- Email: [email protected]
CDF: Run II physics projections
Nuclear Instruments and Methods in Physics Research A 462 (2001) 165–169
CDF: Run II physics projections Masashi Tanaka Institute of Physics, University of Tsukuba, Tsukuba, Ibaraki 305, Japan For the CDF Collaboration
Abstract pffiffi In March 2001, the Fermilab Tevatron will start a new physics run of pp% collisions at s ¼ 2:0 TeV. The CDF 1 experiments will collect a data sample of 2 fb in the first two years. In this paper, we describe the B physics prospects at CDF during the upcoming run. # 2001 Published by Elsevier Science B.V.
1. Introduction In this paper, we describe the B physics prospects at Collider Detector at Fermilab (CDF). The CDF detector collectedp a ffiffidata sample of 110 pb1 of pp% collisions at s ¼ 1:8 TeV, during 1992–96 (Run I). A large number of B physics measurements has been performed with the data sample [1]. The measurement of the CP violation parameter sinð2bÞ [2] is still competitive with the first preliminary results of Babar [3] and Belle [4] experiments. Moreover, it is a unique feature to exploit the B0s and Bþ c mesons, and b baryons which is not produced at the Uð4SÞ machines. The Tevatron will commence pp% collisions again in March 2001. The currently named Run II will provide 20 times greater luminosity than Run I, at a center of mass energy of 2 TeV. The goal of the first phase of Run II is the accumulation of 2 fb1 in the first two years, although, a second step will provide a total luminosity higher than 15 fb1 before the turn-on of the LHC. The main goals of the B physics for Run II are a precision measure-
E-mail address: [email protected] (M. Tanaka).
ment of the angles b and g, and observation of the B0s flavor oscillation as well as the rare B decay searches and studies of the heavier B-hadron 0 states, Bþ c , Lb , etc.
2. Detector and trigger upgrade The CDF detector has been upgraded [5] to prepare for the high radiation and the high crossing rate under Run II Tevatron environment. There are also several upgrades to improve the sensitivity of the CDF detector to the B physics: *
*
*
The acceptances of new silicon vertex detector system and new muon detector system for B decay signals are improved by factors of 1.4 and 2, respectively. A new silicon layer (L 0 0) located immediately outside the beam pipe at a radius of 1:6 cm improves the vertex resolution. The typical time resolution for B decays is 45 fs with the L 0 0 and 60 fs without the L 0 0. A new time of flight system (TOF) with a 100 ps of the flight time resolution provides a 2s separation of kaons and pions for charged tracks with momentum less than 1:6 GeV=c.
0168-9002/01/$ - see front matter # 2001 Published by Elsevier Science B.V. PII: S 0 1 6 8 - 9 0 0 2 ( 0 1 ) 0 0 0 9 2 - 4
III. GENERAL PURPOSE EXPERIMENTS
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M. Tanaka / Nuclear Instruments and Methods in Physics Research A 462 (2001) 165–169
A new trigger system with a 3-level architecture will be installed. In Run II, the Tevatron will be operated with 36 and 121 bunches, and the beam crossing occurs every 396 and 132 ns, respectively. The Level-1 system will reduce the rate to 50 kHz. Besides the calorimeter and muon triggers, this includes a tracking trigger (XFT) for tracks with transverse momentum pT > 1:5 GeV=c. The L1 trigger system will allow us to lower the pT threshold of the muon trigger from 2:2 GeV=c in Run I to 1:5 GeV=c, and increase the acceptance for the J=c ! mþ m trigger by a factor of 2. The level-2 system will work at a rate of 300 Hz, and include a displaced track trigger (SVT), which uses the silicon detector information and measures the track impact parameter with a 35 mm precision. In Run I, all the B-physics analyses are based on the data set triggered with one or two leptons. However, the new trigger system allows us to record the hadronic B decay events without requiring any leptons. We designed dedicated triggers for the hadronic B decay events, which required two XFT tracks and two SVT tracks at Level 1 and Level 2, respectively. For example, we expect 20,000 and 10,000 reconstructed events of the B0s ! D and B0d ! pþ p decays, respecs np 1 tively, in the 2 fb of the two track trigger data.
3. Flavor tagging The determination of the initial B hadron flavor % is important for observing the mixing and (B or B) CP asymmetries. In Run II, we will employ four flavor tagging methods. One of the methods, sameside tagging, uses charge correlation between a B hadron and its fragmentation tracks. In the other three methods, opposite-side taggings use the charge correlation between a B hadron and second % hadron: (1) the lepton tagging uses the charged B lepton from the semileptonic b ! l n% c decay; (2) the kaon tagging uses the charged kaon from the sequential b ! c ! K decay; (3) the jet charge tagging uses the fact that the charge of the b quark to be less than zero. Table 1 shows the prediction of the effective tagging efficiency (eD2 ). The K–p separation with the TOF detector helps the flavor taggings such as
Table 1 Effective tagging efficiency eD2 B0d ! J=cK0S (%)
þ B0s ! D s p (%)
Same side Lepton Jet charge Kaon
1.9 1.7 3.0 2.4
4.2 1.7 3.0 2.4
Total Total (w=o TOF)
9.0 6.1
11.3 5.7
the same side tagging for the B0s , and the opposite þ side kaon tagging. For the B0s ! D s p channel, the TOF almost doubles the effective tagging efficiency (5:7% ! 11:3%).
4. Bs mixing from B0s ! D s np
% 0 mixing frequency xs , For measuring the B0s B s Foulier analysis has been usually employed [6], and significance for the analysis is written by 1 1 Sigðxs Þ ¼ pffiffiffi ð1Þ 2sxs vffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi u st 2 u ðxs Þ tN S t 0 B 2 s eD e ; ¼ 2 SþB
ð2Þ
where N is the number of the signal events, S=B is the signal-to-background ratio, tB0s is the lifetime of the B0s meson, and st is decay time resolution. It is interesting to note that a 5s measurement corresponds to sxs =xs ¼ 0:5% with xs ¼ 30. Thus, once we observe the B0s mixing, the statistical uncertainty for the xs measurement is very small. The two track trigger will collect a large number of the B0s ! Ds np events, and the new silicon strip detector (L 0 0) significantly improves the decay time resolution. Fig. 1 shows the required luminosity for a five sigma observation of the B0s mixing with two different S=B cases. Thus a few hundred pb1 (the first few month) of the Run II data will be enough to observe the Bs mixing with xs ¼ 20 30. The maximum reach of our detector is xs 65.
M. Tanaka / Nuclear Instruments and Methods in Physics Research A 462 (2001) 165–169
167
Fig. 2. The expected statistical uncertainty for extracting the angle g as a function of the g in 2 fb1 of the data. Fig. 1. A required luminosity for a five sigma observation of B0s mixing.
5. sinð2bÞ from Bd ! J=wK0S In Run I, CDF measures the sinð2bÞ to be 0:79 0:39 0:16 in the 400 events of the B0d ! J= cK0S sample [2]. The Run II prospect of the statistical uncertainty is obtained by scaling the Run I measurement according to the equation, 1 sðsinð2bÞÞ / pffiffiffiffiffiffiffiffiffiffiffiffi: eD2 N
ð3Þ
The upgraded CDF II detector and the trigger system improve the acceptance for the B0d ! J= cK0S events by a factor of 23, and we will collect a 20,00030,000 of signal samples in the 2 fb1 of the data. A systematic uncertainty of the sinð2bÞ measurement is mainly caused by the dilution measurement by using B0d ! J=cK * 0 for the sameþ side tagging and Bþ for the oppositeu ! J=cK side taggings. With a signal sample of 10,000 ð30; 000Þ reconstructed events, the expected value will be sðsinð2bÞÞ ¼ 0:067 ð0:043Þ.
6. c from B0d ! pþ p and B0s ! Kþ K To extract the angle g by fitting on the CP violating observables in the Bd ! pþ p ,
B0s ! Kþ K , and B0d ! J=cK0S channels is proposed by Fleisher [7]. The idea is using U-spin symmetry, a subgroup of flavor SU(3), to relate the CP violation in B0d ! pþ p to the one in B0s ! Kþ K . In the limit of flavor SU(3) symmetry, the difference of ‘‘penguin pollution’’ for these two decays is entirely due to CKM matrix elements. Relating the two decays thus allows us to determine a weak phase g with a small uncertainty due to the penguin pollution. Fig. 2 shows the expected uncertainty for the g measurement as a function of the g with 2 fb1 . Each points in the plot show variation of the uncertainty by changing the weak phase b and the strong phase y within the ranges of 15–358 and 0– 3608, respectively. In the plot, we assume to collect 5 k B0d ! pþ p events and 10 k B0s ! Kþ K events, and S=B between the B0d ! pþ p signal to combinatorial background to be 1.0. We will measure g with an error better than 108. 7. Rare B0d ! K * 0 ll decay The B0d ! K * 0 mm decay occurs via the quark transition b% ! s% that involves loop, ‘‘penguin’’ and ‘‘box’’, diagrams. The Run I CDF sets an upper limit on the decay branching fraction to be 4:0 106 at a 90% confidence level [8]. In Run II, we expect 50 events of such decay in the 2 fb1 of the data. Then, the III. GENERAL PURPOSE EXPERIMENTS
168
M. Tanaka / Nuclear Instruments and Methods in Physics Research A 462 (2001) 165–169
*
*
Fig. 3. The expected uncertainty for measuring the AFB ðmmþ m Þ distribution with 50 events ð2 fb1 ) and 400 events ð15 fb1 ) of the data.
Forward–Backward asymmetry (AFB ) is an interesting observable. The AFB is defined as follows, AFB ¼
Nðcos Y > 0Þ Nðcos Y50Þ ; Nðcos Y > 0Þ þ Nðcos Y50Þ
ð4Þ
where Y is the angle in the rest frame of the mþ m system between the direction of the Bd and the direction of the mþ . The Standard Model calculations predict the Ap FBffiffi distribution to cross the zero around Mmþ m ¼ s ¼ 2 GeV=c2 . Although the AAB distribution strongly depends on the B ! K * form factor, the zero position is stable under various form factor parameterization [9]. However, some new physics models predict that there is no zero in the AFB distribution [10]. Fig. 3 shows the expected AFB distribution and its uncertainty with 50 and 400 signal events. The solid lines in the plots correspond to the standard model prediction [11].
8. Other studies *
The B0s ! J=cf decays are sum of the CP-even and CP-odd states, and we can extract the
difference of their width (DG) by fitting the decay time distribution to two exponential components. The Run I CDF experiment observed a 50 events of the B0s ! J=cf decays and measured the CP-even fraction to be 0:77 0:19 [12]. In Run II, we will obtain 4 k events of the B0s ! J=cf sample per 2 fb1 of data and measure the DG with a precision of (0.03 to 0.08) depending on the CP-even fraction. The angle g can be probed by the B0s ! D s K decay [13] for which we will collect 850 k signals in the 2 fb1 of the data. The expected error for sinðgÞ depends on the signal-to-background ratio and approximately 0.7 and 0.4 for the cases with S=B ¼ 1=6 and S=B ¼ 1, respectively. Bc meson was first observed in Run I CDF data þ with 20 events of the Bþ c ! J=cl n decay þ [14]. In Run II, we expect 800 Bc ! J=clþ n þ þ events, 360 Bþ c ! J=cp events, and 30 Bc ! 1 0 Bs p events per 2 fb .
9. Conclusions CDF has a rich program to exploit the data of Run II Tevatron. The main goals of the B physics in the 2 fb1 of the data are the measurement of the Bs oscillation with sensitivity up to xs 65; the measurement of the sinð2bÞ with an error of 0.07; the measurement of the g with an error of 108; the studies of the rare B decays and the Bþ c decays. These are a compatible programs with those at Uð4SÞ B factories and the CDF will significantly contribute to B physics before the turn-on of BTeV and LHC-b.
Acknowledgements We thank the Fermilab staff and the technical staff of the participating institutions for their vital contributions. This work was supported by the U.S. Department of Energy and the National Science Foundation; the Natural Sciences and Engineering Research Council of Canada; the Istituto Nazionale di Fisica Nucleare of Italy; the Ministry of Education, Science, Sports and
M. Tanaka / Nuclear Instruments and Methods in Physics Research A 462 (2001) 165–169
Culture of Japan; the National Science Council of the Republic of China; and the A. P. Sloan Foundation.
[5] [6]
References [1] S. Bailey, Nucl. Instr. and Meth., A 462 (2001) 156, these proceedings. [2] T. Affolder et al., [CDF Collaboration], Phys. Rev. D 61 (2000) 072005. [3] B. Aubert et al. [BABAR Collaboration], Proceedings for 30th International Conference On High-Energy Physics (ICHEP 2000), 27 Jul–2 Aug 2000, Osaka, Japan, hepex=0008048. [4] H. Aihara [BELLE Collaboration], Proceedings for 30th International Conference On High-Energy Physics
[7] [8] [9] [10] [11] [12] [13] [14]
169
(ICHEP 2000), 27 Jul–2 Aug 2000, Osaka, Japan, hepex=0010008. J. Cranshaw, Nucl. Instr. and Meth., A 462 (2001) 170, these proceedings. H.G. Moser, A. Roussarie, Nucl. Instr. and Meth. A 384 (1997) 491. R. Fleischer, Phys. Lett. B 459 (1999) 306. T. Affolder et al., [CDF Collaboration], Phys. Rev. Lett. 83 (1999) 3378. G. Burdman, Phys. Rev. D 57 (1998) 4254. A. Ali, P. Ball, L.T. Handoko, G. Hiller, Phys. Rev. D 61 (2000) 074024. G. Baillie, Z. Phys. C 61 (1994) 667. T. Affolder et al., [CDF Collaboration], Phys. Rev. Lett. 85 (2000) 4668. R. Aleksan, I. Dunietz, B. Kayser, Z. Phys. C 54 (1992) 653. F. Abe et al., [CDF Collaboration], Phys. Rev. D 58 (1998) 112004.
III. GENERAL PURPOSE EXPERIMENTS
CDF: Run II physics projections Masashi Tanaka Institute of Physics, University of Tsukuba, Tsukuba, Ibaraki 305, Japan For the CDF Collaboration
Abstract pffiffi In March 2001, the Fermilab Tevatron will start a new physics run of pp% collisions at s ¼ 2:0 TeV. The CDF 1 experiments will collect a data sample of 2 fb in the first two years. In this paper, we describe the B physics prospects at CDF during the upcoming run. # 2001 Published by Elsevier Science B.V.
1. Introduction In this paper, we describe the B physics prospects at Collider Detector at Fermilab (CDF). The CDF detector collectedp a ffiffidata sample of 110 pb1 of pp% collisions at s ¼ 1:8 TeV, during 1992–96 (Run I). A large number of B physics measurements has been performed with the data sample [1]. The measurement of the CP violation parameter sinð2bÞ [2] is still competitive with the first preliminary results of Babar [3] and Belle [4] experiments. Moreover, it is a unique feature to exploit the B0s and Bþ c mesons, and b baryons which is not produced at the Uð4SÞ machines. The Tevatron will commence pp% collisions again in March 2001. The currently named Run II will provide 20 times greater luminosity than Run I, at a center of mass energy of 2 TeV. The goal of the first phase of Run II is the accumulation of 2 fb1 in the first two years, although, a second step will provide a total luminosity higher than 15 fb1 before the turn-on of the LHC. The main goals of the B physics for Run II are a precision measure-
E-mail address: [email protected] (M. Tanaka).
ment of the angles b and g, and observation of the B0s flavor oscillation as well as the rare B decay searches and studies of the heavier B-hadron 0 states, Bþ c , Lb , etc.
2. Detector and trigger upgrade The CDF detector has been upgraded [5] to prepare for the high radiation and the high crossing rate under Run II Tevatron environment. There are also several upgrades to improve the sensitivity of the CDF detector to the B physics: *
*
*
The acceptances of new silicon vertex detector system and new muon detector system for B decay signals are improved by factors of 1.4 and 2, respectively. A new silicon layer (L 0 0) located immediately outside the beam pipe at a radius of 1:6 cm improves the vertex resolution. The typical time resolution for B decays is 45 fs with the L 0 0 and 60 fs without the L 0 0. A new time of flight system (TOF) with a 100 ps of the flight time resolution provides a 2s separation of kaons and pions for charged tracks with momentum less than 1:6 GeV=c.
0168-9002/01/$ - see front matter # 2001 Published by Elsevier Science B.V. PII: S 0 1 6 8 - 9 0 0 2 ( 0 1 ) 0 0 0 9 2 - 4
III. GENERAL PURPOSE EXPERIMENTS
166
M. Tanaka / Nuclear Instruments and Methods in Physics Research A 462 (2001) 165–169
A new trigger system with a 3-level architecture will be installed. In Run II, the Tevatron will be operated with 36 and 121 bunches, and the beam crossing occurs every 396 and 132 ns, respectively. The Level-1 system will reduce the rate to 50 kHz. Besides the calorimeter and muon triggers, this includes a tracking trigger (XFT) for tracks with transverse momentum pT > 1:5 GeV=c. The L1 trigger system will allow us to lower the pT threshold of the muon trigger from 2:2 GeV=c in Run I to 1:5 GeV=c, and increase the acceptance for the J=c ! mþ m trigger by a factor of 2. The level-2 system will work at a rate of 300 Hz, and include a displaced track trigger (SVT), which uses the silicon detector information and measures the track impact parameter with a 35 mm precision. In Run I, all the B-physics analyses are based on the data set triggered with one or two leptons. However, the new trigger system allows us to record the hadronic B decay events without requiring any leptons. We designed dedicated triggers for the hadronic B decay events, which required two XFT tracks and two SVT tracks at Level 1 and Level 2, respectively. For example, we expect 20,000 and 10,000 reconstructed events of the B0s ! D and B0d ! pþ p decays, respecs np 1 tively, in the 2 fb of the two track trigger data.
3. Flavor tagging The determination of the initial B hadron flavor % is important for observing the mixing and (B or B) CP asymmetries. In Run II, we will employ four flavor tagging methods. One of the methods, sameside tagging, uses charge correlation between a B hadron and its fragmentation tracks. In the other three methods, opposite-side taggings use the charge correlation between a B hadron and second % hadron: (1) the lepton tagging uses the charged B lepton from the semileptonic b ! l n% c decay; (2) the kaon tagging uses the charged kaon from the sequential b ! c ! K decay; (3) the jet charge tagging uses the fact that the charge of the b quark to be less than zero. Table 1 shows the prediction of the effective tagging efficiency (eD2 ). The K–p separation with the TOF detector helps the flavor taggings such as
Table 1 Effective tagging efficiency eD2 B0d ! J=cK0S (%)
þ B0s ! D s p (%)
Same side Lepton Jet charge Kaon
1.9 1.7 3.0 2.4
4.2 1.7 3.0 2.4
Total Total (w=o TOF)
9.0 6.1
11.3 5.7
the same side tagging for the B0s , and the opposite þ side kaon tagging. For the B0s ! D s p channel, the TOF almost doubles the effective tagging efficiency (5:7% ! 11:3%).
4. Bs mixing from B0s ! D s np
% 0 mixing frequency xs , For measuring the B0s B s Foulier analysis has been usually employed [6], and significance for the analysis is written by 1 1 Sigðxs Þ ¼ pffiffiffi ð1Þ 2sxs vffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi u st 2 u ðxs Þ tN S t 0 B 2 s eD e ; ¼ 2 SþB
ð2Þ
where N is the number of the signal events, S=B is the signal-to-background ratio, tB0s is the lifetime of the B0s meson, and st is decay time resolution. It is interesting to note that a 5s measurement corresponds to sxs =xs ¼ 0:5% with xs ¼ 30. Thus, once we observe the B0s mixing, the statistical uncertainty for the xs measurement is very small. The two track trigger will collect a large number of the B0s ! Ds np events, and the new silicon strip detector (L 0 0) significantly improves the decay time resolution. Fig. 1 shows the required luminosity for a five sigma observation of the B0s mixing with two different S=B cases. Thus a few hundred pb1 (the first few month) of the Run II data will be enough to observe the Bs mixing with xs ¼ 20 30. The maximum reach of our detector is xs 65.
M. Tanaka / Nuclear Instruments and Methods in Physics Research A 462 (2001) 165–169
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Fig. 2. The expected statistical uncertainty for extracting the angle g as a function of the g in 2 fb1 of the data. Fig. 1. A required luminosity for a five sigma observation of B0s mixing.
5. sinð2bÞ from Bd ! J=wK0S In Run I, CDF measures the sinð2bÞ to be 0:79 0:39 0:16 in the 400 events of the B0d ! J= cK0S sample [2]. The Run II prospect of the statistical uncertainty is obtained by scaling the Run I measurement according to the equation, 1 sðsinð2bÞÞ / pffiffiffiffiffiffiffiffiffiffiffiffi: eD2 N
ð3Þ
The upgraded CDF II detector and the trigger system improve the acceptance for the B0d ! J= cK0S events by a factor of 23, and we will collect a 20,00030,000 of signal samples in the 2 fb1 of the data. A systematic uncertainty of the sinð2bÞ measurement is mainly caused by the dilution measurement by using B0d ! J=cK * 0 for the sameþ side tagging and Bþ for the oppositeu ! J=cK side taggings. With a signal sample of 10,000 ð30; 000Þ reconstructed events, the expected value will be sðsinð2bÞÞ ¼ 0:067 ð0:043Þ.
6. c from B0d ! pþ p and B0s ! Kþ K To extract the angle g by fitting on the CP violating observables in the Bd ! pþ p ,
B0s ! Kþ K , and B0d ! J=cK0S channels is proposed by Fleisher [7]. The idea is using U-spin symmetry, a subgroup of flavor SU(3), to relate the CP violation in B0d ! pþ p to the one in B0s ! Kþ K . In the limit of flavor SU(3) symmetry, the difference of ‘‘penguin pollution’’ for these two decays is entirely due to CKM matrix elements. Relating the two decays thus allows us to determine a weak phase g with a small uncertainty due to the penguin pollution. Fig. 2 shows the expected uncertainty for the g measurement as a function of the g with 2 fb1 . Each points in the plot show variation of the uncertainty by changing the weak phase b and the strong phase y within the ranges of 15–358 and 0– 3608, respectively. In the plot, we assume to collect 5 k B0d ! pþ p events and 10 k B0s ! Kþ K events, and S=B between the B0d ! pþ p signal to combinatorial background to be 1.0. We will measure g with an error better than 108. 7. Rare B0d ! K * 0 ll decay The B0d ! K * 0 mm decay occurs via the quark transition b% ! s% that involves loop, ‘‘penguin’’ and ‘‘box’’, diagrams. The Run I CDF sets an upper limit on the decay branching fraction to be 4:0 106 at a 90% confidence level [8]. In Run II, we expect 50 events of such decay in the 2 fb1 of the data. Then, the III. GENERAL PURPOSE EXPERIMENTS
168
M. Tanaka / Nuclear Instruments and Methods in Physics Research A 462 (2001) 165–169
*
*
Fig. 3. The expected uncertainty for measuring the AFB ðmmþ m Þ distribution with 50 events ð2 fb1 ) and 400 events ð15 fb1 ) of the data.
Forward–Backward asymmetry (AFB ) is an interesting observable. The AFB is defined as follows, AFB ¼
Nðcos Y > 0Þ Nðcos Y50Þ ; Nðcos Y > 0Þ þ Nðcos Y50Þ
ð4Þ
where Y is the angle in the rest frame of the mþ m system between the direction of the Bd and the direction of the mþ . The Standard Model calculations predict the Ap FBffiffi distribution to cross the zero around Mmþ m ¼ s ¼ 2 GeV=c2 . Although the AAB distribution strongly depends on the B ! K * form factor, the zero position is stable under various form factor parameterization [9]. However, some new physics models predict that there is no zero in the AFB distribution [10]. Fig. 3 shows the expected AFB distribution and its uncertainty with 50 and 400 signal events. The solid lines in the plots correspond to the standard model prediction [11].
8. Other studies *
The B0s ! J=cf decays are sum of the CP-even and CP-odd states, and we can extract the
difference of their width (DG) by fitting the decay time distribution to two exponential components. The Run I CDF experiment observed a 50 events of the B0s ! J=cf decays and measured the CP-even fraction to be 0:77 0:19 [12]. In Run II, we will obtain 4 k events of the B0s ! J=cf sample per 2 fb1 of data and measure the DG with a precision of (0.03 to 0.08) depending on the CP-even fraction. The angle g can be probed by the B0s ! D s K decay [13] for which we will collect 850 k signals in the 2 fb1 of the data. The expected error for sinðgÞ depends on the signal-to-background ratio and approximately 0.7 and 0.4 for the cases with S=B ¼ 1=6 and S=B ¼ 1, respectively. Bc meson was first observed in Run I CDF data þ with 20 events of the Bþ c ! J=cl n decay þ [14]. In Run II, we expect 800 Bc ! J=clþ n þ þ events, 360 Bþ c ! J=cp events, and 30 Bc ! 1 0 Bs p events per 2 fb .
9. Conclusions CDF has a rich program to exploit the data of Run II Tevatron. The main goals of the B physics in the 2 fb1 of the data are the measurement of the Bs oscillation with sensitivity up to xs 65; the measurement of the sinð2bÞ with an error of 0.07; the measurement of the g with an error of 108; the studies of the rare B decays and the Bþ c decays. These are a compatible programs with those at Uð4SÞ B factories and the CDF will significantly contribute to B physics before the turn-on of BTeV and LHC-b.
Acknowledgements We thank the Fermilab staff and the technical staff of the participating institutions for their vital contributions. This work was supported by the U.S. Department of Energy and the National Science Foundation; the Natural Sciences and Engineering Research Council of Canada; the Istituto Nazionale di Fisica Nucleare of Italy; the Ministry of Education, Science, Sports and
M. Tanaka / Nuclear Instruments and Methods in Physics Research A 462 (2001) 165–169
Culture of Japan; the National Science Council of the Republic of China; and the A. P. Sloan Foundation.
[5] [6]
References [1] S. Bailey, Nucl. Instr. and Meth., A 462 (2001) 156, these proceedings. [2] T. Affolder et al., [CDF Collaboration], Phys. Rev. D 61 (2000) 072005. [3] B. Aubert et al. [BABAR Collaboration], Proceedings for 30th International Conference On High-Energy Physics (ICHEP 2000), 27 Jul–2 Aug 2000, Osaka, Japan, hepex=0008048. [4] H. Aihara [BELLE Collaboration], Proceedings for 30th International Conference On High-Energy Physics
[7] [8] [9] [10] [11] [12] [13] [14]
169
(ICHEP 2000), 27 Jul–2 Aug 2000, Osaka, Japan, hepex=0010008. J. Cranshaw, Nucl. Instr. and Meth., A 462 (2001) 170, these proceedings. H.G. Moser, A. Roussarie, Nucl. Instr. and Meth. A 384 (1997) 491. R. Fleischer, Phys. Lett. B 459 (1999) 306. T. Affolder et al., [CDF Collaboration], Phys. Rev. Lett. 83 (1999) 3378. G. Burdman, Phys. Rev. D 57 (1998) 4254. A. Ali, P. Ball, L.T. Handoko, G. Hiller, Phys. Rev. D 61 (2000) 074024. G. Baillie, Z. Phys. C 61 (1994) 667. T. Affolder et al., [CDF Collaboration], Phys. Rev. Lett. 85 (2000) 4668. R. Aleksan, I. Dunietz, B. Kayser, Z. Phys. C 54 (1992) 653. F. Abe et al., [CDF Collaboration], Phys. Rev. D 58 (1998) 112004.
III. GENERAL PURPOSE EXPERIMENTS