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Author 
Abbas, G.; Celis, A.; Li, X.Q.; Lu, J.; Pich, A. 


Title 
Flavourchanging top decays in the aligned twoHiggsdoublet model 
Type 
Journal Article 

Year 
2015 
Publication 
Journal of High Energy Physics 
Abbreviated Journal 
J. High Energy Phys. 


Volume 
06 
Issue 
6 
Pages 
005  26pp 


Keywords 
Rare Decays; Beyond Standard Model; Heavy Quark Physics 


Abstract 
We perform a complete oneloop computation of the twobody flavourchanging top decays t > ch and t > cV (V = gamma, Z), within the aligned twoHiggsdoublet model. We evaluate the impact of the model parameters on the associated branching ratios, taking into account constraints from flavour data and measurements of the Higgs properties. Assuming that the 125 GeV Higgs corresponds to the lightest CPeven scalar of the CPconserving aligned twoHiggsdoublet model, we find that the rates for such flavourchanging top decays lie below the expected sensitivity of the future highluminosity phase of the LHC. Measurements of the Higgs signal strength in the diphoton channel are found to play an important role in limiting the size of the t > ch decay rate when the charged scalar of the model is light. 


Address 
[Abbas, Gauhar; Pich, Antonio] Univ Valencia, CSIC, IFIC, E46071 Valencia, Spain, Email: Gauhar.Abbas@ific.uv.es; 


Corporate Author 

Thesis 



Publisher 
Springer 
Place of Publication 

Editor 



Language 
English 
Summary Language 

Original Title 



Series Editor 

Series Title 

Abbreviated Series Title 



Series Volume 

Series Issue 

Edition 



ISSN 
10298479 
ISBN 

Medium 



Area 

Expedition 

Conference 



Notes 
WOS:000355745800001 
Approved 
no 


Is ISI 
yes 
International Collaboration 
yes 


Call Number 
IFIC @ pastor @ 
Serial 
2255 

Permanent link to this record 




Author 
Celis, A.; Jung, M.; Li, X.Q.; Pich, A. 


Title 
Scalar contributions to b > c(u) tau nu transitions 
Type 
Journal Article 

Year 
2017 
Publication 
Physics Letters B 
Abbreviated Journal 
Phys. Lett. B 


Volume 
771 
Issue 

Pages 
168179 


Keywords 



Abstract 
We perform a comprehensive analysis of scalar contributions in b > c tau nu transitions including the latest measurements of R(D(*)), the q(2) differential distributions in B > D(*) tau nu the tau polarization asymmetry for B > D*tau nu, and the bound derived from the total width of the Bc meson. We find that scalar contributions with the simultaneous presence of both left and righthanded couplings to quarks can explain the available data, specifically R(D(*)) together with the measured differential distributions. However, the constraints from the total Bc width present a slight tension with the current data on B > D*tau nu in this scenario, preferring smaller values for R(D*). We discuss possibilities to disentangle scalar new physics from other newphysics scenarios like the presence of only a lefthanded vector current, via additional observables in B > D(*)tau nu decays or additional decay modes like the baryonic Lambda(b) > Lambda(c)tau nu and the inclusive B > Xc tau nu decays. We also analyze scalar contributions in b > u tau nu transitions, including the latest measurements of B > tau nu providing predictions for Lambda(b) > p tau nu and B > pi tau nu decays. The potential complementarity between the b > u and b > c sectors is finally investigated once assumptions about the flavour structure of the underlying theory are made. 


Address 
[Celis, Alejandro] Ludwig Maximilians Univ Munchen, Fak Phys, Arnold Sommerfeld Ctr Theoret Phys, D80333 Munich, Germany, Email: xqli@itp.ac.cn 


Corporate Author 

Thesis 



Publisher 
Elsevier Science Bv 
Place of Publication 

Editor 



Language 
English 
Summary Language 

Original Title 



Series Editor 

Series Title 

Abbreviated Series Title 



Series Volume 

Series Issue 

Edition 



ISSN 
03702693 
ISBN 

Medium 



Area 

Expedition 

Conference 



Notes 
WOS:000406183300024 
Approved 
no 


Is ISI 
yes 
International Collaboration 
yes 


Call Number 
IFIC @ pastor @ 
Serial 
3260 

Permanent link to this record 




Author 
Celis, A.; Jung, M.; Li, X.Q.; Pich, A. 


Title 
Sensitivity to charged scalars in B > D(*)tau nu(tau) and B > tau nu(tau) decays 
Type 
Journal Article 

Year 
2013 
Publication 
Journal of High Energy Physics 
Abbreviated Journal 
J. High Energy Phys. 


Volume 
01 
Issue 
1 
Pages 
054  27pp 


Keywords 
Beyond Standard Model; BPhysics 


Abstract 
We analyze the recent experimental evidence for an excess of taulepton production in several exclusive semileptonic Bmeson decays in the context of twoHiggsdoublet models. These decay modes are sensitive to the exchange of charged scalars and constrain strongly their Yukawa interactions. While the usual TypeII scenario cannot accommodate the recent BaBar data, this is possible within more general models in which the chargedscalar couplings to uptype quarks are not as suppressed. Both the B > D(*)tau nu(tau) and the B > tau nu(tau) data can be fitted within the framework of the Aligned TwoHiggsDoublet Model, but the resulting parameter ranges are in conflict with the constraints from leptonic charm decays. This could indicate a departure from the family universality of the Yukawa couplings, beyond their characteristic fermion mass dependence. We discuss several new observables that are sensitive to a hypothetical chargedscalar contribution, demonstrating that they are well suited to distinguish between different scenarios of new physics in the scalar sector, and also between this group and models with different Dirac structures; their experimental study would therefore shed light on the relevance of scalar exchanges in semileptonic b > c tau()(nu) over bar (tau) transitions. 


Address 
[Celis, Alejandro; Li, XinQiang; Pich, Antonio] Univ Valencia, CSIC, IFIC, E46071 Valencia, Spain, Email: alejandro.celis@ific.uv.es; 


Corporate Author 

Thesis 



Publisher 
Springer 
Place of Publication 

Editor 



Language 
English 
Summary Language 

Original Title 



Series Editor 

Series Title 

Abbreviated Series Title 



Series Volume 

Series Issue 

Edition 



ISSN 
11266708 
ISBN 

Medium 



Area 

Expedition 

Conference 



Notes 
WOS:000315583200054 
Approved 
no 


Is ISI 
yes 
International Collaboration 
yes 


Call Number 
IFIC @ pastor @ 
Serial 
1368 

Permanent link to this record 




Author 
Chang, Q.; Li, X.Q.; Yang, Y.D. 


Title 
The effects of a family nonuniversal Z ' boson on B > pi pi decays 
Type 
Journal Article 

Year 
2011 
Publication 
International Journal of Modern Physics A 
Abbreviated Journal 
Int. J. Mod. Phys. A 


Volume 
26 
Issue 
78 
Pages 
12731294 


Keywords 
Bphysics; rare decays; beyond Standard Model 


Abstract 
Motivated by the measured large branching ratio of (B) over bar (0) > pi(0)pi(0) (the socalled pi pi puzzle), we investigate the effects of a family nonuniversal Z' model on the treedominated B > pi pi decays. We find that the Z' coupling parameter zeta(LR)(d) similar to 0.05 with a nontrivial new weak phase phi(L)(d) similar to 50 degrees, which is relevant to the Z' contributions to the QCD penguin sector Delta C5, is needed to reconcile the observed discrepancy. Combined with the recent fitting results from B > pi K, pi K* and rho K decays, the Z' parameter spaces are severely reduced but still not excluded entirely, implying that both the “pi pi” and “pi K” puzzles could be accommodated simultaneously within such a family nonuniversal Z' model. 


Address 
[Chang, Qin; Li, XinQiang] Henan Normal Univ, Dept Phys, Xinxiang 453007, Henan, Peoples R China, Email: changqin@htu.cn 


Corporate Author 

Thesis 



Publisher 
World Scientific Publ Co Pte Ltd 
Place of Publication 

Editor 



Language 
English 
Summary Language 

Original Title 



Series Editor 

Series Title 

Abbreviated Series Title 



Series Volume 

Series Issue 

Edition 



ISSN 
0217751x 
ISBN 

Medium 



Area 

Expedition 

Conference 



Notes 
ISI:000289175800004 
Approved 
no 


Is ISI 
yes 
International Collaboration 
yes 


Call Number 
IFIC @ pastor @ 
Serial 
595 

Permanent link to this record 




Author 
Chen, M.C.; Li, X.Q.; Liu, X.G.; Medina, O.; Ratz, M. 


Title 
Modular invariant holomorphic observables 
Type 
Journal Article 

Year 
2024 
Publication 
Physics Letters B 
Abbreviated Journal 
Phys. Lett. B 


Volume 
852 
Issue 

Pages 
138600  13pp 


Keywords 



Abstract 
In modular invariant models of flavor, observables must be modular invariant. The observables discussed so far in the literature are functions of the modulus tau and its conjugate, (tau) over bar. We point out that certain combinations of observables depend only on tau , i.e. are meromorphic, and in some cases even holomorphic functions of tau. These functions, which we dub “invariants” in this Letter, are highly constrained, renormalization group invariant, and allow us to derive many of the models' features without the need for extensive parameter scans. We illustrate the robustness of these invariants in two existing models in the literature based on modular symmetries, Gamma(3) and Gamma(5). We find that, in some cases, the invariants give rise to robust relations among physical observables that are independent of tau. Furthermore, there are instances where additional symmetries exist among the invariants. These symmetries are relevant phenomenologically and may provide a dynamical way to realize symmetries of mass matrices. 


Address 
[Chen, MuChun; Li, Xueqi; Liu, XiangGan; Ratz, Michael] Univ Calif Irvine, Dept Phys & Astron, Irvine, CA 92697 USA, Email: muchunc@uci.edu; 


Corporate Author 

Thesis 



Publisher 
Elsevier 
Place of Publication 

Editor 



Language 
English 
Summary Language 

Original Title 



Series Editor 

Series Title 

Abbreviated Series Title 



Series Volume 

Series Issue 

Edition 



ISSN 
03702693 
ISBN 

Medium 



Area 

Expedition 

Conference 



Notes 
WOS:001221253800001 
Approved 
no 


Is ISI 
yes 
International Collaboration 
yes 


Call Number 
IFIC @ pastor @ 
Serial 
6125 

Permanent link to this record 




Author 
Jung, M.; Li, X.Q.; Pich, A. 


Title 
Exclusive radiative Bmeson decays within the aligned twoHiggsdoublet model 
Type 
Journal Article 

Year 
2012 
Publication 
Journal of High Energy Physics 
Abbreviated Journal 
J. High Energy Phys. 


Volume 
10 
Issue 
10 
Pages 
063  33pp 


Keywords 
Higgs Physics; Beyond Standard Model; BPhysics; CP violation 


Abstract 
In the aligned twoHiggsdoublet model, the alignment of Yukawa matrices in flavour space guarantees the absence of treelevel flavourchanging neutral currents, while allowing at the same time for new sources of CP violation, implying potentially large effects in many lowenergy processes. In this work we study the constraints from exclusive radiative B > V gamma decays, where V denotes a light vector meson. The current experimental data on the CPaveraged branching ratios and the direct CP and isospin asymmetries are analyzed. It is found that, while the branching ratios and direct CP asymmetries do not constrain the parameter space much further compared to the inclusive B > Xs,Xd gamma decays, complementary constraints can be obtained from the isospin asymmetries Delta(K*gamma) and Delta(rho gamma). In addition, correlations between the various observables in exclusive B > V gamma and inclusive B > Xs,Xd gamma decays are investigated in detail, and predictions are made for several so far unmeasured observables. 


Address 
[Jung, Martin] Tech Univ Dortmund, Inst Phys, D44221 Dortmund, Germany, Email: martin2.jung@tudortmund.de; 


Corporate Author 

Thesis 



Publisher 
Springer 
Place of Publication 

Editor 



Language 
English 
Summary Language 

Original Title 



Series Editor 

Series Title 

Abbreviated Series Title 



Series Volume 

Series Issue 

Edition 



ISSN 
11266708 
ISBN 

Medium 



Area 

Expedition 

Conference 



Notes 
WOS:000310851800004 
Approved 
no 


Is ISI 
yes 
International Collaboration 
yes 


Call Number 
IFIC @ pastor @ 
Serial 
1293 

Permanent link to this record 




Author 
Li, X.Q.; Li, Y.M.; Lu, G.R.; Su, F. 


Title 
Bs(0)(B)overbar(s)(0) mixing in a family nonuniversal Z ' model revisited 
Type 
Journal Article 

Year 
2012 
Publication 
Journal of High Energy Physics 
Abbreviated Journal 
J. High Energy Phys. 


Volume 
05 
Issue 
5 
Pages 
049  27pp 


Keywords 
Beyond Standard Model; BPhysics; CP violation 


Abstract 
Motivated by the very recent measurements performed at the LHCb and the Tevatron of the Bs(0) – (B) over bar (0)(s) mixing, in this paper we revisit it in a family nonuniversal Z' model, to check if a simultaneous explanation for all the mixing observables, especially for the likesign dimuon charge asymmetry observed by the D0 collaboration, could be made in such a specific model. In the first scenario where the Z' boson contributes only to the offdiagonal element M12(s), it is found that, once the combined constraints from Delta Ms, phi(s) and Delta Gamma(s) are imposed, the model could not explain the measured flavourspecific CP asymmetry a(fs)(s), at least within its 1 sigma ranges. In the second scenario where the NP contributes also to the absorptive part Gamma(s)(12) via treelevel Z'induced b > c (c) over bars operators, we find that, with the constraints from Delta Ms, phi(s) and the indirect CP asymmetry in (B) over bar (d) > J/psi KS taken into account, the present measured 1 sigma experimental ranges for a(fs)(s) could not be reproduced too. Thus, such a specific Z' model with our specific assumptions could not simultaneously reconcile all the present data on Bs(0) – Bs(0) mixing. Future improved measurements from the LHCb and the proposed superB experiments, especially of the flavourspecific CP asymmetries, are expected to shed light on the issue. 


Address 
[Li, XinQiang; Li, YanMin; Lu, GongRu] Henan Normal Univ, Dept Phys, Xinxiang 453007, Henan, Peoples R China, Email: xqli@itp.ac.cn; 


Corporate Author 

Thesis 



Publisher 
Springer 
Place of Publication 

Editor 



Language 
English 
Summary Language 

Original Title 



Series Editor 

Series Title 

Abbreviated Series Title 



Series Volume 

Series Issue 

Edition 



ISSN 
11266708 
ISBN 

Medium 



Area 

Expedition 

Conference 



Notes 
WOS:000305236000049 
Approved 
no 


Is ISI 
yes 
International Collaboration 
yes 


Call Number 
IFIC @ pastor @ 
Serial 
1103 

Permanent link to this record 




Author 
Li, X.Q.; Lu, J.; Pich, A. 


Title 
Bs,d(0) > l(+)l() decays in the aligned twoHiggsdoublet model 
Type 
Journal Article 

Year 
2014 
Publication 
Journal of High Energy Physics 
Abbreviated Journal 
J. High Energy Phys. 


Volume 
06 
Issue 
6 
Pages 
022  39pp 


Keywords 
Higgs Physics; Rare Decays; Beyond Standard Model; BPhysics 


Abstract 
The rare decays Bs,d(0) > l(+)l() are analyzed within the general framework of the aligned twoHiggs doublet model. We present a complete oneloop calculation of the relevant shortdistance Wilson coefficients, giving a detailed technical summary of our results and comparing them with previous calculations performed in particular limits or approximations. We investigate the impact of various model parameters on the branching ratios and study the phenomenological constraints imposed by present data. 


Address 
[Li, XinQiang] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China, Email: xqli@itp.ac.cn; 


Corporate Author 

Thesis 



Publisher 
Springer 
Place of Publication 

Editor 



Language 
English 
Summary Language 

Original Title 



Series Editor 

Series Title 

Abbreviated Series Title 



Series Volume 

Series Issue 

Edition 



ISSN 
10298479 
ISBN 

Medium 



Area 

Expedition 

Conference 



Notes 
WOS:000338520600002 
Approved 
no 


Is ISI 
yes 
International Collaboration 
yes 


Call Number 
IFIC @ pastor @ 
Serial 
1855 

Permanent link to this record 




Author 
Li, X.Q.; Su, F.; Yang, Y.D. 


Title 
Determination of the strong coupling gB*B pi from semileptonic B > pi l nu decay 
Type 
Journal Article 

Year 
2011 
Publication 
Physical Review D 
Abbreviated Journal 
Phys. Rev. D 


Volume 
83 
Issue 
5 
Pages 
054019  8pp 


Keywords 



Abstract 
According to heavymeson chiral perturbation theory, the vector form factor f+(q(2)) of exclusive semileptonic decay B > pi l nu is closely related, at least in the softpion region ( i.e., q(2) similar to (m(B) – m(pi))(2)), to the strong coupling g(B*B pi) or the normalized coupling (g)overcap. Combining the precisely measured q2 spectrum of B > pi l nu decay by the BABAR and Belle collaborations with several parametrizations of the form factor f +(q(2)), we can extract these couplings from the residue of the form factor at the B* pole, which relies on an extrapolation of the form factor from the semileptonic region to the unphysical point q(2) = m(B*)(2). Comparing the extracted values with the other experimental and theoretical estimates, we can test these various formfactor parametrizations, which differ from each other by the amount of physical information embedded in. It is found that the extracted values based on the BecirevicKaidalov, BallZwicky and BourrelyCapriniLellouch parametrizations are consistent with each other and roughly in agreement with the other theoretical and lattice estimates, while the BoydGrinsteinLebed ansatz, featured by a spurious, unwanted pole at the threshold of the cut, gives a neatly larger value. 


Address 
[Li, XinQiang] Henan Normal Univ, Dept Phys, Xinxiang 453007, Henan, Peoples R China 


Corporate Author 

Thesis 



Publisher 
Amer Physical Soc 
Place of Publication 

Editor 



Language 
English 
Summary Language 

Original Title 



Series Editor 

Series Title 

Abbreviated Series Title 



Series Volume 

Series Issue 

Edition 



ISSN 
15507998 
ISBN 

Medium 



Area 

Expedition 

Conference 



Notes 
ISI:000288244700003 
Approved 
no 


Is ISI 
yes 
International Collaboration 
yes 


Call Number 
IFIC @ pastor @ 
Serial 
553 

Permanent link to this record 




Author 
Li, X.Q.; Yang, Y.D.; Yuan, X.B. 


Title 
Anomalous tqZ coupling effects in rare B and Kmeson decays 
Type 
Journal Article 

Year 
2012 
Publication 
Journal of High Energy Physics 
Abbreviated Journal 
J. High Energy Phys. 


Volume 
03 
Issue 
3 
Pages 
018  22pp 


Keywords 
Rare Decays; Beyond Standard Model; BPhysics; Kaon Physics 


Abstract 
As a topfactory, the LHC is performing a direct study of topquark anomalous FCNC couplings, which are, however, correlated closely with the rare B and Kmeson decays. In this paper, we study the effects of anomalous tqZ (with q = u, c) couplings in the rare decays Bs,Bd > mu(+)mu(), B > Xs nu(nu) over bar, B > K(*)nu(nu) over bar, K+ > pi(+)nu(nu) over bar, and KL > pi(0)nu(nu) over bar. With the uptodate experimental bounds on the branching ratios of these channels, constraints on the lefthanded anomalous couplings Xct(L), and Xut(L) are derived, respectively. With these lowenergy constraints taken into account, we find that, for real couplings Xct(L) and Xut(L), the indirect upper bounds on B(t > qZ) are much lower than that from the D0 collaboration, but are still compatible with the 5 sigma discovery potential of ATLAS with an integrated luminosity of 10 fb(1). With refined measurements to be available at the LHCb, the future superB factories, the NA62 at CERN, and the KOTO at JPARC, closer correlations between the t > qZ and the rare B and Kmeson decays are expected in the near future, which will be helpful for the searches of thu e topquark FCNC decays at the LHC. 


Address 
[Li, XinQiang] Henan Normal Univ, Dept Phys, Xinxiang 453007, Henan, Peoples R China, Email: xqli@itp.ac.cn; 


Corporate Author 

Thesis 



Publisher 
Springer 
Place of Publication 

Editor 



Language 
English 
Summary Language 

Original Title 



Series Editor 

Series Title 

Abbreviated Series Title 



Series Volume 

Series Issue 

Edition 



ISSN 
11266708 
ISBN 

Medium 



Area 

Expedition 

Conference 



Notes 
WOS:000302412100018 
Approved 
no 


Is ISI 
yes 
International Collaboration 
yes 


Call Number 
IFIC @ pastor @ 
Serial 
1011 

Permanent link to this record 