Rubin-LSST

Research group

Research theme

Sub department

About

Double parton scattering in [Formula presented] collisions at [Formula presented]

Physical Review D Particles Fields Gravitation and Cosmology 56:7 (1997) 3811-3832

Authors:

F Abe, H Akimoto, A Akopian, MG Albrow, SR Amendolia, D Amidei, J Antos, S Aota, G Apollinari, T Asakawa, W Ashmanskas, M Atac, F Azfar, P Azzi-Bacchetta, N Bacchetta, W Badgett, S Bagdasarov, MW Bailey, J Bao, P de Barbaro, A Barbaro-Galtieri, VE Barnes, BA Barnett, M Barone, E Barzi, G Bauer, T Baumann, F Bedeschi, S Behrends, S Belforte, G Bellettini, J Bellinger, D Benjamin, J Benlloch, J Bensinger, D Benton, A Beretvas, JP Berge, J Berryhill, S Bertolucci, B Bevensee, A Bhatti, K Biery, M Binkley, D Bisello, RE Blair, C Blocker, A Bodek, W Bokhari, V Bolognesi, G Bolla, D Bortoletto, J Boudreau, L Breccia, C Bromberg, N Bruner, E Buckley-Geer, HS Budd, K Burkett, G Busetto, A Byon-Wagner, KL Byrum, J Cammerata, C Campagnari, M Campbell, A Caner, W Carithers, D Carlsmith, A Castro, D Cauz, Y Cen, F Cervelli, PS Chang, PT Chang, HY Chao, J Chapman, MT Cheng, G Chiarelli, T Chikamatsu, CN Chiou, L Christofek, S Cihangir, AG Clark, M Cobal, E Cocca, M Contreras, J Conway, J Cooper, M Cordelli, C Couyoumtzelis, D Crane, D Cronin-Hennessy, R Culbertson, T Daniels, F DeJongh, S Delchamps, S Dell'Agnello, M Dell'Orso, R Demina, L Demortier

Abstract:

A strong signal for double parton (DP) scattering is observed in a [Formula presented] sample of [Formula presented] data from the CDF experiment at the Fermilab Tevatron. In DP events, two separate hard scatterings take place in a single [Formula presented] collision. We isolate a large sample of data [Formula presented] of which 53% are found to be DP. The process-independent parameter of double parton scattering, [Formula presented] is obtained without reference to theoretical calculations by comparing observed DP events to events with hard scatterings in separate [Formula presented] collisions. The result [Formula presented] represents a significant improvement over previous measurements, and is used to constrain simple models of parton spatial density. The Feynman [Formula presented] dependence of [Formula presented] is investigated and none is apparent. Further, no evidence is found for kinematic correlations between the two scatterings in DP events. © 1997 The American Physical Society.
More details from the publisher
More details

Experimental tests of lepton universality in [Formula presented] decay

Physical Review D - Particles, Fields, Gravitation and Cosmology 55:5 (1997) 2559-2576

Authors:

A Anastassov, S Blinov, JE Duboscq, KD Fisher, D Fujino, R Fulton, KK Gan, T Hart, K Honscheid, H Kagan, R Kass, J Lee, MB Spencer, M Sung, A Undrus, R Wanke, A Wolf, MM Zoeller, B Nemati, SJ Richichi, WR Ross, P Skubic, M Wood, M Bishai, J Fast, E Gerndt, JW Hinson, N Menon, DH Miller, EI Shibata, IPJ Shipsey, M Yurko, L Gibbons, SD Johnson, Y Kwon, S Roberts, EH Thorndike, CP Jessop, K Lingel, H Marsiske, ML Perl, SF Schaffner, D Ugolini, R Wang, X Zhou, TE Coan, V Fadeyev, I Korolkov, Y Maravin, I Narsky, V Shelkov, J Staeck, R Stroynowski, I Volobouev, J Ye, M Artuso, A Efimov, F Frasconi, M Gao, M Goldberg, D He, S Kopp, GC Moneti, R Mountain, Y Mukhin, S Schuh, T Skwarnicki, S Stone, G Viehhauser, X Xing, J Bartelt, SE Csorna, V Jain, S Marka, A Freyberger, D Gibaut, R Godang, K Kinoshita, IC Lai, P Pomianowski, S Schrenk, G Bonvicini, D Cinabro, R Greene, LP Perera, B Barish, M Chadha, S Chan, G Eigen, JS Miller, C O’Grady, M Schmidtler, J Urheim, AJ Weinstein, F Würthwein, DM Asner, DW Bliss, WS Brower, G Masek, HP Paar

Abstract:

The branching fractions for [Formula presented] [Formula presented] and [Formula presented] are measured using data collected with the CLEO detector at the CESR [Formula presented] collider: [Formula presented]=0.1776[Formula presented]0.0006[Formula presented]0.0017, [Formula presented]=0.1737[Formula presented]0.0008[Formula presented]0.0018, and [Formula presented]=0.1152[Formula presented]0.0005[Formula presented]0.0012, where the first error is statistical, the second systematic, and [Formula presented] refers to either a charged [Formula presented] or [Formula presented]. Also measured is the [Formula presented] mass, [Formula presented]=(1778.2[Formula presented]1.4) MeV. Lepton universality is affirmed by the relative branching fractions [Formula presented]/[Formula presented]=0.9777[Formula presented]0.0063[Formula presented]0.0087, [Formula presented]/[Formula presented]=0.6484[Formula presented]0.0041[Formula presented]0.0060) and the charged-current gauge coupling-constant ratios [Formula presented]=1.0026[Formula presented]0.0055, [Formula presented]=0.9990[Formula presented]0.0098). The [Formula presented] mass result may be recast as a [Formula presented] neutrino mass limit, [Formula presented]60 MeV at 95% C.L. © 1997 The American Physical Society.
More details from the publisher
More details

First observation of the all-hadronic decay of tt― pairs

Physical Review Letters 79:11 (1997) 1992-1997

Authors:

F Abe, H Akimoto, A Akopian, MG Albrow, SR Amendolia, D Amidei, J Antos, S Aota, G Apollinari, T Asakawa, W Ashmanskas, M Atac, F Azfar, P Azzi-Bacchetta, N Bacchetta, W Badgett, S Bagdasarov, MW Bailey, J Bao, P De Barbaro, A Barbaro-Galtieri, VE Barnes, BA Barnett, M Barone, E Barzi, G Bauer, T Baumann, F Bedeschi, S Behrends, S Belforte, G Bellettini, J Bellinger, D Benjamin, J Benlloch, J Bensinger, D Benton, A Beretvas, JP Berge, J Berryhill, S Bertolucci, B Bevensee, A Bhatti, K Biery, M Binkley, D Bisello, RE Blair, C Blocker, A Bodek, W Bokhari, V Bolognesi, G Bolla, D Bortoletto, J Boudreau, L Breccia, C Bromberg, N Bruner, E Buckley-Geer, HS Budd, K Burkett, G Busetto, A Byon-Wagner, KL Byrum, J Cammerata, C Campagnari, M Campbell, A Caner, W Carithers, D Carlsmith, A Castro, D Cauz, Y Cen, F Cervelli, PS Chang, PT Chang, HY Chao, J Chapman, MT Cheng, G Chiarelli, T Chikamatsu, CN Chiou, L Christofek, S Cihangir, AG Clark, M Cobal, E Cocca, M Contreras, J Conway, J Cooper, M Cordelli, C Couyoumtzelis, D Crane, D Cronin-Hennessy, R Culbertson, T Daniels, F DeJongh, S Delchamps, S Dell’agnello, M Dell’orso, R Demina, L Demortier

Abstract:

We present the first observation of the all hadronic decay of tt― pairs. The analysis is performed using 109 pb−1 of pp― collisions at s = 1.8 TeV collected with the Collider Detector at Fermilab. We observe an excess of events with five or more jets, including one or two b jets, relative to background expectations. Based on this excess we evaluate the production cross section to be in agreement with previous results. We measure the top mass to be 186±10±12 GeV/c2. © 1997 The American Physical Society.
More details from the publisher
More details

Limits on quark-lepton compositeness scales from dileptons produced in 1.8 TeV pp-collisions

Physical Review Letters 79:12 (1997) 2198-2203

Authors:

F Abe, H Akimoto, A Akopian, MG Albrow, SR Amendolia, D Amidei, J Antos, S Aota, G Apollinari, T Asakawa, W Ashmanskas, M Atac, F Azfar, P Azzi-Bacchetta, N Bacchetta, W Badgett, S Bagdasarov, MW Bailey, J Bao, P de Barbaro, A Barbaro-Galtieri, VE Barnes, BA Barnett, M Barone, E Barzi, G Bauer, T Baumann, F Bedeschi, S Behrends, S Belforte, G Bellettini, J Bellinger, D Benjamin, J Benlloch, J Bensinger, D Benton, A Beretvas, JP Berge, J Berryhill, S Bertolucci, B Bevensee, A Bhatti, K Biery, M Binkley, D Bisello, RE Blair, C Blocker, A Bodek, W Bokhari, V Bolognesi, G Bolla, D Bortoletto, J Boudreau, L Breccia, C Bromberg, N Bruner, E Buckley-Geer, HS Budd, K Burkett, G Busetto, A Byon-Wagner, KL Byrum, J Cammerata, C Campagnari, M Campbell, A Caner, W Carithers, D Carlsmith, A Castro, D Cauz, Y Cen, F Cervelli, PS Chang, PT Chang, HY Chao, J Chapman, MT Cheng, G Chiarelli, T Chikamatsu, CN Chiou, L Christofek, S Cihangir, AG Clark, M Cobal, E Cocca, M Contreras, J Conway, J Cooper, M Cordelli, C Couyoumtzelis, D Crane, D Cronin-Hennessy, R Culbertson, T Daniels, F DeJongh, S Delchamps, S Dell’agnello, M Dell’orso, R Demina, L Demortier

Abstract:

The dilepton mass spectrum in pp-→|+|-+X interactions is studied using dielectrons (ee) and dimuons (μμ) in 100 pb- of data collected with the Collider Detector at Fermilab. The data are consistent with standard model predictions. The mass spectrum, being a probe for new physics, is examined for new interactions of quarks and leptons from a common composite structure. Assuming a contact interaction with the conventional coupling g20/4π = 1, limits on chiral quark-electron and quark-muon compositeness scales in the range of 2.5 to 4.2 TeV are obtained. © 1997 The American Physical Society.
More details from the publisher
More details

Measurement of Diffractive Dijet Production at the Fermilab Tevatron

Physical Review Letters 79:14 (1997) 2636-2641

Authors:

F Abe, H Akimoto, A Akopian, MG Albrow, SR Amendolia, D Amidei, J Antos, S Aota, G Apollinari, T Asakawa, W Ashmanskas, M Atac, F Azfar, P Azzi-Bacchetta, N Bacchetta, W Badgett, S Bagdasarov, MW Bailey, J Bao, P de Barbaro, A Barbaro-Galtieri, VE Barnes, BA Barnett, M Barone, E Barzi, G Bauer, T Baumann, F Bedeschi, S Behrends, S Belforte, G Bellettini, J Bellinger, D Benjamin, J Benlloch, J Bensinger, D Benton, A Beretvas, JP Berge, J Berryhill, S Bertolucci, B Bevensee, A Bhatti, K Biery, M Binkley, D Bisello, RE Blair, C Blocker, A Bodek, W Bokhari, V Bolognesi, G Bolla, D Bortoletto, J Boudreau, L Breccia, C Bromberg, N Bruner, E Buckley-Geer, HS Budd, K Burkett, G Busetto, A Byon-Wagner, KL Byrum, J Cammerata, C Campagnari, M Campbell, A Caner, W Carithers, D Carlsmith, A Castro, D Cauz, Y Cen, F Cervelli, PS Chang, PT Chang, HY Chao, J Chapman, MT Cheng, G Chiarelli, T Chikamatsu, CN Chiou, L Christofek, S Cihangir, AG Clark, M Cobal, E Cocca, M Contreras, J Conway, J Cooper, M Cordelli, C Couyoumtzelis, D Crane, D Cronin-Hennessy, R Culbertson, T Daniels, F DeJongh, S Delchamps, S Dell'Agnello, M Dell'Orso, R Demina, L Demortier

Abstract:

We report the observation and measurement of the rate of diffractive dijet production at the Fermilab Tevatron p¯p collider at √s=1.8TeV. In events with two jets of ET>20GeV, 1.8<|η|<3.5, and η1η2>0, we find that the diffractive to nondiffractive production ratio is RJJ=[0.75±0.05(stat)±0.09(syst)]%. By comparing this result, in combination with our measured rate for diffractive W boson production reported previously, with predictions based on a hard partonic pomeron structure, we determine the pomeron gluon fraction to be fg=0.7±0.2. © 1997 American Physical Society.
More details from the publisher
More details