Corrections to

Problem Solutions for

Volume 2 of

Student Friendly Quantum Field Theory:

The Standard Model

Sorted by Date Posted:  This Page

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Pg

Date Posted

Significant Correction

Reported by

(blank = the author)

9-4

Sept 10, 2025

Prob. 12, Ans.: After the C arrow and before the P arrow, change the L superscripts to R.

Albert Clement

7-1

Aug 23, 2025

Prob. 3, last line on page, last term. Change “lambda/2” to “lambda”. Same change on top of next page 7-2, 3 places.

Albert Clement

6-6

July 22, 2025

Prob. 11, second line: Add “Note you only have to look at the U(1) part.”

14-2

July 22, 2025

Prob. 5, 1^st line: At the end of the line, add “(times a constant)”

2-4

April 1, 2025

Prob. 10, last line of matrices, after 2^nd equal sign: Change w”₃y”₃ to w”₃y”₂

Albert Clement

2-8

April 1, 2025

Prob. 17, last line of expansion, first term: Change “alpha_₀” to “alpha_₁”.

Albert Clement

2-13

April 1, 2025

Prob. 26, Ans (second part), first and last lines: Put a hat ^ on Y_i. Two places.

Albert Clement

2-1

Jan 8, 2025

Prob. 1, Ans (second part, field) : Change “imaginary” to “complex”.

Mikhail Denisov

2-2

Jan 8, 2025

Prob. 4 Problem statement, last two lines: Delete everything after “Explain your answer”.

Also delete entire two lines of Ans (fourth part).

Mikhail Denisov

8-1

Nov 14, 2024

Prob. 1, last two lines of solution: This can be done much more easily, by simply taking A(t_1/2) = .5 A(0) in the relation for A(t) in the problem statement. You then get the beginning of the last row shown in the solution in one step. Taking natural logs of both sides then gives the answer.

David Scharf

6-1

Sept 27, 2024

Prob. 2: Change sign on alpha everywhere. This changes sign on sin alpha everywhere, as well.

2-12

Aug 30, 2024

Pedagogic Aid: Prob. 23, at the end. Note that the result has no matrices, column vectors, or row vectors. It is an opertor simply because there are number operators involved and not because it is a matrix. It is not a matrix.

2-13

Aug 30, 2024

Prob. 25, Answer for third part: at the end of both lines the subscript d should be subscript e.

Alexandra Barnett

2-3

Aug 24, 2024

Prob. 9, first row of solution beginning with “M = “, last matrix on the right, lower left component: change “c” to “d”, two places.

Lou Biegeleisen

3-1

July 2, 2024

Prob. 2 statement, after first sentence, insert Note that like Maxwell’s equation (see Prob. 1), the Dirac equation, when derived from the QED Lagrangian and the Euler-Lagrange equation actually has a minus sign in front (which doesn’t really matter normally, as it equals zero, but does matter here). See Vol. 1, Chap. 4, Prob. 22.

Ans: Insert minus signs after “satisfies” in 1st row and at front of 2^nd row. Delete minus signs in 2^nd row before e^ipy in two places.

Jack Freinhar

2-9

May 11, 2024

Prob. 19. Throughout, note that alpha_0 = 1. alpha_0 is more general notation that was used in SU(2), but not in the Gell-Mann matrix definition of SU(3).

Also, 2^nd line after “and”, last term: “alpha_0” should be “alpha_8”; 3^rd line, last “alpha_1” should be “alpha_2”.

Glenn Rowe

16-1

Oct 5, 2023

Prob. 2, first line: Change “first” to “second”

16-3

Oct 5, 2023

Prob. 7: Delete all subscripts “non-min”, except for the LHS of (16-25) and the LHS of the line below (16-25).

15-2

Oct 14, 2022

Prob. 3 has been deleted. Delete the solution, as well.

Anthony Soong

3-4

March 19, 2022

Prob. 7, last line: change all less than or equal to signs to < .

Nadeem Afana

4-2

March 19, 2022

Prob. 2, 1^st and last lines: Change (4-22) to (4-23).

Nadeem Afana

3-1

Feb 24, 2022

Prob. 1, last line of problem statement: change “ds” to “dy”: 2 places

Nadeem Afana

3-3

Feb 24, 2022

Prob. 6, eq (B): scripts on photon propagators should be subscript μα on first one and subscript βν on the second. Insert gamma matrix with superscript α after the first photon propagator. Insert gamma matrix with superscript β before the second photon propagator. Then, lower the μν on Green function in (B), (C), and (D)

Nadeem Afana

2-14

Feb 20 2022

Prob. 29. Delete the sentence “Then find … antiquark.” Also delete the third part solution and relabel the fourth and fifth parts as third and fourth.

Luc Longtin

2-1

Feb 11 2022

Prob. 2: At beginning of problem statement insert “For the following, assume the appropriate distributive properties exist between operators”. In 2^nd line, before “operation” insert “multiplication”

Nadeem Afana

2-4

Feb 11 2022

Prob. 10, next to last line: Change “A” to “B”

Nadeem Afana

2-11

Feb 11 2022

Prob. 23: In large bracketing expression in mid-page, 1^st and last lines, last factor, insert “2” in the exponents. In the expression right above “So,”, the row and column vectors at the end need to switch “0” and “1” components.

Nadeem Afana

Pg

Date Posted

Minor Correction

Reported by

5-8

July 22, 2025

Prob. 10, 1^st row and last row of Ans (first part): Remove primes on the photon Aslash. The photon field is not a spinor field, so it does not change under spinor transformatin.

Albert Clement

14-1

July 22, 2025

Prob. 2, Ans., 2^nd and 4^th lines: On the left hand side, add “S_iT = “. 2 places.

2-1

April 1, 2025

Prob. 2, first line: Change “operator” to “operation”

Albert Clement

2-8

April 1, 2025

Prob. 18, first line of answer: Change “algebra” to “group”.

Albert Clement

2-13

April 1, 2025

Prob. 26, Ans (first part), 2^nd line: Put “Y^dagger,[iY^dagger, Y]” inside square brackets [ ].

Albert Clement

7-1

Nov 14, 2024

Prob. 1: In problem statement, after “mass term”, insert “in the field equation”

Park Hensley

2-14

Aug 30, 2024

Prob. 29, 3^rd line: Fig. 2-1 should be Fig. 2-2.

Lou Biegeleisen

2-4

Aug 24, 2024

Prob. 11, 2^nd line of problem statement: Put a “hat” on X

3-1

Oct 5, 2023

Probs. 1 and 2: Font size of many equations is too large.

8-1

Oct 5, 2023

Prob. 1: Font size of many equations is too large.

4-1

March 19, 2022

Prob. 1, equation (C), under “Frist part of (A)”: insert subscript i on “k”

Nadeem Afana

4-3

March 19, 2022

Prob. 3, next to last line of solution: before “the inverse”, insert “i times”

Nadeem Afana

3-1

Feb 24, 2022

Prob. 2, 1^st line of answer: Change period between x and y to comma.

Nadeem Afana

2-3

Feb 19 2022

Prob. 8. Change U(θ) everywhere to U(1). 3 places. One third line, insert “a” before “complex”.

Luc Longtin

2-13

Feb 19 2022

Prob. 25, first two lines of equations: At end, change subscript “d” to “e”, two places

Luc Longtin

1-1

Feb 11 2022

Prob. 1, Ans. (third part): After “e”, insert “and the gamma matrix”

Nadeem Afana

2-8

Feb 11 2022

Prob. 18, Ans., after 2^nd equal sign after M^daggerM: one exponent has theta_2. Change to phi_2

Nadeem Afana

2-9

Feb 11 2022

Prob. 19, Ans, in equation after “and”, end of 2^nd line: change derivative wrt alpha_0 to wrt alpha_8

Nadeem Afana

iii

Dec 3 2021

In Acknowledgements section, 2^nd line: change “very” to “every”

Susan Klauber