Prof Dr Armin Reichold: Publications

Measuring CP violation and B0s-B̄0s mixing using B0s → J/ψφ with φ → K+K-, J/ψ → μ+μ-

Journal of Physics G Nuclear and Particle Physics 26:5 (2000) 741-743

Authors:

F Azfar, T Huffman, L Lyons, A Reichold, D Waters

Abstract:

We present a preliminary study of a new technique for measuring B⁰s mixing and CP violation using the decay B⁰s → J/ψφ, φ K⁺K^-, J/ψ → μ⁺μ^-. This technique utilizes the unequal lifetimes of the B⁰s CP even and odd eigenstates, and an angular variable decomposition of the CP content of the final state. This study is based on CDF Run-I observations and Run-II projections, and predicts that the B⁰s mixing parameter cursive Greek chis can be measured with high accuracy in untagged samples if this approach is adopted. A large CP asymmetry may also be possible to measure. The accuracy of this method is shown to increase for higher values of cursive Greek chis as the lifetime splitting of the CP eigenstates increases. The measurement of cursive Greek chis does not depend on tagging, whereas the observation of a CP-violating asymmetry does.

Measuring CP violation and B-s(0)-(B)over-bar(s)(0) mixing using B-s(0) -> J/psi phi with phi -> K+K-, J/psi -> mu(+)mu(-)

J PHYS G NUCL PARTIC 26:5 (2000) 741-743

Authors:

F Azfar, T Huffman, L Lyons, A Reichold, D Waters

Abstract:

We present a preliminary study of a new technique for measuring B-s(0) mixing and CP violation using the decay Bs0 --> J/phi phi, phi --> K+K-, J/phi --> mu(+)mu(-). This technique utilizes the unequal lifetimes of the B-s(0) CP even and odd eigenstates, and an angular variable decomposition of the CP content of the final state. This study is based on CDF Run-I observations and Run-II projections, and predicts that the B-s(0) mixing parameter x(s) can be measured with high accuracy in untagged samples if this approach is adopted. A large CP asymmetry may also be possible to measure. The accuracy of this method is shown to increase for higher values of x(s) as the lifetime splitting of the CP eigenstates increases. The measurement of x(s) does nor depend on tagging, whereas the observation of a CP-violating asymmetry does.

Limits on light gravitino production and new processes with large missing transverse energy in pp^¯ collisions at √s = 1.8TeV

Physical Review Letters 85:7 (2000) 1378-1383

Authors:

T Affolder, H Akimoto, A Akopian, MG Albrow, P Amaral, SR Amendolia, D Amidei, K Anikeev, J Antos, G Apollinari, T Arisawa, T Asakawa, W Ashmanskas, M Atac, F Azfar, P Azzi-Bacchetta, N Bacchetta, MW Bailey, S Bailey, P De Barbaro, A Barbaro-Galtieri, VE Barnes, BA Barnett, M Barone, G Bauer, F Bedeschi, S Belforte, G Bellettini, J Bellinger, D Benjamin, J Bensinger, A Beretvas, JP Berge, J Berryhill, B Bevensee, A Bhatti, M Binkley, D Bisello, RE Blair, C Blocker, K Bloom, B Blumenfeld, BS 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, N Bruner, E Buckley-Geer, J Budagov, HS Budd, K Burkett, G Busetto, A Byon-Wagner, KL Byrum, M Campbell, W Carithers, J Carlson, D Carlsmith, J Cassada, 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, S Cihangir, CI Ciobanu, AG Clark, A Connolly, J Conway, J Cooper, M Cordelli, J Cranshaw, D Cronin-Hennessy, R Cropp, R Culbertson, D Dagenhart, F DeJongh, S Dell’Agnello, M Dell’Orso, R Demina

Abstract:

Events collected by the Collider Detector at Fermilab (CDF) with an energetic jet plus large missing transverse energy can be used to search for physics beyond the standard model. We see no deviations from the expected backgrounds and set upper limits on the production of new processes. We consider in addition the production of light gravitinos and set a limit at 95% F ≥ 217GeV, which excludes gravitino masses smaller than 1.1 × 10−5eV/c2. © 2000 American Physical Society.

Measurement of J/ψ and ψ(2S) polarization in pp collisions at √ s = 1.8 Tev

Physical Review Letters 85:14 (2000) 2886-2891

Authors:

T Affolder, H Akimoto, A Akopian, MG Albrow, P Amaral, SR Amendolia, D Amidei, K Anikeev, J Antos, G Apollinari, T Arisawa, T Asakawa, W Ashmanskas, M Atac, F Azfar, P Azzi-Bacchetta, N Bacchetta, MW Bailey, S Bailey, P de Barbaro, A Barbaro-Galtieri, VE Barnes, BA Barnett, M Barone, G Bauer, F Bedeschi, S Belforte, G Bellettini, J Bellinger, D Benjamin, J Bensinger, A Beretvas, JP Berge, J Berryhill, B Bevensee, A Bhatti, M Binkley, D Bisello, 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, N Bruner, E Buckley Geer, J Budagov, HS Budd, K Burkett, G Busetto, A Byon Wagner, KL Byrum, P Calafiura, M Campbell, W Carithers, J Carlson, D Carlsmith, J Cassada, 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, CI Ciobanu, AG Clark, A Connolly, J Conway, J Cooper, M Cordelli, J Cranshaw, D Cronin Hennessy, R Cropp, R Culbertson, D Dagenhart, F De Jongh, S Dell Agnello, M Dell Orso, R Demina

Abstract:

We have measured the polarization of J/ψ and ψ(2S) mesons produced in pp collisions at √ = 1.8 TeV using data collected at the Collider Detector at Fermilab during 1992–1995. The polarization of promptly produced J/ψ [ψ(2S)] mesons is isolated from those produced in B-hadron decay and measured over the kinematic range 4 [5.5] < PT < 20 GeV/c and |y| < 0.6. For PT ≾ 12 GeV/c we do not observe significant polarization in the prompt component. © 2000 The American Physical Society.

Search for a fourth-generation quark more massive than the Z0 boson in pp^¯ collisions at √s = 1.8 TeV

Physical Review Letters 84:5 (2000) 835-840

Authors:

T Affolder, H Akimoto, A Akopian, MG Albrow, P Amaral, SR Amendolia, D Amidei, J Antos, G Apollinari, T Arisawa, T Asakawa, W Ashmanskas, M Atac, F Azfar, P Azzi-Bacchetta, N Bacchetta, MW Bailey, S Bailey, P de Barbaro, A Barbaro-Galtieri, VE Barnes, BA Barnett, M Barone, G Bauer, F Bedeschi, S Belforte, G Bellettini, J Bellinger, D Benjamin, J Bensinger, A Beretvas, JP Berge, J Berryhill, S Bertolucci, B Bevensee, A Bhatti, C Bigongiari, M Binkley, D Bisello, RE Blair, C Blocker, K Bloom, B Blumenfeld, BS Blusk, A Bocci, A Bodek, W Bokhari, G Bolla, Y Bonushkin, D Bortoletto, J Boudreau, A Brandl, S Van den Brink, C Bromberg, N Bruner, E Buckley-Geer, J Budagov, HS Budd, K Burkett, G Busetto, A Byon-Wagner, KL Byrum, M Campbell, A Caner, W Carithers, J Carlson, D Carlsmith, J Cassada, A Castro, D Cauz, A Cerri, 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, S Cihangir, CI Ciobanu, AG Clark, M Cobal, E Cocca, A Connolly, J Conway, J Cooper, M Cordelli, D Costanzo, J Cranshaw, D Cronin-Hennessy, R Cropp, R Culbertson, D Dagenhart, F DeJongh

Abstract:

We present the results of a search for pair production of a fourth-generation charge -1/3 quark (b′) in √s=1.8 TeV pp¯ collisions using 88 pb−1 of data obtained with the Collider Detector at Fermilab. We assume that both quarks decay via the flavor-changing neutral current process b′→bZ0 and that the b′ mass is greater than mZ+mb. We studied the decay mode b′b′¯→Z0Z0bb¯ where one Z0 decays into e+e− or μ+μ− and the other decays hadronically, giving a signature of two leptons plus jets. An upper limit on the σpp¯→b′b′¯×[B(b′→bZ0)]2 is established as a function of the b′ mass. We exclude at 95% confidence level a b′ quark with mass between 100 and 199 GeV/c2 for B(b′→bZ0)=100%. © 2000 The American Physical Society.

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