arXiv subjects
Publications and source records attributed to P. Zenczykowski.
We study B+- -- > K+-K+K- decays using the QCD factorization model with final state interactions between K+ and K- mesons taken into account. The parameters of the model are fitted to the data of the BABAR and LHCb collaborations. We describe the K Kbar effective mass distributions and examine the CP-violating asymmetry effects in the full range of the Dalitz plot.
Rare B decays to three charged kaons are analysed. The weak decay amplitudes are derived in the QCD factorization approach. The strong final state interactions between pairs of kaons are described using the kaon scalar and vector form factors. The scalar form factors at low K+K- effective mass distributions are constrained by chiral symmetry and are related to the coupled channel meson-meson amplitudes describing all the transitions between three channels consisting of two kaons, two pions and four pions. The vector form factors are fitted to the data on e+e- collisions. The model results are compared with the Belle and BaBar data.
We report on the recently proposed joint resolution of two long-standing puzzles in weak radiative (WR) and nonleptonic (NL) hyperon decays (HD). First, a good VMD-based description of WRHD is presented. In particular, the large negative asymmetry observed in the Σ^+ \to p γdecay is explained through a calculably large SU(3)-breaking effect in the relevant parity-violating amplitude. Second, the achieved description of the parity-violating WRHD amplitudes permits the extraction, via the SU(2)_W + VMD route, of the non-soft-pion correction term in the parity-violating NLHD amplitudes. The latter subtracts a substantial amount from the current-algebra commutator term, thus leading to the resolution of the old S:P discrepancy in NLHD.
We give a joint description of weak radiative (WR) and nonleptonic (NL) hyperon decays (HD) in broken SU(3). The two groups of decays are linked via $SU(2)_W$ spin symmetry and vector meson dominance (VMD). We use experimental information on the parity-conserving (p.c.) NLHD amplitudes to fix the corresponding WRHD amplitudes. With the latter known, the data on the WRHD branching ratios and asymmetries permit us to determine the parity-violating (p.v.) WRHD amplitudes in terms of two parameters corresponding to the two-quark and single-quark transitions. We obtain a good description of the data, and in particular a large $Σ^+ \to p γ$ asymmetry. Then, using the $SU(2)_W$+VMD route we determine the non-soft-meson correction term in the p.v. NLHD amplitudes. The latter is shown to subtract a substantial amount from the current-algebra commutator thus leading towards the resolution of the S:P discrepancy in NLHD.
We point out the conceptual problems related to the application of the standard notion of mass to quarks and recall the arguments that there should be a close connection between the properties of elementary particles and the arena used for the description of classical macroscopic processes. Motivated by the above and the wish to introduce more symmetry between the coordinates of position and momentum we concentrate on the classical nonrelativistic phase space with ${\bf {p}}^2+{\bf {x}}^2$ as an invariant. A symmetry-based argument on how to generalize the way in which mass enters into our description of Nature is presented and placed into the context of the phase-space scheme discussed. It is conjectured that the proposed non-standard way of relating "mass" to the variables of the classical phase space is actually used in Nature, and that it manifests itself through the existence of quarks. Some properties of this proposal, including unobservability of "free quarks" and the emergence of mesons, are discussed.
We consider the $B \to ππ$ and $B \to πρ, πω$ decays alongside each other, taking into account the contributions from all individual penguin amplitudes generated by the internal $t$, $c$, and $u$ quarks. We argue that three ratios of penguin amplitudes, each for a different internal quark, formed by dividing the individual penguin amplitude in $B \to ππ$ by the corresponding amplitude in $B \to πρ, πω$, should be equal. We study the implications of the assumed existence of this connection between $B\to ππ$ and $B \to πρ, πω$. First, accepting that in the $B \to ππ$ decays the ratio $C/T$ of the colour-suppressed factorization amplitude $C$ to the tree factorization amplitude $T$ is negligible, we determine the ratio of individual penguin amplitudes. Then, from the $B \to πρ, πω$ data, we extract the effective (i.e. possibly containing some penguin terms) tree and the effective colour-suppressed amplitudes relevant for these processes, and the corresponding solutions for the factorization amplitudes. Finally, we argue that the $C/T$ ratio in $B \to ππ$ should be identical to its counterpart in $B \to πρ, πω$ (relevant for pion emission from the decaying $b$ quark). This constraint permits the determination of $C/T$ and of other amplitude ratios directly from the data. Although the $|C/T|$ ratio extracted from the available data still carries a substantial error, it is consistent with the expected value of 0.25 - 0.5.
A method parametrizing all inelastic final state interactions (FSI) in $B\to PP$ decays is presented ($P$ - pseudoscalar meson). The method explicitly shows how rescattering leads to the replacement of the short-distance amplitudes with the effective quark diagram amplitudes, and how it affects the extraction of the unitarity triangle angle $γ$ from the data. It is furthermore pointed out that the size of FSI effects cannot be determined from $B^0_d \to K^+ K^-$ decays in a satisfactory way. The case of SU(3)-violating FSI is also discussed. When fits to the branching ratios of all $B \to PP$ decays are performed with all inelastic FSI included, the extracted value of $ γ$ is shifted down by some $20^o-30^o$ when compared to the no-FSI analyses, and becomes consistent with the Standard Model value of $ 65^o \pm 7^o$.
Paper withdrawn by the author after learning that its main conclusion was given earlier in a slightly different language in Appendix D of A. J. Buras, R. Fleischer, S. Recksiegel, and F.Schwab, hep-ph/0402112.
It is shown that inclusion of charming penguins of the size suggested by short-distance dynamics may shift down by $10^o-15^o$ the value of $γ$ extracted via the overall fit to the $B \to PP $ branching ratios. A substantial dependence of the fit on their precise values is found, underscoring the need to improve the reliability of data.
We discuss all contributions from Zweig-rule-satisfying SU(3)-breaking final state interactions (FSIs)in the B -> PP decays (neglecting charmed intermediate states), where PP=pi pi, pi K, KK, pi eta (eta'), and K eta (eta'). First, effects of SU(3) breaking in rescattering through Pomeron exchange are studied. Then, after making a plausible assumption concerning the pattern of SU(3) breaking in non-Pomeron FSIs, we give general formulas for how the latter modify short-distance (SD) amplitudes. In the SU(3) limit, these formulas depend on three effective parameters characterizing the strength of all non-Pomeron rescattering effects. We point out that the experimental bounds on the B -> K^+K^- branching ratio may limit the value of only one of these FSI parameters. Thus, the smallness of the B -> K^+K^- decay rate does not imply negligible rescattering effects in other decays. Assuming a vanishing value of this parameter, we perform various fits to the available B -> PP branching ratios. The fits determine the quark-diagram SD amplitudes, the two remaining FSI parameters and the weak angle gamma. While the set of all B -> PP branching ratios is well described with gamma around its expected SM value, the fits permit other values of gamma as well. For a couple of such good fits, we predict asymmetries for the B -> K pi, pi^+ eta (eta'), K^+ eta (eta') decays as well as the values of the CP-violating parameters S_{pi pi} and C_{pi pi} for the time-dependent rate of B^0(t) -> pi^+ pi^-. Apart from a problem with the recent B^+ -> pi^+ eta asymmetry measurement, comparison with the data seems to favour the values of gamma in accordance with SM expectations.
Using the recent measurement of the $Ξ^0 \to Λγ$ asymmetry as an input, we reanalyse nonleptonic and weak radiative hyperon decays in a single symmetry-based framework. In this framework the old S:P problem of nonleptonic decays is automatically resolved when the most important features of weak radiative decays are taken into account. Experimental data require that symmetry between the two types of hyperon decays be imposed at the level of currents, not fields. Previously established connections between hyperon decays and nuclear parity violation imply that the conflict, originally suggested by weak radiative decays, has to surface somewhere.
The problem of weak radiative hyperon decays (WRHD) is reviewed. With the recent measurement of the $Ξ^0 \to Λγ$ asymmetry confirming Hara's theorem, implications from its violation in low-energy theoretical approaches are discussed. It is shown how an underlying symmetry link should be formulated for a successful description of both nonleptonic and radiative weak hyperon decays. The sign of the $Ξ^0 \to Λγ$ asymmetry and the overall size of parity-violating WRHD amplitudes together lead to the resolution of the old S:P problem in nonleptonic decays.
We discuss all contributions from Zweig-rule-satisfying SU(3)-symmetric inelastic FSI-induced corrections in B decays to $ππ$, $πK$, $K\bar{K}$, $πη(η')$, and $K η(η')$ . It is shown how all of these FSI corrections lead to a simple redefinition of the amplitudes, permitting the use of a simple diagram-based description, in which, however, weak phases may enter in a modified way. The inclusion of FSI corrections admitted by the present data allows an arbitrary relative phase between the penguin and tree short-distance amplitudes. The FSI-induced error of the method, in which the value of the weak phase $γ$ is to be determined by combining future results from $B^+,B^0_d,B^0_s$ decays to $Kπ$, is estimated to be of the order of $5^o$ for $γ\approx 50^o-60^o$.
It is proved that symmetry structure of the parity-viol. (p.v.) amplitudes of weak radiative hyperon decays in the VMD approach, and the violation of Hara's theorem in particular, are also obtained when direct coupling e_q \bar{q}γ_μq A^μ of photon to quarks is used in place of VMD. Thus, violation of Hara's theorem in VMD-based models does not result from the lack of gauge invariance. It is further shown that, in the static limit of the quark model, the CA commutator term in the p.v. amplitudes of nonleptonic hyperon decays (NLHD) and the parity-violating Σ^+ \to p γdecay amplitude are proportional to each other. As a result, Hara's theorem may be satisfied in this limit if and only if the contribution from the CA commutator in NLHD is zero. Violation of Hara's theorem is traced back to the nonlocality of quark model states in the static limit. It is argued that the ensuing intrinsic baryon nonlocality does not have to be unphysical. It is stressed that the Ξ^0 \to Λγasymmetry will provide very important information concerning the presence or absence of nonlocal features in p.v. photon coupling to baryons at vanishing photon momentum. If the Ξ^0 \to Λγasymmetry is found negative, Hara's theorem is satisfied but the gauge-invariant quark model machinery predicting its violation must miss some contribution, or be modified. If experiment confirms positive Ξ^0 \to Λγasymmetry, then, most likely, Hara's theorem is violated. Although positive Ξ^0 \to Λγasymmetry admits of the possibility that Hara's theorem is satisfied, this alternative is in disagreement with hints suggested by the similarity of photon and vector-meson couplings and the observed size of p.v. nuclear forces.
We discuss all contributions from inelastic SU(3)-symmetric rescattering in B decays into a final pair of pseudoscalar mesons $PP = ππ$, $K\bar{K}$, $πK$. FSI-induced modifications of amplitudes obtained from the quark-line approach are described in terms of a few parameters which take care of all possible SU(3)-symmetric forms relevant for final-state interactions. Although in general it appears impossible to uniquely determine FSI effects from the combined set of all $ππ$, $K \bar{K}$, and $πK$ data, drawing some conclusions is feasible. In particular, it is shown that in leading order the amplitudes of strangeness-changing B decays depend on only one additional complex FSI-related parameter apart from those present in the definitions of penguin and tree amplitudes. It is also shown that joint considerations of U-spin-related $ΔS =0$ and $|ΔS|=1$ decay amplitudes are modified when non-negligible SU(3)-symmetric FSI are present. In particular, if rescattering in $B^+ \to K^+\bar{K}^0$ is substantial, determination of the CP-violating weak angle $γ$ from $B^+ \to π^+ K^0$, $B^0_d \to π^-K^+$, $B^0_s \to π^+ K^-$, and their CP counterparts might be susceptible to important FSI-induced corrections.
We show that melting the quark mass, the scalar $σ$ mass and the quark condensate leads uniquely to the quark-level SU(2) linear $σ$ model field theory. Upon thermalization, the chiral phase transition curve requires $T_c =2f^{CL}_π\approx 180 MeV$ when $μ= 0$, while the critical chemical potential is $μ_c =m_q\approx 325 MeV$. Transition to the superconductive phase occurs at $T^{(SC)}_c=Δ/πe^{-γ_E}$. Coloured diquarks suggest $T_c^{(SC)}<180 MeV$.
Inelastic rescattering effects in B decays into a pair $PP$ of pseudoscalar mesons ($PP = ππ$ or $K\bar{K}$) are discussed. It is assumed that $B$ meson decays through a short-distance tree-diagram process into two jet-like states composed of low-mass resonances $M_1 M_2$ which rescatter into $PP$. The rescattering of resonance pair $M_1 M_2$ into the final $PP$ state is assumed to proceed through a Regge flavour exchange. Since such processes constitute a fraction,diminishing with increasing energy, of total inelastic $PP$ scattering, the inelastic rescattering contribution should die out for $m_B \to \infty$. At $m_B = 5.2 ~GeV$, however, explicit estimates show that rescattering corrections could be substantial, leading to long-distance corrections to $B^0 \to K\bar{K}$, comparable to short-distance penguin contributions.
I elaborate on the argument that the violation of Hara's theorem for conserved current requires that the current is not sufficiently well localized. It is also stressed that whatever sign of asymmetry is measured in the $Ξ^0 \to Λγ$ decay, one of the following three statements must be incorrect: 1) Hara's theorem is satisfied, 2) vector meson dominance is applicable to weak radiative hyperon decays, and 3) basic structure of our quark-model description of nuclear parity-violation is correct.