\begin{document}$ b \to c \tau \bar\nu $\end{document} and \begin{document}$ b \to s \ell^+ \ell^- $\end{document} transitions. Recently, the \begin{document}$ D^* $\end{document} and \begin{document}$ \tau $\end{document} polarization fractions \begin{document}$ P_L^{D^*} $\end{document} and \begin{document}$ P_L^\tau $\end{document} in \begin{document}$ B \to D^* \tau \bar\nu $\end{document} decay were likewise measured by the Belle collaboration. Motivated by these intriguing results, we revisit the \begin{document}$ R_{D^{(*)}} $\end{document} and \begin{document}$ R_{K^{(*)}} $\end{document} anomalies in a scalar leptoquark (LQ) model, where two scalar LQs, one of which is a \begin{document}$ SU(2)_L $\end{document} singlet and the other a \begin{document}$ SU(2)_L $\end{document} triplet, are introduced simultaneously. We consider five \begin{document}$ b \to c \tau \bar\nu $\end{document} mediated decays, \begin{document}$ B \to D^{(*)}\tau \bar\nu $\end{document}, \begin{document}$ B_c \to \eta_c \tau \bar\nu $\end{document}, \begin{document}$ B_c \to J/\psi \tau \bar\nu $\end{document}, and \begin{document}$ \Lambda_b \to \Lambda_c \tau \bar\nu $\end{document}, and focus on the LQ effects on the \begin{document}$ q^2 $\end{document} distributions of the branching fractions, LFU ratios, and various angular observables in these decays. Under the combined constraints of the available data on \begin{document}$ R_{D^{(*)}} $\end{document}, \begin{document}$ R_{J/\psi} $\end{document}, \begin{document}$ P_L^\tau(D^*) $\end{document}, and \begin{document}$ P_L^{D^*} $\end{document}, we perform scans for the LQ couplings and make predictions for a number of observables. Numerically it is found that both the differential branching fractions and LFU ratios are largely enhanced by the LQ effects, with the latter expected to provide testable signatures at the SuperKEKB and High-Luminosity LHC experiments."> Phenomenology of <inline-formula><tex-math id="M1">\begin{document}$\,{{b\to c\tau\bar\nu }}\,$\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="//www.macurncorp.com/cpc/article/app/id/f3fd3e01-75f1-4e25-a01f-bf851483fb53/CPC-2019-0100_M1.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="//www.macurncorp.com/cpc/article/app/id/f3fd3e01-75f1-4e25-a01f-bf851483fb53/CPC-2019-0100_M1.png"/></alternatives></inline-formula> decays in a scalar leptoquark model -
  • [1]

    Y. Li and C.-D. L, Sci. Bull.,63: 267-269 (2018), arXiv:1808.02990

  • [2]

    S. Bifani, S. Descotes-Genon, A. Romero Vidal et al, J. Phys. G,46(2): 023001 (2019), arXiv:1809.06229

  • [3]

    BaBar Collaboration, J. P. Lees et al, Phys. Rev. Lett.,109: 101802 (2012), arXiv:1205.5442

  • [4]

    BaBar Collaboration, J. P. Lees et al, Phys. Rev. D,88(7): 072012 (2013), arXiv:1303.0571

  • [5]

    Belle Collaboration, M. Huschle et al, Phys. Rev. D,92(7): 072014 (2015), arXiv:1507.03233

  • [6]

    Belle Collaboration, Y. Sato et al, Phys. Rev. D,94(7): 072007 (2016), arXiv:1607.07923

  • [7]

    Belle Collaboration, S. Hirose et al, Phys. Rev. Lett.,118(21): 211801 (2017), arXiv:1612.00529

  • [8]

    Belle Collaboration, S. Hirose et al, Phys. Rev. D,97(10): 12004 (2018), arXiv:1709.00129

  • [9]

    LHCb Collaboration, R. Aaij et al, Phys. Rev. Lett.,115(11): 111803 (2015), arXiv:1506.08614

  • [10]

    LHCb Collaboration, R. Aaij et al, Phys. Rev. Lett.,120(17): 171802 (2018), arXiv:1708.08856

  • [11]

    LHCb Collaboration, R. Aaij et al, Phys. Rev. D,97(7): 072013 (2018), arXiv:1711.02505

  • [12]

    Heavy Flavor Averaging Group Collaboration, Y. Amhis et al, Eur. Phys. J. C,77: 895 (2017), arXiv:1612.07233

  • [13]

    D. Bigi and P. Gambino, Phys. Rev. D,94(9): 094008 (2016), arXiv:1606.08030

  • [14]

    S. Jaiswal, S. Nandi, and S. K. Patra, JHEP,12: 060 (2017), arXiv:1707.09977

  • [15]

    F. U. Bernlochner, Z. Ligeti, M. Papucci et al, Phys. Rev. D,95(11): 115008 (2017), arXiv:1703.05330

  • [16]

    D. Bigi, P. Gambino, and S. Schacht, JHEP,11: 061 (2017), arXiv:1707.09509

  • [17]

    LHCb Collaboration, R. Aaij et al, Phys. Rev. Lett.,120(12): 121801 (2018), arXiv:1711.05623

  • [18]

    W. Wang, Y.-L. Shen, and C.-D. Lu, Phys. Rev. D,79: 054012 (2009), arXiv:0811.3748

  • [19]

    LHCb Collaboration, R. Aaij et al, Phys. Rev. Lett.,113: 151601 (2014), arXiv:1406.6482

  • [20]

    LHCb Collaboration, R. Aaij et al, JHEP,08: 055 (2017), arXiv:1705.05802

  • [21]

    G. Hiller and F. Kruger, Phys. Rev. D,69: 074020 (2004), arXiv:hep-ph/0310219

  • [22]

    M. Bordone, G. Isidori, and A. Pattori, Eur. Phys. J. C,76(8): 440 (2016), arXiv:1605.07633

  • [23]

    Y. Sakaki, M. Tanaka, A. Tayduganov et al, Phys. Rev. D,91(11): 114028 (2015), arXiv:1412.3761

  • [24]

    B. Bhattacharya, A. Datta, D. London et al, Phys. Lett. B,742: 370-374 (2015), arXiv:1412.7164

  • [25]

    L. Calibbi, A. Crivellin, and T. Ota, Phys. Rev. Lett.,115: 181801 (2015), arXiv:1506.02661

  • [26]

    F. Feruglio, P. Paradisi, and A. Pattori, Phys. Rev. Lett.,118(1): 011801 (2017), arXiv:1606.00524

  • [27]

    D. Choudhury, A. Kundu, R. Mandal et al, Phys. Rev. Lett.,119(15): 151801 (2017), arXiv:1706.08437

  • [28]

    Q.-Y. Hu, X.-Q. Li, and Y.-D. Yang,b→cτν Transitions in the Standard Model Effective Field Theory, arXiv: 1810.04939

  • [29]

    A. Celis, M. Jung, X.-Q. Li et al, JHEP,01: 054 (2013), arXiv:1210.8443

  • [30]

    N. G. Deshpande and X.-G. He, Eur. Phys. J. C,77(2): 134 (2017), arXiv:1608.04817

  • [31]

    A. Celis, M. Jung, X.-Q. Li et al, Phys. Lett. B,771: 168-179 (2017), arXiv:1612.07757

  • [32]

    J. Zhu, B. Wei, J.-H. Sheng et al, Nucl. Phys. B,934: 380-395 (2018), arXiv:1801.00917

  • [33]

    S.-P. Li, X.-Q. Li, Y.-D. Yang et al, JHEP,09: 149 (2018), arXiv:1807.08530

  • [34]

    Q.-Y. Hu, X.-Q. Li, Y. Muramatsu et al, Phys. Rev. D,99(1): 015008 (2019), arXiv:1808.01419

  • [35]

    W. Altmannshofer, P. S. Bhupal Dev, and A. Soni, Phys. Rev. D,96(9): 095010 (2017), arXiv:1704.06659

  • [36]

    A. K. Alok, D. Kumar, S. Kumbhakar et al, arXiv: 1903.10486

  • [37]

    T. Mandal, S. Mitra, and S. Raz, Phys. Rev. D,99(5): 055028 (2019), arXiv:1811.03561

  • [38]

    C.-T. Tran, M. A. Ivanov, J. G. Körner et al, Phys. Rev. D,97(5): 054014 (2018), arXiv:1801.06927

  • [39]

    D. Bečirević, S. Fajfer, N. Košnik et al, Phys. Rev. D,94(11): 115021 (2016), arXiv:1608.08501

  • [40]

    D. Das, C. Hati, G. Kumar et al, Phys. Rev. D,96(9): 095033 (2017), arXiv:1705.09188

  • [41]

    M. Blanke and A. Crivellin, Phys. Rev. Lett.,121(1): 011801 (2018), arXiv:1801.07256

  • [42]

    N. Assad, B. Fornal, and B. Grinstein, Phys. Lett. B,777: 324-331 (2018), arXiv:1708.06350

  • [43]

    K. Azizi, Y. Sarac, and H. Sundu, arXiv: 1904.08267

  • [44]

    R. Dutta, A. Bhol, and A. K. Giri, Phys. Rev. D,88(11): 114023 (2013), arXiv:1307.6653

  • [45]

    B. Fornal, S. A. Gadam, and B. Grinstein, Phys. Rev. D,99(5): 055025 (2019), arXiv:1812.01603

  • [46]

    Belle, Belle II Collaboration, K. Adamczyk,Semitauonic B decays at Belle/Belle II, in 10th International Workshop on the CKM Unitarity Triangle (CKM 2018) Heidelberg, Germany, September 17-21, 2018, 2019. arXiv: 1901.06380

  • [47]

    Belle Collaboration, A. Abdesselam et al,Measurement of the D*−polarization in the decay B0→D*−τ+ντ, arXiv: 1903.03102

  • [48]

    A. K. Alok, D. Kumar, S. Kumbhakar et al, Phys. Rev. D,95(11): 115038 (2017), arXiv:1606.03164

  • [49]

    Z.-R. Huang, Y. Li, C.-D. Lu et al, Phys. Rev. D,98(9): 095018 (2018), arXiv:1808.03565

  • [50]

    J. Aebischer, J. Kumar, P. Stangl et al,A Global Likelihood for Precision Constraints and Flavour Anomalies, arXiv: 1810.07698

  • [51]

    M. Blanke, A. Crivellin, S. de Boer et al,Impact of polarization observables and Bc→τν on new physics explanations of the b→cτν anomaly, arXiv: 1811.09603

  • [52]

    S. Iguro, T. Kitahara, Y. Omura et al, JHEP,02: 194 (2019), arXiv:1811.08899

  • [53]

    M. Tanaka and R. Watanabe, Phys. Rev. D,87(3): 034028 (2013), arXiv:1212.1878

  • [54]

    Belle II Collaboration, W. Altmannshofer et al,The Belle II Physics Book, arXiv: 1808.10567

  • [55]

    LHCb Collaboration, R. Aaij et al.,Physics case for an LHCb Upgrade II - Opportunities in flavour physics, and beyond, in the HL-LHC era, arXiv: 1808.08865

  • [56]

    A. Crivellin, D. Mller, and T. Ota, JHEP,09: 040 (2017), arXiv:1703.09226

  • [57]

    I. Dorner, S. Fajfer, A. Greljo et al, Phys. Rept.,641: 1-68 (2016), arXiv:1603.04993

  • [58]

    M. Freytsis, Z. Ligeti, and J. T. Ruderman, Phys. Rev. D,92(5): 054018 (2015), arXiv:1506.08896

  • [59]

    M. Bauer and M. Neubert, Phys. Rev. Lett.,116(14): 141802 (2016), arXiv:1511.01900

  • [60]

    X.-Q. Li, Y.-D. Yang, and X. Zhang, JHEP,02: 068 (2017), arXiv:1611.01635

  • [61]

    S. Fajfer and N. Konik, Phys. Lett. B,755: 270-274 (2016), arXiv:1511.06024

  • [62]

    F. F. Deppisch, S. Kulkarni, H. Ps et al, Phys. Rev. D,94(1): 013003 (2016), arXiv:1603.07672

  • [63]

    B. Dumont, K. Nishiwaki, and R. Watanabe, Phys. Rev. D,94(3): 034001 (2016), arXiv:1603.05248

  • [64]

    L. Di Luzio, A. Greljo, and M. Nardecchia, Phys. Rev. D,96(11): 115011 (2017), arXiv:1708.08450

  • [65]

    Y. Cai, J. Gargalionis, M. A. Schmidt et al, JHEP,10: 047 (2017), arXiv:1704.05849

  • [66]

    L. Calibbi, A. Crivellin, and T. Li, Phys. Rev. D,98(11): 115002 (2018), arXiv:1709.00692

  • [67]

    J. Kumar, D. London, and R. Watanabe, Phys. Rev. D,99(1): 015007 (2019), arXiv:1806.07403

  • [68]

    C. Hati, G. Kumar, J. Orloff et al, JHEP,11: 011 (2018), arXiv:1806.10146

  • [69]

    A. Crivellin, C. Greub, D. Mller et al, Phys. Rev. Lett.,122(1): 011805 (2019), arXiv:1807.02068

  • [70]

    A. Angelescu, D. Beirevi, D. A. Faroughy et al, JHEP,10: 183 (2018), arXiv:1808.08179

  • [71]

    T. J. Kim, P. Ko, J. Li et al,Correlation betweenRD(*)and top quark FCNC decays in leptoquark models, arXiv: 1812.08484

  • [72]

    D. Marzocca, JHEP,07: 121 (2018), arXiv:1803.10972

  • [73]

    D. Buttazzo, A. Greljo, G. Isidori et al, JHEP,11: 044 (2017), arXiv:1706.07808

  • [74]

    P. Arnan, D. Becirevic, F. Mescia et al, JHEP,02: 109 (2019), arXiv:1901.06315

  • [75]

    W. Detmold, C. Lehner, and S. Meinel, Phys. Rev. D,92(3): 034503 (2015), arXiv:1503.01421

  • [76]

    A. Datta, S. Kamali, S. Meinel et al, JHEP,08: 131 (2017), arXiv:1702.02243

  • [77]

    Flavour Lattice Averaging Group Collaboration, S. Aoki et al,FLAG Review 2019, arXiv: 1902.08191

  • [78]

    A. Cerri et al,Opportunities in Flavour Physics at the HL-LHC and HE-LHC, arXiv: 1812.07638

  • [79]

    K. Hagiwara, A. D. Martin, and M. F. Wade, Nucl. Phys. B,327: 569-594 (1989)

  • [80]

    F. U. Bernlochner, Z. Ligeti, and D. J. Robinson,N = 5, 6, 7, 8: Nested hypothesis tests and truncation dependence of|Vcb|, arXiv: 1902.09553

  • [81]

    Y.-M. Wang, Y.-B. Wei, Y.-L. Shen et al, JHEP,06: 062 (2017), arXiv:1701.06810

  • [82]

    N. Gubernari, A. Kokulu, and D. van Dyk, JHEP,01: 150 (2019), arXiv:1811.00983

  • [83]

    C. W. Murphy and A. Soni, Phys. Rev. D,98(9): 094026 (2018), arXiv:1808.05932

  • [84]

    A. Berns and H. Lamm, JHEP,12: 114 (2018), arXiv:1808.07360

  • [85]

    W. Wang and R. Zhu,Model independent investigation of the RJ/ψ, ηcand ratios of decay widths of semileptonic Bc decays into a P-wave charmonium, arXiv: 1808.10830

  • [86]

    D. Leljak, B. Melic, and M. Patra,On lepton flavour universality in semileptonic Bc→ηc,J/ψ decays, arXiv: 1901.08368

  • [87]

    T. Gutsche, M. A. Ivanov, J. G. Krner et al, Phys. Rev. D,91(7): 074001 (2015), arXiv:1502.04864

  • [88]

    C. G. Boyd, B. Grinstein, and R. F. Lebed, Phys. Rev. D,56: 6895-6911 (1997), arXiv:hep-ph/9705252

  • [89]

    I. Caprini, L. Lellouch, and M. Neubert, Nucl. Phys. B,530: 153-181 (1998), arXiv:hep-ph/9712417

  • [90]

    G. Buchalla, A. J. Buras, and M. E. Lautenbacher, Rev. Mod. Phys.,68: 1125-1144 (1996), arXiv:hep-ph/9512380

  • [91]

    W. Altmannshofer and D. M. Straub,Implications of b → s measurements, in Proceedings, 50th Rencontres de Moriond Electroweak Interactions and Unified Theories: La Thuile, Italy, March 14-21, 2015, pp. 333–338, 2015. arXiv: 1503.06199

  • [92]

    S. Descotes-Genon, L. Hofer, J. Matias et al, JHEP,06: 092 (2016), arXiv:1510.04239

  • [93]

    T. Hurth, F. Mahmoudi, and S. Neshatpour, Nucl. Phys. B,909: 737-777 (2016), arXiv:1603.00865

  • [94]

    Muon g-2 Collaboration, G. W. Bennett et al, Phys. Rev. D,73: 072003 (2006), arXiv:hep-ex/0602035

  • [95]

    Particle Data Group Collaboration, M. Tanabashi et al, Phys. Rev. D,98(3): 030001 (2018)

  • [96]

    CMS Collaboration, A. M. Sirunyan et al, Phys. Rev. Lett.,121(24): 241802 (2018), arXiv:1809.05558

  • [97]

    ATLAS Collaboration, M. Aaboud et al,Searches for third-generation scalar leptoquarks in \begin{document}$ \sqrt s $\end{document} =13 TeV pp collisions with the ATLAS detector, arXiv: 1902.08103

  • [98]

    CKMfitter Group Collaboration, J. Charles, A. Hocker, H. Lacker, S. Laplace, F. R. Le Diberder, J. Malcles, J. Ocariz, M. Pivk, and L. Roos, Eur. Phys. J. C,41(1): 1-131 (2005)

  • [99]

    M. Jung, X.-Q. Li, and A. Pich, JHEP,10: 063 (2012), arXiv:1208.1251

  • [100]

    C.-W. Chiang, X.-G. He, F. Ye et al, Phys. Rev. D,96(3): 035032 (2017), arXiv:1703.06289

  • [101]

    LHCb Collaboration, R. Aaij et al, Phys. Rev. Lett.,118(25): 251802 (2017), arXiv:1703.02508

  • [102]

    C. Bobeth, M. Gorbahn, T. Hermann et al, Phys. Rev. Lett.,112: 101801 (2014), arXiv:1311.0903

  • [103]

    J. Albrecht, F. Bernlochner, M. Kenzie et al,Future prospects for exploring present day anomalies in flavour physics measurements with Belle II and LHCb, arXiv: 1709.10308

  • [104]

    J. F. Kamenik, S. Monteil, A. Semkiv et al, Eur. Phys. J. C,77(10): 701 (2017), arXiv:1705.11106

  • [105]

    Belle Collaboration, G.Caria, Measurement of R(D)and R(D*)with a semileptonic tag at Belle, Talk at ‘54th Rencontres de Moriond, Electroweak Interactions and Unified Theories, 2019’

  • [106]

    elle Collaboration, A. Abdesselam et al.,Measurement of \begin{document}$ \cal{R}$\end{document} (D)and \begin{document}$ \cal{R}$\end{document} (D*)with a semileptonic tagging method, arXiv: 1904.08794

  • [107]

    C. Murgui, A. Peuelas, M. Jung et al,Global fit to b→cτν transitions, arXiv: 1904.09311

  • [108]

    J. G. Korner and G. A. Schuler, Z. Phys. C,46: 93 (1990)

  • [109]

    H. E. Haber,Spin formalism and applications to new physics searches, in Spin structure in high-energy processes: Proceedings, 21st SLAC Summer Institute on Particle Physics, 26 Jul - 6 Aug 1993, Stanford, CA, pp. 231–272, 1994. hep-ph/9405376

  • [110]

    Y. Sakaki, M. Tanaka, A. Tayduganov et al, Phys. Rev. D,88(9): 094012 (2013), arXiv:1309.0301

  • [111]

    D. Bardhan, P. Byakti, and D. Ghosh, JHEP,01: 125 (2017), arXiv:1610.03038

Baidu
map