; Zhao, W.; Bonvicini, G.; Cassel, D. G.; Cattaneo, M.; Comas, P.; Coyle, P.; Drevermann, H.; Engelhardt, A.; Forty, R.; Frank, M.; Hagelberg, R.; Harvey, J.; Jacobsen, R.G.; Janot, P.; Jost, B.; Knobloch, J.; Lehraus, I.; Maggi, M.; Markou, C.; Martin, E. B.; Mató, P.; Meinhard, H.; Minten, A.; Miquel, R.; Oest, T.; Palazzi, P.; Pater, J. R.; Pusztaszeri, J. F.; Ranjard, F.; Rensing, P.; Rolandi, G.; Schlatter, D.; Schmelling, M.; Schneider, O.; Tejessy, W.; Tomalin, I. R.; Venturi, A.; Wachsmuth, H.; Wiedenmann, W.; Wildish, T.; Witzeling, W.; Wotschack, J.; Ajaltouni, Z.; Bardadin-Otwinowska, M.; Barrès, A.; Boyer, C.; Falvard, A.; Guicheney, C.; Henrard, P.; Jousset, J.; Michel, B.; Monteil, S.; Montret, J. C.; Pallin, D.; Perret, P.; Podlyski, F.; Proriol, J.; Rossignol, J. M.; Saadi, F.; Fearnley, T.; Hansen, J. B.; Hansen, J. R.; Hansen, P. H.; Nilsson, B.S.; Kyriakis, A.; Simopoulou, E.; Siotis, I.; Vayaki, A.; Zachariadou, K.; Blondel, A.; Bonneaud, G. R.; Brient, J. C.; Bourdon, P.; Passalacqua, L.; Rougé, A.; Rumpf, M.; Tanaka, R.; Valassi, A.; Verderi, M.; Videau, H.; Candlin, D. J.; Parsons, M. I.; Focardi, E.; Parrini, G.; Corden, M.; Delfino, M.; Georgiopoulos, C.; Jaffe, D. E.; Antonelli, A.; Bencivenni, G.; Bologna, G.; Bossi, F.; Campana, P.; Capon, G.; Chiarella, V.; Felici, G.; Laurelli, P.; Mannocchi, G.; Murtas, F.; Murtas, F.; Pepe-Altarelli, M.; Dorris, S. J.; Halley, A.W.; Have, I. ten; Knowles, I. G.; Lynch, J.G.; Morton, W. T.; O’Shea, V.; Raine, C.; Reeves, P.; Scarr, J. M.; Smith, K. M.; Smith, M. G.; Thompson, A. S.; Thomson, F.; Thorn, S.; Turnbull, R.M.; Becker, U.; Braun, O.; Geweniger, C.; Graefe, G.; Hanke, P.; Hepp, V.; Kluge, E.-E.; Putzer, A.; Rensch, B.; Schmidt, Michael G.; Sommer, J.; Stenzel, H.; Tittel, K.; Werner, S.; Wunsch, M.; Beuselinck, R.; Binnie, D. M.; Cameron, W.; Colling, D.; Dornan, P. J.; Konstantinidis, N.; Moneta, L.; Moutoussi, A.; Nash, J.; Martin, G.; Sedgbeer, J. K.; Stacey, A. M.; Dissertori, G.; Girtler, P.; Kneringer, E.; Kühn, D.; Rudolph, G.; Bowdery, C. K.; Brodbeck, T. J.; Colrain, P.; Crawford, G.; Finch, A. J.; Foster, F.; Hughes, G.; Sloan, T.; Whelan, E. P.; Williams, M.I.; Galla, A.; Greene, A. M.; Kleinknecht, K.; Quast, G.; Raab, J.; Renk, B.; Sander, H. G.; Wanke, R.; Zeitnitz, C.; Aubert, J.J.; Bencheikh, A. M.; Benchouk, C.; Bonissent, A.; Bujosa, G.; Calvet, D.; Carr, J.; Diaconu, C.; Etienne, F.; Thulasidas, M.; Nicod, D.; Payre, P.; Rousseau, D.; Talby, M.; Abt, I.; Assmann, R.; Bauer, C.; Blum, W.; Brown, D. N.; Dietl, H.; Dydak, F.; Ganis, G.; Gotzhein, C.; Jakobs, K.; Kroha, H.; Lütjens, G.; Lütz, G.; Männer, W.; Guenther, J.; Richter, R.; Rosado-Schlosser, A.; Settles, R.; Seywerd, H.; Stierlin, U.; Denis, R. St.; Wolf, G.; Alemany, R.; Boucrot, J.; Callot, O.; Cordier, A.; Courault, F.; Davier, M.; Duflot, L.; Grivaz, J.-F.; Heusse, P.; Jacquet, M.; Kim, D. W.; Diberder, F. Le; Lefrançois, J.; Lutz, A. M.; Musolino, G.; Nikolić, Irena; Park, H. J.; Park, I. C.; Schune, M. H.; Simion, S.; Veillet, J. J.; Videau, I.; Abbaneo, D.; Azzurri, P.; Bagliesi, G.; Batignani, G.; Bettarini, S.; Bozzi, C.; Calderini, G.; Carpinelli, M.; Ciocci, M. A.; Ciulli, V.; Dell’Orso, R.; Fantechi, R.; Ferrante, I.; Foà, L.; Forti, F.; Gambino, D.; Giassi, A.; Giorgi, M. A.; Gregorio, A.; Ligabue, F.; Lusiani, A.; Marrocchesi, P. S.; Messineo, A.; Rizzo, G.; Sanguinetti, G.; Sciabà, A.; Spagnolo, P.; Steinberger, J.; Тенчини, Р.; Tonelli, G.; Triggiani, G.; Vannini, C.; Verdini, P. G.; Walsh, J.; Betteridge, A. P.; Blair, G.A.; Bryant, L. M.; Cerutti, F.; Green, M. G.; Johnson, D.; Medcalf, T.; Mir, L. M.; Perrodo, P.; Strong, J. A.; Bertín, V.; Botterill, D.; Clifft, R. W.; Edgecock, R.; Haywood, S. J.; Edwards, M.; Maley, P.; Norton, P. R.; Thompson, J.C.; Bloch-Devaux, B.; Colas, P.; Duarte, H.; Emery, S.; Kozanecki, W.; Lançon, E.; Lemaire, M. C.; Locci, E.; Marx, B.; Pérez, P.; Rander, J.; Renardy, J. F.; Rosowsky, A.; Roussarie, A.; Schuller, J. P.; Schwindling, J.; Mohand, D. Si; Trabelsi, A.; Vallage, B.; Johnson, R.P.; Kim, H. Y.; Litke, A. M.; McNeil, M.A.; Taylor, G. N.; Beddall, A. J.; Booth, C. N.; Boswell, Rod; Cartwright, S. L.; Combley, F.; Dawson, I.; Koksal, A.; Letho, M.; Newton, W. M.; Rankin, C.; Thompson, L.F.; Böhrer, A.; Brandt, Siegmund; Cowan, G.; Feigl, Eric O.; Grupen, C.; Lutters, G.; Minguet-Rodriguez, J.; Rivera, F.; Saraiva, Pedro; Smolík, L.; Stephan, F.; Apollonio, M.; Bosisio, L.; Marina, R. Della; Giannini, G.; Gobbo, B.; Ragusa, F.; Rothberg, J.; Wasserbaech, S.; Armstrong, S.R.; Bellantoni, L.; Elmer, P.; Feng, Z.; Ferguson, D.P.S.; Gao, Y. S.; González, S.; Grahl, J.; Harton, J. L.; Hayes, O.J.; Hu, H.; McNamara, P.A.; Nachtman, J. M.; Orejudos, W.; Pan, Y.; Saadi, Y.; Schmitt, M.; Scott, I.; Sharma, V.; Turk, J. D.; Walsh, A. M.; Wu, S. L.; Wu, X.; Yamartino, J. M.; Zheng, M.; Zobernig, G.

doi:10.1016/0370-2693(95)00980-y

Cited by 21 publications

(5 citation statements)

References 25 publications

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“…Here also any update would be extremely welcome. In that case two matrix elements are arising that are parameterised by 108) where the operators were defined in Eq. (2.60) and Eq.(2.61).…”

Section: Non-perturbative Parametersmentioning

confidence: 99%

Lifetimes and heavy quark expansion

Lenz

2015

Int. J. Mod. Phys. A

109

114

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The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. AbstractKolya Uraltsev was one of the inventors of the Heavy Quark Expansion (HQE), that describes inclusive weak decays of hadrons containing heavy quarks and in particular lifetimes. Besides giving a pedagogic introduction into the subject, we review the development and the current status of the HQE, which just recently passed several non-trivial experimental tests with an unprecedented precision. In view of many new experimental results for lifetimes of heavy hadrons, we also update several theory predictions:06. The theoretical precision is currently strongly limited by the unknown size of the nonperturbative matrix elements of four-quark operators, which could be determined with lattice simulations. * Alexander. Lenz@durham.ac.uk

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“…Here also any update would be extremely welcome. In that case two matrix elements are arising that are parameterised by 108) where the operators were defined in Eq. (2.60) and Eq.(2.61).…”

Section: Non-perturbative Parametersmentioning

confidence: 99%

Lifetimes and heavy quark expansion

Lenz

2015

Int. J. Mod. Phys. A

109

114

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“…The polarization of the Λ b baryons produced at LEP has been measured to be −30 ± 30% [24]. A non-vanishing left-handed polarization enhances the missing energy from Λ b decays, and therefore neglecting it is conservative.…”

Section: A Theoretical Uncertaintiesmentioning

confidence: 99%

First limit on inclusive decay and constraints on new physics

1996

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In a recent article [1] we presented the derivation of the first limit on the inclusive B → X s νν decay rate. Our work stemmed from the observation that a published ALEPH bound on BR(B → τν) [2], inferred from the absence of large missing energy events in B decays, implies also a limit on BR(B → X s νν). We estimated this limit by comparing the missing energy spectra in the two decay modes. Theoretically, B → X s νν is a very clean process, which is also sensitive to several possible sources of new physics [1]. Therefore, a dedicated experimental search is important. The result of such an analysis by the ALEPH Collaboration, using the full LEP-I data sample, is to appear soon [3].As a result of discussions with members of the ALEPH Collaboration [4], we found two errors in our numerical results. The corrected analysis yields a limit weaker than our original result [1] by about a factor of three. The corrections included here are formally beyond the free quark decay result at tree level (of order α s , Λ QCD /m b , and higher). However, they affect the final limit significantly, due to the specific details of the experimental analysis.First, due to a mistake in our Monte Carlo code, the energy of the X s hadronic final state in the B rest frame was evaluated as a fraction of the b quark mass, rather than as a fraction of the B meson mass. This resulted in a harder missing energy spectrum than the true one. Correcting for this weakens the limit by about 35%.Second, we neglected the effects of the invariant mass distribution of the final hadrons, 1 which we (implicitly) assumed not to extend to high mass states. However, the invariant mass of the X s system can be well above 1 GeV [5]. Because of the large boost into the LEP laboratory frame and the high missing energy range (> 35 GeV) used in the analysis[2] (which is large compared to the average B meson energy at LEP), neglecting this effect yielded a missing energy spectrum in the laboratory frame considerably harder than the correct one.It is not straightforward to include properly this second effect into the analysis. However, an estimate can be obtained by approximating the invariant mass spectrum of the X s system with a Gaussian distribution with mean (µ) and variance (σ) fitted to the averages M 2 X and M 4 X , as given in [5]. Such a fit yields µ ≃ 1.35 GeV and σ ≃ 0.6 GeV. There is about a 10% uncertainty in these values, due to their dependences on the heavy quark effective theory parameterΛ (≃ m B − m b ). Treating the X s mass distribution as independent of the energy spectrum, and including a theoretical uncertainty of about 15% related to the fitted values of µ and σ, we find that the original limit given in [1] is weakened by about a factor of three. While small values of E X favor small values of M X (beyond the trivial kinematic constraint E X > M X ), the correlation between E X and M X only slightly improve the bound.In conclusion, the bound on BR(B → X s νν) given in the Abstract and in Eqs. (1.2) and (6.1) of [1] is weaker by about a facto...

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“…Measurements of the Λ 0 b lifetime prior to 2011 can be found in Refs. [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27]. More recent measurements of the Λ 0 b lifetime include: 1.537 ± 0.045 ± 0.014 ps from CDF [28], 1.303 ± 0.075 ± 0.035 ps from D0 [29], and 1.449 ± 0.036 ± 0.017 ps from ATLAS [30], where the first uncertainties are statistical and the second are systematic.…”

Section: Introductionmentioning

confidence: 99%

“…Figure 4: Evolution over time of the Λ 0b lifetime measurements (left scale)[11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] and the ratio of the measurements to the 2012 world-average B 0 lifetime τ B 0[34] (right scale). The values shown as open circles were not included in the Particle Data Group (PDG) 2012 average[34], displayed as the grey band, while those shown as filled circles were included.…”

mentioning

confidence: 99%

Measurement of the $ \Lambda_{\mathrm{b}}^0 $ lifetime in pp collisions at $ \sqrt{s}=7 $ TeV

Chatrchyan

Khachatryan

Sirunyan

et al. 2013

J. High Energ. Phys.

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A measurement of the Λ 0 b lifetime using the decay Λ 0 b → J/ψΛ in protonproton collisions at √ s = 7 TeV is presented. The data set, corresponding to an integrated luminosity of about 5 fb −1 , was recorded with the CMS experiment at the Large Hadron Collider using triggers that selected dimuon events in the J/ψ mass region. The Λ 0 b lifetime is measured to be 1.503 ± 0.052 (stat.) ± 0.031 (syst.) ps.

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Measurements of the b baryon lifetime

Abstract: Using about 1.5 million hadronic Z decays recorded with the aleph detector, the lifetime of the b baryons has been measured using two independent data samples.

Cited by 21 publications

References 25 publications

Lifetimes and heavy quark expansion

Lifetimes and heavy quark expansion

First limit on inclusive decay and constraints on new physics

Measurement of the $ \Lambda_{\mathrm{b}}^0 $ lifetime in pp collisions at $ \sqrt{s}=7 $ TeV

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