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Test of lepton flavor universality with measurements of 𝑅⁑(𝐷+) and 𝑅⁑(𝐷*+) using semileptonic 𝐡 tagging at the Belle II experiment

Journal Article · · Physical Review. D.
DOI:https://doi.org/10.1103/fmn3-h8fy· OSTI ID:3006445
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; more »; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; « less
We report measurements of the ratios of branching fractions ℛ⁑(𝐷(*)+) = ℬ⁑($$\bar{𝐡}$$0 β†’ 𝐷(*)+β’πœβˆ’β’ $$\bar{𝜈}$$𝜏)/ℬ⁑($$\bar{𝐡}$$0 β†’ 𝐷(*)+β’β„“βˆ’$$\bar{𝜈}$$β„“), where β„“ denotes either an electron or a muon. These ratios test the universality of the charged-current weak interaction. The results are based on a 365 fbβˆ’1 data sample collected with the Belle II detector at the SuperKEKB 𝑒+β’π‘’βˆ’ collider, which operates at a center-of-mass energy corresponding to the ϒ⁑(4⁒𝑆) resonance, just above the threshold for $$𝐡\bar{𝐡}$$ production. Signal candidates are reconstructed by selecting events in which the companion 𝐡 meson from the ϒ⁑(4⁒𝑆) β†’ $$𝐡\bar{𝐡}$$ decay is identified in semileptonic modes. The 𝜏 lepton is reconstructed via its leptonic decays. We obtain ℛ⁑(𝐷+) = 0.418$$^{+0.075}_{βˆ’0.073}$$⁒(stat)$$^{+0.049}_{βˆ’0.056}$$⁒(syst) and ℛ⁑(𝐷*+) = 0.306$$^{+0.035}_{βˆ’0.033}$$⁒(stat)$$^{+0.016}_{βˆ’0.018⁒}$$(syst), which are consistent with world average values. Accounting for the correlation between them, these values differ from the Standard Model expectation by a collective significance of 1.7 standard deviations.
Research Organization:
Univ. of Hawaii, Honolulu, HI (United States)
Sponsoring Organization:
National Science Foundation (NSF); USDOE Office of Science (SC), High Energy Physics (HEP)
Grant/Contract Number:
AC06-76RL01830; SC0007983; SC0009824; SC0009973; SC0010007; SC0010073; SC0010118; SC0010504; SC0011784; SC0012704; SC0019230; SC0021274; SC0021616; SC0022350; SC0023470
Other Award/Contract Number:
23LCG-1C011
DP200101792
DP210101900
DP210102831
DE220100462
LE210100098
LE230100085
947006
2024YFA1610503
2024YFA1610504
11575017
11761141009
11705209
11975076
12135005
12150004
12161141008
12475093
12175041
ZR2022JQ02
22-18469S
246122
PIEF-GA-2013-622527
267104
884719
819127
700525 β€œNIOBE”
101026516
822070
ANR-21-CE31-0009
RTI 4002
UPES/R&D-SEED-INFRA/17052023/01
UPES/R&D-SOE/20062022/06
2476/17
2016113
3-16543
BELLE2
16H03968
16H03993
16H06492
16K05323
17H01133
17H05405
18K03621
18H03710
18H05226
19H00682
20H05850
20H05858
22H00144
22K14056
22K21347
23H05433
26220706
26400255
2016R1-D1A1B-02012900
2018R1-A6A1A-06024970
2021R1-A6A1A-03043957
2021R1-F1A-1060423
2021R1-F1A-1064008
2022R1-A2C-1003993
2022R1-A2C-1092335
RS-2023-00208693
RS-2024-00354342
RS-2022-00197659
K24L2M1C4
237
S-0256-1438
S-0280-1439
RSPD2025R873
J1-9124
P1-0135
PID2022-136510NB-C33
RYC2020-029875-I
CIDEGENT/2018/020
2020.02/0257
PHY-1913789
PHY-2111604
NVCC.05.12/22-23
DL0000.02/24-25
FOINS-296
CB-221329
CB-236394
CB-254409
CB-180023
OSTI ID:
3006445
Journal Information:
Physical Review. D., Journal Name: Physical Review. D. Journal Issue: 3 Vol. 112; ISSN 2470-0029; ISSN 2470-0010
Publisher:
American Physical Society (APS)Copyright Statement
Country of Publication:
United States
Language:
English

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