1 //--------------------------------------------------------------------------
4 // This software is part of the EvtGen package developed jointly
5 // for the BaBar and CLEO collaborations. If you use all or part
6 // of it, please give an appropriate acknowledgement.
8 // Copyright Information: See EvtGen/COPYRIGHT
9 // Copyright (C) 2000 Caltech, UCSB
12 // Description: Form factors for b->sll according to Ali, Ball et al.
15 // Modification history:
17 // Ryd January 5, 2000 Module created
19 // jjhollar October 7 2005 Add Ball & Zwicky '05 LCSR
20 // ofte August 2006 Add some more pi l l FF models
21 //------------------------------------------------------------------------
22 #include "EvtGenBase/EvtPatches.hh"
24 #include "EvtGenBase/EvtPatches.hh"
25 #include "EvtGenBase/EvtPDL.hh"
26 #include "EvtGenModels/EvtbTosllBallFF.hh"
29 EvtbTosllBallFF::EvtbTosllBallFF(int ffmodel)
31 _theFFModel = ffmodel;
35 void EvtbTosllBallFF::getScalarFF(EvtId parent, EvtId daught,
36 double t, double /*mass*/,
37 double& fp,double& f0,double& ft){
39 int model = _theFFModel;
41 double m=EvtPDL::getMeanMass(parent);
42 double md=EvtPDL::getMeanMass(daught);
45 double shat2=shat*shat;
46 double shat3=shat2*shat;
48 if (daught == EvtPDL::getId(std::string("K+")) ||
49 daught == EvtPDL::getId(std::string("K-")) ||
50 daught == EvtPDL::getId(std::string("K_S0")) ||
51 daught == EvtPDL::getId(std::string("K0")) ||
52 daught == EvtPDL::getId(std::string("anti-K0")) ||
53 daught == EvtPDL::getId(std::string("K_L0"))
56 // B --> K form factors
58 //this is Ali-Ball '01 (or really Ali-Ball'99 minimum allowed)
59 fp = 0.278*exp(1.568*shat+0.470*shat2+0.885*shat3);
60 f0 = 0.278*exp(0.740*shat+0.080*shat2+0.425*shat3);
61 ft = 0.300*exp(1.600*shat+0.501*shat2+0.796*shat3);
64 //this is Ali-Ball '99 (central values)
65 fp = 0.319*exp(1.465*shat+0.372*shat2+0.782*shat3);
66 f0 = 0.319*exp(0.633*shat-0.095*shat2+0.591*shat3);
67 ft = 0.355*exp(1.478*shat+0.373*shat2+0.700*shat3);
70 //QCD sum rules (Colangelo et al)
71 fp = 0.25/(1.-t/(5.0*5.0));
72 f0 = 0.25/(1.-t/(7.0*7.0));
73 ft = - 0.14/((1.0 - t/(5.0*5.0))*(1.0 - t/(7.0*7.0)));
76 // Quark model (Melikhov et al - hep-ph/9711362)
77 fp = 0.36/(1. - 0.048*t + 0.00063*t*t);
78 double fm = -0.30/(1. - 0.050*t + 0.00061*t*t);
79 f0 = fp + fm*(t/(m*m - md*md));
80 ft = -(m+md)*0.06/(1 -0.049*t + 0.00064*t*t);
83 fp = 0.341/(1. - 1.41*shat + 0.406*shat*shat);
84 f0 = 0.341/(1. - 0.41*shat -0.361*shat*shat);
85 ft = 0.374/(1. - 1.42*shat + 0.434*shat*shat);
88 // Ball-Zwicky LCSR '05 "set 2" (mb = 4.8)
89 fp = (0.1616 / (1. - (t/29.30))) +
90 (0.1730 / (1. - (t/29.30)) / (1. - (t/29.30)));
91 f0 = (0.3302 / (1. - (t/37.46/37.46)));
92 ft = (0.1614 / (1. - (t/29.30))) +
93 (0.1981 / (1. - (t/29.30)) / (1. - (t/29.30)));
96 // Ball-Zwicky LCSR '05 "set 4" (mb = 4.6)
97 fp = (0.1903 / (1. - (t/29.30))) +
98 (0.1478 / (1. - (t/29.30)) / (1. - (t/29.30)));
99 f0 = (0.3338 / (1. - (t/38.98/38.98)));
100 ft = (0.1851 / (1. - (t/29.30))) +
101 (0.1905 / (1. - (t/29.30)) / (1. - (t/29.30)));
104 else if (daught == EvtPDL::getId(std::string("pi+")) ||
105 daught == EvtPDL::getId(std::string("pi-")) ||
106 daught == EvtPDL::getId(std::string("pi0"))
110 // B --> pi form factors from Ball-Zwicky'01 (tabulated in hep-ph/0306251)
111 fp = 0.261/(1. - 2.03*shat + 1.293*shat*shat);
112 f0 = 0.261/(1. - 0.27*shat -0.752*shat*shat);
113 ft = 0.296/(1. - 1.28*shat + 0.193*shat*shat);
116 // The following two (2) and (3) should preferably be replaced with
117 // something better. ft not provided by the papers, and the ft formula
118 // (from Colangelo'96 (hep-ph/9510403v2) equation (5.1)) seem to be no good.
120 // // LatticeQCD: Okamoto'04
121 // // ... with f_T from eq. (5.1) of Colangelo'95
122 // fp = 0.23/((1.-shat)*(1.-0.63*shat));
123 // f0 = 0.23/((1.-shat)/1.18);
124 // ft = ( -(m+md)/(2*m) )/ (fp - (m*m-md*md) * ((f0-fp)/t) );
127 // // LatticeQCD: Shigemitsu'04
128 // // ... with f_T from eq. (5.1) of Colangelo'95
129 // fp = 0.42*(1.0-0.41)/((1.-shat)*(1.-0.63*shat));
130 // f0 = 0.42*(1.0-0.41)/((1.-shat)/1.18);
131 // ft = ( -(m+md)/(2*m) )/ (fp - (m*m-md*md) * ((f0-fp)/t) );
135 // Quark model - B -> pi set 1 (Melikhov-Nikitin'96)
136 fp = 0.29/pow((1.-t/(6.48*6.48)),2.54);
137 double fm = -0.26/pow((1.-t/(6.34*6.34)),2.49);
138 f0 = fp + fm*(t/(m*m - md*md));
139 ft = -(m+md)*0.05/pow((1.-t/(6.47*6.47)),2.50);
142 // Melikhov-Stech '00. (hep-ph/0001113)
143 // relativistic dispersion approach based on constituent quark picture
144 fp = 0.29/((1.-shat)*(1.-0.48*shat));
145 f0 = 0.29/(1.-0.76*shat +0.28*shat*shat);
146 ft = 0.28/((1.-shat)*(1.-0.48*shat));
149 // Ball-Zwicky LCSR '05 "set 2" (mb = 4.8)
150 fp = (0.744 / (1. - (t/(5.32*5.32)))) + (-0.486 / (1. - (t/40.73)));
151 f0 = (0.258 / (1. - (t/33.81)));
152 ft = (1.387 / (1. - (t/(5.32*5.32)))) + (-1.134 / (1. - (t/32.22)));
155 // Ball-Zwicky LCSR '05 "set 4" (mb = 4.6)
156 fp = (0.944 / (1. - (t/(5.32*5.32)))) + (-0.669 / (1. - (t/34.27)));
157 f0 = (0.270 / (1. - (t/33.63)));
158 ft = (0.152 / (1. - (t/(5.32*5.32)))) +
159 (0.122 / (1. - (t/28.40)) / (1. - (t/28.40)));
162 else if (daught == EvtPDL::getId(std::string("eta")) ||
163 daught == EvtPDL::getId(std::string("eta'"))
167 // B --> eta form factors
168 fp = 0.261/(1. - 2.03*shat + 1.293*shat*shat);
169 f0 = 0.261/(1. - 0.27*shat -0.752*shat*shat);
170 ft = 0.296/(1. - 1.28*shat + 0.193*shat*shat);
173 // Ball-Zwicky LCSR '05 "set 2" (mb = 4.8)
174 fp = (0.1220 / (1. - (t/28.40))) +
175 (0.1553 / (1. - (t/28.40)) / (1. - (t/28.40)));
176 f0 = (0.2734 / (1. - (t/31.03/31.03)));
177 ft = (0.1108 / (1. - (t/28.40))) +
178 (0.1752 / (1. - (t/28.40)) / (1. - (t/28.40)));
181 // Ball-Zwicky LCSR '05 "set 2" (mb = 4.8)
182 fp = (0.1380 / (1. - (t/28.40))) +
183 (0.1462 / (1. - (t/28.40)) / (1. - (t/28.40)));
184 f0 = (0.2799 / (1. - (t/30.46/30.46)));
185 ft = (0.1160 / (1. - (t/28.40))) +
186 (0.1841 / (1. - (t/28.40)) / (1. - (t/28.40)));
190 // cout << "shat "<<shat<<"\t"<<"fp "<<fp<<"\t"<<"f0 "<<f0<<"\t"
191 // <<"ft "<<ft<<endl;
196 void EvtbTosllBallFF::getVectorFF(EvtId parent, EvtId daught,
197 double t, double /*mass*/,
198 double& a1,double& a2,double& a0, double& v,
199 double& t1, double& t2, double& t3 ){
201 int model = _theFFModel;
203 double m=EvtPDL::getMeanMass(parent);
204 double md=EvtPDL::getMeanMass(daught);
207 double shat2=shat*shat;
210 daught == EvtPDL::getId(std::string("K*+")) ||
211 daught == EvtPDL::getId(std::string("K*-")) ||
212 daught == EvtPDL::getId(std::string("K*0")) ||
213 daught == EvtPDL::getId(std::string("anti-K*0")) ||
214 daught == EvtPDL::getId(std::string("K_1+")) ||
215 daught == EvtPDL::getId(std::string("K_1-"))
220 //this is Ali-Ball '01
221 a1 = 0.294*exp(0.656*shat+0.456*shat2);
222 a2 = 0.246*exp(1.237*shat+0.822*shat2);
223 a0 = 0.412*exp(1.543*shat+0.954*shat2);
224 v = 0.399*exp(1.537*shat+1.123*shat2);
226 t1 = 0.334*exp(1.575*shat+1.140*shat2);
227 t2 = 0.334*exp(0.562*shat+0.481*shat2);
228 t3 = 0.234*exp(1.230*shat+1.089*shat2);
231 //this is Ali-Ball '99
232 a1=0.337*exp(0.602*shat+0.258*shat2);
233 a2=0.282*exp(1.172*shat+0.567*shat2);
234 a0=0.471*exp(1.505*shat+0.710*shat2);
235 v=0.457*exp(1.482*shat+1.015*shat2);
237 t1=0.379*exp(1.519*shat+1.030*shat2);
238 t2=0.379*exp(0.517*shat+0.426*shat2);
239 t3=0.260*exp(1.129*shat+1.128*shat2);
242 //QCD sum rules (Colangelo et al)
243 // JJH - Changed in accordance with erratum (Phys. Rev. D 57, 3186 (1998))
244 a1 = 0.37*(1 - 0.023*t);
245 a2 = 0.40*(1 + 0.034*t);
246 a0 = 0.3/(1.- t/(4.8*4.8));
247 v = 0.47/(1.- t/(5.0*5.0));
249 t1 = 0.19/(1.-t/(5.3*5.3));
250 t2 = 0.19*(1. - 0.02*t);
251 t3 = 0.3*(1. + 0.01*t);
255 // Quark model (Melikhov et al)
256 a1 = 1.6/(1 - 0.0288*t + 0.00028*t*t); a1 = a1/(m+md);
257 a2 = (m+md)*0.036/(1. - 0.053*t + 0.00082*t*t);
258 double aminus = 0.041/(1. - 0.055*t + 0.00088*t*t);
259 double f = 1.60/(1. - 0.0288*t + 0.00028*t*t);
260 double aplus = -0.036/(1. - 0.053*t + 0.00082*t*t);
261 a0 = (t*aminus + f + (m*m-md*md)*aplus)/(2.0*md);
262 v = (m+md)*0.048/(1. - 0.057*t + 0.00085*t*t);
264 t1 = 0.28/(1. - 0.058*t + 0.0009*t*t);
265 double gplus = -0.28/(1. - 0.058*t + 0.0009*t*t);
266 double gminus = 0.24/(1. - 0.059*t + 0.00096*t*t);
267 t2 = -gplus - (t*gminus)/(m*m-md*md);
268 double h = 0.0037/(1. - 0.075*t + 0.0016*t*t);
269 t3 = (m+md)*(m+md)*((gminus/(m*m-md*md) - h/2.));
273 a1 = 0.337/(1. - 0.60*shat - 0.023*shat*shat);
274 a2 = 0.283/(1. - 1.18*shat + 0.281*shat*shat);
275 a0 = 0.470/(1. - 1.55*shat + 0.680*shat*shat);
276 v = 0.458/(1. - 1.55*shat + 0.575*shat*shat);
277 t1 = 0.379/(1. - 1.59*shat + 0.615*shat*shat);
278 t2 = 0.379/(1. - 0.49*shat - 0.241*shat*shat);
279 t3 = 0.261/(1. - 1.20*shat + 0.098*shat*shat);
282 // Ball-Zwicky LCSR '05 (mb = 4.8)
283 a1 = 0.290 / (1. - (t/40.38));
284 a2 = (-0.084 / (1. - (t/52.00))) +
285 (0.342 / (1. - (t/52.00))/(1. - (t/52.00)));
286 a0 = (1.364 / (1. - (t/(5.28*5.28)))) +
287 (-0.990 / (1. - (t/36.78)));
288 v = (0.923 / (1. - (t/(5.32*5.32)))) +
289 (-0.511 / (1. - (t/49.40)));
290 t1 = (0.823 / (1. - (t/(5.32*5.32)))) +
291 (-0.491 / (1 - (t/46.31)));
292 t2 = 0.333 / (1. - (t/41.41));
293 double t3tilde = (-0.036 / (1. - (t/48.10))) +
294 (0.368 / (1. - (t/48.10)) / (1. - (t/48.10)));
296 if (fabs(t) > 1e-10) {
297 t3 = (m*m - md*md)*(t3tilde - t2)/t;
301 else if (daught == EvtPDL::getId(std::string("rho+")) ||
302 daught == EvtPDL::getId(std::string("rho-")) ||
303 daught == EvtPDL::getId(std::string("rho0"))
307 // B --> rho form factors
308 a1 = 0.261/(1. - 0.29*shat - 0.415*shat*shat);
309 a2 = 0.223/(1. - 0.93*shat - 0.092*shat*shat);
310 a0 = 0.372/(1. - 1.40*shat + 0.437*shat*shat);
311 v = 0.338/(1. - 1.37*shat + 0.315*shat*shat);
312 t1 = 0.285/(1. - 1.41*shat + 0.361*shat*shat);
313 t2 = 0.285/(1. - 0.28*shat - 0.500*shat*shat);
314 t3 = 0.202/(1. - 1.06*shat - 0.076*shat*shat);
317 // Ball-Zwicky LCSR '05 (mb = 4.8)
318 a1 = 0.240 / (1. - (t/37.51));
319 a2 = (0.009 / (1. - (t/40.82))) +
320 (0.212 / (1. - (t/40.82)) / (1. - (t/40.82)));
321 a0 = (1.527 / (1. - (t/(5.28*5.28)))) +
322 (-1.220 / (1. - (t/33.36)));
323 v = (1.045 / (1. - (t/(5.32*5.32)))) +
324 (-0.721 / (1. - (t/38.34)));
325 t1 = (0.897 / (1. - (t/(5.32*5.32)))) +
326 (-0.629 / (1 - (t/38.04)));
327 t2 = 0.267 / (1. - (t/38.59));
328 double t3tilde = (0.022 / (1. - (t/40.88))) +
329 (0.246 / (1. - (t/40.88)) / (1. - (t/40.88)));
331 if (fabs(t) > 1e-10) {
332 t3 = (m*m - md*md)*(t3tilde - t2)/t;
337 else if (daught == EvtPDL::getId(std::string("omega"))
341 // B --> rho form factors
342 a1 = 0.261/(1. - 0.29*shat - 0.415*shat*shat);
343 a2 = 0.223/(1. - 0.93*shat - 0.092*shat*shat);
344 a0 = 0.372/(1. - 1.40*shat + 0.437*shat*shat);
345 v = 0.338/(1. - 1.37*shat + 0.315*shat*shat);
346 t1 = 0.285/(1. - 1.41*shat + 0.361*shat*shat);
347 t2 = 0.285/(1. - 0.28*shat - 0.500*shat*shat);
348 t3 = 0.202/(1. - 1.06*shat - 0.076*shat*shat);
351 // Ball-Zwicky LCSR '05 (mb = 4.8)
352 a1 = -0.217 / (1. - (t/37.01));
353 a2 = (0.006 / (1. - (t/41.24))) +
354 (0.192 / (1. - (t/41.24)) / (1. - (t/41.24)));
355 a0 = (1.321 / (1. - (t/(5.28*5.28)))) +
356 (-1.040 / (1. - (t/34.47)));
357 v = (1.006 / (1. - (t/(5.32*5.32)))) +
358 (-0.713 / (1. - (t/37.45)));
359 t1 = (0.865 / (1. - (t/(5.32*5.32)))) +
360 (-0.622 / (1 - (t/37.19)));
361 t2 = 0.242 / (1. - (t/37.95));
362 double t3tilde = (0.023 / (1. - (t/40.87))) +
363 (0.220 / (1. - (t/40.87)) / (1. - (t/40.87)));
365 if (fabs(t) > 1e-10) {
366 t3 = (m*m - md*md)*(t3tilde - t2)/t;
370 else if (daught == EvtPDL::getId(std::string("phi"))
374 // Ball-Zwicky LCSR '05 (mb = 4.8)
375 a1 = 0.308 / (1. - (t/36.54));
376 a2 = (-0.054 / (1. - (t/48.94))) +
377 (0.288 / (1. - (t/48.94)) / (1. - (t/48.94)));
378 a0 = (3.310 / (1. - (t/(5.28*5.28)))) +
379 (-2.835 / (1. - (t/31.57)));
380 v = (1.484 / (1. - (t/(5.32*5.32)))) +
381 (-1.049 / (1. - (t/39.52)));
382 t1 = (1.303 / (1. - (t/(5.32*5.32)))) +
383 (-0.954 / (1 - (t/38.28)));
384 t2 = 0.349 / (1. - (t/37.21));
385 double t3tilde = (0.027 / (1. - (t/45.56))) +
386 (0.321 / (1. - (t/45.56)) / (1. - (t/45.56)));
388 if (fabs(t) > 1e-10) {
389 t3 = (m*m - md*md)*(t3tilde - t2)/t;