Rubin-LSST

Research group

Research theme

Sub department

About

Hard X-ray states and radio emission in GRS 1915+105

Monthly Notices of the Royal Astronomical Society Oxford University Press (OUP) 331:3 (2002) 745-764

Authors:

M Klein-Wolt, RP Fender, GG Pooley, T Belloni, S Migliari, EH Morgan, M van der Klis

Initial low/hard state, multiple jet ejections and X-ray/radio correlations during the outburst of XTE J1859+226

Monthly Notices of the Royal Astronomical Society Oxford University Press (OUP) 331:3 (2002) 765-775

Authors:

C Brocksopp, RP Fender, M McCollough, GG Pooley, MP Rupen, RM Hjellming, CJ de La Force, RE Spencer, TWB Muxlow, ST Garrington, S Trushkin

Precision Determination of V_ub at an e+ e- B Factory

ArXiv hep-ex/0203015 (2002)

Authors:

Jik Lee, Ian Shipsey

Abstract:

Current methods of determining V_ub are dominated by theoretical uncertainties. We present Monte Carlo simulations of three promising methods of determining V_ub with small theoretical and experimental errors. We find that with data samples of order 1,000 fb-1 the B factories will attain combined experimental errors of a few % on V_ub, much smaller than the theoretical errors associated with new inclusive methods. Lattice QCD offers the promise of rate calculations of exclusive semileptonic decays with errors of a few %. A data sample of order 10,000 fb-1, beyond the capabilities of the current B factories, may be required to achieve an experimental error on the exclusive rate comparable to the theoretical error.

Searches for new physics in events with a photon and b-quark jet at CDF

Physical Review D Particles Fields Gravitation and Cosmology 65:5 (2002) 520061-5200622

Authors:

T Affolder, H Akimoto, A Akopian, MG Albrow, P Amaral, D Amidei, K Anikeev, J Antos, G Apollinari, T Arisawa, A Artikov, T Asakawa, W Ashmanskas, F Azfar, P Azzi-Bacchetta, N Bacchetta, H Bachacou, S Bailey, P de Barbaro, A Barbaro-Galtieri, VE Barnes, BA Barnett, S Baroiant, M Barone, G Bauer, F Bedeschi, S Belforte, WH Bell, G Bellettini, J Bellinger, D Benjamin, J Bensinger, A Beretvas, JP Berge, J Berryhill, A Bhatti, M Binkley, D Bisello, M Bishai, RE Blair, C Blocker, K Bloom, B Blumenfeld, SR Blusk, A Bocci, A Bodek, W Bokhari, G Bolla, Y Bonushkin, D Bortoletto, J Boudreau, A Brandl, S van den Brink, C Bromberg, M Brozovic, E Brubaker, N Bruner, E Buckley-Geer, J Budagov, HS Budd, K Burkett, G Busetto, A Byon-Wagner, KL Byrum, S Cabrera, P Calafiura, M Campbell, W Carithers, J Carlson, D Carlsmith, W Caskey, A Castro, D Cauz, A Cerri, AW Chan, PS Chang, PT Chang, J Chapman, C Chen, YC Chen, MT Cheng, M Chertok, G Chiarelli, I Chirikov-Zorin, G Chlachidze, F Chlebana, L Christofek, ML Chu, YS Chung, CI Ciobanu, AG Clark, A Connolly, J Conway, M Cordelli, J Cranshaw, R Cropp, R Culbertson, D Dagenhart, S D'Auria, F DeJongh

Abstract:

We have searched for evidence of physics beyond the standard model in events that include an energetic photon and an energetic b-quark jet, produced in 85 pb-1 of p̄p collisions at 1.8 TeV at the Tevatron Collider at Fermilab. This signature, containing at least one gauge boson and a third-generation quark, could arise in the production and decay of a pair of new particles, such as those predicted by supersymmetry, leading to a production rate exceeding standard model predictions. We also search these events for anomalous production of missing transverse energy, additional jets and leptons (e, μ, and τ), and additional b quarks. We find no evidence for any anomalous production of γb or γb + X events. We present limits on two supersymmetric models: a model where the photon is produced in the decay χ̃20→ γχ̃10, and a model where the photon is produced in the neutralino decay into the gravitino LSP, χ̃10→ γG̃. We also present our limits in a model-independent form and test methods of applying model-independent limits.

51ÁÔÆæÈë¿Ú of the heavy flavor content of jets produced in association with W bosons in ppÌ„ collisions at √s=1.8TeV

Physical Review D - Particles, Fields, Gravitation and Cosmology 65:5 (2002) 520071-5200726

Authors:

D Acosta, T Affolder, H Akimoto, A Akopian, P Amaral, D Ambrose, D Amidei, K Anikeev, J Antos, G Apollinari, T Arisawa, A Artikov, T Asakawa, W Ashmanskas, F Azfar, P Azzi-Bacchetta, N Bacchetta, H Bachacou, S Bailey, P de Barbaro, A Barbaro-Galtieri, VE Barnes, BA Barnett, S Baroiant, M Barone, G Bauer, F Bedeschi, S Belforte, WH Bell, G Bellettini, J Bellinger, D Benjamin, J Bensinger, A Beretvas, JP Berge, J Berryhill, A Bhatti, M Binkley, D Bisello, M Bishai, RE Blair, C Blocker, K Bloom, B Blumenfeld, SR Blusk, A Bocci, A Bodek, G Bolla, Y Bonushkin, D Bortoletto, J Boudreau, A Brandl, S van den Brink, C Bromberg, M Brozovic, E Brubaker, N Bruner, E Buckley-Geer, J Budagov, HS Budd, K Burkett, G Busetto, A Byon-Wagner, KL Byrum, S Cabrera, P Calafiura, M Campbell, W Carithers, J Carlson, D Carlsmith, W Caskey, A Castro, D Cauz, A Cerri, J Chapman, C Chen, YC Chen, M Chertok, G Chiarelli, I Chirikov-Zorin, G Chlachidze, F Chlebana, L Christofek, YS Chung, AG Clark, AP Colijn, A Connolly, M Cordelli, J Cranshaw, R Cropp, D Dagenhart, S D'Auria, F DeJongh, S Dell'Agnello, M Dell'Orso, S Demers, L Demortier, M Deninno, PF Derwent, JR Dittmann

Abstract:

We present a detailed examination of the heavy flavor content of the W+jet data sample collected with the Collider Detector at Fermilab during the 1992-1995 collider run at the Fermilab Tevatron. Jets containing heavy flavor quarks are selected via the identification of secondary vertices or semileptonic decays of b and c quarks. There is generally good agreement between the rates of secondary vertices and soft leptons in the data and in the standard model simulation including single and pair production of top quarks. An exception is the number of events in which a single jet has both a soft lepton and a secondary vertex tag. In W+2,3 jet data, we find 13 such events where we expected 4.4±0.6 events. The kinematic properties of this small sample of events are statistically difficult to reconcile with the simulation of standard model processes.