Records |
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 |
7-8 |
Pages |
1273-1294 |
Keywords |
B-physics; rare decays; beyond Standard Model |
Abstract |
Motivated by the measured large branching ratio of (B) over bar (0) --> pi(0)pi(0) (the so-called pi pi puzzle), we investigate the effects of a family nonuniversal Z' model on the tree-dominated 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 C-5, 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, Xin-Qiang] Henan Normal Univ, Dept Phys, Xinxiang 453007, Henan, Peoples R China, Email: changqin@htu.cn |
Corporate Author |
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Thesis |
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Publisher |
World Scientific Publ Co Pte Ltd |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0217-751x |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
ISI:000289175800004 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
595 |
Permanent link to this record |
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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 |
168-179 |
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 B-c meson. We find that scalar contributions with the simultaneous presence of both left- and right-handed couplings to quarks can explain the available data, specifically R(D-(*)) together with the measured differential distributions. However, the constraints from the total B-c 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 new-physics scenarios like the presence of only a left-handed 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 -> X-c 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, D-80333 Munich, Germany, Email: xqli@itp.ac.cn |
Corporate Author |
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Thesis |
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Publisher |
Elsevier Science Bv |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0370-2693 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000406183300024 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
3260 |
Permanent link to this record |
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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, Mu-Chun; Li, Xueqi; Liu, Xiang-Gan; Ratz, Michael] Univ Calif Irvine, Dept Phys & Astron, Irvine, CA 92697 USA, Email: muchunc@uci.edu; |
Corporate Author |
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Thesis |
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Publisher |
Elsevier |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0370-2693 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:001221253800001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
6125 |
Permanent link to this record |
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Author |
Li, X.Q.; Lu, J.; Pich, A. |
Title |
Bs,d(0) -> l(+)l(-) decays in the aligned two-Higgs-doublet 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; B-Physics |
Abstract |
The rare decays B-s,d(0) -> l(+)l(-) are analyzed within the general framework of the aligned two-Higgs doublet model. We present a complete one-loop calculation of the relevant short-distance 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, Xin-Qiang] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China, Email: xqli@itp.ac.cn; |
Corporate Author |
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Thesis |
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Publisher |
Springer |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1029-8479 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000338520600002 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
1855 |
Permanent link to this record |
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Author |
Abbas, G.; Celis, A.; Li, X.Q.; Lu, J.; Pich, A. |
Title |
Flavour-changing top decays in the aligned two-Higgs-doublet 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 one-loop computation of the two-body flavour-changing top decays t --> ch and t --> cV (V = gamma, Z), within the aligned two-Higgs-doublet 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 CP-even scalar of the CP-conserving aligned two-Higgs-doublet model, we find that the rates for such flavour-changing top decays lie below the expected sensitivity of the future high-luminosity phase of the LHC. Measurements of the Higgs signal strength in the di-photon 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, E-46071 Valencia, Spain, Email: Gauhar.Abbas@ific.uv.es; |
Corporate Author |
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Thesis |
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Publisher |
Springer |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1029-8479 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000355745800001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
2255 |
Permanent link to this record |