Publications de Lei Li | EPFL Graph Search

Test of lepton flavor universality and search for lepton flavor violation in B -> Kll decays

Olivier Schneider, Sun Hee Kim, Mingkui Wang, Chao Wang, Donghyun Kim, Lei Li, Yiming Li, Xiao Wang

We present measurements of the branching fractions for the decays B -> K mu(+)mu(-) and B -> Ke(+)e(-), and their ratio (R-K), using a data sample of 711 fb(-1) that contains 772 x 10(6) B (B) over bar events. The data were collected at the Gamma(4S) reson ...

Springer Nature2021

Measurement of R(D) and R(D*) with a Semileptonic Tagging Method

Olivier Schneider, Sun Hee Kim, Tagir Aushev, Mingkui Wang, Chao Wang, Donghyun Kim, Lei Li, Yiming Li, Xiao Wang

The experimental results on the ratios of branching fractions R(D) = B((B) over bar -> D tau(-)(nu) over bar (tau))/B((B) over bar -> Dl(-)(nu) over bar (e)) and R(D*) = B((B) over bar -> Dtau(-)(nu) over bar (tau))/B((B) over bar -> Dtau(-)(nu) over bar ...

2020

Dalitz analysis of D-0 -> K- pi(+)eta decays at Belle

Olivier Schneider, Sun Hee Kim, Tagir Aushev, Mingkui Wang, Chao Wang, Yixing Chen, Donghyun Kim, Lei Li, Yiming Li

We present the results of the first Dalitz plot analysis of the decay D-0 -> K-pi(+)eta. The analysis is performed on a data set corresponding to an integrated luminosity of 953 fb(-1) collected by the Belle detector at the asymmetric-energy e(+)e(-) KEKB ...

American Physical Society2020

Study of B -> ppi pi

Olivier Schneider, Sun Hee Kim, Tagir Aushev, Mingkui Wang, Chao Wang, Donghyun Kim, Lei Li, Xiao Wang

Using a data sample of 772 x 10(6) B (B) over bar pairs collected on the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric energy e(+)e(-) collider, we report the observation of B-0 -> p (p) over bar pi(+)pi(-) and the first observation ...

American Physical Society2020

Measurement of the charm-mixing parameter y(CP) in D-0 -> K-S(0)omega decays at Belle

Olivier Schneider, Sun Hee Kim, Tagir Aushev, Mingkui Wang, Chao Wang, Donghyun Kim, Lei Li, Yiming Li, Xiao Wang

We report the first measurement of the charm-mixing parameter y(CP) in D-0 decays to the CP-odd final state K-S(0 omega). The study uses the full Belle e(+)e(-) annihilation data sample of 976 fb(-1) taken at or near the gamma (4S) centre-of-mass energy. W ...

American Physical Society2020

First search for the decays at Belle

Olivier Schneider, Mingkui Wang, Chao Wang, Donghyun Kim, Lei Li, Yiming Li, Xiao Wang

The first dedicated search for the eta(c2)(1D) is carried out using the decays B+-> eta(c2)(1D)K+, B-0 -> eta(c2)(1D)KS0 with eta(c2)(1D) -> h(c)gamma. No significant signal is found. For the eta(c2)(1D) mass range between 3795 and 3845 MeV/c(2), the branc ...

Springer Nature2020

Evidence for B+ -> h(c)K(+) and observation of eta(c()2S) -> p(p)over-bar pi(+)pi(-)

Olivier Schneider, Sun Hee Kim, Tagir Aushev, Mingkui Wang, Chao Wang, Donghyun Kim, Lei Li, Yiming Li

A search for the decays B+ -> h(c)K(+) and B-0 -> h(c)K(S)(0) is performed. Evidence for the decay B+ -> h(c)K(+) is found; its significance is 4.8 sigma. No evidence is found for B-0 -> h(c)K(S)(0). The branching fraction for B+ -> h(c)K(+) is measured to ...

American Physical Society2019

Transverse momentum dependent production cross sections of charged pions, kaons and protons produced in inclusive e(+)e(-) annihilation at root s=10.58 GeV

Olivier Schneider, Sun Hee Kim, Tagir Aushev, Mingkui Wang, Chao Wang, Jun Yong Kim, Mithilesh Nayak, Donghyun Kim, Lei Li, Ji Hyun Kim, Yiming Li, Xiao Wang

We report measurements of the production cross sections of charged pions, kaons, and protons as a function of fractional energy, the event-shape variable called thrust, and the transverse momentum with respect to the thrust axis. These measurements access ...

American Physical Society2019

Observation of tau(-) -> pi(-)nu(tau)e(+)e(-) and search for tau(-) -> pi(-)nu(tau)mu(+)mu(-)

Olivier Schneider, Sun Hee Kim, Tagir Aushev, Mingkui Wang, Chao Wang, Ke Huang, Donghyun Kim, Lei Li, Yiming Li

We present the first measurements of branching fractions of rare tau-lepton decays, tau(-) -> pi(-)nu(tau)l(+)l(-) (l = e or mu), using a data sample corresponding to 562 fb(-1) collected at a center-of-mass energy of 10.58 GeV with the Belle detector at t ...

American Physical Society2019

Measurements of isospin asymmetry and difference of direct CP asymmetries in inclusive B -> X-s gamma decays

Olivier Schneider, Sun Hee Kim, Steve Michel Berger, Tagir Aushev, Mingkui Wang, Chao Wang, Yong Chan Choi, Arnaud Michel Gelb, Kyung Taek Cho, Jun Yong Kim, Linlin Cao, Carsten Hao Ye Chong, Tara Nanut, Donghyun Kim, Martin Lubej, Chang-Hyun Park, Yifei Guan, Lei Li, Ji Hyun Kim, Yiming Li

We report measurements of isospin asymmetry Delta(0-) and difference of direct CP asymmetries Delta A(CP) between charged and neutral B -> X-s gamma decays. This analysis is based on the data sample containing 772 x 10(6)B (B) over bar pairs that was colle ...

American Physical Society2019

Search for X(3872) and X(3915) decay into chi(c1)pi(0) in B decays at Belle

Olivier Schneider, Sun Hee Kim, Tagir Aushev, Mingkui Wang, Chao Wang, Donghyun Kim, Lei Li, Yiming Li, Xiao Wang

We report a search for X(3872) and X(3915) in B+ ->chi(c1)pi K-0(+) decays. We set an upper limit of B(B+ -> X(3872)K+) x B(X(3872) -> chi(c1)pi(0)) < 8.1 x 10(-6) and B(B+ -> X(3915)K+) x B(X(3915) -> chi(c1)pi(0)) < 3.8 x 10(-5) at 90% confidence level. ...

American Physical Society2019

Observation of Xi(1620)(0) and Evidence for Xi(1690)(0) in Xi(+)(c) -> Xi(-) pi(+) pi(+) Decays

Olivier Schneider, Sun Hee Kim, Tagir Aushev, Mingkui Wang, Chao Wang, Jun Yong Kim, Tara Nanut, Donghyun Kim, Lei Li, Ji Hyun Kim, Yiming Li, Xiao Wang

We report the first observation of the double strange baryon Xi(1620)(0) in its decay to Xi(-) pi(+) via Xi(+)(c) -> Xi(-)pi(+)pi(+) decays based on a 980 fb(-1) data sample collected with the Belle detector at the KEKB asymmetricenergy e(+)e(-) collider. ...

2019

First measurement of the CKM angle phi(3) with B-+/--> D(K-S(0)pi(+)pi(-)pi(0)) K-+/- decays

Olivier Schneider, Sun Hee Kim, Mingkui Wang, Chao Wang, Donghyun Kim, Lei Li, Yiming Li, Xiao Wang

We present the first model-independent measurement of the CKM unitarity triangle angle phi(3) using B-+/--> D(K-S(0)pi(+)pi(-)pi(0)) K-+/- decays, where D indicates either a D-0 or (D) over bar (0) meson. Measurements of the strong-phase difference of the ...

Springer Nature2019

Search for a Light CP-odd Higgs Boson and Low-Mass Dark Matter at the Belle Experiment

Roberto Gargiani, Olivier Schneider, Sun Hee Kim, Tagir Aushev, Chao Wang, Hiroyasu Yamamoto, Yong Chan Choi, Seyed Sina Mirrazavi Salehian, Arnaud Michel Gelb, Ke Huang, Gaétan Charles Antoine Giriat, Jun Yong Kim, Mithilesh Nayak, Linlin Cao, Jiayun Shen, Tara Nanut, Donghyun Kim, Martin Lubej, Chang-Hyun Park, Lei Li, Ji Hyun Kim, Yiming Li

We report on the first Belle search for a light CP-odd Higgs boson, A(0), that decays into low mass dark matter, chi, in final states with a single photon and missing energy. We search for events produced via the dipion transition (sic)(2S) -> (sic)(1S)pi( ...

2019

Measurement of time-dependent CP violation in B-0 -> K-S(0)pi(0)pi(0) decays

Olivier Schneider, Sun Hee Kim, Tagir Aushev, Mingkui Wang, Chao Wang, Jun Yong Kim, Tara Nanut, Donghyun Kim, Lei Li, Ji Hyun Kim, Yiming Li

We report a measurement of time-dependent CP violation in B-0 -> K-S(0)pi(0)pi(0) decays using a data sample of 772 x 10(6) B (B) over bar pairs collected by the Belle experiment running at the (sic)(4S) resonance at the KEKB e(+)e(-) collider. This decay ...

American Physical Society2019

Observation of a new structure near 10.75 GeV in the energy dependence of the e(+)e(-)-> Upsilon (nS)pi(+)pi(-) (n=1, 2, 3) cross sections

Olivier Schneider, Sun Hee Kim, Tagir Aushev, Mingkui Wang, Chao Wang, Kyung Taek Cho, Donghyun Kim, Lei Li

We report a new measurement of the e(+)e(-)-> Upsilon(nS)pi(+)pi(-) (n = 1, 2, 3) cross sections at energies from 10.52 to 11.02 GeV using data collected with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. We observe a new structure in ...

Springer Nature2019

Observation of B+ -> p(Lambda)over-barK(+) K- and B+ -> (p)over-bar Lambda K+ K+

Olivier Schneider, Sun Hee Kim, Tagir Aushev, Mingkui Wang, Chao Wang, Jun Yong Kim, Tara Nanut, Donghyun Kim, Lei Li, Ji Hyun Kim, Yiming Li, Xiao Wang

We report the study of B+ -> p (Lambda) over barK(+)K(-) and B+ -> (p) over barK(+)K(+) decays using a 772 x 10(6) B (B) over bar pair data sample recorded on the gamma(4S) resonance with the Belle detector at KEKB. The following branching fractions are me ...

American Physical Society2019

First measurements of absolute branching fractions of the Xi(+)(c) baryon at Belle

Olivier Schneider, Sun Hee Kim, Tagir Aushev, Mingkui Wang, Chao Wang, Donghyun Kim, Lei Li, Yiming Li

We present the first measurements of the absolute branching fractions of Xi(+)(c) decays into Xi(-)pi(+)pi(+) and pK(-)pi(+) final states. Our analysis is based on a data set of (772 +/- 11) x 10(6) B (B) over bar pairs collected at the Upsilon(4S) resonan ...

American Physical Society2019

Measurement of the CKM matrix element vertical bar V-cb vertical bar from B-0 -> D*(-)l(+)nu(l) at Belle

Olivier Schneider, Sun Hee Kim, Tagir Aushev, Mingkui Wang, Chao Wang, Donghyun Kim, Lei Li, Yiming Li

We present a new measurement of the Cabibbo-Kobayashi-Maskawa matrix element vertical bar V-cb vertical bar from B-0 -> D*(-)l(+)nu(l) decays, reconstructed with the full Belle data set of 711 fb(-1) integrated luminosity. Two form factor parametrizations, ...

American Physical Society2019

Search for Omega(2012) -> K Xi(1530) -> K pi Xi at Belle

Olivier Schneider, Sun Hee Kim, Tagir Aushev, Mingkui Wang, Chao Wang, Ke Huang, Donghyun Kim, Lei Li, Yiming Li

Using data samples of e(+)e(-) collisions collected at the Upsilon(1S), Upsilon(2S), and Upsilon(3S) resonances with the Belle detector, we search for the three-body decay of the Omega(2012) baryon to K pi Xi. This decay is predicted to dominate for models ...

American Physical Society2019